2026-05-26T16:40:00Z https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2017 2014-08-22T21:00:00Z 1

Inverted Fins for Cooling of a Non-uniformly Heated Domain Erdal Çetkin Constructal; Inverted fins; Vascular; Non-uniform heating; Conductive cooling; Tree-shaped This paper shows that the peak temperature of a non-uniformly heated region can be decreased by embedding high-conductivity tree-shaped inserts which is in contact with a heat sink from its stem. The volume fraction of the high-conductivity material is fixed, and so is the volume of the solid region. The length scale of the solid domain is L. Inside there is a cube-shaped region with length scale of 0.1L and heat production 100 times greater than the rest of the domain. The location of this hot spot was varied to uncover how its location affects the peak temperature and the design of inverted fins, i.e. high-conductivity tree-shaped inserts. The volume fraction of the high-conductivity tree was varied for number of bifurcation levels of 0, 1 and 2. This showed that increasing the number of the bifurcation levels decreases the peak temperature when the volume fraction decreases. The optimal diameter ratios and optimal bifurcation angles at the each junction level are also documented. Y-shaped trees promise smaller peak temperatures than T-shaped trees. The location of the vascular tree in the z direction also affects the peak temperature when the heat generation is non-uniform. In addition, the peak temperature is minimum when z = 0.65L even though the hot spot is located on z = 0.75L. Journal of Thermal Engineering Journal of Thermal Engineering 2014-08-22T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2017 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2017 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2017

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2018 2014-08-22T21:00:00Z 1

Numerical 3-D Heat Flow Simulations on Double-pass Solar Collector with and without Porous Media Abdel Illah Nabil Korti Solar air collector, Double pass, Porous media, Numerical simulation, Flowdistribution A transient 3-D mathematical model for double-pass solar collector with porous media in the lower channel has been developed. Numerical simulations model based on setting mass, momentum and energy balances on finite volumes method are carried out. The governing equations inside the two channels, together with the energy equation in the absorber, insulating and glass cover walls were solved iteratively in a segregated manner. Effects of porosity (70-90 %), mass flow (0.03-0.07 kg/s), solar intensity (514-714 W/m2) and spacing glass-absorber-insulation (7-10 cm) on the dynamic and thermal behaviors of the double-pass solar collector with and without porous media have been discussed. The study concluded that the presence of the porous media at the bottom of the absorber is the best configuration and allow increasing the outlet temperature. Journal of Thermal Engineering Journal of Thermal Engineering 2014-08-22T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2018 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2018 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2018

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2023 2014-08-28T21:00:00Z 1

Mathematical Models and Numerical Solutions of Liquid-Solid and Solid-Liquid Phase Change Karan Surana, Aaron Joy, Luis quiros, JN Reddy liquid-solid , solid-liquid , phase change , Lagrangian , Eulerian , mathematical models , space-time methods , time marching This paper presents numerical simulations of liquid-solid and solid-liquid phase change processes using mathematical models in Lagrangian and Eulerian descriptions. The mathematical models are derived by assuming a smooth interface or transition region between the solid and liquid phases in which the specific heat, density, thermal conductivity, and latent heat of fusion are continuous and differentiable functions of temperature. In the derivations of the mathematical models we assume the matter to be homogeneous, isotropic, and incompressible in all phases. The change in volume due to change in density during phase transition is neglected in all mathematical models considered in this paper. This paper describes various approaches of deriving mathematical models that incorporate phase transition physics in various ways, hence results in different mathematical models. In the present work we only consider the following two types of mathematical models: (1) We assume the velocity field to be zero i.e. no flow assumption, and free boundaries i.e. zero stress field in all phases. Under these assumptions the mathematical models reduce to first law of thermodynamics i.e. the energy equation, a nonlinear diffusion equation in temperature if we assume Fourier heat conduction law relating temperature gradient to the heat vector. These mathematical models are invariant of the type of description i.e. Lagrangian or Eulerian due to absence of velocities and stress field. (2) The second class of mathematical models are derived with the assumption that stress field and velocity field are nonzero in the fluid region but in the solid region stress field is assumed constant and the velocity field is assumed zero. In the transition region the stress field and the velocity field transition in a continuous and differentiable manner from nonzero at the liquid state to constant and zero in the solid state based on temperature in the transition zone. Both of these models are consistent with the principles of continuum mechanics, hence provide correct interaction between the regions and are shown to work well in the numerical simulations of the phase transition model problems presented in the paper. Details of other mathematical models, problems associated with them, and their limitations are also discussed in this paper. Numerical solutions of phase transition model problems in 1D and 2D are presented using these two types of mathematical models. Numerical solutions are obtained using hpk space-time finite element processes based on residual functional for an increment of time with time marching in which variationally consistent space-time integral forms ensure unconditionally stable computations during the entire evolution. Journal of Thermal Engineering Journal of Thermal Engineering 2014-08-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2023 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2023 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2023

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2022 2014-08-22T21:00:00Z 6

Numerical Simulation and Mathematical Analysis of Flow-wall Interaction in the Large Deformation Application to the Dynamics of the Aneurysms Hamadiche Mahmoud numerical The paper considers how induced vibration in elastic channel. A numerical method is derived to take account of full flow-wall interaction in la large deformation domain. To this end, a simplied Lagrangian and nonlinear model is derived to describe the wall motion. the ow is described by two dimensional Naiver stokes equation. The projection method is used to solve for the ow and fourth Rung-Kutta method is used to solve wall equation. The formulation of the problem allows full ow and wall interaction via the boundary conditions at the interface flow-wall. Some numerical simulation will be presented with periodic inlet flow. The method is applied to study the dynamics of aneurysms in arteries and veins. The flow inside the aneurysm is examined under the effects of a steady inlet flow as well as a pulsatile inlet flow for different aneurysm sizes. The wall model is analyzed when the wall is subjectted to a constant transmural pressure and a quasi uniform inviscid flow. For a steady constant transmural pressure, a formal solution of the non linear integral-partial differential equation governing the wall motion is derived. For a steady and a quasi uniform inviscid flow, a first integral of the Wall equation is obtained, then the solution is found to satisfy an integral non linear equation which is solved by numerical iteration. Journal of Thermal Engineering Journal of Thermal Engineering 2014-08-22T21:00:00Z Keynote Speech application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2022 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2022 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2022

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2034 2014-09-14T21:00:00Z 1

Multi-objective Optimization of a Three-dimensional Internally Finned Tube Based on Response Surface Methodology (RSM) Sachindra K. Rout, Ahmed Kadhim Hussein, Chinmaya P. Mohanty Response Su face Methodology (RSM), Heat exchanger, Optimization, Internally finned tube, Computational fluid dynamics (CFD) The modelization and optimization of mixed convection flow through an internally finned tube is a complicated task due to its complex geometry and flow pattern. Advancement of layout for modelling and optimization may direct to quick and successful commercialization of heat transfer enhancement. In the present work, computational fluid dynamics (CFD) together with multi-objective optimization study of an internally finned tube has been performed using the response surface methodology (RSM). For the optimization, the Box-Behnken of response surface methodology (RSM) is exploited from the Design Expert 7.0.0 software. The main purpose of the present work is to find an appropriate combination between maximize the heat transfer enhancement and the reduction in friction loss. The effects of the fin height, fin width and the fin number on the heat transfer enhancement in the form of Nusselt number (Nu) and friction factor multiplied by Reynolds number (fRe) have been investigated. The experimental investigation recommends a strong interaction between the input parameter and the output responses. The results of the numerical model are compared with the analytical results for validation of the model. The numerical model provides an inexpensive and time saving alternative to study the performance of responses avoiding the experimental error runs. Finally a non-dominated sorting genetic algorithm (NSGA) has been proposed for the multi objective optimization of the responses. It was found that numerical and RSM can be applied for optimization of heat transfer analysis of internally finned tube. The results show that at the lower level of fin height , the Nusselt number has an increasing trend with the increase in fin number but decreases beyond fin number of 7. Similar trend is also observed at higher level of fin height. Moreover , it is found that the contribution of fin thickness, for variations of Nusselt number (Nu) and (fRe) , is not significant as compared to fin height and fin number. Journal of Thermal Engineering Journal of Thermal Engineering 2014-09-14T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2034 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2034 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2034

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2024 2014-08-28T21:00:00Z 1

Heat Transfer Performance of Silver/water Nanofluid in a Solar Flat-plate Collector Siddharth Roy, Lazarus Godson Asirvatham, Deepak Kunhappan, Enoch Cephas, Somchai Wongwises silver, nanoparticles, solar flat plate collector, convection, heat transfer An experimental study is carried out to investigate the heat transfer characteristics of silver/water nanofluid in a solar flat-plate collector. The solar radiation heat flux varies between 800 W/m2and 1000W/m2, and the particle concentration varies between 0.01%, 0.03%, and 0.04%. The fluid Reynolds number varies from 5000 to 25000. The influence of radiation heat flux, mass flow rate of nanofluid, inlet temperature into the solar collector, and volume concentration of the particle on the convective heat transfer coefficient and the collector efficiency are studied. Both parameters increase with increases in the particle volume concentration and flow rate. The maximum percentage increase obtained in the convective heat transfer coefficient is 18.4% for the 0.04% volume concentration at a Reynolds number of 25000. An increase in performance of the nanofluid is also witnessed when compared to the base fluid, which had a strong dependency on volume concentration and mass flow rate. Journal of Thermal Engineering Journal of Thermal Engineering 2014-08-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2024 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2024 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2024

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2019 2014-08-22T21:00:00Z 1

Utilisation of Fluids with Low Global Warming Potential in Supercritical Organic Rankine Cycle Jovana Radulovic ORC, supercritical cycle, GWP, thermal efficiency, exergy analysis Organic Rankine cycle is simple and convenient technology for power and electricity production that can successfully exploit low temperature heat sources by the use of a refrigerant as a working fluid. However, as high GWP refrigerants are being phased out, the pursuit for the suitable low GWP working fluid continues. We have compared the performance of several wet, dry and isentropic fluids in a supercritical Rankine cycle. Thermal efficiency and net work produced were the primary parameters for comparison of high GWP R134a with its suggested low GWP replacements, namely R1234yf and R152a. Exergy analysis shows superior exergetic efficiency of R134a at high evaporator pressures. Nevertheless, R152a is a promising working fluid for a supercritical cycle, achieving larger net work and good thermal efficiency, albeit demanding a higher heat input. Journal of Thermal Engineering Journal of Thermal Engineering 2014-08-22T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2019 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2019 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2019

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2020 2014-08-22T21:00:00Z 4

Project, Development and Test of an Artificial Multifunctional Foot João D. Almeida, Maria José Ferreira, Pedro A. Lobarinhas, Luís Ferreira da Silva, Abílio Leite, Alfredo Araújo, Fernando Sousa Footwear testing; thermal comfort; lab prototype; sweating; thermal insulation The main purpose of this project is the development of a multifunctional artificial foot, capable of duplicate a human foot in a laboratory environment, in order to evaluate and simulate footwear’s performance under certain conditions. This foot is used as a laboratory prototype and is multisegmented, in order that each section is controlled independently in terms of heat generation and sweating rate, therefore it is possible to simulate more accurately the real behaviour of a human foot. The device produces thermal insulation values that will help to design footwear with better ability in terms of thermal comfort, replacing human volunteers in thermal comfort perception tests, which are very subjective. The prototype was already tested, and preliminary results indicated that thermal insulation values are within the range of expected values produced by other foot thermal manikins and by human volunteers’ tests. This fact suggests that this lab prototype can be used in future thermal comfort evaluations. Journal of Thermal Engineering Journal of Thermal Engineering 2014-08-22T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2020 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2020 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2020

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2021 2014-08-22T21:00:00Z 6

Social Responsibility as a Key Performance Indicator for the Quality of Educational Processes Tzvetelin Gueorguiev quality of education, social responsibility, key performance indicator (KPI), university ranking Quality of education is a key issue in providing a sustainable future. University rankings have remarkable reputation among various stakeholders but they lack personality. This paper raises questions and proposes alternatives for possible solution for the problem. The change for the better is seen as implementing and in the same time adapting international standards to different regional, national and cultural settings. Journal of Thermal Engineering Journal of Thermal Engineering 2014-08-22T21:00:00Z Keynote Speech application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2021 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2021 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2021

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2025 2014-08-28T21:00:00Z 6

Nanofluid Heat Transfer and Applications Godson Lazarus Heat transfer, Forced Convection, Nanofluids, Nano particles In many industrial applications, the conventional heat transfer fluids are refrigerants, water, engine oil, ethylene glycol etc. Even though an improvement in energy efficiency is possible from the topological and configuration points of view, much more is needed from the perspective of the heat transfer fluid. Despite considerable research and developmental efforts on enhanced heat transfer surfaces, major improvements in cooling capabilities have been constrained because of the poor thermal conductivities of traditional heat transfer fluids used in today’s thermal management systems. In the development of any energy-efficient heat transfer fluids, the thermal conductivity enhancement in heat transfer plays a vital role. One such latest advancement in heat transfer fluids, is the use of nano-sized (1 - 100 nm) solid particles as an additive suspended in the base fluid which is a technique for heat transfer enhancement. Improving the thermal conductivity is the key idea in enhancing the heat transfer characteristics of conventional fluids and in turn the heat transfer coefficient. Hwang et al [1] reported that the nanofluids are claimed to be a non-agglomerated mono-dispersed particles in the base fluids, which proved to be enhancing the heat transfer more than 50% in real-time applications even when the volume ratio of the nano-particle to base fluid is less than 0.3%. It has been reported by Das et al [2] that nanofluids with less than 2% volume fraction are extremely stable and remain suspended in the liquid indefinitely. In many thermal industrial appliances, heat exchangers are used to exchange the heat between the hot and cold fluids; for example, solar water heater. A survey of the published literature indicates that only very limited work has been done till date in finding the heat transfer coefficient of a nanofluid with metal nanoparticles in variety of heat exchangers, while undergoing the cooling process. Cooling heat transfer experiments with nanofluids would find application in solar air conditioning, solar water heaters, building heating, industrial process heaters, and milk pasteurization etc. Therefore, it is important to study the heat transfer characteristics, such as, thermal conductivity, viscosity, heat transfer coefficient and pressure drop of any new working fluid before it is used in a system for any specific application. Journal of Thermal Engineering Journal of Thermal Engineering 2014-08-28T21:00:00Z Keynote Speech application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2025 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2025 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2025

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2026 2014-08-28T21:00:00Z 4

Centrifugal Deposition of Iron Oxide Magnetic Nanorods for Hyperthermia Application Eric Duong, Sophia Chan, Yong Gan, Lihua Zhang Centrifugal deposition; iron oxide; magnetic nanomaterials; external field induced heating; hyperthermia Centrifugal deposition of iron oxide was performed to manufacture magnetic nanorods in an aqueous solution. The nanorods were examined by electron microscopy. The diameter of the nanorods ranges from 10 to 20 nm. The length is about 150 nm. The nanorods were incorporated into a silicone polymer to simulate body tissues injected with magnetic nanomaterials. Then the magnetic nanorod-containing silicone samples were put into a microwave to examine the external electromagnetic field induced heating behavior. Dramatic increase in temperature was observed when the nanorods were exposed to the external electromagnetic field for 2 seconds. It is concluded that the nanorods generate intensive heating effect and they have the potential for hyperthermia application. Journal of Thermal Engineering Journal of Thermal Engineering 2014-08-28T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2026 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2026 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2026

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2052 2014-10-25T21:00:00Z 1

Heat Insulation Analysis of an Aluminum Honeycomb Sandwich Structure Kantha Konka, Jayathirtha Rao, Kumar Swamy AVSS Gupta Hexagonal core, Square core, aluminum panel, Adhesive, Finite Element Analysis (FEA) Heat-transfer has been performed on a sandwich thermal protection system (TPS) for future flight vehicles. The sandwich structures are built from thin walled metal sheets. These structures as a part of the airframe outer cover provide thermal protection to the interior parts mounted inside the vehicle. The temperature protection materials used for sandwich structures should have high strength even at the elevated temperatures. It is easier to simulate the 1500 C (after 1500 C material properties are changed) temperature on the Aluminium sandwich structures and find the temperature gradient across the sandwich depth. Though the experiment was done on hexagonal cells honeycomb, the ANSYS analyses have been done for both square cell’s sandwich panel and hexagonal honeycomb panel for comparison. Experiments are done on using Al alloy honeycomb sandwich panels and the validations of experimental work using ANSYS analysis have been performed. ANSYS modeling, analysis has been done for both, the square and hexagonal honeycomb sandwich panels of the Al alloy. This paper focuses on the heat transfer analysis and in exploring the ways to reduce the heat transfer effect with the methods mentioned above, which could be effectively used for flight vehicle applications. Journal of Thermal Engineering Journal of Thermal Engineering 2014-10-25T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2052 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2052 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2052

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2027 2014-09-07T21:00:00Z 1

CFD Analysis of Smoke and Temperature Control System of an Indoor Parking Lot with Jet Fans Anil Senveli, Tolga Dizman, Ali Celen, Duriye Bilge, Ahmet Selim Dalkılıç, Somchai Wongwises Normal Pollution Ventilation (NPV), Computational Fluid Dynamics (CFD), Jet Fans, Impulse Ventilation, Smoke and Heat Control (SHC) The aim of this study is to perform analysis and interpretation of daily emission ventilation and fire ventilation system design in indoor parking lots with jet fans with the help of CFD program. In the study, ventilation of 8-story parking lot of a major business center in Istanbul with jet fans have been carried out, and the analysis on one story of this parking lot is provided as a case study. The airflow in all the regions of parking lot has been examined, the most suitable jet fan placements have been determined for daily emission and fire ventilation, and accuracy of this placement has been proved through the analysis with this study. The performed CFD analysis has enabled us to see correct placement of the jet fans and to intervene and decide the best placement. And for the fire case, the optimal results have been obtained by creating various scenarios in accordance with the international standards. It has been observed that the use of CFD analysis in the solution of the problem has allowed significant savings in time and money. Journal of Thermal Engineering Journal of Thermal Engineering 2014-09-07T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2027 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2027 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2027

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2044 2014-10-11T21:00:00Z 6

Performance and Flow Distribution of the Plate Heat Exchanger with Supercritical Fluid of Carbon Dioxide Chi-Chuan Wang, Chen-Xi Zhu, Yi-Chun Tang Supercritical fluid; plate heat exchanger; carbon dioxide; flow distribution The present study proposes a plate heat exchanger model that is capable of simulating the supercritical fluids like CO2. The plate heat exchanger is of U-type configuration, and the size of the plate is 600 mm wide and 218 mm in height. Simulations are carried out for both isothermal and non-isothermal cases with water-to-water and water-to-CO2 plate heat exchanger. The proposed model was first compared with some existing water-to-water plate heat exchanger data. Generally, the predicted water flow distributions are in line with the experimental data. Yet the simulation results of temperature distribution alongside the plate agree excellently with other predicted model. For the water side distribution within the plate heat exchanger, it is found that a detectable mal-distribution prevails and the flowrate shows a consistent decline from the first to the last plate. Basically, a larger mal-distribution is seen when the inlet flowrate is increased or when the plate number is increased. The simulation indicates that the inlet temperature of water casts negligible influence on the water flowrate distribution. By contrast, it is found that the inlet temperature difference for the CO2 side may raise significant changes of thermodynamics and transport property of CO2, and result in a great difference in flow distribution. Generally the mal-distribution of the CO2 is much less severe due to more even pressure difference between the intake and exhaust manifold. The effect of pressure on heating capacity for the water-CO2 plate heat exchanger also depends on the ratio of heat capacity flow. Journal of Thermal Engineering Journal of Thermal Engineering 2014-10-11T21:00:00Z Keynote Speech application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2044 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2044 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2044

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2045 2014-10-11T21:00:00Z 6

Volumetric Solar Absorber and Performance Characteristics Bekir Yilbas, Osman K. Siddiqui Solar Harvesting, Volumetric Absorber Volumetric solar absorption system accommodating the absorber plate in a rectangular channel is investigated. The influence of the location of the absorbing plate on the heat transfer and hydrodynamic characteristics are examined in the channel. Phase change material (Lauric acid) of 5% concentration is used to increase the thermal storage capacity of the working fluid and water is incorporated as the carrier fluid in the channel. Thermal performance and pump power loss parameters are introduced to assess the thermal performance of the volumetric solar absorption system. The findings revealed that thermal performance parameter attains the highest value for the absorber plate location at the center and bottom of the channel. The pump power loss parameter becomes the highest for the absorber plate location at the mid-height of the channel. Journal of Thermal Engineering Journal of Thermal Engineering 2014-10-11T21:00:00Z Keynote Speech application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2045 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2045 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2045

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2053 2014-11-05T22:00:00Z 1

Characteristics of Magnetohydrodynamic Mixed Convection in a Parallel Motion Two-Sided Lid-Driven Differentially Heated Parallelogrammic Cavity with Various Skew Angles Ahmed Kadhim Hussein, Salam Hadi Hussain Magneto-hydrodynamic, Mixed convection, two-sided, lid-driven, parallelogrammic cavity, Skew angle, finite volume. A numerical study is presented for mixed convection flow of air (Pr=0.71) within a parallel motion two sided lid-driven parallelogrammic cavity in the presence of magnetic field. The left and right lid-driven sidewalls of the parallelogrammic cavity are maintained at isothermal hot and cold temperatures respectively and slide from bottom to top in upward parallel direction with a uniform lid-driven velocity. A magnetic field of strength (Box) is subjected in the horizontal direction. The horizontal walls of the cavity are considered thermally insulated. The finite volume method has been used to solve the governing Navier–Stokes and energy conservation equations of the fluid medium in the parallelogrammic cavity in order to investigate the effect of magnetic field on the flow and heat transfer for various values of Richardson number, skew angle and Hartmann number. The values of the governing parameters are the Hartmann number (0 ? Ha ? 75), Richardson number (0.01? Ri ?100) and skew angle (- 60° ? ? ? 60°). The present numerical approach is found to be consistent and the results is presented in terms of streamlines and isotherm contours in addition with average Nusselt number. It is found that as the Hartmann number increases the circulation of the rotating vortices is reduced and the conduction mode of heat transfer is dominant. Also, it is found that both Richardson number and direction of two sided lid-driven sidewalls affect the heat transfer and fluid flow in the parallelogrammic cavity. Journal of Thermal Engineering Journal of Thermal Engineering 2014-11-05T22:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2053 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2053 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2053

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2051 2014-10-25T21:00:00Z 5

Investigation of the Effects of Geometric and Load Perturbation to Buckling in Multilayered Torispherical Pressure Vessel Heads Zafer Şenalp Multilayer, perturbation; torispherical pressure vessel heads; buckling; instability; eigenvalue. The object of this paper is to investigate the effects of geometry and load perturbation to buckling in multilayered pressure vessel heads. The pressure vessel head in concern is thin walled torispherical geometry. Geometric and load perturbation can alter both the critical load for buckling and the buckled shape. Two and three layered torsispherical heads are considered. Two layered models include steel–aluminum and titanium–aluminum configurations and three layered models include copper–steel–copper configuration. Internally pressurized three-dimensional torispherical pressure vessel head model that is previously used in literature is constructed. As a first step eigenvalue solutions are obtained for each model. After this instability solutions with large deformation effects are conducted to obtain more realistic instability pressure values nonlinear. The solution is performed by finite element program ANSYS Workbench. In nonlinear analyses, perfectly plastic material model is used. It is concluded that geometric and load perturbations cause the instability pressure to decrease and cause the structure to buckle at a lower pressure value. It is also observed that for steel-aluminum configuration geometric perturbation is more critical than load perturbation whereas for aluminum-titanium the reverse is valid. Journal of Thermal Engineering Journal of Thermal Engineering 2014-10-25T21:00:00Z Extended Conference Paper application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2051 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2051 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2051

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2046 2014-10-11T21:00:00Z 1

Effect of Process Conditions on Temperature Distribution in the Powder Bed during Laser Sintering of Polyamide-12 Jack A. Nelson, Allan E.W Rennie, Tom N Abram, Graham R Bennett, Alex C Adiele, Mathew Tripp, Martyn Wood, Greg Galloway Polyamide-12, SLS, Powder, Sinterstation, thermal, distribution A sintered part‟s mechanical properties are often variable dependent on the temperature at which it was sintered. Prior research has investigated how predefined process conditions (such as scan speed and laser power) in the „Sinter‟ software affect built parts (Majewski & Hopkinson, 2011), however, little work focuses on other process conditions that can directly affect the temperature distribution in the bed relative to these parts. These conditions are not always controllable in the „Sinter‟ software. By replacing the scanner at the top of the Sinterstation 2000 with a thermal imaging camera, an insight into the temperature distribution on the part bed was obtained. A temperature variance of up to 7°C was found across the bed, as well as a large temperature drop and recovery period on powder layer recoat. This paper explores the possible causes of this variation in the processing of DuraForm™ Polyamide-12 powder by monitoring and assessing build operations, enabled by replacing the front viewing window with a retro-fitted thermal imaging camera. The part bed was observed and various process conditions analyzed including powder recoat, part and feed heaters, and swing gate configuration. On powder recoat, the part bed exhibited a drop in temperature because the fresh layer of powder is at a lower temperature than the powder already present in the part bed. The part bed temperature drop lessens with raised feed bed temperatures however there are limitations. Thermal analysis of the part heater proved that the uneven part bed heat distribution was not linked to the temperature gradient of the part heater. Swing gates were found to minimise hot and cold spots but spend a substantial time oscillating on roller passing. Journal of Thermal Engineering Journal of Thermal Engineering 2014-10-11T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2046 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2046 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2046

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2084 2015-01-15T22:00:00Z 1

A Comparative Study of Different Reaction Models for Turbulent Methane/Hydrogen/Air Combustion S. Muppala, B. Manickam, F. Dinkelacker reaction rate modelling; turbulent premixed combustion; hydrogen enriched flames; molecular transport effects; multi-component flame modelling Reaction modelling of methane/hydrogen combustion has two important aspects. First, such mixtures may be used in future in combustion devices like gas turbines and gas engines in the frame of the demand for efficient energy storage systems, where the amount of hydrogen in natural gas delivering systems may vary according to varying hydrogen production from re-newable energies. Second, this can be an important aspect for safety, as such mixtures may occur in disastrous situations and calculations may allow the prediction of safety issues. Mod-elling of such mixed fuel combustion processes is non-trivial due to the involved preferential diffusion effects coming from the different diffusivities of methane and hydrogen. In turbulent flame modelling, this topic is of special interest, as also thermo-diffusive instabilities and local influence of the local burning velocity near leading edges of the flame seem to be of importance even for highly turbulent flames. This numerical work deals therefore with a com-parative study of five different turbulent combustion models to the situation of turbulent methane/hydrogen/air flames. Validation is done with extensive experimental data obtained by a low swirl burner in the group of Cheng et al. Besides a basic case with pure methane/air special emphasis is laid on flames with 40 to 100 % hydrogen content. It is shown that for such methane/hydrogen fuel mixtures common reaction rate models are not sufficient where the fuel effects are included only via a laminar flame speed. Instead, a recently proposed reaction model with the incorporation of an effective Lewis number of the fuel mixture is found to work rather well. This is of both, practical as well as theoretical importance, as for the latter it confirms controversially discussed assumptions of the influence of preferential diffusion. Journal of Thermal Engineering Journal of Thermal Engineering 2015-01-15T22:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2084 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2084 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2084

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2049 2014-10-21T21:00:00Z 1

Performance Analysis and Design of Liquid Based Solar Heating System Esa kerme, Zakariya Kaneesamkandi Solar heating,solar fraction,f-chart method,solar energy,heating load Designing of a solar heating system involves appropriate sizing of different components based on predicted solar insolation and heating load demand. But, it is a complex problem due to unpredictable weather data components. A number of design methods are available for solar heating systems. In this paper, f-chart method has been used due to its simplified design procedure, analysis and low cost in selecting the sizes and type of solar collectors and in estimating the annual thermal performance of solar heating system. Using this method, the design of liquid solar heating system and the estimation of the fraction of total heating load (domestic water and space heating load) that will be supplied by solar energy for a family of six in Riyadh have been conducted. The study includes the effect of different collector areas and storage capacity per square meter of collector area and collector tilt angle on fraction of the load supplied by solar energy. It has been found that increasing the collector area results in an increasing of annual load fraction supplied by solar energy. It has also been seen that increasing the specific storage capacity results in small increase in solar load fraction and the effect is more visible during the summer than during the winter. The result of the study reveals that collector configurations with lower tilt angles are better during the summer and higher values of angles are better during the winter. The optimal annual collector configuration tilt angle which gives the maximum solar load fraction has been found to be 30o. Journal of Thermal Engineering Journal of Thermal Engineering 2014-10-21T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2049 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2049 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2049

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2050 2014-10-21T21:00:00Z 1

Exergy-based Thermodynamic Analysis of Solar Driven Organic Rankine Cycle Esa kerme, Jamel Orfi Parabolic trough solar collectors, organic Rankine cycle, exergetic efficiency,exergy destruction rate, irreversibility ratio In this paper thermodynamic modeling of organic Rankine cycle (ORC) driven by parabolic trough solar collectors is presented. Eight working fluids for the ORC were examined. The effect of turbine inlet temperature on main energetic and exergetic performance parameters were studied. The influences of turbine inlet temperature on turbine size parameter, turbine outlet volume flow rate and expansion ratio were also investigated. Important exergetic parameters including irreversibility ratio and total exergy destruction rate were also included in the analysis and evaluated. The study reveals that increasing the turbine inlet temperature results in increasing the net electric efficiency, net power output, exergy efficiency and expansion ratio while the total exergy destruction rate and turbine size parameter are reduced. From the considered working fluids, o-xylene gives the best energetic and exergetic performance. The results of the study also show that the main source of exergy destruction occurs in the solar collector where 74.9% of the total exergy loss is destructed. Next to collectors, 18.2% of the total destructed exergy occurs in the condenser. Journal of Thermal Engineering Journal of Thermal Engineering 2014-10-21T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2050 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2050 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2050

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2047 2014-10-14T21:00:00Z 5

Constructal Structures for Self-cooling: Microvascular Wavy and Straight Channels Erdal Çetkin Constructal; Vascular; Self-cooling; Bio-mimicry; Heat generation This paper shows that a conductive domain which is subjected to heating from its bottom can be cooled with embedded microvascular cooling channels in it. The volume of the domain and the coolant are fixed. The actively cooled domain is mimicked from the human skin (which regulates temperature with microvascular blood vessels). The effect of the shape of cooling channels (sinusoidal or straight) and their locations in the direction perpendicular to the bottom surface on the peak and average temperatures are studied. In addition, the effect of pressure difference in between the inlet and outlet is varied. The pressure drop in the sinusoidal channel configurations is greater than the straight channel configurations for a fixed cooling channel volume. The peak and average temperatures are the smallest with straight cooling channels located at y = 0.7 mm. Furthermore, how the cooling channel configuration should change when the heat is generated throughout the volume is studied. The peak and average temperatures are smaller with straight channels than the sinusoidal ones when the pressure drop is less than 420 Pa, and they become smaller with sinusoidal channel configurations when the pressure drop is greater than 420 Pa. In addition, the peak and average temperatures are the smallest with sinusoidal channels for a fixed flow rate. Furthermore, the peak temperatures for multiple cooling channels is documented, and the multiple channel configurations promise to the smallest peak temperature for a fixed pressure drop value. This paper uncovers that there is no optimal cooling channel design for any condition, but there is one for specific objectives and conditions. Journal of Thermal Engineering Journal of Thermal Engineering 2014-10-14T21:00:00Z Extended Conference Paper application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2047 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2047 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2047

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2048 2014-10-14T21:00:00Z 6

Semianalytical Methods for Heat and Fluid Flow Between Two Parallel Plates Balaram Kundu Semianalytical, Temperature distribution, Transient, Velocity distribution The present study attempts to investigate the effects the viscous dissipation on the unsteady temperature distribution in the conduction limit for both hydro-dynamically and thermally fully developed, laminar flow of Newtonian fluid between two asymmetrically heated infinitely long parallel plates. Utilizing the assumptions routinely employed in the literature, we devise here a semi-analytical formalism to investigate the temperature distribution for two different flow configurations, i.e., the poiseuille flow and the simple shear driven flow. In the analysis, we give focus to the viscous dissipative effect arises because of the two individual aspects in case of shear-driven flow: the shear heating produced by the movable upper plate along with fluid friction, while only due to the internal fluid friction in case of Poiseuille flow. Finally, we show the variation of velocity and the temperature distribution in the flow field for several non-dimensional parameters as emerge in the present study, and highlight their individual role in delineating the temperature distribution in the flow field, which essentially alters transient thermal transport characteristics of heat in different cases of flow dynamics. Journal of Thermal Engineering Journal of Thermal Engineering 2014-10-14T21:00:00Z Keynote Speech application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2048 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2048 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2048

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2074 2014-12-26T22:00:00Z 1

Characterization of the Effects of Insulating Wall Paint on Space Conditioning in a Room David Buckmaster, Alexis Abramson insulating paint, buildings, space conditioning, envelope loss, computational fluid dynamics Manufacturers of "insulating paints" continue to enter the marketplace with claims of their products' exceptional potential to reduce building energy consumption. To help dispel this myth, this paper presents the simple theoretical analysis disproving this claim, backed by a more in-depth computational fluid dynamics (CFD) analysis testing the performance of such products. The CFD analysis is conducted in a simulation of a room as a function of various parameters. The benefits of insulating paint are shown to be minimal; even under highly favorable conditions, energy consumption is reduced by less than 1%. Journal of Thermal Engineering Journal of Thermal Engineering 2014-12-26T22:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2074 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2074 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2074

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2054 2014-11-11T22:00:00Z 1

Influence of Drying Conditions and Mathematical Models on the Drying Curves and the Moisture Diffusivity of Mushrooms Athina Stegou-Sagia, Dimitra V. Fragkou Drying curves, drying of mushrooms, drying methods In the present research, experimental data from several studies about drying behavior of mushrooms have been selected and used to compare different drying methods and different mathematical thin layer drying models to simulate mushroom drying rates. The white button (Agaricus Bisporus), the oyster (Pleurotus Ostreatus) and the milky mushroom slices have been considered for drying in different dryers with different slice thicknesses, drying air temperatures (45 °C to 90 °C) and drying air velocities (0.2 m/s to 5 m/s). The entire drying process has taken place in the falling rate period, assuming that internal mass transfer occurred by diffusion in mushroom slices. Additionally, the effective moisture diffusivity was calculated by using the method of slopes. The diffusivity increases with drying air temperature. The study shows that the drying air temperature and the drying air velocity have an effect on the moisture removal from mushrooms and also on the drying time. Mathematical models have been proved to be useful for design and analysis of heat and mass transfer during drying processes. All the drying models considered in this study could adequately represent the thin layer drying behavior of mushrooms. Furthermore, as it is obvious, any type of mushrooms has its own most suitable model. Journal of Thermal Engineering Journal of Thermal Engineering 2014-11-11T22:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2054 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2054 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2054

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2071 2014-12-18T22:00:00Z 5

Monitoring and Simulation of Mechanically Ventilated Underground Car Parks Adil Eshack, Leo Samuel D.G., Shiva Nagendra S.M., M. Prakash Maiya Ventilation, simulation, basement car park, Carbon monoxide Rapid motorization in developed and developing countries demands more parking spaces in urban areas. Underground car parking space in multi story buildings offers viable solution. However, lack of natural ventilation accumulates the harmful emissions from cars, operating in underground car parks. Exposure to these hazardous pollutants causes health risk to the users. Therefore, proper mechanical ventilation system should be adopted for the removal of harmful pollutants. This paper discusses the usage of modeling and simulation tools in the design of the mechanical ventilation system. Two widely used modeling techniques, multi-zone modeling and CFD modeling were used to simulate the contaminant distribution in a mechanical ventilated environment. The former provides an approximate macroscopic solution of the carbon monoxide (CO) distribution, while the later provides precise distribution of CO contours. The two models were validated against field measurements made at Chennai, India. The model predictions were very close to the actual site measurements. The impact of garage height and CO generation rate on ventilation requirement has been analysed. Journal of Thermal Engineering Journal of Thermal Engineering 2014-12-18T22:00:00Z Extended Conference Paper application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2071 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2071 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2071

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2070 2014-12-16T22:00:00Z 4

A closed Form Solution for AC Electo-kinetic-driven Flow in a Microchannel Balaram Kundu Analytical; Electrical potential; Green’s function; Microchannel The electro-osmotic fully-developed flow in a circular micro-channel was studied under an alternative electric field. An analytical approach based on the linearized poisson-Boltzmann equation was selected to obtain an exact solution of the electrical potential inside the channel. The velocity distribution was then determined by using Green’s function approach. The velocity distribution has been plotted under a design condition. Journal of Thermal Engineering Journal of Thermal Engineering 2014-12-16T22:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2070 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2070 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2070

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2069 2014-12-16T22:00:00Z 8

Solar Distillation Practice For Water Desalination Systems Omid Mahian, Ali Kianifar, Raviwat Srisomba, Phubate Thiangtham, Chaiwat Jumpholkul, Somchai Wongwises Desalination, Solar Energy, Energy Saving, Drinking Water Based on the best knowledge of the authors, the present book “Solar Distillation Practice For Water Desalination Systems” authored by G. N. Tiwari and A. K. Tiwari, published in 2008, Anamaya Publishers, New Delhi, is the most comprehensive source for the researchers that deal with solar energy based desalination systems. In this article, a review of this book is conducted and some suggestions are given for the next editions. Journal of Thermal Engineering Journal of Thermal Engineering 2014-12-16T22:00:00Z Book Review application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2069 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2069 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2069

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2056 2014-12-07T22:00:00Z 6

Determination of Fin Pitches for Maximum Performance Index of L-footed Spiral Fin-and-tube Heat Exchangers Somchai Wongwises, Parinya Pongsoi fin, tube, heat transfer, heat exchanger, optimum, air-water In this study, the fin pitches were determined that maximize the performance index of L-footed spiral finned tube heat exchangers. The experiments studied various fin pitches (fp = 2.4, 3.2, and 4.2 mm) for L-footed spiral fin-and-tube heat exchangers in the range of high Reynolds numbers (5,000–15,000). All of the test sections had a parallel and counter cross-flow in a two-row configuration, and were tested in a well-insulated, open wind tunnel. The two working fluids were the ambient air and hot water. The performance indexes (??, ????and ??) were used to analyze the experimental data at different fin pitches. The performance indexes were defined as the ratio of the desired output to the required input. The results show that the optimal fin pitches for L-footed spiral finned tube heat exchangers are 2.4 and 3.2 mm. Fin pitch has been a particular concern and an important factor for the optimal design of heat exchangers. In addition, based on the performance evaluation criteria for the heat exchanger (VG-1 criterion), it was found that the spiral fin-and-tube heat exchangers had significant effects on the compact heat exchangers’ design. Our hope is that this study can be used as a guideline for designing future heat exchangers. Journal of Thermal Engineering Journal of Thermal Engineering 2014-12-07T22:00:00Z Keynote Speech application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2056 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2056 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2056

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2057 2014-12-13T22:00:00Z 1

Effects of Various Parameters on the Efficiency of a CO2 Heat Pump: A Statistical Approach Paul Maina, Zongjie Huan Carbon Dioxide, Coefficient of Performance, Heat Pump, Refrigerant, Regression Analysis. The influence of variables such as; refrigerant amount, chilling and cooling water temperature, throttle valve opening, cooling and chilling water flow rates, on the efficiency (coefficient of performance – COP) of a water to water carbon dioxide heat pump was investigated. Design of experiments was done using design-expert® 6 software for regression analysis. A response surface method known as central cubic design was used to provide optimum results with minimum experiments. Through multiple regression analysis, an empirical equation relating the COP to the variables was derived. Analysis of variance revealed that these regressions are statistically significant at 95% confidence level compounded with a very low standard deviation and a high adequate precision. The close relationship between the predicted COP values and the actual values further proves the worthiness of the empirical equation. It was observed that cooling water temperature had the highest influence followed by the chilling water temperature. Surprisingly, the amount of the refrigerant was third followed by the throttle valve opening. Understandably, chilling water flow rate had the least effect on the COP. Through response surface diagrams, the interactive influence of the variables were also observed. The COP values arrived at varied from 1.545 to 6.914 although if the variables were optimized fully within the scope of this study, a value of up to 11.8 could be achieved. Still, if the variables range is increased further, higher COP could be achieved. Finally, a discussion was done in a bid to explain these results. Journal of Thermal Engineering Journal of Thermal Engineering 2014-12-13T22:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2057 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2057 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2057

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2075 2014-12-26T22:00:00Z 4

Biodiesel Production and Fuel Properties from Non-edible Champaca (Michelia champaca) Seed Oil for Use in Diesel Engine Siddalingappa Hotti, Omprakah Hebbal Transesterification; Free fatty acid; non-edible oil; Michelia champaca In the present paper investigations were carried out to determine fatty acid composition and fuel properties of non-edible, renewable, champaca seed oil (CSO), champaca seed oil biodiesel (CBD), for its use in diesel engine. Methyl ester of seed oil was analyzed by Gas Chromatography (GC) - Mass Spectroscopy (MS) for the determination of fatty acid composition. The major fatty acids found in CSO were, palmatic , 32.52%, linoleic, 30.72%, palmitoleic, 13.39%, stearic, 8.88%, oleic , 6.03%, palmitelaidic, 5.18%, ecosenic, 0.71% and myristic, 0.57% and the total unsaturated fatty acid composition accounts for 56.03%. The biodiesel was produced by two step process i.e. acid pretreatment process followed by base-catalyzed transesterification process as the free fatty acid (FFA) content found to be 5.30% ( corresponding to acid value of 10.55, mg KOH/g) . The first step of process was carried out with methanol and sulphuric acid as catalyst, followed by second step, base- catalyzed transesterification process with methanol and sodium hydroxide as catalyst the biodiesel yield was found to be 83.50 %. The fuel properties of biodiesel produced were determined as per the ASTM standard test procedures and compared with diesel, ASTM D6751-09a, biodiesel standard specifications and were found to meet the required standards. Journal of Thermal Engineering Journal of Thermal Engineering 2014-12-26T22:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2075 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2075 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2075

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2055 2014-12-04T22:00:00Z 6

An Analysis of Current and Future Wind Energy Gain Potential for Central Iowa Farrokh Sharifi, Nastaran Hashemi Wind Energy Using a significant quantity of fossil fuels has adverse impacts on our lives and will affect future generations. Additionally, there are limited and decreasing numbers of non-renewable resources around the world. In contrast, renewable resources are not depleted and provide energy with negligible pollution. Wind energy is one of the more common renewable energy resources. This project aims to evaluate Iowa's wind energy potential and to provide suggestions to improve the future well-being of this state. A preliminary analysis shows that Iowa has great potential for wind energy. Based on the preliminary analysis, Ames, Iowa, is selected as a case study of its potential in terms of wind energy. Some important characteristics of wind energy, such as mean wind speed, wind distribution, and wind direction are evaluated for Ames. It is observed that although Iowa has the greatest wind power capacity density in the U.S., there are some untapped places in Iowa that can be utilized to harvest wind power. Results indicate that the city of Ames is one of the places that have strong wind speeds. According to the results, if a wind farm is installed in the city of Ames, reliance on non-renewable energy resources will be considerably decreased. Journal of Thermal Engineering Journal of Thermal Engineering 2014-12-04T22:00:00Z Keynote Speech application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2055 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2055 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2055

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2068 2014-12-16T22:00:00Z 1

Power Optimization of an Irreversible Regenerative Brayton Cycle with Isothermal Heat Addition Rajesh Kumar, S C Kaushik, Raj Kumar Thermodynamic Optimization, Irreversible Brayton cycle, Regenerator, Power, Efficiency An irreversible regenerative Brayton cycle model with two heat additions is analyzed here. The external irreversibilities due to finite temperature difference and internal irreversibilities due to fluid friction losses in compressor / turbine, regenerative heat loss, pressure loss are included in the analysis. Power output of the model is obtained and thermodynamically optimized. A detailed analysis shows that with judicious selection of parameters viz. efficiency of turbine and compressor, effectiveness of various heat exchangers, isothermal pressure drop ratio, pressure drop recovery coefficients and heat capacitance rate of the working fluid, the power output of the model can be made to reach its highest possible value. It is well proven with the obtained results that induction of two heat additions significantly enhances model efficiency above 20% as compared to conventional gas power plants. The power output remains constant while the corresponding thermal efficiency increases as regenerator side effectiveness is increased. This particular result is different from those obtained by previous researchers. The model analyzed in this paper gives lower values of power output and corresponding thermal efficiency as expected and replicates the results of an irreversible regenerative Brayton cycle model discussed in the literature at pressure recovery coefficients of ?1=?2=1. Journal of Thermal Engineering Journal of Thermal Engineering 2014-12-16T22:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2068 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2068 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2068

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2096 2015-01-29T22:00:00Z 1

Energy and Exergy Analysis of Cogeration System with Biogas Engines Nadezhda Doseva, Daniela Chakyrova Biogas internal combustion engines, Cogeneration system, Energy, Exergy, Thermodynamic performance assessment parameters In this paper, an existing cogeneration system driven by biogas internal combustion engines (ICE) is a subject of an investigation by energy and exergy analyses. The system is installed in the Varna Wastewater Treatment Plant (Varna WWTP), Bulgaria and its purpose is to utilize the methane produced as a byproduct of the solids stabilization process at Varna WWTP. Otherwise, the produced methane would pollute the environment. The presented paper has been organised in the following way: first, in order to define the basic thermodynamic parameters on the stations of the cogeneration system streams, the energy balance equations for each component of the system are formulated. Then, the rate of exergy destruction within the the kth system component is calculated using the exergy balance equations. Moreover, according to the methodology introduced in (The European Education Tool on Cogeneration System (EDUCOGEN), 2001), energy efficiency, power to heat ratio, energy saving ratio, energy efficiency used under the Public Utilities Regulatory Policy Act (PURPA efficiency) are defined for the cogeneration system. The same thermodynamic performance assessment parameters (without PURPA efficiency) are determined on exergy base. In addition to the thermodynamic performance assessment parameters of the cogeneration system, a detailed exergy analysis on the component level is performed. To our knowledge, there has been little discussion about exergy efficiency of ICE based cogeneration systems for use with biogas from wastewater treatment plants. To address this niche in the global research work, in this investigation is suggested detailed exergy analysis permitting us to assess thermodynamic performance of similar class energy conversion systems. Journal of Thermal Engineering Journal of Thermal Engineering 2015-01-29T22:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2096 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2096 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2096

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2083 2015-01-14T22:00:00Z 1

Development and Application of a Modular- based, Multi- level Approach for Increasing Energy Efficiency Stefano Coss, Milan topic, Karin Tschiggerl, Harald Raupenstrauch Energy efficiency, Modelling, Foundry industry, Top-Down approach, Bottom-Up approach, This paper presents a methodology how energy consumption and energy inefficiencies can be quantified for industrial processes based on a general, branch- independent approach for the purpose of increasing energy efficiency. For many companies the information of the actual energy use of their processes is very limited. Therefore, knowledge of energy consumption is only available on an overall basis and the product- specific energy costs are often calculated with a common cost- plus system. This deficiency in information is part of the reasons, why energy efficiency potentials are often neither known nor realized. For that reason a general approach is needed, which (1) uses the actual economic data of a company and (2) combines and compares it with thermodynamic analyses in order to (3) calculate the actual energy consumption of processes and products to (4) identify and quantify the energy efficiency potentials. The suggested general approach is branch- independent and analyses energy efficiency potentials. Firstly this is conducted through a modular- based, three- level industrial model mapping process. Each module contains production units (industrial plant assets), where main industrial processes are integrated into one module. The different modules are then connected on different levels in order to find product- specific production pathways. Secondly, both a top- down and a bottom- up approach are implemented. The top- down approach uses economic and overall energy consumption data and transfers it to the modular view. The bottom- up approach applies technical data of the used production units and quantifies energy consumption based on thermodynamic and general technical data. Through this methodology it is possible to derive actual energy consumption of processes and corresponding manufactured products, which furthermore helps to understand energy cost generation for various products. It also divides the possible inefficiencies into a technical and an organisational part which leads to technical, organisational and social measures. The described modelling of industrial processes on a modular, multi- level approach is applied to case studies for several Austrian foundry companies. Actual data is used for (1) building the model (2) evaluate the model and (3) make the actual energy consumption of processes more transparent. The case studies show that important information is concealed through wrong energy allocations and thus prevents the knowledge of energy efficiency potentials. The application of the model approach in foundry companies enables to (1) calculate energy consumption for various important modules, (2) transfer economic and technical data to a process- oriented picture of the energy use, (3) calculate energy demand of various products and (4) provides the first basis for energy efficiency potential analysis. Journal of Thermal Engineering Journal of Thermal Engineering 2015-01-14T22:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2083 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2083 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2083

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2098 2015-02-08T22:00:00Z 1

Design, Modelling and Simulation of a Fuel Cell Power Conditioning System Makani Mwinga, Ben Groenewald, Michael McPherson fuel cell, dc-dc converter, MATLAB/Simulink, Power Conditioning, Input Current Ripple In this paper we present work carried out in order to stabilize the output voltage ( V_O) of a 1 kW Horizon fuel cell (FC). The work involves the design, modeling and simulation of a power conditioning system (PCS). In the process to stabilize the voltage, it is required to also reduce the input current ripple and to improve the system response to load changes. We present here preliminary results that show that the system works, with the voltage smoothed, the input current ripple reduced and the response time increased. This work also covers a comparative evaluation of the dynamic behavior of three converter topologies employed in power conditioning: boost converter, sepic converter and interleaved boost converter. The simulation results for the three topologies show that the output voltage of the fuel cell (FC) was stabilized. Furthermore, the results indicate that the interleaved boost converter is a better topology compared to the boost and sepic topologies in terms of our work. Journal of Thermal Engineering Journal of Thermal Engineering 2015-02-08T22:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2098 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2098 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2098

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2072 2014-12-20T22:00:00Z 4

Conception and Study of a Galvanized Tubes Hybrid PV / T Collector for Building Application Khaled Touafek, Abdelkrim Khelifa, Hocine Ben Moussa, Ismail Tabet, Mabrouk Adouane collector, photovoltaic; Thermal; Efficiency; Galvanized sheet During operation of a photovoltaic module, a heat is generated, which systematically increase the temperature of the photovoltaic cell with respect to the ambient temperature and this will cause a drop in performance. Several research projects aimed at developing solutions to limit the rise in temperature of photovoltaic modules, is born beyond the concept of hybrid photovoltaic thermal collectors / (PV / T), which is to superimpose both electrical and thermal energy functions. In this hybrid collector, the fluid flowing in the thermal part to be heated also cools the photovoltaic cells and thereby increases their electric yield. These absorber tubes can have different shapes: round, square and rectangular tubes. In this paper a new configuration of absorber is studied. A thermal and electrical model is performed and tested. Journal of Thermal Engineering Journal of Thermal Engineering 2014-12-20T22:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2072 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2072 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2072

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2085 2015-01-20T22:00:00Z 1

Thermal conductivity of CNT water based nanofluids: Experimental trends and models overview Patrice Estellé , Salma Halelfadl, Thierry Maré CNT nanofluids, Thermal conductivity, Experiments, Models, Temperature, Nanoparticle aspect ratio, surfactant Thermal conductivity measurement of carbon nanotubes water-based nanofluids is here reported. We have considered in particular the influence of nanoparticle volume fraction, temperature, carbon nanotube aspect ratio and different kind of surfactant (SDBS, Lignin, Sodium polycarboxylate) on thermal conductivity enhancement of nanofluids. The experiments show that TC enhancement of nanofluids produces at very low volume fraction. It is also mainly governed by both volume fraction and temperature increase. However, TC enhancement of nanofluids is weakly affected by carbon nanotubes aspect ratio and surfactant type used in the study. In addition, various theoretical thermal conductivity models are used to possibly correlate the experimental data and explain the TC enhancement of nanofluids. The selected models do not capture the experimental findings within the range of this parametric study, evidencing the need to develop appropriate model for TC enhancement prediction of CNT nanofluids and measure TC of this kind of nanofluids before performing numerical studies in heat exchangers and cavities. Journal of Thermal Engineering Journal of Thermal Engineering 2015-01-20T22:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2085 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2085 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2085

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2081 2015-01-08T22:00:00Z 5

Improving energy efficiency within manufacturing by recovering waste heat energy Yang Luo, Elliot Woolley, Shahin Rahimifard, Alessandro Simeone Energy efficiency; Waste heat recovery; Manufacturing sector In the UK, 25% of final energy consumption is attributed to the industrial sector (DECC 2013) which also accounts for one third of the electricity consumption. However it is estimated that between 20 to 50 percent of industrial energy consumption is ultimately wasted as heat (Johnson et al. 2008). Unlike material waste that is clearly visible, waste heat can be difficult to identify and evaluate both in terms of quantity and quality. Hence by being able to understand the availability of waste heat, and the ability to recover it, there is an opportunity to reduce energy costs and associated environmental impacts. This research describes the design of a novel framework that aids manufacturers in making decisions regarding the most suitable solution to recover Waste Heat Energy (WHE) from their activities. The framework consists of four major sections: 1) survey of waste heat sources in a facility; 2) assessment of waste heat quantity and quality; 3) selection of appropriate technology; 4) decision making and recommendations. In order to support the implementation of the framework within the manufacturing industry, an associated software tool is discussed. Journal of Thermal Engineering Journal of Thermal Engineering 2015-01-08T22:00:00Z Extended Conference Paper application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2081 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2081 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2081

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2073 2014-12-24T22:00:00Z 3

Fundamental Assessments and New Enabling Proposals for Heat Transfer Correlations and Flow Regime Maps for Shear Driven Condensers in the Annular/stratified Regime A. Narain, R.R. Naik, S. Ravikumar, S. S. Bhasme mm-scale condensers, annular condensation, heat-transfer rate correlations, flow regime transition Modern-day applications need mm-scale shear-driven flow condensers. Condenser designs need to ensure large heat transfer rates for a variety of flow conditions. For this, good estimates for heat-transfer rate correlations and correlations for the length of the annular regime (beyond which plug-slug flows typically occur) are needed. For confident use of existing correlations (particularly the more recent ones supported by large data sets) for shear-pressure driven internal condensing flows, there is a great need to relate the existing correlation development approaches to direct flow-physics based fundamental results from theory, computations, and experiments. This paper addresses this need for millimeter scale shear driven and annular condensing flows. In doing so, the paper proposes/compares a few new and reliable non-dimensional heat-transfer coefficient correlations as well as a key flow regime transition criteria/correlation. Journal of Thermal Engineering Journal of Thermal Engineering 2014-12-24T22:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2073 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2073 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2073

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2082 2015-01-09T22:00:00Z 1

Performance Optimization of Brayton Heat Engine at Maximum Efficient Power using Temperature Dependent Specific Heat of Working Fluid Rajesh Kumar, S C Kaushik, Raj Kumar Brayton heat engine, Efficiency, Efficient power, Finite time thermodynamics, Temperature dependent specific heat Efficient power optimization of Brayton heat engine with variable specific heat of the working fluid is analyzed from the view of finite time thermodynamics. The efficient power is defined as the multiplication of power output and engine efficiency. Therefore, this criterion considers not only the power output but also the engine efficiency. Optimizing the efficient power gives a compromise between power and engine efficiency. Results obtained are compared with those obtained by using the maximum power and maximum power density conditions. The results show that the engine designed at maximum efficient power criterion is more efficient as compared with those designed at maximum power and maximum power density conditions. Moreover, engine designed at maximum efficient power criterion requires lesser pressure ratio over those designed at maximum power density conditions. Brayton heat engine with temperature dependent specific heat of the working fluid gives realistic prediction of engine efficiency and engine power than does the isentropic Brayton heat engine with constant specific heat. Journal of Thermal Engineering Journal of Thermal Engineering 2015-01-09T22:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2082 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2082 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2082

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2099 2015-02-26T22:00:00Z 1

Aerodynamic Performance of Small-Scale Horizontal Axis Wind Turbines Under Two Different Extreme Wind Conditions Emre Alpman Horizontal axis wind turbines, extreme wind conditions, computational fluid dynamics Aerodynamic performance of two small-scale horizontal axis wind turbines are analyzed under the extreme operating gust and extreme direction change conditions with initial wind speeds of 7, 10, 13, 15 and 20 m/s. Performance predictions are performed using computational fluid dynamics, and time variations of shaft torque and hub bending moment produced by the turbines are presented and compared with each other. Sectional flow field and sectional blade loading details along with surface skin friction line predictions are also presented in order to explain the loading behavior of the turbine blades at the mentioned extreme wind conditions. Predictions show that variations in wind speed and blade loadings are similar at low wind speeds, however, this similarity degrades as the wind speed increases. Also compared to wind speed changes, aerodynamic forces are shown to adapt more slowly to wind direction changes. Journal of Thermal Engineering Journal of Thermal Engineering 2015-02-26T22:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2099 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2099 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2099

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2144 2015-06-29T21:00:00Z 1

A Holistic Modeling and Simulation Approach to Optimize a Smart Combined Grid System of Different Renewable Energies Martin Griese, Thomas Schulte, Jürgen Maas HIL simulation, combined grid system, CHP model In this contribution, a model-based method for analyzing and designing energy systems comprising the electrical, thermal and chemical domains is presented. Beside the energy generation and consumption, the bidirectional coupling between all energy domains is considered, as well. This method is an adapted variant of the so called Hardware-in-the-Loop simulation where virtual energy components are combined with geographically distributed real energy components. In order to integrate the real components with minimal instrumentation efforts, measured quantities are included as information flows, only, while the physical power flows are connected to local available grid structures. This virtual coupling has the further advantage of a simple scalability so that existing real components can be used for different applications. The virtual energy components are represented by real-time capable models describing their physical behavior. In this contribution, a CHP unit is described as a first virtual energy component. The modeling approach is based on a time domain approach using state variables of the multiple domains to describe the dynamic behavior. Furthermore, the model is scalable regarding the modeling depth and the power ratings which allows an application for different simulation scenarios. Besides the modeling of a standalone CHP unit, its integration into a simulated electrical grid is discussed as well. Afterwards, the overall model is parameterized and validated with data of a medium size CHP unit. Finally, the model is used for simulations of an exemplary electrical grid. Journal of Thermal Engineering Journal of Thermal Engineering 2015-06-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2144 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2144 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2144

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2115 2015-03-25T22:00:00Z 1

Energy, Exergy and Sustainability Analysis of Two-stage Vapour Compression Refrigeration System Kapil Chopra, V. Sahni, R.S. Mishra COP, Irreversibility, Exergetic efficiency In this paper comparative analysis of R152a, R600, R600a, R410a, R290, R1234yf, R404a and R134a as refrigerants in two stage vapour compression refrigeration system has been done on the basis of energetic and exergetic performance. Performance parameters such as entropy generations, COP, exergetic efficiency, sustainability index were investigated at different ambient condition. It was found that both energy and exergy efficiencies of R134a is 8.97% and 5.38% lower than R152a and R600 respectively at -50 oC evaporating and 45 oC condensing temperatures. It was also observed that Irreversibility was minimal at higher evaporating temperatures and condenser was responsible for highest irreversibility or losses in two stage vapour compression refrigeration system. Sustainability index for R152a (1.96) was highest compared to other refrigerants. Journal of Thermal Engineering Journal of Thermal Engineering 2015-03-25T22:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2115 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2115 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2115

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2097 2015-02-06T22:00:00Z 4

Thermoelectric Properties of Bismuth Telluride Filled Silicone Bruce Y. Decker, Sinclair Calderon, Yong Gan Thermoelectric materials; bismuth telluride; composite material Bismuth telluride filled silicone rubber composite was extruded into millimeter-sized wires using electrospinning. The composite wires were tested in view of the electrical resistance and Seebeck coefficient. The highest electrical resistance measured is 2.9*1010 ohms. The composite material exhibited high Seebeck effect because silicone rubber exhibits low thermal conductivity as a result of increased phonon scatters. Moreover, compared with the bulk reference material, the thermoelectric property of bismuth telluride is notably enhanced. Due to the inherent flexibility of silicone rubber and thermoelectric property of bismuth telluride, it is possible for making a flexible thermoelectric material for alternative energy applications. Journal of Thermal Engineering Journal of Thermal Engineering 2015-02-06T22:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2097 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2097 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2097

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2156 2015-08-14T21:00:00Z 1

Experimental Analysis of the Effect of Cold Fluid Inlet Temperature on the Thermal Performance of a Heat Exchanger Bahadır Doğan, Latife Berrin Erbay Heat exchanger, louvered fin, mini channel, cold fluid This paper focuses on the effect of inlet temperature of the cold fluid on the thermal performance of two mini channel flat-tube with multi-louvered fin compact heat exchangers experimentally. Two louvered fin heat exchangers in the same sizes with different number of fin rows are tested in a constant temperature test room by a wind-tunnel. The cold fluid flowing on the external side of the heat exchanger is air. The hot fluid flowing through the mini channels is water. The inlet temperature of the water passes through the mini channel flat-tube is predetermined and supplied at a temperature of 42oC. Mass flow rate of the water is regulated by a water circulator at a rate of 0.025 kg/s. The mass flow rate of the air is measured 0.0472 kg/s. It is found that the model which has two fin rows is more effective in terms of overall thermal conductance, number of transfer units and effectiveness at all values of inlet temperature of the air. In addition, both of the heat exchangers have the highest thermal performance at an air inlet temperature of 24oC. Journal of Thermal Engineering Journal of Thermal Engineering 2015-08-14T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2156 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2156 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2156

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2100 2015-03-07T22:00:00Z 1

Building Envelope Performance with Different Insulating Materials – An Exergy Approach Yatheshth Anand, Sanjeev Anand, Ankush Gupta, Sudhir Tyagi Exergy Demand Rate, Exergy, Thermal Comfort, Building Envelope Buildings are now considered as investments, everyone is interestd in. But they end up consuming lot of energy, hence its performance is necessary to be checked. Building performance can best analysed by keeping a close watch on the bulding operations and the exergy analysis is a better and comprehensive way to understand it in totality. Buildings have now a days become the largest producer of green house gases, thus making them a potential option for analysis. This is why national and international organizations have joined hands to raise governances to carryout symbolic proposals in building’s sustainability, energy efficiency and environmental protection. The energy consumption due to thermal loads can be minimized by effective and judicious use of building resources which includes building design and its operations. The present communication deals with the detailed analysis of a building envelope for four different cases i.e. no insulation on walls and roof and oven dry wood, polyurethane foam and fiberglass as insulation for the roof and walls respectively. The behavior of the building envelope for all the cases, with the variation of the ambient temperature revealed that the exergy analysis is a quintessential analyzing the buildings for optimizing their energy consumption. Results revealed that polyurethane (PU) foam can be considered to be the best option for optimum performance from the building envelope. Journal of Thermal Engineering Journal of Thermal Engineering 2015-03-07T22:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2100 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2100 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2100

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2148 2015-08-14T21:00:00Z 1

Numerical Simulation of a Stepped Capillary Tube Used in Residential Heat Pump Systems Octavio Garcia-Valladares Capillary tubes, Refrigeration, Two-phase flow, Expansion devices, New design A stepped capillary tube is a new design that consist of two serial-connected capillary tubes with different diameter as an alternative in order to reduce the manufacturing cost of the typical assembly of two capillary tubes and a by-pass check valve widely used to achieve different mass flow rates in residential heat pump systems. One-dimensional numerical modelling of fluid-flow inside stepped capillary tubes was performed, and successfully validated against experimental data. Governing equations (continuity, momentum, energy, and entropy) for describing the fluid flow have been solved by using a fully implicit step-by-step method. A numerical treatment has been codified for considering thermodynamic and flow transitions (subcooled liquid region, metastable liquid region, metastable two-phase region and equilibrium two-phase region). Sudden contraction and enlargement were also considered. These results demonstrate a robust application of the model developed to predict reliably the mass flow rate through stepped capillary tubes, which enable this tool to be reliably used for the design of this kind of systems. Journal of Thermal Engineering Journal of Thermal Engineering 2015-08-14T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2148 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2148 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2148

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2142 2015-06-29T21:00:00Z 6

A More Complete Thermodynamic Framework for Solid Continua Karan S. Surana, Michael J. Powell, J.N. Reddy Polar solid continua, Polar decomposition, Lagrangian description The Jacobian of deformation at a material point can be decomposed into the stretch tensor and the rotation tensor. Thus, varying Jacobians of deformation at the neighboring material points in the deforming volume of solid continua would yield varying stretch and rotation tensors at the material points. Measures of strain, such as Green’s strain, at a material point are purely a function of the stretch tensor, i.e. the rotation tensor plays no role in these measures. Alternatively, we could also consider decomposition of displacement gradient tensor into symmetric and skew symmetric tensors. Skew symmetric tensor is also a measure of pure rotations whereas symmetric tensor is a measure of strains, i.e. stretches. The measures of rotations in these two approaches describe the same physics but are in different forms. Polar decomposition gives the rotation matrix and not the rotation angles whereas the skew symmetric part of the displacement gradient tensor yields rotation angles that are explicitly and conveniently defined in terms of the displacement gradients. The varying rotations and rotation rates arise in all deforming solid continua due to varying deformation of the continua at neighboring material points, hence are internal to the volume of solid continua and are explicitly defined by the deformation, therefore do not require additional degrees of freedom to define them. If the internal varying rotations and their rates are resisted by the continua, then there must exist internal moments corresponding to these. The internal rotations and their rates and the corresponding moments can result in additional energy storage and dissipation. This physics is all internal to the deforming continua (hence does not require consideration of additional external degrees of freedom and associated external moments) and is neglected in the presently used continuum theories for isotropic, homogeneous solid continua. The continuum theory presented in this paper considers internal varying rotations and associated conjugate moments in the derivation of the conservation and balance laws, thus the theory presented in this paper is “a polar theory for solid continua” but is different than the micropolar theories published currently in which material points have six external degrees of freedom i.e. rotations are additional external degrees of freedom. This polar continuum theory only accounts for internal rotations and associated moments that exist as a consequence of deformation but are neglected in the present theories. We call this theory “a polar continuum theory” as it considers rotations and moments as conjugate pairs in a deforming solid continua though these are internal, hence are purely related to the deformation of the solid. It is shown that the polar continuum theory presented in this paper is not the same as the strain gradient theories reported in the literature. The differences are obviously in terms of the physics described by them and the mathematical details associated with conservation and balance laws. In this paper, we only consider polar continuum theory for small deformation and small strain. This polar continuum theory presented here is a more complete thermodynamic framework as it accounts for additional physics of internally varying rotations that is neglected in the currently used thermodynamic framework. This thermodynamic framework is suitable for isotropic, homogeneous solid matter such as thermoelastic and thermoviscoelastic solid continua with and without memory when the deformation is small. The paper also presents preliminary material helpful in consideration of the constitutive theories for polar continua. Journal of Thermal Engineering Journal of Thermal Engineering 2015-06-29T21:00:00Z Keynote Speech application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2142 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2142 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2142

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2143 2015-06-29T21:00:00Z 6

A More Complete Thermodynamic Framework for Fluent Continua Karan S. Surana, Michael J. Powell, J.N. Reddy Polar solid continua, Polar decomposition, Lagrangian description Polar decomposition of the changing velocity gradient tensor in a deforming fluent continua into pure stretch rates and rates of rotations shows that a location and its neighboring locations can experience different rates of rotations during evolution. Alternatively, we can also consider decomposition of the velocity gradient tensor into symmetric and skew symmetric tensors. The skew symmetric tensor is also a measure of pure rates of rotations whereas the symmetric tensor is a measure of strain rates. The measures of the internal rates of rotations due to deformation in the two approaches describe the same physics but in different forms. Polar decomposition gives the rate of rotation matrix and not the rates of rotation angles whereas the skew symmetric part of the velocity gradient tensor yields rates of rotation angles that are explicitly defined in terms of velocity gradients. These varying rates of rotations at neighboring locations arise due to varying deformation of the continua, hence are internal to the volume of matter and are explicitly defined by deformation. If the internal varying rates of rotations are resisted by the continua, then there must exist internal moments corresponding to these. The internal rates of rotations and the corresponding moments can result in additional rate of energy storage or rate of dissipation. This physics is all internal to the deforming continua and exists in all deforming isotropic, homogeneous fluent continua but is completely neglected in the presently used thermodynamic framework for fluent continua. In this paper we present derivation of a more complete thermodynamic framework in which the derivation of the conservation and balance laws consider additional physics due to varying rates of rotations. The currently used thermodynamic framework for fluent continua is a subset of the thermodynamic framework presented in this paper. The continuum theory presented here considers internal varying rates of rotations and the associated conjugate moments in the derivation of conservation and balance laws, thus the theory presented in this paper can be called “a polar continuum theory” but is different than micropolar continuum theories published currently in which material points have six external degrees of freedom i.e. the rotation rates are additional external degrees of freedom. In the remainder of the paper we refer to this new thermodynamic framework as ‘a polar continuum theory’. The continuum theory presented here only accounts for internal rotation rates and associated moments that exist as a consequence of deformation but are neglected in the present theories hence this theory results in a more complete thermodynamic framework. The polar continuum theory and the resulting thermodynamic framework presented in this paper is suitable for compressible as well as incompressible thermoviscous fluent continua such as Newtonian, Power law, Carreau-Yasuda fluids etc. and thermoviscoelastic fluent continua such as Maxwell, Oldroyd-B, Giesekus etc. The thermodynamic framework presented here is applicable to all isotropic, homogeneous fluent continua. Obviously the constitutive theories will vary depending upon the choice of physics. These are considered in subsequent papers. Journal of Thermal Engineering Journal of Thermal Engineering 2015-06-29T21:00:00Z Keynote Speech application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2143 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2143 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2143

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2149 2015-08-14T21:00:00Z 4

Analytical Temperature Distribution on a Turbine Blade Subject to Combined Convection and Radiation Environment Balaram Kundu, Pramod A Wankhade Analytical, temperature distribution, Turbine blade, Differential transformation method The overall operating cost and operation of a turbine is greatly influenced by the durability of the hot section components operating at very high temperatures. Modern day turbine blades become a critical component for the designers as it receives heat and as a result produces great thermal stresses due to variation of high temperature. Thus the turbine blade metal temperature distribution and temperature gradients are the most important parameters to determine the blade life. In this paper the analysis is done by developing an analytical method to find the temperature distribution in lumped system of combined convection-radiation effect on a turbine blade. Journal of Thermal Engineering Journal of Thermal Engineering 2015-08-14T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2149 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2149 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2149

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2150 2015-08-14T21:00:00Z 3

Applications of Nanotechnology to Enhance the Performance of the Direct Absorption Solar Collectors Ahmed Kadhim Hussein, A.A. Walunj, Lioua Kolsi Nanofluid , Direct absorption solar collector , Literature review , Renewable energies This research gives a comprehensive overview about the recent advances related with the application of the nanotechnology in the direct absorption solar collectors. Papers reviewed including theoretical , numerical and experimental up to date works related with the nanotechnology applications in this kind of the solar collectors. A lot of literature are reviewed and summarized carefully in a useful table (Table 1) to give a panoramic overview about the role of the nanotechnology in improving the direct absorption solar collectors. It was found that the use of the nanofluid in the direct absorption solar collectors can play a crucial role in increasing the efficiency of these devises. Journal of Thermal Engineering Journal of Thermal Engineering 2015-08-14T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2150 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2150 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2150

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2145 2015-06-29T21:00:00Z 1

Stability of Turbine Blades, Aircraft Wings and Their Acoustic Radiation Hamadiche Mahmoud Aeroelasticity, wing stability, noise generation, vibration control The stability of the wing is revisited in this work, the natural modes of the thin wing in incidence under the action of aerodynamic forces are calculated. The wing in this study has two degrees of freedom corresponding to the bending and torsion. Boundary between stable and instable zone are calculated. Wing stabilization by piezoelectric material are considered. The noise level produced by unsteady impinging gust is predicted. Journal of Thermal Engineering Journal of Thermal Engineering 2015-06-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2145 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2145 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2145

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2151 2015-08-14T21:00:00Z 1

Energy and Exergy Analysis of a Double Effect Parallel Flow LiBr/H2O Absorption Refrigeration System Akhilesh Arora, Manoj Dixit, S.C. Kaushik Parallel flow, Absorption system, Exergy, Exergetic efficiency, Solution distribution ratio In the present communication the analysis of a parallel flow double effect absorption refrigeration system is performed to compute the optimum solution distribution ratio (optimum distribution of strong solution masses between low and high pressure generators) from the viewpoint of maximum COP and maximum exergetic efficiency. A computational model is developed for the parametric investigation of a double effect parallel flow LiBr/H2O absorption refrigeration system. The effect of generator, absorber and evaporator temperatures on optimum solution distribution ratio is also studied. The results show that the maximum COP and maximum exergetic efficiency is achieved corresponding to same value of optimum solution distribution ratio. Journal of Thermal Engineering Journal of Thermal Engineering 2015-08-14T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2151 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2151 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2151

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2147 2015-07-06T21:00:00Z 1

A Numerical Approach for Modelling Thermal Profiles and Effects of Process Parameters on it in Submerged Arc Welding of AISI 1518 Grade Steel Abhijit Sarkar, Aparesh Datta, Prasenjit Dey, R. N. Rai, S.C. Saha Submerged Arc Welding (SAW), Finite Volume Method (FVM), Gaussian Heat Distribution, Transient temperature distribution, AISI 1518 grade steel A comprehensive methodology for the analysis of thermal analysis due to welding has been studied in this present investigation. A finite volume methodology (FVM) among term of the basic heat transfer equation was enforced to simulate the temperature profiles in submerged arc welding (SAW) of AISI 1518 grade steel. The supply of the arc is assumed to be a moving conicoidal heat supply with a Gaussian distribution. The obtained results from the simulation methodology are compared with experimental results and determined a good agreement with experimental results, with associate degree overall proportion of error calculable to be between 5.23%. The influence of welding current and speed of temperature analysis has been evaluated and located that each one those parameters are playing a necessary role in moving the temperature distribution of the assembly, i.e.when current inflated, the temperature conjointly inflated with constant speed yet like higher speed temperature is decreased for constant current . Finally, the influence of heat input on peak temperature variations in various welding parameters has been evaluated and shown that the higher heat input in higher temperature is obtained Journal of Thermal Engineering Journal of Thermal Engineering 2015-07-06T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2147 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2147 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2147

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2160 2015-09-02T21:00:00Z 1

Thermo-Hydraulic Performance of Solar Air Heater Duct having Triangular Protrusions as Roughness Geometry Jasjeevan Singh, Ranjit Singh, Brij Bhushan Keywords: Solar air heater, Artificial roughness; Nusselt number; Friction factor An experimental investigation has been carried out for a range of system and operating parameters in order to analyze effect of artificial roughness on heat transfer and friction in solar air heater duct having triangular protrusions as roughness geometry. An increase in heat transfer and friction loss has been observed in solar for duct having roughened absorber plate. Experimental data have been used to develop Nusselt number and friction factor correlations as function of system and operating parameters for predicting performance of the system having investigated type of roughness geometry Journal of Thermal Engineering Journal of Thermal Engineering 2015-09-02T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2160 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2160 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:7 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2160

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2146 2015-06-29T21:00:00Z 3

An Overview on Pulsatile Flow Dynamics Melda Özdinç Çarpinlioğlu Pulsatile flow, Oscillation, Oscillation Frequency, Oscillation Amplitude, Time –averaged Reynolds Number, Womersley Number Pulsatile flow dynamics in reference to the relevant experimental research on the manner between the time periodsof 1997- 2015 is presented in this paper.The flow field under discussion isgenerated through a rigid circular cross-sectional pipe asan axial slightly- compressible and sinusoidal one in a controlledrange of the oscillation parameters. Laminar and turbulent flow regimes are considered with a particular emphasis devoted to the transitional characteristics of laminar pulsatile flow into turbulence. The definitions of the flow characteristics,the methodology of the experimental studies and theresults on the physical nature of the field are described. The departure of pulsatile flow from a steady one is presented in reference to the velocity field and frictional field analysesunder the influence ofoscillation frequency and amplitude. In this context, thecritical magnitudes of Womersley number, time-averaged Reynolds number and oscillation amplitude to estimate the ranges of pulsatile flow field are proposed. Journal of Thermal Engineering Journal of Thermal Engineering 2015-06-29T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2146 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2146 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2146

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2153 2015-08-14T21:00:00Z 1

Simulation of Wind Turbines Utilising Smart Blades Alireza Maheri wind turbine, smart blade, adaptive blade, morphing blade, microtab, trailing edge flap, telescopic blade Wind turbine smart blades change their aerodynamic characteristics in response to changes in operating condition, aiming at enhancing the power capture capability or controlling the power and aerodynamic load. Smart blades span a wide range of technologies. Some of these technologies have been proposed and developed specially for wind turbines, while some others have been borrowed from aircraft applications. Adaptive blades, telescopic blades, morphing blades, blades equipped with active control surfaces are some examples of smart blades. This paper presents a summary of wind turbine smart blades and advances in simulation and design of these blades. Journal of Thermal Engineering Journal of Thermal Engineering 2015-08-14T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2153 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2153 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2153

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2154 2015-08-14T21:00:00Z 1

Pre-Stressed Stayed Cross-Armed Wind Turbine Towers Jack Callaghan, Alireza Maheri wind turbine tower, cross-armed columns, stayed column, buckling, tower design One of the major components of horizontal axis wind turbines is the tower, which supports the weight of the rotor and nacelle as well as the thrust force produced by the rotor. Wind turbine towers are designed for static stability under the axial load, for strength to withstand the cantilever thrust force and for dynamic stability in interaction with rotating rotor and blades. This paper presents the results of a numerical investigation into an innovative wind turbine tower design, using the concept of pre-stressed stayed cross-armed columns. Pre-stressed stayed cross-armed columns restrain the column buckling deformation as a result of the tension in the cables causing compression in the horizontal cross-arms. This essentially decreases the effective length of the column, thereby giving it superior axial load resistance against buckling. Journal of Thermal Engineering Journal of Thermal Engineering 2015-08-14T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2154 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2154 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2154

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2155 2015-08-14T21:00:00Z 1

Experimental Performance of R134a and R152a Using Microchannel Condenser V.W. Bhatkar, V.M. Kriplani, G. Awari R134a, R152a, microchannel condenser An experimental performance study on vapour compression refrigeration system with R134a and drop in substitute R152a with aluminium microchannel condenser was carried out for condensation temperature of 48°C while evaporation temperature varied from -10 to 15°C. Refrigerant charge of R152a was reduced by 40% over R134a with the microchannel condenser. Performance parameters like work input to the compressor, coefficient of performance, refrigerating capacity, condenser capacity and the product of the overall heat transfer coefficient & surface area of the condenser are plotted and results are discussed. Journal of Thermal Engineering Journal of Thermal Engineering 2015-08-14T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2155 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2155 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:7 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2155

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2223 2015-12-30T22:00:00Z 1

Computation of Optimum Parameters of a Half Effect Water-Lithium Bromide Vapour Absorption Refrigeration System Akhilesh Arora, Manoj Dixit, S. C. Kaushik Half effect, exergy analysis, Vapour Absorption Refrigeration, Water-lithium bromide In this research paper, energy and exergy analyses of water lithium bromide half effect vapour absorption refrigeration system has been carried out. Based on energy and exergy analysis the optimum intermediate pressure is computed corresponding to maximum values of coefficient of performance and exergetic efficiency under various operating conditions. It is found that the optimum intermediate pressure corresponding to maximum values of coefficient of performance and exergetic efficiency is same. The effects of low and high pressure generator temperatures, evaporator temperature, effectiveness of solution heat exchangers and difference between low and high pressure generator temperatures have been considered in computing optimum intermediate pressure. The maximum COP varies between 0.415 - 0.438 and maximum exergetic efficiency varies between 6.96-13.74%. Journal of Thermal Engineering Journal of Thermal Engineering 2015-12-30T22:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2223 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2223 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2223

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2224 2015-12-30T22:00:00Z 4

Recent Developments of Computational Methods on Natural Convection in Curvilinear Shaped Enclosures Hakan Öztop, Fatih Selimefendigil, Eiyad Abu-Nada, Khaled Al-Salem Curvilinear geometry, natural convection, nanofluid In this review work, thermal and flow fields due to natural convection of in curvilinear enclosures was conducted for different geometries using nnaofluids. Different computational techniques are applied to get results for this geometries. The main difficulties on this problem is to obtain of grid distribution.It was found that the geometry parameter is an important control parameter on heat and fluid flow in natural convection. In general, heat transfer increases with the addition of nanoparticle into the base fluid. Journal of Thermal Engineering Journal of Thermal Engineering 2015-12-30T22:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2224 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2224 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2224

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2152 2015-08-14T21:00:00Z 4

Application of Numerical Modelling to Biomass Grate Furnaces Ramin Mehrabian Bardar, Ali Shiehnejadhesar, Robert Scharler Biomass, Grate furnace, Combustion, Numerical modelling The direct combustion of the biomass is the most advanced and mature technology in the field of energetic biomass utilisation. The legislations on the amount of emitted pollutants and the plant efficiency of biomass combustion systems are continually being restricted. Therefore constant improvement of the plant efficiency and emission reduction is required Numerical modelling is gaining increasing importance for the development of biomass combustion technologies. In this paper an overview about the numerical modelling efforts deal with the most relevant phenomena in biomass grate firing systems is given. The numerical modelling results in a deeper understanding of the underlying processes in biomass combustion plants. Therefore, it leads to a faster and safer procedure of development of a new technology. Journal of Thermal Engineering Journal of Thermal Engineering 2015-08-14T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2152 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2152 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2152

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2161 2015-09-02T21:00:00Z 4

Microfluidic Technology and its Biomedical Applications Yasaman Daghighi Microfluidics, Biomedical application, Induced-charge Electrokinetics Microfluidics is the field of handling small volume of fluids and/or manipulating micron-size and submicron-size particles in a microchannel. Microfluidic devices require only small amounts of samples and can run the process in a short period of time. These features have made Microfluidics a powerful technique in lab-on-chip and biomedical applications. These microsystems play important roles in tissue engineering, drug screening, determining the point-of-care diagnoses, and also generating clinically relevant tumor microenvironment for cancer studies. The current paper focuses on the studies conducted on transportation of fluids and particles in small scale systems. It will also introduce the latest developments of the microfluidic components and will provide several biomedical applications of such devices. Journal of Thermal Engineering Journal of Thermal Engineering 2015-09-02T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2161 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2161 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:7 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2161

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2162 2015-09-02T21:00:00Z 1

Design Considerations of Conformal Cooling Channels in Injection Moulding Tools Design: An Overview Eric Dimla Thermoplastic, cooling channels, conformal cooling, injection moulding, temperature distribution, cycle time Design of the cooling system in the thermoplastic injection moulding process is one of the most important steps during mould design. It has a direct influence on the quality of the parts produced and thereby impinging on the cycle time. Cooling channels design traditionally was limited to relatively simple configurations due to the main process for manufacturing being limited to drilling of straight holes. Nowadays, helped by 3D printers, complex shapes are able to be produced with intricate details and more complex geometries. The objective of this study is to determine the temperature profile along the mould tool cavity wall to improve the cooling system design. Virtual models from a suitable 3D modelling software such as Solidworks and Moldflow are used to design a simple artefact and simulations studies conducted to include different cooling systems such as straight and conformal channels. The effects of cooling channels form and their location on the temperature distribution of the mould and the solidification degree of polymer are studied. The bulk of the results indicate that in order to improve the productivity of the process, the cooling and cycle times have to be minimized while at the same time a homogeneous cooling is necessary to maintain a consistent quality of the product. Journal of Thermal Engineering Journal of Thermal Engineering 2015-09-02T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2162 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2162 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:7 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2162

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2157 2015-08-14T21:00:00Z 4

Control of Wake and Vortex Shedding Behind Solid Circular Obstacle by Magnetohydrodynamics Javad Abolfazli Esfahani, Ali Kianifar, Saman Rashidi, Masood Bovand, Kamel Milani Shirvan wake; magnetic field; Stuart number; vortex shedding Control of vortex shedding leads to a reduction in the unsteady forces acting on the bluff bodies and can significantly reduce their vibrations. In this paper, the finite volume method (FVM) is used to simulate the flow around and through two-dimensional circular obstacle. An external magnetic field is applied to control the wake behind the obstacle and also to suppress the vortex shedding phenomena. Maxwell equations are applied to provide the coupling between the flow field and the magnetic field. The range of Stuart (N) and Reynolds (Re) numbers are 0-10 and 1-200, respectively. The effects of magnetic field on control of wake structure behind the obstacle are investigated in details. It is found that for higher Stuart number (i.e. N=5), drag coefficient increases rapidly by using magnetic field. Journal of Thermal Engineering Journal of Thermal Engineering 2015-08-14T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2157 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2157 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:7 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2157

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2262 2016-05-29T21:00:00Z 1

Performance of Low GWP Fluids in Heat Pump Systems Jovana Radulovic heat pump, low GWP fluids, COP, exergy analysis Heat pumps are increasingly gaining popularity as the world is moving towards low-carbon energy systems. Use of heat pumps for domestic heating and hot water is widely seen as a sustainable option, and a step further from conventional fuel dependence. In spite of being ‘green’ in terms of carbon-pollution, there is a need to move towards low GWP working fluids in heat pump systems to ensure minimal impact to the environment. Low GWP fluids and mixtures have been emerging in the light of sterner legislations being introduced to limit, if not to totally prevent, further use of high GWP fluids. Replacement fluid has to satisfy a number of criteria, primarily to perform similarly to the original fluid. We have compared high and low GWP fluids, as well as several mixtures, as working fluids in the same operational scenario. Low GWP fluids are fundamentally different from conventionally used one, but their performance has some promising features. Journal of Thermal Engineering Journal of Thermal Engineering 2016-05-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2262 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2262 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2262

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2225 2015-12-30T22:00:00Z 3

Geothermal Energy Use in Hydrogen Production Mehmet Kanaoğlu, Ceyhun Yılmaz, Asegul Abusoglu Hydrogen, geothermal energy, hydrogen production, hydrogen liquefaction We propose the use of geothermal energy for hydrogen production and liquefaction, and investigate six possible models for accomplishing such a task. The models are studied thermodynamically in order to assess their performance for maximizing hydrogen production rate while minimizing the used geothermal energy. The effect of geothermal water temperature on various thermodynamic performance of the models is investigated. The models include using geothermal work output as the work input for an electrolysis process (Model 1); using part of geothermal heat to produce work for electrolysis process and part of geothermal heat in an electrolysis process to preheat the electrolysis water (Model 2); using geothermal heat in an absorption refrigeration process to precool the gas before the gas is liquefied in a liquefaction cycle (Model 3); using part of the geothermal heat for absorption refrigeration to precool the hydrogen gas and part of the geothermal heat to produce work with a binary geothermal cycle and use it in a liquefaction cycle (Model 4); using geothermal work output as the electricity input for a liquefaction cycle (Model 5); and using part of geothermal work for electrolysis and the remaining part for liquefaction (Model 6). Journal of Thermal Engineering Journal of Thermal Engineering 2015-12-30T22:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2225 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2225 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2225

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2226 2015-12-30T22:00:00Z 1

Flow and Thermal Fields Investigation in Divergent Micro/Nano Channels Amin Ebrahimi, Ehsan Roohi DSMC, Gaseous flow, micro/nano-channel,Transition regime, Simplified Bernoulli Trials The present work is related to the study of the nitrogen gas flow through diverging micro/nano-channels. The direct simulation Monte-Carlo (DSMC) method has been used to study the flow. The Simplified Bernoulli Trials (SBT) collision scheme has been employed to reduce the computational costs and required amounts of the computer resources. The effects of various divergence angles on flow and thermal fields have been studied for different Knudsen numbers in late-slip and early-transition regimes. The inlet-to-outlet pressure ratio has been set to 2.5 for micro/nano-channels with a uniform constant wall temperature. By analyzing the numerical results no flow separation has been found due to slip at the wall which is different than flow behavior in continuum regime. The results indicate that the viscous component has a relatively large contribution in the overall pressure drop and flow behavior. It observed that for low divergence angles the effects of pressure forces dominate the effects of shear stress and divergence angle and cause the flow accelerate along the channel while by increasing the divergence angle and therefore effects of flow expansion, the flow decelerates along the channel. The mass flow rate through channel increases by increasing the divergence angle.Cold-to-hot heat transfer has been observed in diverging micro/nano-channels. In order to investigate the thermal behavior in diverging micro/nano-channels, the results have been compared to weakly non-linear constitutive laws derived from Boltzmann’s equation. Journal of Thermal Engineering Journal of Thermal Engineering 2015-12-30T22:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2226 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2226 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2226

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2158 2015-08-14T21:00:00Z 1

Numerical Simulation on the Effect of Latent Heat Thermal Energy Storage Unit Abdel Illah Nabil Korti Latent heat; Thermal storage; Phase change material PCM; Numerical simulation; Flow distribution Thermal energy storage is a practical and important way in conserving available energy and improving its utilization. Unlike the sensible heat storage method, the latent heat storage method provides much higher storage density, with a smaller temperature difference between charging and discharging heat phase. This work presents a numerical study of a latent heat storage exchanger filled with phase change material (PCM). Water flows by forced convection through the inner tube and transfers the heat to PCMs. A mathematical model based on the conservation energy equations was numerically resolved by a commercial FLUENT 6.3.2 code. Several numerical investigations were conducted in order to examine the impact of the key parameters: mass quantity of PCM used, number of pass and the mass flow rate of the water. This parametric study provides guidelines for system thermal performance and design optimization. Journal of Thermal Engineering Journal of Thermal Engineering 2015-08-14T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2158 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2158 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2158

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2274 2016-06-06T21:00:00Z 1

Stability Analysis of Plane Couette-Poiseuille Flow With Porous Walls Under Transverse Magnetic Field Mustapha Lamine, Ahmed Hifdi Stability analysis, Couette-Poiseuille flow, Orr-Sommerfeld equation, Spectral method, Cross-flow, magnetic field A linear stability analysis of a plane Couette-Poiseuille flow of an electrically conducting fluid with uniform cross-flow is investigated in the presence of a transverse magnetic field. The Chebyshev spectral collocation method is utilized to obtain eigenvalues of the modified classical Orr-Sommerfeld equation. The effect of cross-flow with its sense and transverse magnetic field on the stability are examined. The results show that cross-flow acts to stabilize or destabilize the flow. The cross-flow’s sense produces a significant influence on the stability. This effect becomes more important in the presence of a magnetic field. The dependence of the magnetic field’s effect on the cross-flow’s sense is also presented. Journal of Thermal Engineering Journal of Thermal Engineering 2016-06-06T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2274 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2274 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2274

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2229 2016-01-04T22:00:00Z 1

Experimental Determination of Convective Heat Transfer Coefficient During Open Sun and Greenhouse Drying of Apple Slices Kamil Neyfel Çerçi, Ebru Kavak Akpınar Convective heat transfer coefficient, drying, forced convection, natural convection, greenhouse, open sun, apple A small scale greenhouse type dryer was designed and tested. Convective heat transfer coefficient of apple slices was identified under open sun at natural convection mode and in greenhouse drying at natural and forced convection mode. The experiments were carried out in May-June, 2014 under the climatic conditions of Elazığ, Turkey (39o14’ E 38o41’ N). The rate of moisture removal, crop temperature, relative humidity inside and outside the greenhouse and ambient air temperature for complete drying was recorded at 30 min intervals. The values of constants (C and n) in Nusselt number expression were found by using linear regression analysis of the data gathered from apple slices. Finally, convective heat transfer coefficients were determined. The average convective heat transfer coefficient values for apple slices were calculated as 2.863 W/m2 oC for open sun drying under natural convection mode, 2.065 W/m2 oC for greenhouse drying under natural convection mode, 2.724 W/m2 oC for greenhouse drying under forced convection mode, respectively. The convective heat transfer coefficient in open sun drying was slightly higher than forced convection in greenhouse drying. The convective heat transfer coefficient in greenhouse drying under natural mode was found as the lowest one. Journal of Thermal Engineering Journal of Thermal Engineering 2016-01-04T22:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2229 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2229 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2229

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2227 2016-01-02T22:00:00Z 1

Investigation of Nanofluid Flow Characteristics and Wall Stress Concentration Locations in a 3d Channel with Sharp Edge Rectangular Ribs Mustafa Murat Yavuz, Nehir Tokgöz Channel flow, Stress concentrations Flow regimes in various channels can introduce different responses that interact with inside of channel walls. Hence both flow characteristic and its effect on wall surfaces should be investigated, especially for a new channel design or usage of a new fluid. In this work, flow characteristics of a nanofluid flow and wall stress concentration locations are investigated numerically in a 3D channel with including sharp edge rectangular ribs. The ribs are arranged with periodic order and transverse positions at inside of upper and below surfaces of channel. The nanofluid flow consists of Al2O3-water solution with %8 particle volume concentrations. The used Reynolds number (Re) changes from 75 to 2000. Furthermore, commonly used two different fluids are investigated for detecting differences of flow characteristics of nanofluid. Tresca yield criterion is used with considering channel's ductile material properties in stress analysis. Interactions between ribs and flow are observed in detail. Flow separation and vortex formations effectively depend on Reynolds number. Values of wall stress concentrations depend on Reynolds number and pressure effects with respect to sharp edge rectangular ribs. Stress values of upper surfaces are less than along path of below surfaces on channel wall surfaces. Journal of Thermal Engineering Journal of Thermal Engineering 2016-01-02T22:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2227 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2227 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2227

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2163 2015-09-02T21:00:00Z 1

Nature Inspired Optimal Design of Heat Conveying Networks for Advanced Fiber-Reinforced Composites Mahmoud Hamadiche, Natalya Kizilova Heat transfer, fiber reinforced composites, optimal design, nature inspired solutions, MEMS devices A concept of composite materials reinforced by branching micro or nanotubes optimized for both heat transfer and strength of the material is presented. Numerous examples of reinforcement by branched fibers in cells, tissues and organs of plants and animals are studied. It is shown orientation of the fibers according to principals of the stress tensor at given external load is the main principle of optimal reinforcement in nature. The measurement data obtained on venations of the plant leaves revealed clear dependencies between the diameters, lengths and branching angles that correspond to delivery of the plant sap to live cells of the leaf with minimal energy expenses. The mathematical problem on geometry of asymmetrical loaded branched fibers experienced minimal maximal stress is solved. Heat propagation in the fibers is described by generalized Guyer-Krumhansl equation. It is shown the optimality for the heat propagation, fluid delivery and structural reinforcement are based on the same relations between the diameters, lengths and branching angles. The principle of optimal reinforcement is proposed for technical constructions, advanced composite materials and MEMS devices. Journal of Thermal Engineering Journal of Thermal Engineering 2015-09-02T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2163 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2163 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:7 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2163

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2228 2016-01-03T22:00:00Z 1

Thermodynamic Analysis of Bi-Evaporater Ejector Refrigeration Cycle Using R744 as Natural Refrigerant Çağrı Kutlu, Şaban Ünal, Mehmet Tahir Erdinç, Bi-evaporator, Ejector, Refrigeration, R744, COP Researchers have been focused on refrigerant R744 because it is a natural refrigerant and its Global Warming Potential value is 1. However, coefficient of performance (COP) of refrigeration systems that use R744 as refrigerant has lower values than refrigeration systems that use CFC and HCFC refrigerants as refrigerant. Previous studies showed that COP of the refrigeration system with R744 can be increased by using two-phase ejector. In this study, additional evaporators are used instead of the separator. Thus, the refrigeration system can be constructed more accurately. Theoretical analysis of the bi-evaporator refrigeration system with two-phase ejector is carried out by using energy and momentum equations. COP and entrainment ratio are obtained for various operating conditions. Results show that COP improvement can be achieved about 21% for proper design in Mediterranean climate zone. Journal of Thermal Engineering Journal of Thermal Engineering 2016-01-03T22:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2228 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2228 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2228

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2263 2016-05-29T21:00:00Z 1

Experimental Investigation of Flow Characteristics of Corrugated Channel Flow Using PIV Nehir Tokgöz, Muhammed Murat Aksoy, Beşir Şahin PIV, corrugated channel, turbulent kinetic energy, phase angle The aim of the study is to determine the flow characteristics of corrugated duct. The whole study has been conducted for Reynolds numbers, Re=4000 and 6000. The corrugated duct geometry was designed for aspect ratios, s/H=0.3 and phase shift angle, ?=180§. Variations in flow characteristics of corrugated duct were investigated using the Particle Image velocimetry (PIV) technique. Time-averaged velocity distributions, patterns of streamline and corresponding turbulent statistics were determined. Augmentation of the Reynolds number leads to an increase in velocity due to the sharp corner edges of cavity. Dimensionless turbulent kinetic energy, <TKE> contours indicate that the magnitude of turbulent kinetic energy, <TKE> increases as a result of sharp corner edges of the cavities. High rate of momentum transfer is expected due to an increase of turbulence intensity. Journal of Thermal Engineering Journal of Thermal Engineering 2016-05-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2263 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2263 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2263

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2187 2015-10-24T21:00:00Z 1

Experimental Fully-Developed Thermal Convection for Non-Darcy Water Flow in Metal Foam Nihad Dukhan, Özer Bağcı, Mustafa Özdemir, Levent Kavurmacıoğlu experiment; metal foam; convection; Forchheimer; fully developed Experimental heat transfer data for water flow in commercial open-cell aluminum foam cylinder heated at the wall by a constant heat flux, is presented. The foam had 20 pores per inch (ppi) and a porosity of 87%. The measurements included wall temperature along flow direction as well as average inlet and outlet temperatures of the water. Flow speeds were in the non-Darcy regimes (transitional and Forchheimer). Heat fluxes were 14,998 W/m2 and 26,347 W/m2. The behavior of the wall temperature clearly shows thermal fully-developed conditions. The experimental Nusselt number is presented as a function of axial distance in flow direction, and showed what seemed to be a periodic development. A correlation for the average Nusselt number as a function of flow Reynolds number is provided. The experimental data can be used for validation of other analytical solutions, numerical models and heat-exchange engineering designs based on metal foam. Journal of Thermal Engineering Journal of Thermal Engineering 2015-10-24T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2187 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2187 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2187

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2264 2016-05-29T21:00:00Z 1

Flow Boiling Heat Transfer in a Rectangular Copper Microchannel Mehmed Rafet Ozdemir, Mohamed M. Mahmoud, Tassos G. Karayiannis Flow boiling, microchannel, heat transfer coefficient, flow patterns, instability Flow boiling characteristics of de-ionized water were tested experimentally in a rectangular copper single microchannel of 1 mm width, 0.39 mm height and 62 mm length. De-ionized water was supplied to the microchannel at constant inlet temperature (89°C) and constant inlet pressure (115 kPa). The mass flux ranged from 200 to 800 kg/m2s and the heat flux from 56 to 865 kW/m2. The heat transfer rate data are presented as plots of local heat transfer coefficient versus vapour quality and distance along the channel. Flow visualization was also conducted using a high-speed, high-resolution camera. The results indicate that unstable flow boiling occurred starting at boiling incipience for all mass flux values. The local heat transfer coefficient depends on heat flux only at very low heat and mass fluxes. At high mass flux, there is no heat flux effect with little dependence on vapour quality after the entry region. The mass flux effect was more complex. Journal of Thermal Engineering Journal of Thermal Engineering 2016-05-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2264 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2264 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2264

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2265 2016-05-29T21:00:00Z 4

An Experimental Study of Effective Factors on Soil Removal Efficiency in Cleaning Process by Solid Stream Jet Nozzles Mert Patkavak, Yusuf Koç, Özden Ağra Cleaning performance, soil removal, water jet, solid stream, jet nozzles, image processing Cleaning is achieved by using cleaning agents and water to remove soil from surfaces. Following parameters affect cleaning performance: chemical factors, water temperature, cleaning time and mechanical impact on the surfaces. This paper is related with these impacts of cleaning processes. A Water Jet Test Apparatus was used to obtain soil removal efficiency, provided by a water jet as it strikes the dirty plate under various experimental conditions. Removal efficiency of treated plate was determined by image processing technique. The percentage of soil removal of soiled spinach samples were between 25.5 and 2.2, these were a function of flow rates, angle of impact surface, cross-sectional area of nozzle, water temperature, detergent concentration and exposure time. The results show that the higher flow rate provides a greater soil removal with the same nozzle. If the cross-sectional areas of nozzles increase, the removal efficiency decreases on similar flow rate values. For same experimental conditions, the cleaning performance increases with water temperature and cleaning agent concentration. The most effective parameter on soil removal was water temperature for spinach samples. The impact of angle of jet impact surface and exposure time has limited effect on the soil removal for this experimental operating range. Journal of Thermal Engineering Journal of Thermal Engineering 2016-05-29T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2265 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2265 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2265

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2266 2016-05-29T21:00:00Z 4

Incorporating End-User Requirements in Design of Hybrid Renewable Energy Systems Alireza Maheri, Ulugbek Azimov, Ibrahim Unsal, Nearchos Stylianidis hybrid renewable energy system, HRES, power reliability, optimisation, user requirement, levelised cost of energy, reliability analysis Hybrid Renewable Energy Systems (HRES) utilise local renewable resource to supply a local demand load. Traditional size optimisation methods of standalone HRES aim at finding solutions with highest reliability in power supply and producing energy at lowest levelised cost of energy (LCE). In these methods, irrespective of the actual user requirements, the highest reliability of a system is normally defined as zero unmet load. To achieve this aim, adopting a deterministic approach, concepts such as margin of safety and autonomy period are used to size storage and backup components, assuring designing reliable systems. The present study investigates the effect of actual user requirements on the design solutions. In this paper, four different sets of user requirements are considered and for each case, a standalone hybrid wind-PV-battery-diesel-fuel cell system is designed with minimum LCE while meeting the user requirements. Comparing the results with those obtained by using traditional methods show how using the proposed method can lead to more cost effective solutions. Journal of Thermal Engineering Journal of Thermal Engineering 2016-05-29T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2266 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2266 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2266

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2164 2015-09-02T21:00:00Z 1

Dye Visualization of a Yawed Slender Delta Wing İlyas Karasu, Beşir Şahin, Hüseyin Akıllı, Çetin Canpolat, Delta wing, vortex breakdown Delta wing, vortex breakdown Delta wing, vortex breakdownDelta wing, vortex breakdown Delta wing, vortex breakdown Delta wing, vortex breakdownDelta wing, vortex breakdownDelta wing, vortex breakdown , yaw , yaw, yaw angleangle , flow visualization. , flow visualization. , flow visualization. , flow visualization. , flow visualization., flow visualization., flow visualization. , In the present experimental study, effects of yaw angle, ß on the flow structure at high angles of attack, ? with 70° sweep angle, ? were investigated using the dye visualization technique. In the case of zero yaw angle, ß a pair of leading edge vortices take place on both sides of cords axis are more or less symmetrical over the delta wing. These symmetrical vortical flow structures start deteriorating when yaw angle, ß is introduced. Onset of vortex breakdown location on the windward side occurs further upstream, on the other hand, the leading edge vortex on the leeward side breaks down further downstream. A perceivable interactions are consisted between structures of vortical flows developed from pair of leading edge vortices after onset of vortex breakdowns. It can be concluded that the magnitude of the leading-edge vortices, onset of vortex breakdowns, and formation of unsteady flow structures generated after vortex breakdowns are substantially affected by yaw angle, ß. Angles, ?1 and ?2 between centerline of the delta wing and both central axes of spiral vortices vary as a function of yaw angle, ß. Journal of Thermal Engineering Journal of Thermal Engineering 2015-09-02T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2164 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2164 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:7 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2164

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2267 2016-05-29T21:00:00Z 1

Radiation Heat Transfer in the Fuel of Nuclear Rocket Bradley K. Heath, Fatih Aydogan Corrosion, Heat Transfer, Emissivity, Pewee, Nuclear Propulsion Rocket, Radiation Heat Transfer Nuclear power propulsion for space applications is essential for long term high payload missions. Several nuclear reactor types were investigated between the late 1950’s and early 1970’s under the National Aeronautical and Space Administration’s (NASA) Nuclear Engine for Rocket Vehicle Application (NERVA). The NERVA reactors developed had various geometrical configurations using the same common materials and propellant, namely graphite moderated fuel elements impregnated with uranium carbide (UC) fuel particles surround by a beryllium reflector with hydrogen as the propellant. The hot hydrogen propellant flowing through the graphite core led to substantial corrosion problems and several efforts were made to protect the graphite from corrosion by the hot hydrogen propellant. Although several coating types and methods were employed only partial success was achieved. The effects of corrosion can lead to changes in heat transfer characteristics, flow changes, and reactivity degradation. This study, supported by NASA, focuses on the effects of hydrogen induced corrosion on the emissivity of the graphite fueled core. The reference data is primarily taken from the NERVA reactor identified as the Pewee Nuclear Rocket. An overview of the postmortem results of corrosion on the fuel of Pewee is described. The effects of corrosion from hydrogen exposure on graphite and the coatings used to protect the fuel elements are given. A model to calculate the effective emissivity coefficient inside a coolant channel due to varying stages of corrosion is developed. Lastly, the implementation of the effective emissivity coefficient into the radiative heat transfer equation with a brief discussion on surface area effects is provided. Journal of Thermal Engineering Journal of Thermal Engineering 2016-05-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2267 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2267 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2267

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2268 2016-05-29T21:00:00Z 4

Determination of Avoidable and Unavoidable Exergy Destructions of Furnace-Air Preheater Coupled System in a Petrochemical Plant Selay Sert, Firuz Balkan energy, exergy, advanced exergy, air preheater, furnace This study was performed with the intention of giving a deeper insight about the thermodynamic effectiveness of a thermal system. In this study, a fired heater (or furnace) existing in a petrochemical plant located in Aliağa, İzmir, Turkey were investigated from both first and second law point of view to identify the true magnitude of thermodynamic inefficiencies and reveal the true potential improvements for the system components. Hence, apart from the classical energy analysis, both conventional and advanced exergy analysis were applied to the system. The major source of inefficiencies within the system was enlightened by determining the exergy destructions and recommendation for possible modifications for improving thermodynamic efficiencies were stated. For each system component, amount of exergy destructions were determined and exergy efficiencies were calculated as 40.9% and 39.3% for fired heater (FH) and air preheater(APH), respectively in conventional exergy analysis. Besides, applying the advanced exergy analysis method it was seen that exergy efficiencies can be increased up to 52.4% and 85.8%, respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2016-05-29T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2268 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2268 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2268

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2269 2016-05-29T21:00:00Z 4

Effects of Drying Methods on Drying Characteristic, Energy Consumption and Color of Nectarine Osman İsmail, Berceste Beyribey, İbrahim Doymaz Drying, nectarine, modelling, colour, energy consumption The effect of drying methods on drying characteristic, energy consumption and color has been investigated for nectarine in this study. Sun, hot air, microwave and infrared drying techniques were applied as drying methods. The drying temperature was determined as 50 ºC for hot air drying of nectarine, as the applied powers were 90W and 83W for microwave and infrared dryings, respectively. The results obtained from the experiments indicate that the infrared drying method is the most effective method for drying of nectarine. The results has been modelled with six different models in the literature to determine the drying kinetics for nectarine. Comparing the high R2, low RMSE and ?2 values for all drying methods; it is presented that “Midilli et al.” model is the most convenient model for drying of nectarine. Journal of Thermal Engineering Journal of Thermal Engineering 2016-05-29T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2269 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2269 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2269

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2298 2016-08-01T21:00:00Z 4

A numerical Investigation of the Flow in Water Jet Nozules Ahmet Çağrı Bilir, Ali Doğrul, Taner Coşgun, Ahmet Yurtseven, Nurten Vardar Nozzle, water jet, k-w turbulence model, CFD In this study, flow inside the nozzles are investigated by means of finite volume method. Firstly, some analyses are carried out in 2-D in order to compare and validate the results with the experimental ones. Later, 3-D models are created to have different nozzle geometries. 3-D analyses are made and outlet mass flow rates, velocities and reaction forces are calculated in the same inlet pressure level for different nozzle geometries. Two equation k-w turbulence model is chosen as the turbulence model. At the end of this numerical study, the nozzle geometry with minimum reaction force and maximum mass flow rate is determined thanks to computational fluid dynamics (CFD) based on finite volume method (FVM). Journal of Thermal Engineering Journal of Thermal Engineering 2016-08-01T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2298 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2298 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2298

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2299 2016-08-01T21:00:00Z 1

A CFD Based Thermo-Hydroulic Performance Analysis in a Tube Fitted with Stepped Conical Nozzle Turbulators Orhan Keklikcioglu, Toygun Dagdevir, Veysel Ozceyhan Heat transfer enhancement; Stepped conical nozzle; Nozzle turbulator; Turbulator The paper presents a numerical analysis of heat transfer and friction characteristics in a stepped nozzle inserted tube. Nine different configurations are used for numerical analysis. In the first part of study, to certify the Nu (average Nusselt number) and the f (average friction factor), the computational fluid dynamics (CFD) models of tube with conical nozzle turbulators are validated with the experimental results available in the literature. In the present work, the turbulators are thoroughly inserted in the tube three different pitch ratios, with various Reynolds numbers ranging from 6000 to 22000, and also with three step numbers. The investigations were carried out with the RNG k-? turbulence model in a CFD package program, after some different turbulence models were tried, and grid independency with three different grid models were analyzed, for the average Nusselt number, and the average friction factor. As a consequence, Nusselt number increases and friction factor decreases with increasing Reynolds number. The highest Nusselt number and friction factor is obtained for s/a=4, p/s=2 model. The overall enhancement ratio rises with decreasing spacing of the stepped conical nozzle and increasing step value. The ultimate overall enhancement of 11% was achieved for Re=6000 where the spacing and step ratios are 4, 2 respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2016-08-01T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2299 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2299 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2299

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2275 2016-06-03T21:00:00Z 4

Heat Pumps with Internal Combustion Engines Using Natural Gas as an Alternative to Electric Heat Pumps Martina Janovcová heat pump, renewable energy, efficiency, consumption The subject of this article is to analyze the heating performance of the heat pump driven by an internal combustion engine for natural gas in the system of the air / water. In recent years, increased attention has been paid to gas heat pumps in heating, ventilation and air conditioning due to its advantage and to reduce power consumption during heating and cooling. Gas heat pumps have significant advantages over electric heat pumps, although do not reach a significant coefficient of performance. The advantage of gas heat pumps is the ability to use the waste heat from the engine cooling and exhaust gas while saving fossil fuels in connection with the production of energy from renewable sources - air. Journal of Thermal Engineering Journal of Thermal Engineering 2016-06-03T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2275 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2275 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2275

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2300 2016-08-01T21:00:00Z 1

Analysis of Control Strategies and Simulation of Heating Systems Using Simulink/Matlab Potential Ahmad Saleh, M. Rosa Thermal Control; Dynamic Modeling; On-Off Controller; PID Controller; Simulink/Matlab In this work the Simulink/Matlab potential is used to develop a dynamic model of a forced air type heating system. The main concern was centered on the analysis of control strategies to improve the system performance and to investigate the effect of thermal parameters on system performance and energy efficiency. A comparative analysis of On-Off and PID control strategies was conducted to investigate the features of each in terms of comfort and power consumption. The effects of thermal parameters such as thermal capacity, equivalent thermal resistance and set point setting were investigated. The results showed that Simulink/Matlab has a very high potential to analyze control strategies and to investigate thermal characteristics. Although the On-Off strategy is recommended for its constructive simplicity, lower cost and energy saving capability, the results showed to be oscillatory, inaccurate and instable. On the other hand, it was found that PID strategy performs better in terms of overshoot, settling time reduction and in suppressing the effect of external temperature disturbances. The overshoot was around 4 % and the steady state error disappeared quickly. Simulation results showed that high thermal mass buildings can significantly reduce the room air temperature variation; lower set point setting reduced the cumulative energy consumed and an increase in the equivalent thermal resistance led to a significant saving in energy consumption. Journal of Thermal Engineering Journal of Thermal Engineering 2016-08-01T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2300 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2300 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2300

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2301 2016-08-01T21:00:00Z 4

Cooling of Solar Pv Panels Using Evaporative Cooling Zeyad A. Haidar, J. Orfi, H.F. Oztop, Z. Kaneesamkandi panel panel ; coolingcooling cooling cooling ; evaporation evaporation evaporation ; modellingmodelling modelling modelling modelling The efficiency of solar collection systems particularly the The efficiency of solar collection systems particularly the The efficiency of solar collection systems particularly the The efficiency of solar collection systems particularly the The efficiency of solar collection systems particularly the The efficiency of solar collection systems particularly the The efficiency of solar collection systems particularly the The efficiency of solar collection systems particularly the The efficiency of solar collection systems particularly the The efficiency of solar collection systems particularly the The efficiency of solar collection systems particularly the The efficiency of solar collection systems particularly the The efficiency of solar collection systems particularly the The efficiency of solar collection systems particularly the The efficiency of solar collection systems particularly the The efficiency of solar collection systems particularly the The efficiency of solar collection systems particularly the The efficiency of solar collection systems particularly the The efficiency of solar collection systems particularly the The efficiency of solar collection systems particularly the The efficiency of solar collection systems particularly the The efficiency of solar collection systems particularly the The efficiency of solar collection systems particularly the The efficiency of solar collection systems particularly the The efficiency of solar collection systems particularly the The efficiency of solar collection systems particularly the The efficiency of solar collection systems particularly the photovoltaic panels is generally low. However, it affected by photovoltaic panels is generally low. However, it affected by photovoltaic panels is generally low. However, it affected by photovoltaic panels is generally low. However, it affected by photovoltaic panels is generally low. However, it affected by photovoltaic panels is generally low. However, it affected by photovoltaic panels is generally low. However, it affected by photovoltaic panels is generally low. However, it affected by photovoltaic panels is generally low. However, it affected by photovoltaic panels is generally low. However, it affected by photovoltaic panels is generally low. However, it affected by photovoltaic panels is generally low. However, it affected by photovoltaic panels is generally low. However, it affected by photovoltaic panels is generally low. However, it affected by photovoltaic panels is generally low. However, it affected by photovoltaic panels is generally low. However, it affected by photovoltaic panels is generally low. However, it affected by photovoltaic panels is generally low. However, it affected by photovoltaic panels is generally low. However, it affected by photovoltaic panels is generally low. However, it affected by photovoltaic panels is generally low. However, it affected by photovoltaic panels is generally low. However, it affected by photovoltaic panels is generally low. However, it affected by photovoltaic panels is generally low. However, it affected by photovoltaic panels is generally low. However, it affected by photovoltaic panels is generally low. However, it affected by photovoltaic panels is generally low. However, it affected by photovoltaic panels is generally low. However, it affected by the increase of temperature PV panels. This is the increase of temperature PV panels. This is the increase of temperature PV panels. This is the increase of temperature PV panels. This is the increase of temperature PV panels. This is the increase of temperature PV panels. This is the increase of temperature PV panels. This is the increase of temperature PV panels. This is the increase of temperature PV panels. This is the increase of temperature PV panels. This is the increase of temperature PV panels. This is the increase of temperature PV panels. This is the increase of temperature PV panels. This is the increase of temperature PV panels. This is the increase of temperature PV panels. This is the increase of temperature PV panels. This is the increase of temperature PV panels. This is the increase of temperature PV panels. This is the increase of temperature PV panels. This is the increase of temperature PV panels. This is the increase of temperature PV panels. This is the increase of temperature PV panels. This is the increase of temperature PV panels. This is the increase of temperature PV panels. This is the increase of temperature PV panels. This is associated with the absorbed solar radiation that is not associated with the absorbed solar radiation that is not associated with the absorbed solar radiation that is not associated with the absorbed solar radiation that is not associated with the absorbed solar radiation that is not associated with the absorbed solar radiation that is not associated with the absorbed solar radiation that is not associated with the absorbed solar radiation that is not associated with the absorbed solar radiation that is not associated with the absorbed solar radiation that is not associated with the absorbed solar radiation that is not associated with the absorbed solar radiation that is not associated with the absorbed solar radiation that is not associated with the absorbed solar radiation that is not associated with the absorbed solar radiation that is not associated with the absorbed solar radiation that is not associated with the absorbed solar radiation that is not associated with the absorbed solar radiation that is not associated with the absorbed solar radiation that is not associated with the absorbed solar radiation that is not converte converte d into electricity causing a drop in the PV module d into electricity causing a drop in the PV module d into electricity causing a drop in the PV module d into electricity causing a drop in the PV module d into electricity causing a drop in the PV module d into electricity causing a drop in the PV module d into electricity causing a drop in the PV module d into electricity causing a drop in the PV module d into electricity causing a drop in the PV module d into electricity causing a drop in the PV module d into electricity causing a drop in the PV module d into electricity causing a drop in the PV module d into electricity causing a drop in the PV module d into electricity causing a drop in the PV module d into electricity causing a drop in the PV module d into electricity causing a drop in the PV module d into electricity causing a drop in the PV module d into electricity causing a drop in the PV module d into electricity causing a drop in the PV module d into electricity causing a drop in the PV module d into electricity causing a drop in the PV module d into electricity causing a drop in the PV module d into electricity causing a drop in the PV module efficiency. efficiency. efficiency. efficiency. Several methods are available to reduce the cells temperature Several methods are available to reduce the cells temperature Several methods are available to reduce the cells temperature Several methods are available to reduce the cells temperature Several methods are available to reduce the cells temperature Several methods are available to reduce the cells temperature Several methods are available to reduce the cells temperature Several methods are available to reduce the cells temperature Several methods are available to reduce the cells temperature Several methods are available to reduce the cells temperature Several methods are available to reduce the cells temperature Several methods are available to reduce the cells temperature Several methods are available to reduce the cells temperature Several methods are available to reduce the cells temperature Several methods are available to reduce the cells temperature Several methods are available to reduce the cells temperature Several methods are available to reduce the cells temperature Several methods are available to reduce the cells temperature Several methods are available to reduce the cells temperature Several methods are available to reduce the cells temperature Several methods are available to reduce the cells temperature Several methods are available to reduce the cells temperature Several methods are available to reduce the cells temperature and their respective effectiveness has been investigated in and their respective effectiveness has been investigated in and their respective effectiveness has been investigated in and their respective effectiveness has been investigated in and their respective effectiveness has been investigated in and their respective effectiveness has been investigated in and their respective effectiveness has been investigated in and their respective effectiveness has been investigated in and their respective effectiveness has been investigated in and their respective effectiveness has been investigated in and their respective effectiveness has been investigated in and their respective effectiveness has been investigated in and their respective effectiveness has been investigated in and their respective effectiveness has been investigated in and their respective effectiveness has been investigated in and their respective effectiveness has been investigated in and their respective effectiveness has been investigated in and their respective effectiveness has been investigated in and their respective effectiveness has been investigated in and their respective effectiveness has been investigated in several previous works. This study deals with cooling PV using several previous works. This study deals with cooling PV using several previous works. This study deals with cooling PV using several previous works. This study deals with cooling PV using several previous works. This study deals with cooling PV using several previous works. This study deals with cooling PV using several previous works. This study deals with cooling PV using several previous works. This study deals with cooling PV using several previous works. This study deals with cooling PV using several previous works. This study deals with cooling PV using several previous works. This study deals with cooling PV using several previous works. This study deals with cooling PV using several previous works. This study deals with cooling PV using several previous works. This study deals with cooling PV using several previous works. This study deals with cooling PV using several previous works. This study deals with cooling PV using several previous works. This study deals with cooling PV using several previous works. This study deals with cooling PV using several previous works. This study deals with cooling PV using several previous works. This study deals with cooling PV using several previous works. This study deals with cooling PV using several previous works. This study deals with cooling PV using several previous works. This study deals with cooling PV using several previous works. This study deals with cooling PV using several previous works. This study deals with cooling PV using several previous works. This study deals with cooling PV using several previous works. This study deals with cooling PV using evaporative cooling of water. A theoretical model based on the evaporative cooling of water. A theoretical model based on the evaporative cooling of water. A theoretical model based on the evaporative cooling of water. A theoretical model based on the evaporative cooling of water. A theoretical model based on the evaporative cooling of water. A theoretical model based on the evaporative cooling of water. A theoretical model based on the evaporative cooling of water. A theoretical model based on the evaporative cooling of water. A theoretical model based on the evaporative cooling of water. A theoretical model based on the evaporative cooling of water. A theoretical model based on the evaporative cooling of water. A theoretical model based on the evaporative cooling of water. A theoretical model based on the evaporative cooling of water. A theoretical model based on the evaporative cooling of water. A theoretical model based on the evaporative cooling of water. A theoretical model based on the evaporative cooling of water. A theoretical model based on the evaporative cooling of water. A theoretical model based on the evaporative cooling of water. A theoretical model based on the evaporative cooling of water. A theoretical model based on the evaporative cooling of water. A theoretical model based on the evaporative cooling of water. A theoretical model based on the evaporative cooling of water. A theoretical model based on the evaporative cooling of water. A theoretical model based on the evaporative cooling of water. A theoretical model based on the heat and mass transfer occurring in the vicinity of bottom heat and mass transfer occurring in the vicinity of bottom heat and mass transfer occurring in the vicinity of bottom heat and mass transfer occurring in the vicinity of bottom heat and mass transfer occurring in the vicinity of bottom heat and mass transfer occurring in the vicinity of bottom heat and mass transfer occurring in the vicinity of bottom heat and mass transfer occurring in the vicinity of bottom heat and mass transfer occurring in the vicinity of bottom heat and mass transfer occurring in the vicinity of bottom heat and mass transfer occurring in the vicinity of bottom heat and mass transfer occurring in the vicinity of bottom heat and mass transfer occurring in the vicinity of bottom heat and mass transfer occurring in the vicinity of bottom heat and mass transfer occurring in the vicinity of bottom heat and mass transfer occurring in the vicinity of bottom heat and mass transfer occurring in the vicinity of bottom heat and mass transfer occurring in the vicinity of bottom heat and mass transfer occurring in the vicinity of bottom heat and mass transfer occurring in the vicinity of bottom heat and mass transfer occurring in the vicinity of bottom heat and mass transfer occurring in the vicinity of bottom heat and mass transfer occurring in the vicinity of bottom heat and mass transfer occurring in the vicinity of bottom heat and mass transfer occurring in the vicinity of bottom side of the solar PV panel has been developed. The model side of the solar PV panel has been developed. The model side of the solar PV panel has been developed. The model side of the solar PV panel has been developed. The model side of the solar PV panel has been developed. The model side of the solar PV panel has been developed. The model side of the solar PV panel has been developed. The model side of the solar PV panel has been developed. The model side of the solar PV panel has been developed. The model side of the solar PV panel has been developed. The model side of the solar PV panel has been developed. The model side of the solar PV panel has been developed. The model side of the solar PV panel has been developed. The model side of the solar PV panel has been developed. The model side of the solar PV panel has been developed. The model side of the solar PV panel has been developed. The model side of the solar PV panel has been developed. The model side of the solar PV panel has been developed. The model side of the solar PV panel has been developed. The model side of the solar PV panel has been developed. The model side of the solar PV panel has been developed. The model side of the solar PV panel has been developed. The model side of the solar PV panel has been developed. The model side of the solar PV panel has been developed. The model side of the solar PV panel has been developed. The model side of the solar PV panel has been developed. The model side of the solar PV panel has been developed. The model incorporates the heat and mass exchange occurring between a incorporates the heat and mass exchange occurring between a incorporates the heat and mass exchange occurring between a incorporates the heat and mass exchange occurring between a incorporates the heat and mass exchange occurring between a incorporates the heat and mass exchange occurring between a incorporates the heat and mass exchange occurring between a incorporates the heat and mass exchange occurring between a incorporates the heat and mass exchange occurring between a incorporates the heat and mass exchange occurring between a incorporates the heat and mass exchange occurring between a incorporates the heat and mass exchange occurring between a incorporates the heat and mass exchange occurring between a incorporates the heat and mass exchange occurring between a incorporates the heat and mass exchange occurring between a incorporates the heat and mass exchange occurring between a incorporates the heat and mass exchange occurring between a incorporates the heat and mass exchange occurring between a incorporates the heat and mass exchange occurring between a incorporates the heat and mass exchange occurring between a incorporates the heat and mass exchange occurring between a incorporates the heat and mass exchange occurring between a incorporates the heat and mass exchange occurring between a incorporates the heat and mass exchange occurring between a incorporates the heat and mass exchange occurring between a layer of wate layer of wate layer of wate layer of wate layer of wate r and ambient air as well the heat transfer with r and ambient air as well the heat transfer with r and ambient air as well the heat transfer with r and ambient air as well the heat transfer with r and ambient air as well the heat transfer with r and ambient air as well the heat transfer with r and ambient air as well the heat transfer with r and ambient air as well the heat transfer with r and ambient air as well the heat transfer with r and ambient air as well the heat transfer with r and ambient air as well the heat transfer with r and ambient air as well the heat transfer with r and ambient air as well the heat transfer with r and ambient air as well the heat transfer with r and ambient air as well the heat transfer with r and ambient air as well the heat transfer with r and ambient air as well the heat transfer with r and ambient air as well the heat transfer with r and ambient air as well the heat transfer with r and ambient air as well the heat transfer with r and ambient air as well the heat transfer with r and ambient air as well the heat transfer with r and ambient air as well the heat transfer with the PV panel. The obtained results show effect of some the PV panel. The obtained results show effect of some the PV panel. The obtained results show effect of some the PV panel. The obtained results show effect of some the PV panel. The obtained results show effect of some the PV panel. The obtained results show effect of some the PV panel. The obtained results show effect of some the PV panel. The obtained results show effect of some the PV panel. The obtained results show effect of some the PV panel. The obtained results show effect of some the PV panel. The obtained results show effect of some the PV panel. The obtained results show effect of some the PV panel. The obtained results show effect of some the PV panel. The obtained results show effect of some the PV panel. The obtained results show effect of some the PV panel. The obtained results show effect of some the PV panel. The obtained results show effect of some the PV panel. The obtained results show effect of some the PV panel. The obtained results show effect of some the PV panel. The obtained results show effect of some the PV panel. The obtained results show effect of some the PV panel. The obtained results show effect of some geometrical parameters as well the air flow rate, temperature geometrical parameters as well the air flow rate, temperature geometrical parameters as well the air flow rate, temperature geometrical parameters as well the air flow rate, temperature geometrical parameters as well the air flow rate, temperature geometrical parameters as well the air flow rate, temperature geometrical parameters as well the air flow rate, temperature geometrical parameters as well the air flow rate, temperature geometrical parameters as well the air flow rate, temperature geometrical parameters as well the air flow rate, temperature geometrical parameters as well the air flow rate, temperature geometrical parameters as well the air flow rate, temperature geometrical parameters as well the air flow rate, temperature geometrical parameters as well the air flow rate, temperature geometrical parameters as well the air flow rate, temperature geometrical parameters as well the air flow rate, temperature geometrical parameters as well the air flow rate, temperature geometrical parameters as well the air flow rate, temperature geometrical parameters as well the air flow rate, temperature geometrical parameters as well the air flow rate, temperature geometrical parameters as well the air flow rate, temperature geometrical parameters as well the air flow rate, temperature geometrical parameters as well the air flow rate, temperature geometrical parameters as well the air flow rate, temperature geometrical parameters as well the air flow rate, temperature geometrical parameters as well the air flow rate, temperature geometrical parameters as well the air flow rate, temperature geometrical parameters as well the air flow rate, temperature and humidity on the cooling process. It was found that air and humidity on the cooling process. It was found that air and humidity on the cooling process. It was found that air and humidity on the cooling process. It was found that air and humidity on the cooling process. It was found that air and humidity on the cooling process. It was found that air and humidity on the cooling process. It was found that air and humidity on the cooling process. It was found that air and humidity on the cooling process. It was found that air and humidity on the cooling process. It was found that air and humidity on the cooling process. It was found that air and humidity on the cooling process. It was found that air and humidity on the cooling process. It was found that air and humidity on the cooling process. It was found that air and humidity on the cooling process. It was found that air and humidity on the cooling process. It was found that air and humidity on the cooling process. It was found that air and humidity on the cooling process. It was found that air and humidity on the cooling process. It was found that air and humidity on the cooling process. It was found that air and humidity on the cooling process. It was found that air and humidity on the cooling process. It was found that air and humidity on the cooling process. It was found that air and humidity on the cooling process. It was found that air and humidity on the cooling process. It was found that air and humidity on the cooling process. It was found that air and humidity on the cooling process. It was found that air and humidity on the cooling process. It was found that air inlet temperature inlet temperatureinlet temperature inlet temperature inlet temperature inlet temperature inlet temperature decreases, the temperature of PV panel decreases, the temperature of PV panel decreases, the temperature of PV panel decreases, the temperature of PV panel decreases, the temperature of PV panel decreases, the temperature of PV panel decreases, the temperature of PV panel decreases, the temperature of PV panel decreases, the temperature of PV panel decreases, the temperature of PV panel decreases, the temperature of PV panel decreases, the temperature of PV panel decreases, the temperature of PV panel decreases, the temperature of PV panel decreases, the temperature of PV panel decreases, the temperature of PV panel decreases, the temperature of PV panel decreases, the temperature of PV panel decreases significantly. Also, at low air flow rates, the decreases significantly. Also, at low air flow rates, the decreases significantly. Also, at low air flow rates, the decreases significantly. Also, at low air flow rates, the decreases significantly. Also, at low air flow rates, the decreases significantly. Also, at low air flow rates, the decreases significantly. Also, at low air flow rates, the decreases significantly. Also, at low air flow rates, the decreases significantly. Also, at low air flow rates, the decreases significantly. Also, at low air flow rates, the decreases significantly. Also, at low air flow rates, the decreases significantly. Also, at low air flow rates, the decreases significantly. Also, at low air flow rates, the decreases significantly. Also, at low air flow rates, the decreases significantly. Also, at low air flow rates, the decreases significantly. Also, at low air flow rates, the decreases significantly. Also, at low air flow rates, the decreases significantly. Also, at low air flow rates, the decreases significantly. Also, at low air flow rates, the decreases significantly. Also, at low air flow rates, the decreases significantly. Also, at low air flow rates, the decreases significantly. Also, at low air flow rates, the temperature at exit is higher than that high flow rates. temperature at exit is higher than that high flow rates. temperature at exit is higher than that high flow rates. temperature at exit is higher than that high flow rates. temperature at exit is higher than that high flow rates.temperature at exit is higher than that high flow rates. temperature at exit is higher than that high flow rates. temperature at exit is higher than that high flow rates. temperature at exit is higher than that high flow rates.temperature at exit is higher than that high flow rates. temperature at exit is higher than that high flow rates.temperature at exit is higher than that high flow rates. temperature at exit is higher than that high flow rates.temperature at exit is higher than that high flow rates. temperature at exit is higher than that high flow rates.temperature at exit is higher than that high flow rates. temperature at exit is higher than that high flow rates. temperature at exit is higher than that high flow rates. temperature at exit is higher than that high flow rates. temperature Journal of Thermal Engineering Journal of Thermal Engineering 2016-08-01T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2301 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2301 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2301

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2165 2015-09-02T21:00:00Z 4

Relation Between Drill Bit Temperature and Chip Forms in Drilling of Carbon Black Reinforced Polyamide Alper Uysal Polyamide, carbon black, drill tip temperature, chip form Polyamides have many application fields due to their good mechanical strength, high impact strength, good sliding properties etc. Recently, electrically conductive polyamides can be produced by adding carbon black, graphene, metals and carbon nanotubes and their usage have increased. Polyamides are generally manufactured by injection molding and extrusion method but drilling is often needed for the final product. In literature, there are not many studies on the drilling of polyamides and polyamide composites. In this study, drill bit temperature and chip forms were investigated during the drilling of unreinforced polyamide and carbon black reinforced electrically conductive polyamide. Drilling experiments were performed at three different feeds and cutting speeds. Depending on the experimental results, the drill bit temperature increased with increasing the cutting speed and decreasing the feed. Higher drill tip temperatures were measured in the drilling of carbon black reinforced polyamide than that occurred in the drilling of unreinforced polyamide. The chips were more deformed at high cutting speed and low feed. In addition, the chip forms of carbon black reinforced polyamide were observed more regular than that of unreinforced polyamide due to the fact that the chips of carbon black reinforced polyamide could conduct the heat to the drill bit and they were less affected by the heat. Journal of Thermal Engineering Journal of Thermal Engineering 2015-09-02T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2165 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2165 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:7 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2165

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2302 2016-08-01T21:00:00Z 3

Hydro Energy and Enviromental Policies in Turkey Ibrahim Yuksel, Hasan Arman, Ugur Serencam Hydropower, Renewable energy; Clean Energy, Environmental Policies, Turkey Hydro energy is a renewable, sustainable and clean energy in the other alternative energy sources. Moreover, it does not deprive future generations in terms of raw materials, or burdening them with pollutants or waste. Hydroelectric power plants utilize the basic national and renewable resource of the country. Although the initial investment cost of hydropower seems relatively high, the projects have the lowest production costs and do not depend on foreign capital and support, when considering environmental pollution and long-term economic evaluation. Hydropower is available in a broad range of project scales and types. Projects can be designed to suit particular needs and specific site conditions. As hydropower does not consume or pollute the water it uses to generate power, it leaves this vital resource available for other uses. At the same time, the revenues generated through electricity sales can finance other infrastructure essential for human welfare. This can include drinking water supply systems, irrigation schemes for food production, infrastructures enhancing navigation, recreational facilities and ecotourism. Journal of Thermal Engineering Journal of Thermal Engineering 2016-08-01T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2302 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2302 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2302

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2303 2016-08-01T21:00:00Z 1

Design and Performance Analysis of a District Heating System Utilizing Waste Heat of a Thermal Power Plant Raşit Yıldıran, Selçuk Ataş, Murat Kahraman District heating system, Peak heat load, Annual heat load distribution, Heat storage system District heating (DH) systems that utilize waste heat have a great energy saving impact. Based on detailed energetic and exergetic performance analysis of the power plant cycle, it is possible to supply cheaper energy to consumers rather than conventional heating systems meanwhile a small portion of power reduction takes place. In this study, a district heating system, which uses waste heat of a thermal power plant (PP) as energy source was designed and then analyzed for various operational conditions from viewpoint of thermal and hydraulic performance. The implementation site in this study was selected as dwelling estate located at Soma which is in Manisa province of Turkey. Throughout the study, design and analysis of DH system contained several steps: Before all, based on architectural, meteorological and fieldwork studies, peak heat loads were determined for each type of buildings, considering various types of heat transfer factors. Using a software package, network design was carried out numerically. Then a tool was developed to analyze annual heat demand distribution in order to compare estimated and realized data given for 2013-2014 heating season. Lastly, a heat storage tank coupled with existing DH system was dimensioned. Journal of Thermal Engineering Journal of Thermal Engineering 2016-08-01T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2303 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2303 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2303

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2276 2016-06-07T21:00:00Z 4

Effect of Dispatch Strategy on the Performance of Hybrid Wind-PV-Battery-Diesel-Fuel Cell Systems Alireza Maheri hybrid renewable energy system, HRES, dispatch strategy, fuel cell, system size optimisation This paper presents a variety of dispatch strategies for hybrid renewable systems including wind turbine, PV panel, fuel cell, diesel generator and battery bank. These strategies are distinguished based on the priority of the usage of battery bank, fuel cell and diesel generator in case of power deficit and the precedence of charging of battery bank and filling the hydrogen tank. For a given system, resource and load profile, the performance of the system corresponding to each dispatch strategy is evaluated against both cost related and reliability related measures. It is found that the performance of the system is highly under the influence of the dispatch strategy incorporated in the system. Therefore, in sizing hybrid renewable energy systems, dispatch strategy should be also considered as a decision variable that needs to be found along with the optimum size of other components of the system. Journal of Thermal Engineering Journal of Thermal Engineering 2016-06-07T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2276 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2276 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2276

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2172 2015-09-14T21:00:00Z 1

Investigation of Thermoforming Tool Design and Pocket Quality Moustafa Moustafa, Krassimir Dotchev, Simon Wells, Nick Bennett, James Cawkell Thermoforming, Mould tool, Carrier tape, 3D rapid manufacturing Thermoforming is widely used in manufacturing industries to produce a range of polymer products. The Reflex tape thermoforming system is designed to form flat tape film into pockets. These formed pockets, also called carrier tape, are used in numerous applications to package a large variety of electronic or small mechanical parts. Thermoformed pocket walls are generally not uniform in thickness and often break during the forming process. Uniform wall thickness distribution, especially for deep pockets, plays significant role on pocket quality improvement and scrap reduction. This paper investigates the influence of the tool design, tool material, and some thermoforming process parameters on wall thickness distribution in formed pockets using polymer flat films. Conventional tool and a hybrid tool with 3d printed inserts were used in the experiments. The process parameters, plastic film and tool set temperatures were controlled by the Reflex machine and also measured using infrared thermometer and thermocouple. Film temperature ranges from 150 to 200 °C and a range of tool set temperatures (40 to 85°C) were used in the thermoforming. It has been found that the temperature difference between the plastic film and the forming tool was important for uniform wall thickness distribution. The results from this experimental study concluded that the most influential factors for good pocket quality are the tool design, tool material, and heat transfer dynamics in the plastic film - tool set system. Another aim of the study was to investigate the viability of the 3D printing process to manufacture rapidly tool inserts compared to conventional CNC machining. Journal of Thermal Engineering Journal of Thermal Engineering 2015-09-14T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2172 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2172 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:7 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2172

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2166 2015-09-02T21:00:00Z 1

Coupled Flexural-Lateral-Torsional of Shear Deformable Thin-Walled Beams with Asymmetric Cross-Section – Closed Form Exact Solution Mohammed Ali Hjaji, Magdi Mohareb Asymmetric cross-section, Flexural-Lateral-torsional response, Vlasov-Timoshenko beam theory, closed-form solution This paper develops the exact solutions for coupled flexurallateral- torsional static response of thin-walled asymmetric open members subjected to general loading. Using the principle of stationary total potential energy, the governing differential equations of equilibrium are formulated as well as the associated boundary conditions. The formulation is based on a generalized Timoshenko- Vlasov beam theory and accounts for the effects of shear deformation due to bending and warping, and captures the effects of flexural– torsional coupling due to cross-section asymmetry. Closed-form solutions are developed for cantilever and simply supported beams under various forces. In order to demonstrate the validity and the accuracy of this solution, numerical examples are presented and compared with well-established ABAQUS finite element solutions and other numerical results available in the literature. In addition, the results are compared against non-shear deformable beam theories in order to demonstrate the shear deformation effects. Journal of Thermal Engineering Journal of Thermal Engineering 2015-09-02T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2166 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2166 Journal of Thermal Engineering, Year:2015, Vol:1, Issue:7 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2166

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2304 2016-08-01T21:00:00Z 1

Numerical Investigation of the Bottom Cabinet of a Household Refrigerator Haluk Yılmaz, Latife Berrin Erbay, Bahadır Doğan Household refrigerator, Condenser, Bottom Cabinet, Cooling In this study, the bottom cabinet of a commercial household refrigerator is investigated numerically. The numerical model is formed in two stages. The first stage includes the fan motion, and the second stage includes the heat rejection process at the condenser. The compressor is included in the numerical model to get the accurate simulation of the real conditions. A protective lid covering the condenser surface and the fan is taken into consideration for both stages of the numerical solution. In the numerical analysis, the total amount of heat transfer, temperature, pressure and velocity gradients and streamlines are studied in detail. Due to the location and the design of the fan, a static fluid region occurs at the mid-section of the condenser. Therefore, the number of wires on the mid-section of the condenser tubes and the cost can be decreased. It is observed that the compressor is also cooled by the discharged air from the condenser. Journal of Thermal Engineering Journal of Thermal Engineering 2016-08-01T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2304 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2304 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2304

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2305 2016-08-01T21:00:00Z 1

Energy and Exergy Analysis of a Waste Heat Driven Cycle for Triple Effect Refrigeration Manoj Dixit, Akhilesh Arora, S.C. Kaushik Exergy, Waste heat, triple effect, ejector organic Rankine cycle In this paper waste heat driven triple effect refrigeration cycle is analyzed from the viewpoint of both energy and exergy concept of thermodynamics. In this cycle ejector organic Rankine cycle, absorption refrigeration cycle and cascade vapour compression refrigeration cycles are integrated in order to obtain a range of temperature for varied simultaneous use. Exergy analysis determines the destruction and losses of exergy in various components and hence in overall system. Exergy efficiencies provide measure of approach to ideality while exergy destruction and losses provide measure of the deviation from ideality. Energy efficiency is found to be around 21.79% while exergy efficiency is 12.91%. The maximum thermodynamic irreversibility occurs in heat recover vapour generator followed by ejector and condenser of combined ejector organic Rankine refrigeration cycle Journal of Thermal Engineering Journal of Thermal Engineering 2016-08-01T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2305 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2305 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2305

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2277 2016-06-07T21:00:00Z 1

Thermal Design Methodology and Prediction of Heat Sink Performance Dongmei Zhou, Timothy Rau Heat sink; Natural convection performance; Thermal design methodology; Hand calculation; CFD simulation; Mock-up testing The ability to identify heat sources and predict their temperatures across a variety of operating conditions is the key in the design of a reliable electronic system such as a computer, a server, or any other system containing a printed circuit board assembly. The goal of this paper is to investigate a heat sink to come up with a framework to correlate hand calculations and numerical simulations with experimentally obtained results. The thermal design methodology is discussed and a natural convection study of a heat sink is used to demonstrate this thermal design process. Multiple fin heights of a heat sink at different ambient temperatures are analyzed by hand calculations, numerical simulations using ANSYS Icepak 14.0, and a mock-up testing using a copper slug with a Minco heater attached to simulate a processor on a printed circuit board assembly. These three methods can help check upon each other’s accuracy and credibility. Results from the experiment demonstrate how one can improve the accuracy of results by using known correlated data to future investigations. This allows for improved optimization studies and helps reduce design cycle time. Journal of Thermal Engineering Journal of Thermal Engineering 2016-06-07T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2277 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2277 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2277

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2278 2016-06-07T21:00:00Z 1

A New Solar Fuels Reactor Using a Liquid Metal Heat Transfer Fluid: Modeling and Sensitivity Analysis Cansheng Yuan, Colby Jarrett, William Chueh, Yoshiaki Kawajiri, Asegun Henry Solar Fuels, Thermochemical, Liquid Metal A numerical model is developed to analyze a new solar thermochemical reactor using liquid metal as a heat transfer fluid. Reaction kinetics for both reduction and oxidation in two-step redox cycles using a metal oxide are modeled by fitting to experimental data. The transient model includes the heat and mass transfer and reaction kinetics for an analysis of the efficiency of this new reactor, and to elucidate limiting factors. The reactor can achieve the efficiency of 20% for the conversion of thermal to chemical energy for our base design. For this design, the removal of oxygen was determined to be the bottleneck to achieve a higher efficiency. In a sensitivity analysis, the optimal reaction temperature can be found considering the trade-off between fast reaction kinetics and material compatibility. Journal of Thermal Engineering Journal of Thermal Engineering 2016-06-07T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2278 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2278 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2278

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2279 2016-06-07T21:00:00Z 1

Effects of Porosity on Thermal-Fluid Phenomena in PBMR Core Masoumeh Sadat Latifi, Saeed Setayeshi CFD, heat transfer, porosity, PBMR, packed bed, pressure drop This paper discusses about the effect of the porosity on the heat transfer and fluid flow phenomena in Pebble Bed Modular Reactors (PBMR) core. Computational fluid dynamics (CFD) code is employed to simulate the unsteady state thermal – fluid phenomena in the PBMR core, in which helium is used as the coolant. In this work, the ratio of coolant mass flow rate to fuel volume is assumed to be constant. The outer wall of the core is kept at a constant temperature, while the top and bottom walls are assumed to be adiabatic. In this paper, we study how the change of the porosity’s value effects the flow and heat transfer in the core. The results show increasing the porosity from 0.36 to 0.43 causes such parameters as the pressure drop, power and coolant mass flow rate to decrease, whereas the coolant inlet-outlet temperature difference and normalized power are observed to increase. Journal of Thermal Engineering Journal of Thermal Engineering 2016-06-07T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2279 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2279 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2279

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2280 2016-06-07T21:00:00Z 1

Thermo-economic Optimization and Parametric Study of an Irreversible Regenerative Brayton Cycle S C Kaushik, Raj Kumar, Rajesh Arora Thermo-economic objective function; Irreversible Brayton cycle; Regenerator; Power; Efficiency Thermo-economic optimizations along with a detailed parametric analysis of an irreversible regenerative Brayton cycle with finite heat capacity of external reservoirs have been carried out. The external irreversibilities due to finite temperature difference and internal irreversibilities due to fluid friction losses in compressor / turbine, regenerative heat loss, pressure loss are included in the analysis. The thermo-economic function is the ratio of power output to the sum of annual investment, energy consumption and maintenance cost. The optimization of the objective function is done for maximizing the power output and thermal efficiency of the model. A detailed analysis on the efficiency of turbine and compressor, effectiveness of various heat exchangers, heat source inlet temperature and pressure drop irreversibility on power, efficiency and economic function has been carried out. It is found that the cold side effectiveness is more prominent for the power output while regenerative effectiveness is dominant factor for thermal efficiency. It is also found that at an effectiveness of 0.75 on either side of the heat exchanger, the better the performance of the cycle. Parametric analysis shows that turbine efficiency has more effect on the performance of model than compressor efficiency for the same set of operating conditions. The model analyzed in this paper gives lower values of various performance parameters as expected and replicates the results of an irreversible regenerative Brayton cycle model discussed in the literature at pressure recovery coefficients of ?1=?2=1. Thermo-economic optimizations along with a detailed parametric analysis of an irreversible regenerative Brayton cycle with finite heat capacity of external reservoirs have been carried out. The external irreversibilities due to finite temperature difference and internal irreversibilities due to fluid friction losses in compressor/turbine, regenerative heat loss, and pressure loss are included in the analysis. The thermo-economic function is the ratio of power output to the sum of annual investment, energy consumption and maintenance cost. The optimization of the objective function is done for maximizing the power output and thermal efficiency of the model. A detailed analysis on the efficiency of turbine and compressor, effectiveness of various heat exchangers, heat source inlet temperature and pressure drop irreversibility on power, efficiency and economic function has been carried out. Parametric analysis shows that turbine efficiency has more effect on the performance of model than compressor efficiency for the same set of operating conditions. The model analyzed in this paper gives lower values of various performance parameters as expected and replicates the results of an irreversible regenerative Brayton cycle model discussed in the literature at pressure recovery coefficients of ?1=?2=1. Journal of Thermal Engineering Journal of Thermal Engineering 2016-06-07T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2280 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2280 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2280

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2408 2017-03-31T21:00:00Z 1

Experimental Investigation of Indirect Evaporative Cooler using Clay Pipe R. Ramakrishnan, A. Ragupathy Evaporative cooler, Relative humidity, Porosity, Clay pipe, Effectiveness, aligned, staggered The aim of the experimental study is to investigate the performance of indirect evaporator cooler in hot and humid regions. A novel approach is implemented in the cooler using clay pipe with different orientation as aligned and staggered position for potential and feasibility study. The clay pipe is the ceramic material where the water filled inside the tube and due to the property of porosity, the water comes outer surface of the tube and contact with the air passing over the tube and air get cooled. A test rig was designed and fabricated to collect experimental data. The clay pipes were arranged in aligned and staggered position. In our study heat transfer was analysed with various air velocity of 1m/s to 5m/s. The air temperature, relative humidity, pressure drop and water evaporation rate were measured and the performance of the evaporative cooler was evaluated. The experimental results were compared with mathematical values. The analysis of the data indicated that cooling effectiveness improve with decrease of air velocity at staggered position. It was shown that staggered position has the higher performance (53%) at 5 m/s air velocity in comparison with aligned position. The experimental of heat and mass transfer coefficients were compared with Colburn heat and mass transfer group. The test results were within the limit of 20% of mathematical values. Journal of Thermal Engineering Journal of Thermal Engineering 2017-03-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2408 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2408 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2408

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2282 2016-06-08T21:00:00Z 1

Effects of Partial Heating of Top Rotating Lid with Axial Temperature Gradient on Vortex Breakdown in Case of Axisymmetric Stratified Lid Driven Swirling Flow Subas Dash, Navtej Singh Stratified fluid, partial Heating, lid driven swirling flow, axisymmetric. The present numerical simulation investigates the effects of partial heating on confined stratified swirling flow in a cylindrical cavity with a top rotating lid. The surface of top rotating lid of cylindrical cavity, having radius (r), up to radius (rh) from centre is at a higher temperature ( h T ) .The bottom stationary wall is at a lower temperature ( c T ) .The remaining part of the top rotating lid is insulated. Steady state solutions are obtained in axisymmetric regime at constant governing parameters, the Reynolds number Re= 1500, Richardson number Ri =0.05, Prandtl number Pr=1.0 and aspect ratio AR=1.8.The flow patterns and the heat transfer characteristics are numerically investigated under the Boussinesq assumptions. The vortex breakdown size, numbers and position are found to be changed with increase in partial heating. Variation in magnitude of local as well as average Nusselt number in vicinity to top rotating lid are found increasing with increase in partial heating radius of top rotating lid. Also variations in coefficient of torque are studied. Journal of Thermal Engineering Journal of Thermal Engineering 2016-06-08T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2282 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2282 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2282

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2335 2016-10-20T21:00:00Z 1

Effect of Exhaust Gas Recirculation (EGR) on Performance, Emissions and Combustion Characteristics of a Low Heat Rejection (LHR) Diesel Engine Using Pongamia Biodiesel Shivakumar Shankar, Harishchandra V Astagi, S R Hotti, Omprakash Hebbal Diesel engine, LHR diesel engine, Biodiesel (Pongamia), EGR, NOx emission The main objective of the present work is to study the performance, emission and combustion characterstics using single cylinder, four stroke, naturally aspirated, direct injection, water cooled diesel engine with exhaust gas recirculation (EGR) system on LHR engine with Pongamia biodiesel. The experiments are conducted varying the load at rated engine speed of 1500 rpm, and the percentage of EGR used being 5%, 10%, and 15%. It is observed that brake thermal efficiency increases for all fuels without EGR and with EGR up to 75% of load. At this load normal engine running on diesel exhibits 28.68%, followed by biodiesel without EGR, 5%, 10%, and 15% EGR with biodiesel on LHR engine are 27.42%, 24.4%, 27.05% and 27.1% respectively. At full load increasing the percentage of EGR there is an increase in smoke emission and the values being 99.22%, 99.9% and 99.9 for 5%, 10% and 15% EGR respectively. Carbon monoxide and HC emission for Pongamia biodiesel without EGR is lower than that of normal diesel engine for entire load operation. However increasing percentage of EGR there is increase in the CO emissions and the values being 0.925%, 1.32%, 2.53% for 5%, 10%, and 15% EGR respectively. Maximum peak pressure in the cylinder for biodiesel is 72.65 bars against 70.65 bars of that of diesel. A considerable reduction in NO formation is possible at 15% EGR with a little sacrifice in efficiency. Hence 15% EGR is optimum. Journal of Thermal Engineering Journal of Thermal Engineering 2016-10-20T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2335 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2335 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2335

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2281 2016-06-07T21:00:00Z 1

Effect of End Control Plugs on the Performance of Vortex Tube with Dual Forced Vortex Flow G.Maruthi Prasad Yadav, P.Mallikarjuna Reddy, B.Uma Maheswar Gowd Forced vortex flow, End plugs, temperature drop, cold fraction Vortex tube splits the compressed air into two parts: a free vortex as the peripheral warm stream at the conical valve end and a forced vortex as the inner cold stream through the orifice. In the present work the conical valve at the hot end in existing model is replaced with a hollow conical valve gives a provision for flow through the inner core. A conical valve is introduced at the orifice, directs the forced vortex yet again to hit back develops one more forced vortex flow, which escapes through the central core of the hollow conical valve. Thus the revised vortex tube with three outlets: one hot outlet and two cold outlets, is named as dual forced flow vortex tube (DFFVT). Tests were made to evaluate the effect of end control plugs at both ends on the performance of the modified vortex tube with various cone angles. Results reveal that 450 hollow cone angle with 550 solid cone angle is the optimum for effective temperature separation. Also, it is identified that moderate cold fraction of 0.34 through the cold end-II with 0.21 cold fraction-I give optimum temperature drops together with both the cold ends. Also the temperature drop through both ends-I & II increases with increase of pressure. Journal of Thermal Engineering Journal of Thermal Engineering 2016-06-07T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2281 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2281 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2281

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2334 2016-10-19T21:00:00Z 1

Energy and Exergy Analysis of Absorption- Compression Cascade Refrigeration System Manoj Dixit, S. C. Kaushik, Akhilesh Arora absorption, compression, COP, exergy destruction, exergetic efficiency In this study, an Absorption- Compression Cascade Refrigeration, comprising of a VCR system in low temperature stage and a VAR system at the high temperature stage, is analyzed. CO2, NH3 and R134a have been considered as refrigerants in the compression stage and the H2O-LiBr refrigerant absorbent pair in the absorption stage. The analysis has been realized by means of a mathematical model of the refrigeration system. The study presents the results obtained regarding the performance of the refrigeration system based on energy and exergy analysis. The comparative study helps to find out the best refrigerant and appropriate operation parameters. It is found in the study that cascade condenser, compressor and refrigerant throttle valve are the major source of exergy destruction. Journal of Thermal Engineering Journal of Thermal Engineering 2016-10-19T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2334 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2334 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2334

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2330 2016-10-18T21:00:00Z 1

Current Advances in the Standardization of Management Systems Tzvetelin Kirilov Gueorguiev, Boris Borisov Sakakushev Management systems, ISO 9001, ISO 14001, ISO 50001, Annex SL The article 'Current Advances in the Standardization of Management Systems' presents an overview and proposals for implementation of the new series of standards for management systems- for quality (ISO 9001), environment (ISO 14001), and energy (ISO 50001). Discussed is their integration with the Annex SL (previously ISO Guide 83) and the implications for organizations which already have implemented such management systems- both in the view of potential risks and new possibilities. Journal of Thermal Engineering Journal of Thermal Engineering 2016-10-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2330 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2330 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2330

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2297 2016-06-18T21:00:00Z 1

Using Phase Change Materials in Photovoltaic Systems for Cell Temperature Reduction: A finite Difference Simulation Approach Panagiotis Kladisios, Athina Stegou-Sagia photovoltaic,phase change material,finite difference method,implicit scheme,solar cell,effective heat capacity Photovoltaic manufacturers rate their modules based on their maximum power output. This nominal power corresponds to the commonly accepted standard test conditions (STC: cell temperature Tcell=25 oC, insolation G=1 kW/m2, air mass ΑΜ=1.5). In reality, insolation is lower and cell temperature higher, both being factors that affect power generation in a negative fashion. In the present paper, the possibility of cell temperature reduction will be investigated using one of the proposed methods of thermal control, phase change materials. The photovoltaic module, both as a unit and as a system in direct contact with a phase change material, will be simulated using a finite difference method. Journal of Thermal Engineering Journal of Thermal Engineering 2016-06-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2297 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2297 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2297

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2331 2016-10-18T21:00:00Z 4

Sepiolite for Powder-Glass Fiber Hybrid Core Materials for Vacuum Insulated Panels: Critical Inner Pressure and Thermal Insulation Performance for Long Service-Time Approach Zhao Feng Chen, Deniz Eren Erisen insulation, sepiolite, glass fiber, Knudsen, vacuum With increasing driving force on insulation panels with higher insulation performance with lower thicknesses, create market need to develop new insulation materials. Especially, vacuum insulated panels as super insulation materials, still have opportunity to invent new core materials from locally occur materials like natural fibers and different kind silicates with high porosity like zeolite, sepiolite, diatomite etc. Those kind of materials can be used to produce powder-glass fiber hybrid core materials. They have positive effect on critical inner pressure of core material. Sepiolite is a Magnesium Hydroxyl Silicate clay with high surface area and fiber like structure. Journal of Thermal Engineering Journal of Thermal Engineering 2016-10-18T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2331 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2331 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2331

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2333 2016-10-18T21:00:00Z 4

Modeling of Hybrid Renewable Energy System: The Case Study of Istanbul, Turkey Moslem Sharifishourabi, Hamed Alimoradiyan, Uğur Atikol Atikol Stand-alone energy system, Hybrid, Renewable energy, HOMER PRO Traditionally, the stand-alone hybrid electricity system has been viewed as an alternative renewable energy source. Therefore, the primary objective of this paper will be to look at a stand-alone hybrid system combination that will generate electricity, from a mix of renewable energy sources, to fulfill the electrical needs of an off-grid remote apartment in Istanbul, Turkey. Both solar photovoltaic systems and wind turbine will be considered as renewable energy sources. The paper will also demonstrate the residential demand in the HOMER PRO analysis and define the optimal off-grid system. The solution obtained from the studies shows that a hybrid combination of renewable energy and generators at an off-grid location can be a suitable alternative to grid extension (by considering the life cost cycle for 25 years). This is because it is both techno-economically viable and environmentally sound. Journal of Thermal Engineering Journal of Thermal Engineering 2016-10-18T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2333 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2333 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2333

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2351 2016-12-25T21:00:00Z 1

Exergy Based Optimization of a Biomass and Solar Fuelled CCHP Hybrid Seawater Desalination Plant Amir Ghasemi, Nasim Hashemian, Alireza Noorpoor, Parisa Heidarnejad Exergy, CCHP, Desalination, Optimization, Solar Energy, Biomass Integrated energy systems utilizing renewable sources are a sustainable and environmentally substitution for conventional fossil fired energy systems. A CCHP hybrid seawater desalination plant with two inputs such as biomass and solar energy and four useful outputs such as cooling, heating, power and distillated water is presented and investigated in this paper. The proposed system includes evacuated tube solar collectors, biomass burner, organic rankine cycle (ORC), absorption chiller, heater and multi effect desalination system (MED). The results showed that the proposed system is able to produce 802.5 KW as power, 10391 KW as heating, 5658 KW as cooling and 9.328 kg/s distillated water. Energy efficiency of the system is 61 %, the exergy efficiency is 7 % and the main sources of exergy destructions are biomass burner, evacuated tube solar collectors and vapor generator. Exergy optimization is carried out in order to find the optimum point of system. Journal of Thermal Engineering Journal of Thermal Engineering 2016-12-25T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2351 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2351 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2351

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2356 2016-12-27T21:00:00Z 4

Study of Solar Driven Adsorption Cooling Potential in Indonesia Nasruddin Nasruddin, Lemington Lemington, Dylan Budiman, M. Idrus Alhamid, S. Sholahudin adsorption chiller, Indonesia climate, solar driven, pre-heat Indonesia has a big potential in utilizing solar energy. In fact, tropical area like Indonesia has a quite stable solar radiation. This paper presented a study using simulation to investigate the performance of solar driven two bed adsorption chiller based on Indonesia climate. Climatic data of several cities in Indonesia is being used. The chiller is being mathematically modeled and calculated numerically using MATLAB®. The simulation is run transiently at working hours to achieve temperature in some points in the system. Moreover, additional Phase Change Material (PCM) is also added to the hot water tank in order to achieve a better performance. The results demonstrated the running characteristic of the chiller with the range of COP 0.043-0.342. The chiller performance can reach COP 0.26 with 37.4 kW cooling capacity when utilizing the solar radiation. Moreover, Adding PCM in hot water tank also can improve the chiller’s performance. Since the amount of heat is essential to the performance of the adsorption chiller, it is better to pre-heat the water before using. By pre-heating and getting the water to a higher temperature, it will generate a higher cooling power needed to meet demand which can be sustained and stable throughout the use of adsorption chiller. Journal of Thermal Engineering Journal of Thermal Engineering 2016-12-27T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2356 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2356 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2356

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2354 2016-12-27T21:00:00Z 1

Experimental Investigation of Dual-Purpose Solar Collector using with Rectangular Channels Hassan Kavoosi Balotaki, Mohammad Hassan Saidi Solar collector, Dual-purpose, water heater, air heater, efficiency Solar heat energy, one of the typical renewable energy absorbs radiation energy from the sun and converts it into heat energy. Since it is sustainable and eco-friendly, it can be a good alternative to solve the problem of the depletion of fossil fuels. But it has low density. So, solar collector is very important to use more efficiently. There are some possible approaches to scaling-up the effectiveness of a collector by re-thinking of using the collector as a heat exchanger. In the design of dual-purpose collector with rectangular ?n (DPCRF), can be used for heating air and water simultaneously using incident solar radiation resulting in optimum usage of energy and space. Journal of Thermal Engineering Journal of Thermal Engineering 2016-12-27T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2354 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2354 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2354

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2355 2016-12-27T21:00:00Z 4

The Importance of Internal Heat Gains for Building Cooling Design Turgay Coşkun, Cihan Turhan, Zeynep Durmuş Arsan, Gülden Gökçen Akkurt internal heat gains, cooling load, dynamic simulation This paper aims to investigate the effect of internal heat gains on the cooling load of a building. The house occupied by three adult men is selected as the case study for paper. The house is in the third floor of the apartment. The apartment has four flats and it has no insulation around the external walls. The heat dissipation from lighting devices, electrical equipments and the occupants are calculated by using the DesignBuilder v4 Beta release simulation program. The temperature of the house is observed during three weeks by using hobo data loggers and calibration of the measurements is made with respect to weather data file of the flat. Detailed schedule based on time of operation and occupancy is prepared to get more accurate results. Annual energy consumption and cooling load of the house is determined by using the dynamic simulation program. Journal of Thermal Engineering Journal of Thermal Engineering 2016-12-27T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2355 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2355 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2355

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2336 2016-10-21T21:00:00Z 4

Effect of Heat Treatment on the Microstructural Evolution in Weld Region of 304l Pipeline Steel Pipeline Steel Boumerzoug Zakaria, Hamza Soumia, Ji Vincent TIG Welding, 304L, heat treatments, microstructures In this work, the effect of isothermal heat treatments on microstructure evolution after welding by Tungsten Inert Gas (TIG) welding technique of 304L pipeline steel have been studied. Microstructures of the weldments were investigated using scanning electron microscopy (SEM), and X-ray diffraction analysis (XRD). Microstructural evolution in welded joint was identified. Results indicated that the microstructure of fusion zones exhibited dendritic structure and highest hardness. The applied heat treatments affected the microstructure of the welded joint. Journal of Thermal Engineering Journal of Thermal Engineering 2016-10-21T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2336 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2336 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2336

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2404 2017-03-31T21:00:00Z 1

Performance Analysis of a Steam Turbine Power Plant at Part Load Conditions Asım Sinan Karakurt, Ümit Güneş Off design conditions, thermal efficiency, isentropic efficiency, power plant, steam turbine Power consumption highly increases which is related with the growing of the industrial plants and daily using. Increasing power demand can be supplied with building up more efficient plants or optimized old power plants. One of the most important items of a power plant is steam turbine which is designed according to defined parameters (inlet pressure and temperature, flow rates, outlet pressure and power) which also effect the dimensions and performance of the turbine. Turbine loses and irreversibilities are minimum and so efficiencies and power generation are maximum at design conditions. However, power plants always have to operate at off-design or part-load conditions because of the changing of power demands and drop outs of the turbines and other items of the plants. In this study, it is aimed to analyses the isentropic efficiency of a high pressure steam turbine and thermal efficiency of power plant at different load conditions. Analyses showed that both steam turbines and power plant performance were reduced when the power plant operates at partial load conditions. Journal of Thermal Engineering Journal of Thermal Engineering 2017-03-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2404 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2404 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2404

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2353 2016-12-27T21:00:00Z 4

Optimum Orientation of a Mutually-Shaded Group of Buildings with Respect to External Solar Radiation Meshal F. Almutairi, Raed I. Bourisli Solar radiation, HVAC systems, energy conservation, mutual shading, group of buildings External, mainly solar, load can constitute up to 80% of the energy consumed by Heating, Ventilating and Air-Conditioning (HVAC) systems in buildings. Proportional attention is rarely given by designers to the optimum positioning or orientation of a building with respect to the sun so as to achieve minimal solar load. Even less attention has been given to groups of buildings located within a building complex for potential mutual shading. The general practice is to place them in a row or square formation. In this work, the optimum positioning of three high-rise buildings in close proximity to each other is investigated numerically with respect to solar radiation and potential mutual shading. Specifically, the effect of the relative locations of the buildings is tested with respect to solar radiation direction for a typical summer day in Kuwait City, Kuwait. The transient three-dimensional problem is solved using the Solar Load Model of the FluentTM finite volume computational fluid dynamics code. The solar load model calculates radiation effects from the sun's rays that enter a computational domain transiently based on the selected location. Specifically, the ray tracing approach in the model applies solar loads as heat sources in the energy equations. The solar calculator utility is used to construct the sun's location in the sky for the selected time-of-day, date, and position. As the circle containing the three buildings is rotated, the energy absorbed by the shaded one or two buildings changes significantly. Combined with air flow around the buildings, the interaction between convection and radiation heat transfer rates to the buildings can vary greatly. This variation should be taken into account when sizing HVAC equipment for the individual building. Typical TMY (Typical Meteorological Year) data for Kuwait City, Kuwait, is used to obtained boundary conditions for air velocity and temperature. Mass, momentum and energy conservation equations are solved in conjunction with the radiative Solar Load equations to obtained the combined effect. Results show that there exists an optimum orientation for the group for the selected locale and that the reduction in solar load for the optimum orientation for the group of three buildings and that the orientation effect on the total HVAC energy requirement (represented by the cooling load) is significant. The difference between the best and worst orientations was about 6%. Convection, even though non-negligible, has a somewhat smaller effect on the total heat transfer and thus cooling load. Ongoing work examines the effect of the sensitivity of energy savings to wind direction and convection heat transfer, by altering strength and direction of the breeze. Journal of Thermal Engineering Journal of Thermal Engineering 2016-12-27T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2353 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2353 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2353

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2352 2016-12-27T21:00:00Z 1

Determination of 1/V-T (P, Constant) Diagrams of Hydrogen Gases by Graph-Analytical Methods Beycan İbrahimoğlu, Çiğdem Kanbeş Dindar, Hazal Erol, Salih Karasari grapho-analytical method, hydrogen, ionization temperature of hydrogen Graph-analytical methods provide more accurate results in the analysis of V-T (P=constant) and 1/V-T (P=constant) diagrams of gases. In this study, as a continuation of [1, 2]*, the behavior of hydrogen gas was examined by using graph-analytical method under consideration of volume and density parameters at high pressure and temperature. In this paper, graph- analytical method was applied to draw and examine V-T (P=constant) and 1/V-P (T=constant) diagrams which were based on experimental data of hydrogen and other gases (Hydrogen, carbon dioxide, oxygen, argon, helium, neon, xenon and other gases) at high pressure and temperature. The results indicate that the behavior of hydrogen gas is different from the other gases. Journal of Thermal Engineering Journal of Thermal Engineering 2016-12-27T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2352 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2352 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2352

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2337 2016-10-24T21:00:00Z 1

Flow Regimes in Commercial Metal Foam Having 10 Pores Per Inch Altay Arbak, Özer Bağcı, Nihad Dukhan thermal development; Darcy; experiment; metal foam; water Metal foam- a relatively new class of porous media- has many advantageous properties relevant to many engineering applications. The internal structure of the foam has connected cells each having many ligaments that form a web. In addition, metal foam has very high porosity (often greater than 90%) and a large accessible surface area per unit volume. These properties are relevant to filtration, heat exchange and reactors. Flow regimes, and transition from one to another, are critical for understanding the pumping power for flow through the foam. The current study will shed some light on pressure drop and flow regimes in metal foam. In particular, a large set of experimental data for pressure drop of water flow in commercial open-cell aluminum foam having 10 pores per inch and a porosity of 88.5% was collected. The range of flow Reynolds number covered all important flow regimes. The current data correlated very well using the friction factor based on the square root of the permeability (measured in the Darcy regime) as a function of Reynolds number based on the same length scale. It is shown that the same foam exhibits different values of its permeability and Forchheimer coefficient in different flow regimes. The findings of this study can help in numerical and analytical work concerning flow and heat transfer in commercial open-cell metal foam and other similar foam-like porous media. Journal of Thermal Engineering Journal of Thermal Engineering 2016-10-24T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2337 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2337 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2337

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2338 2016-10-24T21:00:00Z 4

Bioenergy Production from Freeze Dried Chlorella Vulgaris Biomass via Microbial Fuel Cell Muhammad Haikal Zainal, Oskar Hasdinor Hassan, Tunku Ishak Tunku Kudin, Sharifah Aminah Syed Mohamad, Hazlini Mohmad Ameran, Nurul Khamsatul Akma Kamalruzaman, Ab Malik Marwan Ali, Muhd Zu Azhan Yahya microbial fuel cell, algea, freeze dried Algae biomass has strong and complex cell wall structure that is a hindrance for microbial digestion. In this work, two extracted algae biomass, which are freeze dried and spray dried Chlorella vulgaris biomass is applied to investigate the generation of bioelectricity by using single chamber air-cathode Microbial Fuel Cell (MFC). MFC was fed with freeze-dried algae powder to produce energy and determine its degradation efficiency. MFC with freeze-dried algae biomass was generating voltage around 739 mV from bacterial metabolism with algae substrate and phosphate buffered medium. Based on the power curve obtained, the maximum power density is 159 mW/m2 with 2.5 g/L of substrate concentration. The Chemical Oxygen Demand (COD) removal efficiency is 54.2% and Coulombic efficiency (CE) obtained is 28.4%. Journal of Thermal Engineering Journal of Thermal Engineering 2016-10-24T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2338 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2338 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2338

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2363 2016-12-27T21:00:00Z 1

An Experimental Study on a Bus Air Conditioner to Determine its Conformity to Design and Comfort Conditions Şaban Ünal bus air conditioning, cooling load, thermal sensation, comfort conditions The air conditioning system for a bus should be selected considering a number of parameters, including passenger capacity, local climatic conditions, and fuel consumption. It is possible to determine whether a selected air conditioning system provides desired performance through testing. This study examines how to verify experimentally whether a bus air conditioning system meets design and comfort requirements. An experimental study was conducted on a prototype bus and was tested when driving on the Adana-Ceyhan highway in Turkey. The internal and external temperatures, evaporator inlet and outlet temperatures and relative humidity values were measured. Thermal sensation values were calculated using empirical correlations given by ASHRAE. Furthermore, the instantaneous cooling load of the bus was obtained according to the experimental data, and the results are compared with the calculated cooling load of the bus using the radiant time series method provided by ASHRAE. With respect to the obtained results, the selected air conditioning system conformed to design and comfort requirements. Journal of Thermal Engineering Journal of Thermal Engineering 2016-12-27T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2363 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2363 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2363

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2332 2016-10-18T21:00:00Z 1

Wind Turbine Blade Flapwise and Edgewise Bending Vibration Analyses Using Energy Methods Ahmet Çelik, Nader Javani Blade Profile, Energy Method, Wind Turbine, Natural Frequency Renewable based electricity, generated from wind turbines is considered as a clean alternative energy resource. In a wind power plant, it is of vital importance to avoid resonance of the blade when a frequency of an exciting force exists, especially when it coincides with one of the natural frequencies of the system. The present study deals with the vibrational behaviour of a typical wind turbine blade, NACA 4415. Once the blade is under static load, its natural frequencies are analysed. Two energy methods of Rayleigh-Ritz and optimized Rayleigh-Ritz are employed to carry out the analyses. For the applied loads, the natural frequencies have also been specified. In case of bending is applied in vertical and horizontal directions has been investigated. There is a good agreement between the results of both methods. The results show that for the given blade profile, rotational speeds corresponding to the specific dimensional natural frequency should be avoided during the blade operation to maximize the output power of the wind turbine and extend its lifespan. Journal of Thermal Engineering Journal of Thermal Engineering 2016-10-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2332 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2332 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2332

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2405 2017-03-31T21:00:00Z 1

Investıgation of Newtonian and Non-Newtonian Droplets in Collision With the Heated Ultraphobic Surface on Various Weber Numbers Morteza Bayareh hydrophobic surfaces, VOF method, Weber number, Newtonian Droplet, Non-Newtonian droplets. Super hydrophobic surfaces due to water repelling property, have a considerable potential for the use in various modern technologies. In this paper, the collision between Newtonian and non-Newtonian droplets with a super-hydrophobic hot surface like graphite has been simulated. The contact angle is 140 and 160 degree. Simulation yielded proper result compared to the experimental results. It is found that the temperature effect on hydrophobic surfaces is negligible. Our results demonstrate that the dimensionless drop diameter increases with the Weber number. It is revealed that a Newtonian droplets shows different behavior compared to a non-Newtonian one especially at higher temperatures. Journal of Thermal Engineering Journal of Thermal Engineering 2017-03-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2405 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2405 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2405

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2409 2017-03-31T21:00:00Z 1

Experimental Validation of LMTD Method for Microscale Heat Transfer Nezaket Parlak, Mesut Gür, Tahsin Engin, Hasan Küçük Microscale flow and heat transfer, LMTD method, Scaling effects. been investigated experimentally. Experiments were conducted to cover transition zone for the Reynolds numbers ranging from 100 to 4800 by fused silica and stainless steel microtubes having diameters of 103-180 µm. The applicability of the Logarithmic Mean Temperature Difference (LMTD) method was revealed and an experimental method was developed to calculate the heat transfer coefficient. Moreover the scaling effects in micro scale such as axial conduction, viscous heating and entrance effects were discussed. The heat transfer coefficients were compared with data obtained by the correlations available in the literature in the study. The Nusselt numbers of microtube flows do not accord with the conventional results when the Reynolds number was lower than 1000. After that, the Nusselt number approaches the conventional theory prediction. On the aspect of fluid characteristics, the friction factor was well predicted with conventional theory and the conventional friction prediction was valid for water flow through microtube with a relative surface roughness less than about 4 %. Journal of Thermal Engineering Journal of Thermal Engineering 2017-03-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2409 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2409 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2409

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2406 2017-03-31T21:00:00Z 1

Advanced Exergy Analysis of an Organic Rankine Cycle Waste Heat Recovery System of a Marine Power Plant Turgay Koroglu, Oguz Salim Sogut Marine Power Plant, Combined Cycle, Organic Rankine Cycle, Advanced Exergy Analysis Energy efficiency has a great importance to reduce both fuel consumption and greenhouse gas emissions, which are the most important focus points for researchers in maritime industry. Exergy analysis, which is widely used to design, analyze and evaluate thermal energy systems, plays an important role to increase energy efficiency. It reveals destruction of available energy in components and leads the researcher to achieve better engineering and systems. Advanced exergy analysis has the capability to reveal the interconnections among system components and improvement potential of inspected components and also the overall system. Steam cycle is used in ships as main or auxiliary power production means for a long time. Also, it is used to recover waste heat from high temperature exhaust gases. Organic rankine cycle (ORC) is an alternative energy recovery strategy to utilize relatively low temperature heat sources to produce power. Usage of ORC in marine power plants is relatively new field to explore. In this paper, a marine power plant with ORC is investigated. Energy and exergy analyses have been carried out to identify conditions and parameters that affect the efficient operation of the system. Then, a parametric study has been conducted to determine the optimum range of operation for power plant and ORC considering different load conditions. Finally, exergy destruction of each component is calculated to give further insight information about the potential of improvement for the efficient operation. Journal of Thermal Engineering Journal of Thermal Engineering 2017-03-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2406 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2406 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2406

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2402 2017-03-31T21:00:00Z 1

The Effect of Different Types of Core Material on the Flexural Behavior of Sandwich Composites for Wind Turbine Blades Cihan Kaboglu, Soraia Pimenta, Andy Morris, John P. Dear Composite sandwich structure, failure mode In this study, three differently-configured sandwich structures were manufactured with three different core materials: Balsa wood, Tycor and Polyethylene terephthalate (PET). Glass-Fibre Reinforced Polymer (GFRP) skins were used to understand the effects of different types of core materials on the flexural behavior of sandwich composites under four point bending (4PB) condition, using digital image correlation (DIC). DIC is one of the most outstanding techniques to understand the mechanical behavior of the structure during the test, thus defining any problematic regions in the structures. The failure mechanisms of the structures were observed by using strain maps of the structures. The results show that the sandwich structure with Balsa wood as a core material has the highest stiffness; however, catastrophic failure appeared in the early stages of the test. The sandwich structure with PET and Tycor exhibited very similar behaviour under load. Journal of Thermal Engineering Journal of Thermal Engineering 2017-03-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2402 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2402 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2402

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2414 2017-05-22T21:00:00Z 1

The Renewable Energy Potential of Turkish Coasts and a Concept Design of a Near Shore Sea Platform B. Şener, S. Aytaç Renewable Energy, near shore sea platform, Turkish coasts There are several types of renewable energy platforms. Because of requirements of places, where platforms were built, every platform has different energy systems and qualities. In this paper, the renewable energy potential of Turkish coasts was investigated according to different renewable energy types. It is aimed to find suitable places for a near shore renewable energy platform and create a concept design. Firstly, the regions with highest energy potential according to four renewable energy types; wind, wave, current and solar; were determined and five different regions were selected to analyze. For each region, the power data of the different energy types were converted to same unit and the regions were ranked with respect to these results. Then the existing platform types and alternative energy conversion systems were examined and for each energy type a conversion system was chosen according to the characteristics of selected region. Finally, a concept near shore platform was designed with selected systems. Journal of Thermal Engineering Journal of Thermal Engineering 2017-05-22T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2414 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2414 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2414

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2403 2017-03-31T21:00:00Z 1

Numerical Simulation of Film Cooling a Turbine Blade Through a Row of Holes Djamel Cherrared Film cooling, turbulent flows, numerical simulation, cooling effectiveness We undertake a numerical three-dimensional study of the interaction of a row of discrete jets in a wall with a transversal incompressible flow for different injection rate (M=0.3, 0.5, 0.7 and 1.4). This simulation is applied to the stator blade of the CFM56 engine and is performed using the computational fluid dynamics (CFD) simulation tool, with CFX. 13 software. Reynolds averaged Navier-Stokes equations were solved using a finite volume method. Turbulence closure was achieved using the Shear-Stress Transport model (SST). The velocity and temperature distributions and the film cooling effectiveness are presented and discussed. We found that the best cooling effectiveness occurs at M= 0.7. More, for higher injection rate (M=1.4), the results show the existence of two counter- rotating vortices. These vortices transport the hot gas in the jet and thus degrade the protective wall. Journal of Thermal Engineering Journal of Thermal Engineering 2017-03-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2403 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2403 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2403

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2496 2017-12-11T21:00:00Z 1

Computational Analysis of Inserted Porous Blocks into Horizontal Concentric Annuli in Mixed Convection Mode Yacine Ould-Amer Mixed convection, concentric annuli, porous, thickness This study numerically investigates the effect of porous blocks thickness on laminar mixed convection in a horizontal annulus. With attached four porous blocks on the inner cylinder, steady 3D laminar mixed convection is presented for the fully developed region of horizontal concentric annuli. Results are presented for two values of porous blocks thickness and a range of the values of the Grashoff number, Darcy number and the conductivity ratio between the porous medium and the fluid. Results are presented in the form of contours plots of the streamlines and for the temperature isotherms, and in terms of the overall heat transfer coefficients and friction factor. The average Nusselt number increases significantly with an increase of the thickness of porous blocks. With the use of the four porous blocks, the friction factor is consequently increased compared with the situation without porous blocks. The decrease of the Darcy number leads to an increase of the friction factor. If the fully fluid case is taken as a reference, the use of porous blocks is justified only when the ratio of the average Nusselt number to the friction factor is enhanced. Journal of Thermal Engineering Journal of Thermal Engineering 2017-12-11T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2496 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2496 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2496

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2438 2017-05-31T21:00:00Z 1

Design Basis Accident Analysis of a Small Modular Reactor Jivan Khatry, Fatih Aydogan Passive safety systems, IRIS, RELAP5, small modular reactor, SBLOCA The International Reactor Innovative and Secure (IRIS) is an integrated small modular reactor (SMR) designed by Westinghouse Electric Company and a consortium of organizations. It has a thermal electric power rating of 1000 MWth and an electric power rating of 335 MWe. Being an SMR that features a derivative pressurized water reactor design, it contains the core, upper plenum, lower plenum, pressurizer, reactor coolant pumps, and steam generators in a single reactor vessel. An important feature of the IRIS is passive safety systems. Passive safety systems don’t require mechanical/electrical inputs for operation and rely on natural laws, material properties, and stored internal energy for hazard mitigation. In this work, a RELAP55 model of IRIS was constructed. A small-break loss-of coolant accident (SBLOCA) is simulated where the six major stages of SBLOCA response: (i) break initiation; (ii) blowdown; (iii) vessel depressurization by condensation and automatic depressurization system (ADS); (iv) pressure equalization; (v) reactor vessel/containment vessel depressurization; and (vi) long-term cooling are demonstrated. This paper demonstrates how efficiently the passive cooling systems work in mitigating the hazard. Journal of Thermal Engineering Journal of Thermal Engineering 2017-05-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2438 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2438 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2438

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2457 2017-09-18T21:00:00Z 1

Exergetic Optimization of Phosphoric Acid Factory Power Plant Khir Tahar, Hafdhi Fathia, Ben Yahia Ali, Ben Brahim Ammar Steam Turbine Generator, Energy efficiency, Exergy efficiency, Phosphoric Acid plant, Heat exchanger An Energetic and Exergetic Analysis is conducted on a Steam Turbine Power Plant of an existing Phosphoric Acid Factory. The heat recovery systems used in different parts of the plant are also considered in the analysis. Mass, thermal and exergy balances are established on the main components of the factory. A numerical code is established using EES software to perform the calculations required for the thermal and exergy plant analysis. The effects of the key operating parameters such as steam pressure and temperature, mass flow rate as well as seawater temperature, on the cycle performances are investigated. The minimum Exergy Destruction Rates are obtained for the condensers and deaerators followed by the blowers and turbines. The Steam Turbine Generator STGI presents the maximum irreversibility rates of about 4.1 MW. For the explored ranges of HP steam pressure, the energy efficiencies of steam turbine generators STGI and STGII increase of about 1.37 % and 8.8 % respectively. While the exergy efficiencies increase of about 2.46 for STGI and 6.8 % for STGII. In the same way optimum HP steam flow rate values, leading to the maximum exergy efficiencies are defined. Keywords: Condenser, Energy efficiency, Exergy efficiency, Phosphoric Acid plant, Steam Turbine Generator. Journal of Thermal Engineering Journal of Thermal Engineering 2017-09-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2457 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2457 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2457

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2439 2017-06-30T21:00:00Z 1

Analysis on Solar Panel Performance and PV-Inverter Configuration for Tropical Region Eko Adhi Setiawan, Aiman Setiawan, Duli Siregar Photovoltaic, PV-Inverter Configuration, PV Modeling, Solar Panel Characteristics, Temperature, Tropics In this paper, proper inverter topology for tropical region will be determined with temperature effect as considered factor and it will be represented by PV I-V and P-V characteristic curves. PV characteristics on certain temperature are obtained through mathematical equations in MATLAB-Simulink. Based on that modeling, some PV parameters such as temperature coefficients of short circuit current (ISC), open circuit voltage (VOC), maximum output power (PMAX), and maximum power voltage (VMP) can be determined as high as 0.56%/oC, -0.31%/oC -0.4%/oC, and 0.43 %/oC respectively. As the result, for tropical region, the central inverter is the most proper inverter topology to supply 5 kWAC PV system, string inverter in the 2nd place, and AC module with utility rates of 97.34%, 96.32 %, 88.1% based on direct measurement on PV panel’s temperature respectively. From NOCT approach, the utility rates are around 92.96 % for central inverter, 91.98% for string inverter and 91.8 % for AC module. Journal of Thermal Engineering Journal of Thermal Engineering 2017-06-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2439 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2439 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2439

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2440 2017-06-30T21:00:00Z 1

A Lime Production of the Fludized Bed Boiler's Energy and Exergy Analyse Tolga Taner, Mecit Sivrioglu Lime production, energy and exergy analyse, fluidized bed boiler, energy quality In this study, it was calculated energy and exergy analysis of a lime production for the fluidized bed boiler by a case of sugar factory. The aim of this study is to show calculation of the energy and exergy analysis of a lime production for the fluidized bed boiler, and to determine a lime mass quantity for the factory process. This factory is a sugar factory that has got many heat processes for the sugar raw filtration and defection. The production of lime mass was found 1.2973 [kg/s]. The production of lime (CaO) energy result was found 4121.92 [kW] and exergy result was found 2766.97 [kW]. Energy (CaO) quality was found 0.671. Journal of Thermal Engineering Journal of Thermal Engineering 2017-06-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2440 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2440 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2440

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2441 2017-06-30T21:00:00Z 1

Effect of Roof Pond on the Energy and Exergy Performance of a Single Space Building Abdul Hadi Khalifa Roof pond; Passive cooling; thermal analysis; Exergy analysis. In a hot, arid zone, the load imposed on the building load due to the roof is more than that for all the four walls; one of the proposed solutions to this condition is to use the roof pond. Using roof pond can reverse the performance of roof from heat source to heat sink that can withdraw the heat from building envelope. In this work a mathematical model, using the complex Fourier series was built for a single space building. Ambient temperature, solar radiation, and sol-air temperature have been treated as a periodic function of time. The effect of roof pond on the indoor temperature, heat flow to the building, temperature distribution through walls and roof were studied, as well as an exergy analysis to the roof pond was achieved. The result showed that using roof pond can reduce the mean indoor temperature by about 4 oC as compared with a building using the traditional roof. The exergy analysis showed that the maximum exergy efficiency conjunct with the maximum exergy destruction through roof pond. Journal of Thermal Engineering Journal of Thermal Engineering 2017-06-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2441 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2441 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2441

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2442 2017-06-30T21:00:00Z 1

Testing and Analysis of Low Pressure, Transparent Tube Solar Receiver for the SUNSPOT Cycle Jaap Hoffman, C. van der Merwe Low pressure solar receiver, transparent tube, linear Fresnel, porous medium This paper proposes a low pressure tubular solar receiver for a solarized gas turbine. The receiver comprises of concentric tubes with a transparent outer tube, and the annular space is filled with a porous medium. Air is heated by concentrated solar radiation as it flows through the porous medium. To proof our concept, a single 1.5 m long tube was tested on an existing eight mirror linear Fresnel collector, and test data is documented. A temperature increase of about 40 °C was recorder for a concentration ratio of 7:1 and superficial velocity of 1 m/s. Volumetric absorption was a disappointingly low 28 %, mainly due to the low packing factor and reflection of sunlight from the tube’s outer surface. A computational fluid dynamics (CFD) model of the test set-up was used to extract the extinction and absorption coefficients of the porous medium, by fitting a quadratic response surface through the mean square errors between experimental and CFD data. Our analysis indicates that we can increase receiver efficiency significantly through raising the packing factor and applying and anti-reflection coating to the tube surface. Journal of Thermal Engineering Journal of Thermal Engineering 2017-06-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2442 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2442 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2442

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2407 2017-03-31T21:00:00Z 1

Effect of Flow Structure on Heat Transfer in Compact Heat Exchanger by using Finite Thickness Winglet at Acute Angle Bhupender Sharma, Gian Bhushan, Gulshan Sachdeva Longitudinal vortices, vortex generator, finite thickness, triangular channel, Heat Transfer enhancement Longitudinal vortex generation is a well known passive technique for thinning the thermal boundary layer and hence enhancing the heat transfer, but its performance while considering the thickness is essentially unknown. In this study, a single triangular shaped winglet type vortex generator having finite thickness is analyzed in a plate fin heat exchanger with triangular inserts as secondary fins. The vortex generators are mounted on bottom and top plates of the heat exchanger and triangular inserts forms a channel, each representing the symmetry for the gas-side element of the compact heat exchanger. Heat transfer and pressure drop is computed to determine the effectiveness of the vortex generator while varying its thickness, size, and angle of attack under confined laminar flow condition. In addition the winglet is tilted from vertical at an angle known as acute angle and it was found to produce two longitudinal vortices which better did the thinning of boundary layer. It is shown that adding thickness to triangular winglet and mounting at ? = 45°, augment heat transfer along the channel wall as high as 19.7% with a corresponding increase of 7.8% in pressure loss. Journal of Thermal Engineering Journal of Thermal Engineering 2017-03-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2407 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2407 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2407

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2443 2017-07-20T21:00:00Z 1

Impacts of Nanoscale Inclusions on Fire Retardancy, Thermal Stability, and Mechanical Properties of Polymeric PVC Nanocomposites A. Ghazinezami, W. S. Khan, A. Jabbarnia, R. Asmatulu Polymer, Nanoscale Inclusions, PVC Nanocomposites, Fire Retardancy, Physical Properties A number of different nanoscale inclusions including nanoclay, nanotalc, and graphene were incorporated with polyvinyl chloride (PVC), dispersed in N,N-Dimethylacetmide (DMAC) and cast in rectangular aluminum (Al) molds prior to the testing. The fire retardancy, thermal stability, and mechanical properties of the PVC nanocomposites were determined using the ASTM UL 94 standard, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and microtensile test units. Surface morphology studies of the resultant materials were also carried out using scanning electron microscopy (SEM). Test results showed that the fire retardancy, thermal stability, and mechanical properties of the PVC nanocomposites were significantly enhanced in the presence of nanoscale inclusions. Among the inclusions, graphene had the major impact on improving the physical properties, which may be because of its higher thermal conductivity, mechanical strength, size, and shape. Polymers have a wide range of applications in daily life, but they are highly flammable and mechanically not stable for different applications. This study has shown that the weakness of the PVC could be significantly enhanced by incorporating nanoscale inclusions for various industrial purposes. Journal of Thermal Engineering Journal of Thermal Engineering 2017-07-20T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2443 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2443 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2443

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2306 2016-09-07T21:00:00Z 1

Investigation of the Thermal Performance of Cryogenic Regenerator as a Porous Structure Muhammad Shad, Muhammad Ali Kamran cryocooler; regenerator; CFD; hydrodynamic parameters; in-efficiency An efficient cryocooler is one of the essential requirements for cooling of Infrared (IR) sensors to low temperatures in high resolution night vision systems. A regenerator is an imperative component of cryocooler which has a significant effect on cooling performance of a cryocooler. In this research work a computational fluid dynamic (CFD) methodology based on thermal equilibrium modelling approach has been implemented to analyze the thermal performance of a regenerator under different design conditions. The regenerator was modeled as a porous media with time varying boundary conditions in the commercial software package FLUENT by incorporating the effects of temperature dependent physical properties of both, matrix material and working fluid. Simulations were conducted at different cyclic flow velocities and effect of these variations on temperature swing, pressure drop, in-efficiency, capacity ratio and number of heat transfer units of the regenerator have been studied for design of better regenerators. The results show that any increment in the velocity of flow, increase the temperature swing, pressure drop and in-efficiency while decrease the capacity ratio and number of heat transfer units of the regenerator with fixed geometry. In this research work, it is also concluded that the thermal performance of regenerator strongly depend upon the temperature dependent physical properties of both matrix material and working fluid. Journal of Thermal Engineering Journal of Thermal Engineering 2016-09-07T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2306 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2306 Journal of Thermal Engineering, Year:2016, Vol:2, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2306

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2458 2017-09-18T21:00:00Z 1

Numerical Investigation of Isothermal Flow Around Impingement Plates in a Shell and Tube Exchanger Ram Subash Maurya, Satinder Singh Impingement plate; Heat Exchanger; Flow Distribution; TEMA; Numerical; Simulation The impingement plate is an important protecting device of tube bank which is located on shell side at the nozzle inlet of shell and tube heat exchanger. Current work presents a 2D numerical investigation of the flow structure developing around different impingement plate design under different flow conditions using ANSYS Fluent. Location, size and arrangement of impingement plate are the investigated parameters which provides significant information for the selection of ideal location and size of required impingement plate. Study compares different plate geometry and concludes the best one which apart from protecting the tube banks, also removes the stagnation zone developing behind them because of their placements. Journal of Thermal Engineering Journal of Thermal Engineering 2017-09-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2458 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2458 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2458

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2459 2017-09-18T21:00:00Z 1

Numerical Study of Pressure Drop and Heat Transfer in a Straight Rectangular and Semi Cylindrical Projections Microchannel Heat Sink Mohammad Zunaid, Anant Jindal, Dishant Gakhar, Abhishrut Sinha ANSYS; CFX; microchannel; heat sink; Reynolds number. The heat transfer and pressure drop characteristics of a straight rectangular and semi cylindrical projections microchannel heat sink were investigated. The heat sinks were made of copper. The heat sinks consisted of a cluster of microchannels 231 µm wide and 713 µm deep. There are 21 parallel small scale equidistantly placed microchannels. Water was used as cooling fluid and was made to flow through the channels. In both the cases different values of Reynolds number ranging from 200 to 1000 were used with constant heat flux of 10 6 W/m^2 defined relative to the platform area of the heat sink. The temperature rise and pressure drop of the flowing fluid in straight microchannel heat sink for different Reynolds number was found using ANSYS-CFX package and has been validated using experimental data. Similar analysis is done for semi cylindrical projections microchannel heat sink. Similar analysis is done for semi cylindrical projections microchannel heat sink by solving the conjugate heat transfer problem. Results shows that heat transfer increases with the use of semi cylindrical projections microchannel heat sink. Also the heat transfer decreases with increase in the Reynolds number. Journal of Thermal Engineering Journal of Thermal Engineering 2017-09-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2459 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2459 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2459

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2460 2017-09-18T21:00:00Z 1

Unsteady Numerical Simulation of Turbulent Forced Convection in a Rectangular Pipe Provided with Waved Porous Baffles Fakiri Fethallah, Rahmoun Khadidja Porous media; Horizontal Canal; Thermal transfer and matter; Model Darcy-Brinkman-Forchheimer; Forced convection; Porous baffles. Numerical simulations of flow and heat transfer in a serpentine heat exchanger configuration are presented to demonstrate application of porous media techniques in heat exchanger analyses. In this study, steady-state 3D turbulent forced convection flow and heat transfer characteristics in a rectangular pipe with baffles attached inside pipe have been numerically investigated under constant wall heat flux boundary condition. Numerical study has been carried out for Reynolds number of 20000-50,000, Prandtl number of 0.71, baffle distances h/Dh of 1/3 and 2/3, and baffle thickness e of 1/12, 2/3. Ansys Fluent 6.3.26 software has been used to solve the flow field. It is observed that rectangular pipe having waved baffles has a higher Nusselt number and friction factor compared to the smooth rectangular pipe without baffles. Periodically fully developed conditions are obtained after a certain module. Maximum thermal performance factor is obtained for the baffle waved. Results show that baffle distance, waved porous baffle, and Reynolds number play important role on both flow and heat transfer characteristics. All the numerical results are correlated within accuracy of ±2% and ±2.5% for average Nusselt number and friction factor, respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2017-09-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2460 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2460 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2460

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2362 2016-12-27T21:00:00Z 1

Application of an Aggregation Technique to Facility Layout Design Selection Serkan Altuntas, Turkay Dereli Facility layout, Facility design, Facility location Facility layout in manufacturing and service systems affects the productivity and efficiency of the systems. Generally, more than one appropriate location is available based on associations among facilities. This leads to alternative facility layout designs. It is not an easy activity to select the best facility layout design among alternatives for facility engineers and decision makers. Many number of ranking of alternative facility layout designs can be generated by the use of different approaches. However, rankings obtained from these approaches do not suggest unique ranking. In this study, an aggregation technique is conducted to sort facility layout design alternatives generated by multiple conventional approaches. It is mainly based on a linear programming model. The results of this study show that alternative facility layout designs can be easily ranked in descending order by the aggregation technique. Journal of Thermal Engineering Journal of Thermal Engineering 2016-12-27T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2362 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2362 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2362

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2453 2017-09-18T21:00:00Z 1

Application of a Novel Thermo-Ecological Performance Criterion: Effective Ecological Power Density (EFECPOD) To a Joule-Brayton Cycle (JBC) Turbine Güven Gonca Joule-Brayton cycle; Gas turbine performance; Power density; Finite-time thermodynamics This study presents an application of a new performance analysis criterion named as Effective Ecological Power Density (EFECPOD) to a Joule-Brayton cycle (JBC) turbine. The turbine performance is expressed a single value by the proposed criterion using effective efficiency, effective power, cycle temperature ratio and volume. NOx formation and turbine dimensions are considered by the cycle temperature ratio and turbine volume, respectively. The turbine volume is also related to production cost of the heat engine. Therefore, the proposed criterion is essential for multi purpose optimization. Furthermore, this criterion can be developed and applied to the other gas cycle and heat engines. Also, the influences of engine design parameters such as cycle temperature ratio, pressure ratio, turbine speed, and equivalence ratio on the EFECPOD have been examined based on Finite-Time Thermodynamics Modelling (FTTM). In order to obtain realistic results, temperature-dependent specific heats for working fluid have been used and heat transfer and exhaust output losses have been taken into consideration. The results presented could be an essential tool for JBC turbine designers. Journal of Thermal Engineering Journal of Thermal Engineering 2017-09-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2453 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2453 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2453

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2454 2017-09-18T21:00:00Z 4

Two- and Three-Dimensional Transient Analysis of Flow and Heat Transfer In Structures with Domical and Curved Roofs Zekeriya Altaç, Nihal Uğurlubilek buoyancy flow, domical structure, natural convection, turbulent heat transfer In this study, transient buoyancy driven free convection heat transfer in domical (with a dome) structures or curved roofs is numerically investigated. Two- and three-dimensional turbulent free convection are considered for the Rayleigh number intervals (108?Ra?1010). The aspect ratios of H/L=1 and 2, with respect to the heated length, are considered. The heating is provided from a lateral surface while cooling is from opposing lateral surface. The hot and cold surfaces are kept isothermal, and all other surfaces are adiabatic. The Boussineq approximation is used for modeling the buoyancy flow. The RNG k-? turbulence model is used. The pertinent transient equations are solved using Fluent 6.3.26 software. The flow of air (streamlines) and temperature distribution (isotherms) are produced. The mean Nusselt number is evaluated over the isothermal hot wall is computed, and the results are analyzed with respect to the flow and geometric variations. Journal of Thermal Engineering Journal of Thermal Engineering 2017-09-18T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2454 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2454 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2454

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2455 2017-09-18T21:00:00Z 4

Performance Analyzing of an Organic Rankine Cycle Under Different Ambient Conditions Ali Volkan Akkaya Organic Rankine cycle, Cooling tower, Ambient Conditions, Performance The goal of this study is to develop a thermodynamic model in order to show the effect of ambient conditions on performance of an Organic Rankine Cycle based power generation system. This system is simply consisted of a turbine, a condenser, a boiler, pumps and a cooling tower. Each component in this system is modeled based on energy and mass balance equations. Then, the system model is obtained with integration of component models. After that, simulation studies are iteratively carried out to determine the performance of the considered system under variation of ambient conditions. Journal of Thermal Engineering Journal of Thermal Engineering 2017-09-18T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2455 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2455 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2455

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2482 2017-11-14T21:00:00Z 1

Aerodynamics Assessment Using CFD for a Low Drag Shell Eco-Marathon Car Essam Abo-Serie, Elif Oran, Oya Utcu Vehicle Aerodynamics, Shell Eco-marathon Car, Low Drag Car, Vehicle CFD Having a small car running with low power can be achieved by reducing the aerodynamics drag, rolling resistance and mechanical frictions between the moving parts. The Shell Eco-Marathon competition held around the world with events in Europe, USA and Asia shows every year new techniques and ideas to reduce the power needed to drive the car. The record of over 3400 km on the equivalent of a single litre of fuel is an indication of how car can run efficiently. The problem with these low drag cars is the driver perception about the shape of the car. Although the tear drop shape is known as having the minimum drag, practically this shape cannot be used due to size and packaging limitations in addition to the safety issue. In this work, a low drag concept car is proposed using initial CAD design. The concept car is examined using a commercial CFD software by simulating the airflow around car. The spatial distribution of the pressure and velocity vectors are utilized to improve the car shape and to achieve a low drag force coefficient while keeping the down force at its minimum value. By changing the car front, underneath and rear shapes, it was possible to reduce the drag coefficient from 0.430 for the baseline to 0.127 for the final design, while meeting the competition regulations. Journal of Thermal Engineering Journal of Thermal Engineering 2017-11-14T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2482 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2482 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2482

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2444 2017-07-20T21:00:00Z 1

Design and Simulation of A Novel C-DEP Microfluidics for Single Cell Trapping Iman Isaac Hoseini, Mahdi Moghimi Zand Single cell trapping, DEP, cDEP, Microfluidic, FEM, Joule heating Dielectrophoresis (DEP), as a promising tool, have been used to separate, sort and deform bio-particles. In traditional method of DEP, the direct contact of electrodes with bio-particles leads to contamination and lysis of cells and joule heating in medium. In new DEP methods, such as isolated DEP (iDEP) or contactless DEP (cDEP), some of these rigors are overcame. In the method presented herein, these new techniques are used to provide a non-uniform electric field to trap a single cell in a desired area. We used the insulating structures to guide a flow as well as the manipulation of particles. Finite element analysis (FEA) is used to obtain an optimized microstructure. The joule heating and maximum DEP force is compared with traditional method and results prove the capability of these systems to trap a single cell efficiently. Journal of Thermal Engineering Journal of Thermal Engineering 2017-07-20T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2444 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2444 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2444

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2494 2017-12-11T21:00:00Z 1

Thermodynamic Modeling of a Pulse Tube Refrigeration System Prokash C. Roy, Balaram Kundu Pulse Tube Refrigeration, Thermodynamic Model, Cooling Effect, Comparison Thermodynamic model of the pulse tube refrigeration (PTR) system has been developed based on the ideal gas behaviour to study the cooling effect at the cold end of the refrigerator. Compression and expansion processes of the gas column have been assumed to be isothermal. Mass flow in the regenerator has been evaluated through Ergun's law. Mass flow through the orifice and double inlet valve has been assumed a nozzle flow with a correction factor. Model predicted results have been validated with in-house experimental results as qualitative basis. Model predicted results in compression and expansion processes are also validated with that of the experimental data. Model predicted results are presented to understand the basic phenomenon for the refrigeration effect in various pulse tube refrigerators (BPTR, OPTR and DIPTR). Time duration for expansion process is more than the compression process in case of OPTR and DIPTR, which leads to lower pressure during the expansion and more cooling capacity obtained compared to the BPTR. A distinct comparison among three types of PTRs has been done based on the work done at the cold end. It has been clearly observed that a DIPTR shows better cooling capacity compared to OPTR or BPTR. Journal of Thermal Engineering Journal of Thermal Engineering 2017-12-11T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2494 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2494 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2494

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2445 2017-07-20T21:00:00Z 1

Electronic Measurement of Weather Conditions for An Engine Test Room Barış Doğru, Mehmet Murat Özdemir Internal Combustion Engines, Real-time Weather Data, Arduino Microcontroller,Correction Factor Frequently used internal combustion engines for driving highway vehicles are often tested to adjust performance outputs and exhaust emissions, with consideration for the production standardization and regulations of motor vehicles. In this work, a mini air station was designed and produced using the Arduino micro-controller to test the performance of an internal combustion engine. Instantaneous ambient temperature, pressure and relative humidity during engine operation are measured. At this time, the engine is subjected to steady state and transient regime tests and the performance data are reduced by a power correction factor to sea level conditions. The real-time weather data coming from the sensors over a 6-hour period every half-hour is continuously transmitted to the micro-controller. The microcontroller also continuously processes the measured data on an Excel page with the help of the environmental software of the microcontroller. According to the measurement results, the pressure and temperature results can be accepted at the tolerable interval. However, the relative humidity in the mini-station is considerably lower than the reference stations, and the room air is quite dry as a result of the atmospheric temperature rising and the large heat transfer between the engine and the environment. In the tests of the heavy duty diesel test engine, where the power correction factors are calculated thanks to the developed mini air station, the effective motor power has increased by 1.9% to 4.7%. The effect of the correction factor on brake specific fuel consumption varies between 1.9 and 4.5% for 2100 rpm and 1200 rpm engine rpm respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2017-07-20T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2445 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2445 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2445

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2492 2017-12-10T21:00:00Z 1

Effect of Pre-Treatment and Air Temperature on Drying Time of Cherry Tomato İbrahim Doymaz, Azmi Seyhun Kıpçak Cherry tomato, Pre-treatment, drying, rehydration, effective moisture diffusivity, activation energy The effects of pre-treatment and air temperature with on drying and rehydration characteristics of cherry tomato slices were studied. Drying experiments are carried out with the air temperature of 55, 65, and 75°C. Drying time decreased with pre-treatment, and it also decreased considerably with increase in air temperature. The results indicated that the cherry tomatoes which were pre-treated with potassium solution were explored within the shortest time. Furthermore, superior rehydration was observed the samples which were pre-treated with potassium solution. The moisture effective diffusivity calculated from the second Fick’s law of diffusion ranged from 2.26 to 6.22?10-9 m2/s over the temperature range studied. Activation energy was estimated by an Arrhenius type equation and the activation energy values varied from 26.51 to 32.79 kJ/mol. Journal of Thermal Engineering Journal of Thermal Engineering 2017-12-10T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2492 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2492 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2492

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2446 2017-07-20T21:00:00Z 1

Vascular Structures for Smart Features: Self-Cooling and Self-Healing Erdal Çetkin Constructal; Vascular; Smart features; Self-cooling; Self-healing Here we show how smart features of self-cooling and self-healing can be gained to mechanical systems with embedded vascular structures. Vascular structures mimic the circulatory system of animals. Similar to blood distribution from heart to the animal body, vascular channels provide the distribution of coolant and/or healing agent from a point to the entire body of a mechanic system. Thus the mechanic system becomes capable of cooling itself under unpredictable heat attacks and capable of healing itself as cracks occur due to applied mechanical loads. These smart features are necessary for advanced devices, equipment and vehicles. The essential design parameter is vascularization in order to provide smart features. There are distinct configurations for vascularization such as radial, tree-shaped, grid and hybrids of these designs. In addition, several theories are available for the shape optimization of vascular structures such as fractal theory and constructal theory. Unlike fractal theory, constructal theory does not include constraints based on generic algorithms and dictated assumptions. Therefore, constructal theory approach is discussed in this paper. This paper shows how smart features can be gained to a mechanical system while its weight decreases and its mechanical strength increases simultaneously. Journal of Thermal Engineering Journal of Thermal Engineering 2017-07-20T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2446 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2446 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2446

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2485 2017-11-14T21:00:00Z 2

Advances in Zero Energy Transportation Systems Othman Ahmad, M. N. Ali, A. Chekima Evacuated Tube Transport, Hyperloop, Vacuum, Vacuum Tube, Zero Energy Transportation System Hyperloop mass transportation systems are actively developed at the moment. They represent the forefront development of the Zero Energy Transportation systems where air drag is minimised by travelling in a vacuum and friction is reduced by non-contact bearings. Hyperloop supporters are confident that the cost of their transportation systems would be low compared to existing transportation systems because of the low loss and therefore low energy consumption as well as other cost-saving techniques documented in the Hyperloop Alpha specifications. However, there are other published designs in the form of patents that may improve on the designs of the Hyperloop systems so that sustainable mass transportation systems can be realised. Journal of Thermal Engineering Journal of Thermal Engineering 2017-11-14T21:00:00Z Short Communication application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2485 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2485 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2485

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2491 2017-12-04T21:00:00Z 1

Numerical Investigation of Heat Transfer from a Porous Plate With Transpiration Cooling Mustafa Kılıç CFD, Heat Transfer, Porous Plate, Transpiration cooling The present study is focused on investigation of heat transfer from a porous plate by cooling of air and surface with transpiration cooling. Effects of Reynolds number of hot air (Re= 3035, 3200, 3300, 3580), effects of flow rate of water as a coolant (?water= 0.000083, 0.000116, 0.000166, 0.000249 kg/s) on local wall temperature and cooling efficiency of porous flat and the system inside a rectangular channel with air as a hot gas stream and water as a coolant were investigated numerically. In this study; different from the literature, transpiration cooling was used as a cooling mechanism of air. It was observed from the results that increasing Reynolds number causes an increase on surface temperature and a decrease on cooling efficiency of porous plate and system. Increase of Reynolds number from Re=3035 to 9430 causes a decrease of efficiency of the system of 13.7%. Increasing water flow rate nine times causes not only a decrease on average surface temperature of 1.1% but also an increase of 6.5% on efficiency of porous plate and an increase of 19.1% on cooling efficiency of the system. Numerical results prepared by RNG k-e turbulence model generally have a good approximation with experimental results. Journal of Thermal Engineering Journal of Thermal Engineering 2017-12-04T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2491 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2491 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2491

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2447 2017-07-20T21:00:00Z 1

Effect of Uniaxial Initial Stresses, Piezoelectricity and Third Order Elastic Constants on the Near-Surface Waves in a Stratified Half-Plane İlkay Kurt, Surkay D. Akbarov, Semih Sezer Uniaxial initial stress, dispersion, near-surface waves, piezoelectric, third order elastic constants Dispersion curves of a system consisting of a piezoelectric covering layer and metal half-plane under the uniaxial initial stresses perpendicular to the wave propagation direction are obtained within the scope of the Three-dimensional Linearized Theory of Elastic Waves in Initially Stressed Bodies. The elasticity relations of the metal half-plane material are described by the Murnaghan potential. The numerical results are discussed for PZT-2 covering layer and aluminum half-plane material. The influence of the initial stresses, the piezoelectricity of the covering layer, and the third order elastic constants on the near-surface wave propagation velocity is illustrated. Journal of Thermal Engineering Journal of Thermal Engineering 2017-07-20T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2447 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2447 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2447

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2497 2017-12-13T21:00:00Z 1

Theoretical Investigation of a Solar Air Heater Roughened by Ribs and Grooves C. Yıldırım, N. F. Tümen Özdil Solar Energy; Artificial Roughness of Solar Air Heater; Rib and Groove Type Roughness In this study, thermal and thermohydraulic efficiencies of a solar air collector having a roughened absorber with rib-grooved artificial roughness elements have been investigated and compared with the flat plate solar air collectors. The system has been theoretically investigated for different geometrical roughness parameters by help of energy balance equations between the elements of collector. Geometrical roughness parameters such as ratio of the relative roughness height (RRH), relative roughness pitch (RRP), and groove positions to pitch (GP/PR) are examined for Reynolds number range from 3000 to 21,000. Journal of Thermal Engineering Journal of Thermal Engineering 2017-12-13T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2497 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2497 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2497

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2486 2017-11-14T21:00:00Z 1

Fem Analyses of Low Velocity Impact Behavior of Sandwich Panels With Eps Foam Core Umut Çalışkan, M. Kemal Apalak Impact, Sandwich Panel, Foam, Non-Linear Finite Element Analysis, Cohesive Zone Model This study presents a numerical investigation on low velocity impact response of sandwich panels with EPS foam core. The face-sheets and foam core are made of aluminum 6061-T6 and expanded polystyrene foam (EPS). The effect of foam core density was investigated on the impact energy absorption of the panel. The dynamic response of the panels was predicted using the finite element analysis package ABAQUS/Explicit. The material and geometrical nonlinearities were considered and the foam material was modeled as a crushable foam material. The cohesive response of the adhesive interface was modeled using the cohesive zone model. The temporal variations of contact force, kinetic energy histories and central permanent deflections were compared for different foam core densities and impact energies. The peak contact force levels and central permanent deflections are increased with increasing the impact energies. As the foam core density is increased, the capability of energy absorbing is increased. Journal of Thermal Engineering Journal of Thermal Engineering 2017-11-14T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2486 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2486 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2486

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2487 2017-11-14T21:00:00Z 1

Experimental Study on Turning with Self-Propelled Rotary Cutting Tool U. Emiroğlu, M. Kiyak, E. Altan Self-Propelled Rotary Cutting Tool, Flank Wear, Surface Roughness In metal cutting, self-propelled rotary tools in which the contact zone between tool and workpiece continuously changes have been used in recent years. The previous researchers used the self -propelled rotary tools specially designed and manufactured for experimental study. This study presents an experimental investigation to evaluate the performance of a new designed and manufactured self-propelled rotary tool. The experiments were realized by turning mild steel under different cutting parameters in order to determine the flank wear and the surface roughness. It has been seen that the new designed cutting tool has major advantage over stationary cutting tool providing longer tool life, but poor workpiece surface quality. Journal of Thermal Engineering Journal of Thermal Engineering 2017-11-14T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2487 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2487 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2487

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2495 2017-12-11T21:00:00Z 1

Thin Layer Drying Modeling of Apples and Apricots in A Solar-Assisted Drying System A. Stegou – Sagia, D.V. Fragkou Tray Dryer, Solar Assisted, Apricots, Apples, Logarithmic Model This work presents the drying process of apricots and apples which have been considered for drying in a solar-assisted forced convection tray dryer. The logarithmic model has been used to describe the drying behavior of apples and apricots at different air temperatures (50 °C to 80 °C) and at different air velocities (0.5 m/s to 2 m/s) based on experimental data from several studies. The slice thickness of apples has been assumed at 10 mm with initial moisture content 87 % d. b; the main diameter of apricots was 40 mm with initial moisture content 80 % d. b. The changes in moisture content with drying time during the drying period have been presented indicating the absence of the constant rate period. In addition, drying air flow rates and temperatures had an important effect on the drying time and on the moisture removal from apricots and apples. Finally, the effective moisture diffusivity values have been estimated from Fick’s diffusion model pointing out that it has been increased with the increase of the drying air temperature. Journal of Thermal Engineering Journal of Thermal Engineering 2017-12-11T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2495 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2495 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2495

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2493 2017-12-11T21:00:00Z 1

Receiver Temperature Maps of Parabolic Collector Used for Solar Food Cooking Application in Algeria F. Yettou, A. Gama, N.L. Panwar, B. Azoui, A. Malek Solar Radiation, Parabolic Solar Cooker, Temperature Maps, Food Cooking Knowledge of solar residential device’s thermal performance is necessary in order to optimize their output. This requires a database of solar radiation for locations for which the system is being installed. In this regard, temperature maps are generated for a realized parabolic solar cooker using an improved solar radiation model for 48 cities in Algeria. The maps are drawn for two cases: clear and cloud skies in winter and summer seasons, which allow comparison between cooker performances. The developed approach consists in converting obtained results from optical simulation to thermal values based on Stefan-Boltzmann law. Experimental data for receiver temperatures and solar radiation measured at Ghardaîa city in January month were used for the validation. It was found that cooker temperature values obtained from the measurements and that estimated using the proposed approach were in good agreement. The mapping results indicate that the realized cooker is efficient in all the country throughout the summer season with temperatures exceeding 110 °C. The use of the cooker will be reduced by going in South to North regions during the winter months, depending on the amount of solar radiations received. Nevertheless, the major area of the country is favorable for the use of the cooker during this period of the year even when the sky remains cloud. Journal of Thermal Engineering Journal of Thermal Engineering 2017-12-11T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2493 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2493 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2493

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2498 2017-12-16T21:00:00Z 1

Natural Convection of a Nanofluid in a Conical Container Brahim Mahfoud, Ali Bendjaghloli Heat Source , Truncated Cone, Nanofluid, Natural Convection Natural convection is simulated in a truncated cone filled with Cu-water nanofluid, pure water is considered as the base fluid with Pr=6.2 and (Cu) is the nanoparticle . Inclined and top walls have constant temperature where the heat source is located on the bottom wall of the conical container which is thermally insulated. A finite volume approach is used to solve the governing equations using the SIMPLE algorithm for different parameters such as Rayleigh number (103, 104, 105 and 106), inclination angle of inclined walls of the enclosure and heat source length (0.3L, 0.7L and L). The results showed an enhancement in cooling system by using a nanofluid, when conduction regime is assisted. The inclination angle of inclined sidewall and heat source length affect the heat transfer rate and the maximum temperature. Journal of Thermal Engineering Journal of Thermal Engineering 2017-12-16T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2498 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2498 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2498

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2448 2017-07-20T21:00:00Z 1

Performance Indices of Soft Computing Models to Predict the Heat Load of Buildings in Terms of Architectural Indicators Cihan Turhan, Tuğçe Kazanasmaz, Gülden Gökçen Akkurt heat load, residential buildings, ANN, fuzzy logic, ANFIS, soft computing This study estimates the heat load of buildings in Izmir/Turkey by three soft computing (SC) methods; Artificial Neural Networks (ANNs), Fuzzy Logic (FL) and Adaptive Neuro-based Fuzzy Inference System (ANFIS) and compares their prediction indices. Obtaining knowledge about what the heat load of buildings would be in architectural design stage is necessary to forecast the building performance and take precautions against any possible failure. The best accuracy and prediction power of novel soft computing techniques would assist the practical way of this process. For this purpose, four inputs, namely, wall overall heat transfer coefficient, building area/ volume ratio, total external surface area and total window area/total external surface area ratio were employed in each model of this study. The predicted heat load is evaluated comparatively using simulation outputs. The ANN model estimated the heat load of the case apartments with a rate of 97.7% and the MAPE of 5.06%; while these ratios are 98.6% and 3.56% in Mamdani fuzzy inference systems (FL); 99.0% and 2.43% in ANFIS. When these values were compared, it was found that the ANFIS model has become the best learning technique among the others and can be applicable in building energy performance studies. Journal of Thermal Engineering Journal of Thermal Engineering 2017-07-20T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2448 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2448 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2448

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2555 2018-03-21T21:00:00Z 1

Analysis of Vapour Compressıon Refrigeration (VCR) Based Air Conditioning (AC) System for Hot and Dry Climatic Conditions in Oman Muthuraman S., Sivaraj M. Evaporative Cooler, VCR System, Cooling Load, Humidifying Efficiency, Conditioned Space An evaporative-VCR combined air conditioning system for providing good human comfort conditions working under hot & dry climate is proposed in this paper. The proposed system is thermodynamically analyzed for hot & dry climate of Muscat, Oman under some reasonable assumptions. Analysis was done on various parameters for the data from April-July2015Muscat, provided by Oman meteorological department, Muscat. The proposed system was also compared on the basis of saving (%) in cooling load on the cooling coil for the same sensible cooling rate to the conditioned space from the conventional vapour compression air conditioner working on 100 % fresh air assumption. The saving of cooling load on the coil was found maximum with a value of 64.19 % in the month of April due to lower outside temperature and it is minimum for the month of June with a value of 27.36 % due to higher outside temperature. Saving in the month of July is -51.21% due to higher relative humidity. Negative sign indicates that proposed system is only for hot & dry climate & worked well from April-June. Reasons that lead to the variations of curve in the graph have been explained in detail. The proposed system can be made more energy efficient by utilizing the exhaust air in cooling the condenser of VCR system which will improve the COP & hence reduce the power consumption of the compressor. Journal of Thermal Engineering Journal of Thermal Engineering 2018-03-21T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2555 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2555 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2555

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2500 2017-12-19T21:00:00Z 1

Heat Transfer Characteristics of Propylene Glycol/Water Based Magnesium Oxide Nanofluid Flowing through Straight Tubes and Helical Coils Parminder Singh, Puja Sharma, Ritu Gupta, R.K. Wanchoo Magnesium Oxide, Straight Tube, Helical Coil, Convective Heat Transfer Coefficient, Constant Wall Temperature, Nusselt Number Forced convective heat transfer studies on glycol based magnesium oxide nanofluids flowing through straight tubes and helical coils under laminar flow and constant wall temperature conditions have been conducted. Propylene glycol – water mixture (60:40 by wt.%) was used as the base fluid and nanofluids with MgO nano- particle volume concentration of 0.66% and 0.3% were used as the working fluids. Results showed that the convective heat transfer coefficient of nanofluid was higher than that of the base fluid for both straight tubes and helical coils. In straight tube, Nusselt number enhancement was 20% w.r.t. base fluid and it increased to 29% with increase in Peclet number from 44000 to 111400 for nanofluid having volume concentration of 0.66%.While in helical coils, maximum enhancement in experimental Nusselt number was found to be 19.5% and 23% at volume concentration of 0.3% and 0.66 % respectively for a curvature ratio of 0.0727 corresponding to a Dean number of 490.Two new correlations have been proposed to predict the heat transfer coefficient of magnesium oxide nanofluid flowing under laminar conditions through straight tube and helical coils. Journal of Thermal Engineering Journal of Thermal Engineering 2017-12-19T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2500 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2500 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2500

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2499 2017-12-16T21:00:00Z 1

Performance Analysis of R22 and its Substitutes in Air Conditioners Suneel Kalla, Bharat Arora, Jamshed Usmani Refrigerant; Energy; Cycle-D; Vapour Compression; Exergy The aim of this paper is to evaluate the performance of refrigerants R22, R407C, R432A, R438A and NM1 (R32/R125/R600a) in order to find a suitable alternative refrigerant for HCFC 22. For this purpose energy as well as exergy analysis has been performed using NIST Cycle-D program for vapour compression refrigeration cycle design and TEWI (total equivalent warming impact) has also been computed for these refrigerants. From the analysis it is found that the values of COP were nearer to those of R-22, e.g. at 25, 45 and 55 °C condensing temperature, COP of R432a is lower than that of R22 by about 5.5%, 4% and 4.38% respectively. The results show that by considering the energetic efficiency, exergetic efficiency, TEWI and flammability simultaneously, R438A proves to be a better option to replace R22. Journal of Thermal Engineering Journal of Thermal Engineering 2017-12-16T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2499 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2499 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2499

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2582 2018-03-27T21:00:00Z 1

Alternative Refrigerants for HCFC 22—A Review Suneel Kalla, Bharat Arora, Jamshed Usmani HCFC, R22, Refrigerant, Alternative, HFC, HC, TEWI The aim of this paper is to determine the best available alternative which could replace existing refrigerant R22, with minimum or no changes in the air conditioning system. For this purpose, both the theoretical as well as experimental studies done in this area of research have been reviewed. The most popular HFC, R410A is having lower critical temperature, which restricts its usage in compression based systems working at higher condensing temperatures whereas for R407C, a change to synthetic lubricant is required and HC-290 is flammable. It is suggested that until the safety issue of use of hydrocarbon refrigerants in quantities exceeding 500gm is resolved, we should go for those mixtures of HFCs and HCs for which TEWI index is the lowest. Journal of Thermal Engineering Journal of Thermal Engineering 2018-03-27T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2582 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2582 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2582

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2558 2018-03-25T21:00:00Z 1

The Numerical Study of Heat Transfer Enhancement Using Al2O3-Water Nanofluid in Corrugated Duct Application Nehir Tokgöz, Erdem Alıç, Önder Kaşka, Muhammed Murat AKSOY Channel Flow, Corrugated Duct, Heat Transfer Enhancement, Nanofluid Heat transfer enhancement in channel flow is investigated in the present study by using corrugated duct in lieu of smooth duct. In this regard, periodic different cavities are applied on the duct walls using the same aspect ratios. The values of the Reynolds numbers are in the range of 10,000 ≤ Re ≤ 20,000. The effects of the alumina-water nanofluid flow on the corrugated ducts are alternatively investigated by using the constant nanoparticle size for further improvement of the thermal characteristics. Computations are performed by means of finite volume approach on three different corrugated shapes. The effects of various parameters on the heat and fluid flow are also studied. The obtained results have revealed that the application of corrugated duct increases the rate of turbulent intensity on the central axis of the duct. In addition, it is found that the rate of heat transfer changes as a result of corrugated shape and Reynolds number. Furthermore, it is demonstrated that the application of the alumina-water flow in such ducts enhances the rate of the heat transfer and thermal performance when compared with the water flow. It is hoped that the obtained results will arouse interest towards thermal design. Journal of Thermal Engineering Journal of Thermal Engineering 2018-03-25T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2558 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2558 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2558

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2449 2017-07-20T21:00:00Z 1

Chemical and Thermal Investigations of Electrospun Polyacrylonitrile (PAN) Nanofibers Incorporated with Various Nanoscale Inclusions Ramazan Asmatulu, Waseem Khan, Muhamet Ceylan, Amir Jabarrania, Leyla Saeednia Electrospun Nanocomposite Fibers, MWCNTs, Graphene, Thermal Analysis, Properties Thermal behaviors of electrospun polyacronitrile (PAN) fibers incorporated with graphene nanoplatelets and multiwall carbon nanotubes (MWCNTs) were evaluated using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) techniques. DSC was used to determine the glass transition temperature (Tg), melting temperature (Tm) and heat flow of the polymeric fibers, while TGA was used to determine the stages of thermal breakdown, weight loss in each stage, thermal stability, and threshold temperatures. Glass transition temperature is an especially important property during the processing of polymers, applications, and storage. Pure PAN fiber has a Tg of 104.09?C; however, in the presence of 2 and 4 wt% of graphene in PAN fibers, Tg values were increased to 105.07?C and 105.75?C, respectively, and then decreased to 102.82?C at 8 wt% of graphene. Similarly, Tg values of PAN fibers were increased to 105.08?C and 108.19?C in the presence of 2 and 4 wt% of MWCNTs, and then decreased to 104.98?C at 8 wt% MWCNTs. The TGA curves of pure PAN and PAN fibers with different weight percentages of graphene nanoplatelets and MWCNTs exhibited a four-step weight loss. In FTIR spectra, the intensities between 2,400 and 2,200 cm-1 for all samples of PAN having different weight percentages of MWCNTs and graphene nanoplatelets corresponded to the C?N band for saturated nitrile groups. Journal of Thermal Engineering Journal of Thermal Engineering 2017-07-20T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2449 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2449 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2449

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2633 2018-06-28T21:00:00Z 1

Variable Capacity Absorption Cooling System Performance for Building Application Yatheshth Anand, Ankush Gupta, Sudhir Tyagi, Sanjeev Anand Absorption Refrigeration System, Coefficient of Performance, Exergy Analysis, Exergy Efficiency, Solar heat The increasing energy costs and the environmental awareness call for a shift towards some interesting energy alternatives preferably the use of renewable energy. The present study investigates the impact of varying cooling capacity and other operating parameters in a single-effect absorption refrigeration system, using the concept of energy and exergy as a building heating/cooling alternative. The solar heat is used as an input to the generator. The results obtained from investigation revealed that variation in cooling capacity influences coefficient of performance (COP), exergy loss in different components as well as exergy efficiency. The values of COPcooling and COPheating lies in the range of 0.71-0.89 and 1.71-1.89 respectively for variations in cooling capacities ranging from 1 TR to 20 TR at maximum generator temperature of 80oC. However, exergy efficiency of the system lies in the range of 0.32-0.41 for same variation in cooling capacities. It has also been established that an increase in evaporator temperature and at maximum cooling capacity both COPcooling and COPheating shows an increasing trend. The exergy efficiency also shows maximum value at the highest cooling capacity at a particular evaporator temperature which further with an increase in evaporator temperature shows a decreasing trend. The irreversibility behavior in all the components i.e., solution heat exchanger, absorber, generator, evaporator and condenser shows an expected trend with the variation in cooling capacity. Hence, use of the above mentioned system as a heating and/or cooling alternative for buildings is suggested. Journal of Thermal Engineering Journal of Thermal Engineering 2018-06-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2633 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2633 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2633

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2415 2017-06-06T21:00:00Z 1

A Nonlinear Constitutive Theory for Deviatoric Cauchy Stress Tensor for Incrompressible Viscous Fluids K.S. Surana, A.D. Joy, S.R. Kedari, D. Nunez, J.N. Reddy, S. Wongwises Nonlinear constitutive theory, viscous fluid, Eulerian description, generators and invariants, entropy inequality, integrity Newton’s law of visocosity is a commonly used constitutive theory for deviatoric Cauchy stress tensor. In this constitutive theory originally constructed based on experimental observation, the deviatoric Cauchy stress is proportional to the symmetric part of the velocity gradient tensor. The constant of proportionality is the viscosity of the fluid. For all continuous media if the deforming matter is in thermodynamic equilibrium then all constitutive theories including those considered here must satisfy conservation and balance laws. It is well known that only the second law of thermodynamics provides possible conditions or mechanisms for deriving constitutive theories. The constitutive theory for deviatoric stress tensor used here can be shown to be a simplified form of the constitutive theory derived using conditions resulting from the entropy inequality in conjunction with the theory of generators and invariants that contains up to fifth degree terms in the components of the symmetric part of the velocity gradient tensor. In general the constitutive theory for deviatoric stress tensor is basis (covariant, contravariant, or Jaumann) dependent as it uses convected time derivatives of the Green and Almansi strain tensors of orders higher than one. However, the first convected time derivative of the Green and Almansi strain tensors are in fact symmetric part of the velocity gradient tensor which is basis independent. Thus, if the constitutive theory for deviatoric Cauchy stress tensor is only dependent on the symmetric part of the velocity gradient tensor, then it is basis independent. This is the case for the theory presented in this paper. In this paper we limit the constitutive theory for deviatoric Cauchy stress tensor to contain only up to quadratic terms in the components of the symmetric part of the velocity gradient tensor. The objective is to study the resulting flow physics due to the constitutive theory for deviatoric Cauchy stress tensor that contains up to quadratic terms in the velocity gradient tensor. Model problems consisting of fully developed flow between parallel plates, square liddriven cavity, and asymmetric sudden expansion are used to present numerical solutions. Numerical solutions of the model problems are calculated using least squares finite element formulation based on residual functional in which the local approximations are considered in higher order scalar product spaces that permit higher order global differentiability solutions. Journal of Thermal Engineering Journal of Thermal Engineering 2017-06-06T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2415 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2415 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2415

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2490 2017-11-26T21:00:00Z 1

A Nonlinear Constitutive Theory for Heat Conduction in Lagrangian Description Based on Integrity K. S. Surana, A. D. Joy, S. R. Kedari, D. Nunez, J. N. Reddy, A. S. Dalkilic Nonlinear heat conduction, solid continua, Lagrangian description, generators and invariants, entropy inequality, integrity, temperature gradient If the deforming matter is to be in thermodynamic equilibrium, then all constitutive theories, including those for heat vector, must satisfy conservation and balance laws. It is well known that only the second law of thermodynamics provides possible conditions or mechanisms for deriving constitutive theories, but the constitutive theories so derived also must not violate other conservation and balance laws. In the work presented here constitutive theories for heat vector in Lagrangian description are derived (i) strictly using the conditions resulting from the entropy inequality and (ii) using theory of generators and invariants in conjunction with the conditions resulting from the entropy inequality. Both theories are used in the energy equation to construct a mathematical model in R 1 that is utilized to present numerical studies using p-version least squares finite element method based on residual functional in which the local approximations are considered in higher order scalar product spaces that permit higher order global differentiability approximations. The constitutive theory for heat vector resulting from the theory of generators and invariants contains up to cubic powers of temperature gradients and is based on integrity, hence complete. The constitutive theory in approach (i) is linear in temperature gradient, standard Fourier heat conduction law, and shown to be subset of the constitutive theory for heat vector resulting from the theory of generators and invariants. Journal of Thermal Engineering Journal of Thermal Engineering 2017-11-26T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2490 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2490 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2490

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2483 2017-11-14T21:00:00Z 1

RANS Numerical Simulation of Lean Premixed Bluff Body Stabilized Combustor: Comparison of Turbulence Models A.F. Sudarma, A. Al-Witry, M.H. Morsy Combustion modeling, bluff-body flame stabilizer, k-ε turbulence model, Reynolds-stress model Many gas turbine combustors use bluff-body flameholders to enhance mixing and maintain flame stabilization inside the combustor. Computational Fluid Dynamics (CFD) can greatly help in the design and development of gas turbine combustors. In this regard, CFD analyses using k-? and Reynold Stress Model (RSM) approaches are being evaluated through simulating the combustion processes inside a bluff body stabilized gas turbine combustor where a mixture of lean premixed methane-air are burnt. The numerical study is performed under a steady state condition utilizing the commercial software ANSYS-FLUENT. The simulated results are compared with available experimental data as well as published simulation results found in the literature. The results are presented and compared in terms of velocity fields, temperature profiles and species distributions. The results show that both adopted turbulence models k-? and RSM reasonably made a well predictions of the combustion process with such kind of combustor, especially k-? turbulence model. Journal of Thermal Engineering Journal of Thermal Engineering 2017-11-14T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2483 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2483 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2483

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2488 2017-11-14T21:00:00Z 1

Sensitivity Analysis of Coal Gasification in Two-Stage Entrained-Flow Gasifier: Syngas and Carbon Conversion Prediction Md Saiful Alam, Agung Tri Wijayanta, Koichi Nakaso, Jun Fukai Sensitivity Analysis, Two-stage Gasifier, Syngas Heating Value, CO2-blown The energy production from coal-fired power plant is increasing day by day, which result in increased CO2 emission from the existing power plant. However, CO2 emission from coal gasification can be reduced if an efficient CO2/O2/N2 coal gasification is implemented in IGCC system. Numerical simulations of coal gasification under CO2/O2/N2 gasification condition are carried out with the aim of describing the effects of model parameters, char reaction rates, operating conditions and heat losses to increase the syngas heating value and carbon conversion in a two stage entrained flow coal gasification process. The Eulerian–Lagrangian approach is applied to solve the Navier–Stokes equation and the particle dynamics. Finite rate/eddy dissipation model is used to calculate the rate of nine homogeneous gas-to-gas phase reactions. While only finite rate is used for the heterogeneous solid-to-gas phase reactions. It is found that the carbon conversions of combustor coal lie in the ranges from 97 wt% to 99 wt% for most of the calculated conditions. On the other hand, the carbon conversion of reductor coals varies from 45 wt% to 57 wt%. A noticeable change is obtained when the gasification occurs under a high-temperature condition. Remarkable outlet results of about 32 wt% CO, 0.58 wt% H2 and 89 wt% overall carbon conversion are predicted if a high temperature of 1673K is maintained in the reductor. On the other hand, a reduced soot concentration is predicted if the O2 concentration and/or the reductor gas temperature increase(s) in the gasifier. Journal of Thermal Engineering Journal of Thermal Engineering 2017-11-14T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2488 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2488 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2488

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2489 2017-11-14T21:00:00Z 1

Study of Axisymmetric Nature in 3-D Swirling Flow in a Cylindrical Annulus with a Top Rotating Lid under the Influence of Axial Temperature Gradient or Axial Magnetic Field Subas Dash, Navtej Singh Three Dimensional, Swirling Flows, Magneto Hydrodynamics, Stratified Flow, Incompressible Fluid The three dimensional swirling flow has been obtained by solving Navier Stokes equations, expressed in cylindrical coordinate system, using finite difference technique on a staggered grid. An explicit finite difference method using pressure correction technique, for the solution of Navier-Stokes has been implemented to solve three dimensional flows. Present study explores the 3-D axisymmetric nature of stratified swirling flow and vortex breakdown in a cylindrical annulus cavity with top rotating lid. The annulus is obtained by inserting a thin coaxial rod in cylindrical cavity. This rod may be stationary or rotating depending on the particular study. Three dimensional swirling flows in annuli have also been studied subjected to axial temperature gradient or under the influence of axial magnetic field. Influence of governing parameters Re, Ri and Ha on the overall heat transfer has been investigated through variation of the average Nusselt number with these parameters. Further, the present numerical results are shown to be in good agreement with the available benchmark solutions under the limiting conditions. Journal of Thermal Engineering Journal of Thermal Engineering 2017-11-14T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2489 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2489 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2489

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2413 2017-05-15T21:00:00Z 1

The Effects of Coolant Pipe Geometry and Flow Conditions on Turbine Blade Film Cooling Muhammad Akbar, Bashir Alsaidi, Roger Painter, Lonnie Sharpe, Mostafa Ghiaasiaan Numerical study; gas turbine blade; counter rotating vortex pairs; recirculation zone; flow hydrodynamics; film cooling effectiveness The performance of gas turbine engines can be improved by increasing the inlet gas temperature. Turbine blades can be damaged by high gas temperature, unless additional cooling mechanisms are incorporated to maintain the blades below an acceptable temperature limit. Film cooling techniques are often used to cool the blades to avoid damages. The performance of film cooling depends on several parameters, however. In this paper past research on film cooling is reviewed and areas in need of further investigation are identified. Computational fluid dynamics (CFD) simulations are then conducted on the widely-used single-hole film cooling arrangements in which coolant jets are injected into air flows inside a straight channel before issuing onto the blades. Cooling pipe-blade configurations and flow conditions are varied and the resulting flow hydrodynamics are examined. Counter rotating vortex pairs (CRVPs) formed in the flow strongly influence the film cooling performance. Small coolant inclination angles, exit holes enlargement in span wise direction, higher injected fluid density, and higher injected-ambient fluid velocity ratios are all found to maintain the CRVPs away from each other and close to wall - both of which promote cooling. Pipe curvature can be used for enhancing cooling by exploiting the centrifugal force effect. Journal of Thermal Engineering Journal of Thermal Engineering 2017-05-15T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2413 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2413 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2413

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2553 2018-03-21T21:00:00Z 1

Aerothermal Optimization of Squealer Geometry in Axial Flow Turbines Using Genetic Algorithm Kaan Deveci, Hıdır Maral, Cem Berk Şenel, Emre Alpman, Levent Kavurmacıoğlu, Cengiz Camcı Multi-objective Optimization, Squealer, Tip Leakage Flow In turbomachines, a tip gap is required in order to allow the relative motion of the blade and to prevent the blade tip surface from rubbing. This gap which lay out between the blade tip surface and the casing, results in fluid leakage due to the pressure difference between the pressure side and the suction side of the blade. The tip leakage flow causes almost one third of the aerodynamic loss and unsteady thermal loads over the blade tip. Previous experimental and numerical studies revealed that the squealer blade tip arrangements are one of the effective solutions in increasing the aerothermal performance of the axial flow turbines. In this paper the tip leakage flow is examined and optimized with the squealer geometry as a means to control those losses related with the tip clearance. The squealer height and width have been selected as design parameters and the corresponding computational domain was obtained parametrically. Numerical experiments with such parametrically generated multizone structured grid topologies paved the way for the aerothermal optimization of the high pressure turbine blade tip region. Flow within the linear cascade model has been numerically simulated by solving Reynolds Averaged Navier-Stokes (RANS) equations in order to produce a database. For the numerical validation a well-known test case, Durham cascade is investigated in end wall profiling studies has been used. Sixteen different squealer tip geometries have been modeled parametrically and their performance have been compared in terms of both aerodynamic loss and convective heat transfer coefficient at blade tip. Also, these two values have been introduced as objective functions in the optimization studies. A state of the art multi-objective optimization algorithm, NSGA-II, coupled with an Artificial Neural Network is used to obtain the optimized squealer blade tip geometries for reduced aerodynamic loss and minimum heat transfer coefficient. Optimization results are verified using CFD. Journal of Thermal Engineering Journal of Thermal Engineering 2018-03-21T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2553 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2553 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2553

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2450 2017-07-20T21:00:00Z 1

Performance Map Measurement, Zero-Dimensional Modelling and Vibration Analysis of a Single Cylinder Diesel Engine Daniyal Khan, Zafer Gül Single-cylinder, Diesel Engines, Zero-dimensional Model, Combustion Analysis, Engine Maps, Vibration Analysis Single Cylinder Diesel Engines are simple and very economical in manufacturing. Their multipurpose usability and the capability to deliver the maximum power possible within a given envelope makes them very demanding engines in the market. Simulation tools are widely used nowadays to minimize the energy and time needed for a real engine design and development. Zero-dimensional models are very suitable and reliable to observe the engine operation under different conditions. Contrary to the previous studies, this paper presents a comparison between the practical and simulation model data of a single cylinder Diesel Engine. The purpose of this research was to investigate the fundamental variations between the simulation and experimental results with the help of characteristic engine performance maps. Experiments were conducted on a practical 1.16 L Diesel Engine under variable conditions which were then repeated on the simulation model to analyze and evaluate the differences between the obtained results. Zero-dimensional modelling was performed using GT-Power, a powerful commercial engine simulation software. This study also involved the prediction of optimum speed (RPM) of the engine by performing a vibration analysis using a wireless accelerometer. The maximum torque of the 1.16 L Erin Engine is given to be 80 Nm @ 1,800 RPM, while the simulation model indicated it to be 78 Nm at the same RPM value. Likewise, maximum power output was indicated to be 18 kW @ 2,400 RPM, while the experimental results showed it to be 15 kW @ 2,400 RPM. These results laid down a liable basis for the prediction of several operating parameters of the engine which could act as a solid rung for further studies on this subject. Journal of Thermal Engineering Journal of Thermal Engineering 2017-07-20T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2450 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2450 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2450

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2451 2017-07-20T21:00:00Z 1

Optimization Study of the Operating Conditions to Improve the Quality of Surfaces Coating Obtained by Plasma Spraying Process R. Djebali, A. Hleli, A. Lamari, M.A. Abbassi, B. Pateyron Plasma spraying, thin coatings, deposit quality, Sommerfeld number, Taguchi experimental design. In the present paper we aim to present a numerical optimizing study on the operating conditions of an atmospheric plasma spraying process. The focus is mainly made on the powder injection parameters and the objective is to improve the quality of surface coatings. First, a ‘validation’ test of the Jets&Poudres code is conducted based on various numerical and experimental former works. The results of the Jets & Powders code seem to be a good compromise between the results of different numerical methods and the experimental measurements. Second, a Taguchi experimental design is conducted to explore the influence parts for five operating parameters in the spraying process. This, results in a primary gas flow rate of 45 SL/min, the spray distance of 12 cm, a particle size around 55µm, a powder feed rate ranging close to 1 l/min and finally an electric power of about 25 kW. Finally, a test case for a ternary gas mixture is conducted on 15000 particles using the Jets&Poudres code to assess the conclusions drawn in the studies using the experimental design. The results are confronted together and discussed. Journal of Thermal Engineering Journal of Thermal Engineering 2017-07-20T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2451 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2451 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2451

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2583 2018-03-30T21:00:00Z 1

Effects of Heater Dimensions on Nanofluid Natural Convection in a Heated Incinerator Shaped Cavity Containing a Heated Block Mohamed Ammar Abbassi, Djebali Ridha, Guedri Kamel Heat transfer, incinerator geometry, Lattice Boltzmann Method, Natural convection, Nanofluid The present work reports a numerical study of natural convection in an incinerator shaped enclosure with a localized heated source situated at the bottom. Lattice Boltzmann Method (LBM) is used to simulate nanofluid (water-Al2O3) flow and heat transfer. Simulations have been carried out for the pertinent parameters: Rayleigh number (Ra=103-106), solid volume fraction relative heat source high ( ), relative heat source width ( ), and inclination angle of the incinerator ( ). The comparison of the obtained results is in excellent agreement with results from literature. It may be noted that the Rayleigh number, the solid volume fraction, the heat source tallness enhances the heat transfer and influences the flow pattern and the thermal structures. However for the relative heat source width plays opposite role for values superior to 0.4. Journal of Thermal Engineering Journal of Thermal Engineering 2018-03-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2583 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2583 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2583

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2554 2018-03-21T21:00:00Z 1

A Numerical Study of Forced Convective Flow in Microchannels Heat Sinks with Periodic Expansion-Constriction Cross Section Abdelkadir Belhadj, Racgid Bouchenafa, Rachid Saim Cooling Systems, Heat Transfer Enhancement, Heat Sink, Microchannels, MEMS, Cross Section This paper aims to study numerically the laminar convective heat transfer of ionized water flow inside rectangular heat sinks with periodic expansion-constriction cross-section; each heat sink consists of parallel microchannels system with 4 mm wide and 0.1 mm deep in constant cross-section segment. Two-dimensional laminar numerical simulations, based on Navier-Stoks equations and energy equation, are obtained under the same boundary conditions for different microchannels. In this study, the heat transfer and pressure drop inside microchannels with cross-section (dimples and triangular cavities) are compared with that of simple smooth microchannel at Reynolds number ranging from 150-1500; an increase in pressure drop of 44% for all microchannels is observed with Reynolds number increasing. The obtained results indicate an enhancement in Nusselt number for all microchannels at all Reynolds with a maximum enhancement of 36%, these enhanced thermal parameters attribute to enhance the heat transfer efficiency of proposed microchannels. Which improve the effect of periodic expansion-constriction cross-section on the heat transfer performance for Micro Electo Mechanical systems (MEMS) cooling phenomena. Journal of Thermal Engineering Journal of Thermal Engineering 2018-03-21T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2554 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2554 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2554

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2581 2018-03-27T21:00:00Z 1

Performance Analysis and Thermodynamic Modeling of a Poly Generation System by Integrating a Multi-Effect-Desalination Thermo-Vapor Compression (MED-TVC) System with a Combined Cooling, Heating and Power (CCHP) System Hadi Ghaebi, Ghader Abbaspour Desalination, CCHP, Gas turbine, MED-TVC, Thermodynamic analysis In the present study, performance analysis of a multi effect distillation with thermos vapor compressor (MED-TVC) desalination system coupled to a combined cooling, heating and power (CCHP) system with gas turbine prime mover has been carried out to cogeneration of cooling, heating, power and potable water. The system incorporates air compressor, combustion chamber, gas turbine, triple pressure heat recovery system generator (HRSG), absorption chiller and MED-TVC. A thermodynamic modeling based on mass and energy balance equations is applied for each component of the integrated system. The engineering equation solver (EES) software was used for modeling. It is found that the efficiency of the integrated system reached to 84% (the efficiency of the gas turbine cycle was 32%). Furthermore, a parametric study has been presented in order to investigate the effects of the operational parameters on the performance of the integrated system. Journal of Thermal Engineering Journal of Thermal Engineering 2018-03-27T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2581 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2581 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2581

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2630 2018-06-27T21:00:00Z 1

Numerical Investigation of Forced Convection of Nanofluid in Microchannels Heat Sinks A. Belhadj, R. Bouchenafa , R. Saim Laminar, Forced convection, Nanofluid; Heat transfer, Microchannels, Al2O3, Nanoparticles This paper presents a numerical study of laminar forced convective flow of nanofluid-based water/Al2O3 in a two-dimensional horizontal microchannel heat sink, the governing equations are solved by using the finite volume method based on simple algorithm. The effect of solid nanoparticles on the heat transfer is investigated after comparing our results with experimental data. The founding results showed that the use of nanofluid has enhanced the heat transfer in comparison with pure fluid, and the increasing of Al2O3 concentration enhances the thermal and dynamic parameters. Nusselt number and friction coefficient have been enhanced with the increasing of Reynolds number. This work contributes to ameliorate the cooling systems by integrating the nanofluids in the next generation of microchannels heat sinks. Journal of Thermal Engineering Journal of Thermal Engineering 2018-06-27T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2630 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2630 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2630

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2688 2018-09-28T21:00:00Z 1

A New Analytical Investigation of Natural Convection of Nanofluids Flow Non-Newtonian between Two Vertical Flat Plates by the Generalized Decomposition Method (GDM) Tabet Ismail, Mohamed Kezzar, Nouredine Nafire, Abdelkader Khanetout Natural Convection, Nanofluids, Analytical Methods, Adomian Generalized Method (GDM) In this research work, a special attention is dedicated to the study of natural convection in a nano fluid - non-Newtonian between two vertical plates. This study is carried out for three types of nano- fluids, i.e. Water-Silver, Oxide Copper-Water and Water Titanium oxide. The mathematical formulation of the proposed problem provided a set of nonlinear ordinary differential equations of the second order strongly coupled. In fact, these equations which characterize the velocity and temperature distributions of the problem studied were solved numerically and analytically; numerically by the Runge -Kutta method of order four, analytically obtained equations must be handled by a new Adomian of decomposition approach named the Adomian generalized method (GDM). The results clearly show the effectiveness, applicability and accuracy of the technique used (GDM). Journal of Thermal Engineering Journal of Thermal Engineering 2018-09-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2688 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2688 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2688

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2524 2018-01-19T21:00:00Z 1

Experimental Investigation on Al6061 Silver Coated Copper Metal Matrix Composite Circular Extended Surfaces Pre and Post Heat Treatment Pavan Konchada, Vinay Pragada, Anil Chintada, Anil Mudunuri Stir Casting, Al 6061, MMC’s, Taguchi Analysis, ANOVA, Heat Dissipation Heat alleviation from surfaces exposed to high heat has been of prominence with the advent of new technologies in the electronic industry. The usage of regular materials and alloys has been used to the hilt and the manufacture of new alloys being slow and with the advent of Metal Matrix Composites, their usage as heat dissipation materials has taken a front row. This is the initiation into developing an MMC of Al6061 with silver coated copper particles to be researched. The usage of Al6061 as a heat sink material and the addition of copper to it to enhance the heat dissipation capability of the material is found to yield encouraging results. This composite when further heat treated yielded even good results that surpassed the usual Al6061 capability of heat augmentation by 39%. Taguchi analysis and ANOVA are performed and a regression equation formulated and its error estimated for various parameters. Journal of Thermal Engineering Journal of Thermal Engineering 2018-01-19T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2524 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2524 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2524

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2522 2018-01-15T21:00:00Z 1

Using of Flow Routing Plate for Cooling of Printed Circuit Boards Burak Kurşun, Mecit Sivrioğlu Flow routing plate, Protruded heat sources, Mixed convection, Horizontal channel Effective cooling of electronic components plays an important role in system design and efficiency. In this study, the effects of using the flow routing plate in cooling printed circuit boards have been investigated. For this purpose, effects of the flow routing plate on the laminar mixed convection heat transfer from protruded heat sources at the side walls of the horizontal channel, were investigated numerically. The air was used as cooling fluid, and protruded heat sources were equipped as rows into the rectangular channel with insulated walls. Numerical investigatings were carried out for different plate inclination angles at different Reynolds and modified Grashof numbers. It is observed that the using of flow routing plate increases the heat transfer at different ratios by comparison to the case without plate and enhances the cooling conditions for all values of parameters in the analyses. The highest heat transfer enhancement occurred at values where Reynolds number (Re) was Re = 1000 and plate inclination angle (?) was ? = 60 °.The results obtained during the numerical analyses are presented in detail in the form of graphics for the row averaged Nusselt number, heater temperatures, velocity vectors, and temperature contours. Journal of Thermal Engineering Journal of Thermal Engineering 2018-01-15T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2522 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2522 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2522

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2456 2017-09-18T21:00:00Z 1

An Experimental Study on Subcooling Process of a Transcritical CO2 Air Conditioning Cycle Working with Microchannel Evaporator Thanhtrung Dang, Kimhang Vo, Chihiep Le, Tronghieu Nguyen CO2 refrigerant, air conditioning system, subcooling, heat transfer, microchannel An experimental study on subcooling process of a transcritical CO2 air conditioning cycle working with microchannel evaporator was done. In this cycle there are two different subcoolers namely S1 and S2 were installed and tested. The experimental data show that the COP of the cycle working with the subcooler S2 is better which is at 7.2. The evaporator pressure, the subcooler pressure, the subcooling temperature and the compressor current corresponding to the above-mentioned COP are 44 bar, 75 bar, 26 ºC, and 2.4 A, respectively. A total comparison between the present study and other literatures was also indicated which confirms that the results gained by the present study look better. Journal of Thermal Engineering Journal of Thermal Engineering 2017-09-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2456 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2456 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2456

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2556 2018-03-21T21:00:00Z 1

Investigation of The Effect of The Primary Nozzle Throat Diameter on The Evaporator Performance of an Ejector Expansion Refrigeration Cycle Candeniz Seçkin Ejector, Ejector expansion refrigeration, constant-pressure ejector, two-phase ejector The present work aims to perform the thermodynamic analysis of an ejector expansion refrigeration cycle (EERC) with a constant-pressure two phase flow ejector and to present the effect of primary nozzle throat diameter on cooling capacity of the EERC. The refrigerant is R134a. In order to achieve these objectives, a computational program is developed using EES software to simulate the system. Mathematical modeling of EERC and applied computational procedure are reported in detail. Operation under critical mode is favorable in ejector operation in terms of high entrainment ratio and enhanced ejector performance. As a result, in this present study, ejector of the refrigeration cycle operates under critical conditions and normal shock occurs at the end of the constant area mixing section. Not an iteration process but Henry and Fauske model is applied to determine the physical properties of the fluid under critical conditions. Journal of Thermal Engineering Journal of Thermal Engineering 2018-03-21T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2556 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2556 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2556

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2452 2017-07-20T21:00:00Z 1

Investigation of Characterization and Composition of Dental Wastes in Samsun City Center S. E. Akkaya, O.N. Ergun Medical waste, Dental waste, Waste characterization, Samsun. As a result of daily activities, besides domestic wastes, many hazardous wastes also come out. These wastes constitute hazards in terms of environment and human health. Taking these potential hazards into account, waste must be disposed of in such a way as not to jeopardize the environment and human health. Looking at the overall hazardous wastes, it appears that dental wastes are a small fraction. Although it is thought to be a trivial part, it is in fact an important waste resource, with poor management, complicated infection risk and even heavy metal output from materials such as amalgam. Therefore waste characterization and composition should be determined to develop appropriate waste management systems. Just as dental residues are found in many countries, management of "medical waste control" is carried out by regulations in Turkey as well. In this study, it was aimed to determine the composition and characterization of dentistry wastes of Samsun city center. For this purpose, wastes of faculty of Dentistry, 2 dental clinics and 2 private dental examinations were taken and studied in two different days. In this study, wastes are classified by type, so that percentage distributions are calculated and quantities are examined. Journal of Thermal Engineering Journal of Thermal Engineering 2017-07-20T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2452 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2452 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2452

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2598 2018-06-12T21:00:00Z 1

Destination Marketing Activities for Sustainable Urban Development (Following the Example of the Town of Pleven) Eva Tsvetanova Destination Marketing, Sustainable Development, Regional Economy This Paper aims to present the specific characteristics of destination marketing as a tool for sustainable urban development; to explore, analyze and assess the cultural tourism potential of the town of Pleven, Bulgaria, and to conceptualize a model of integrated marketing strategy to promote the town of Pleven as a destination for cultural tourism. Journal of Thermal Engineering Journal of Thermal Engineering 2018-06-12T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2598 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2598 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2598

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2749 2018-12-29T21:00:00Z 4

Experimental Investigation of Nano Compressor Oil Effect on the Cooling Performance of a Vapor-Compression Refrigeration System Fatih Selimefendigil, Tansel Bingölbalı Nanoparticle, Refrigeration System, Thermodynamic Analysis, Compressor Oil In this study, cooling performance of a refrigeration system under the effects of nanoparticle (TiO2) addition to the compressor oil (poly alkaline glycol (PAG)) was experimentally investigated. Thermodynamics analysis of the vapor-compression refrigeration system with various nanoparticle volume fractions of TiO2 (between 0.5%, and 1%) added to the compressor oil was performed. R-134a was used as the refrigerant. Two –step method was used to prepare the nano-lubricant for different solid particle volume fractions. It was observed that COP of the refrigeration system enhances with the addition of nanoparticles and it is an increasing function of nanoparticle volume fraction. Journal of Thermal Engineering Journal of Thermal Engineering 2018-12-29T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2749 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2749 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2749

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2631 2018-06-27T21:00:00Z 1

Mathematical Calculation and Experimental Investigation of Expanded Perlite Based Heat Insulation Materials’ Thermal Conductivity Values O.Uluer, M. Aktaş, İ. Karaağaç, G. Durmuş, A. Khanlari, Ü. Ağbulut, D.N. Çelik expanded perlite, heat insulation, thermal conductivity, theoretical models, insulation technology Thermal resistance can be increased by using proper heat insulation materials. Traditional heat insulation materials do not stand all desired properties. Thus, developing new heat insulation materials is very important. In this study, expanded perlite based heat insulation material was developed as an alternative to the traditional insulation materials. The composition of the developed material was designed and prepared using the theoretical thermal conductivity prediction models. The prepared material was molded in a rectangular shape panel. Thermal conductivities of panels were measured experimentally and the results were compared with the calculated results. Also, the results showed that the developed panels can be used for heat insulation applications. On the other hand, the closest model to the experimental results is the parallel model whose average deviation is 4.22% while the farthest model is the Cheng and Vachon model whose average deviation is 12.43%. It is obtained that parallel and series models are generally in good agreement with the experimental results. Nevertheless, it is seen some deviations between experimental and theoretical calculation results. The theoretical prediction models do not include any processing conditions such as molding and curing. It is thought that these deviations have originated because of the missing processing parameters in theoretical prediction models. As a result of experimental studies, the lowest thermal conductivity value of expanded perlite based panels was obtained 43.5 mW/m.K. Consequently, the heat transfer coefficient of the panels containing expanded perlite can be calculated nearly by the parallel method. Journal of Thermal Engineering Journal of Thermal Engineering 2018-06-27T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2631 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2631 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2631

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2634 2018-06-28T21:00:00Z 1

Numerical Investigation of Flow and Heat Transfer in Communicating Converging and Diverging Channels M. Tahir Erdinç, T. Yılmaz Communicating Converging and Diverging Channel, Numerical, Periodic Boundary Condition, Boundary Layer Fluid flow and heat transfer in communicating converging and diverging channel has been numerically investigated. Channels are assumed to be at constant wall temperature and the flow is assumed to be steady state, incompressible. Since the flow and temperature fields to repeat periodically after a certain developing length, periodic boundary conditions are used for the calculations. Finite volume method is used to solve the governing differential equations numerically. Computations are performed for different values of the plate angles and Reynolds numbers. Moreover, velocity distributions along the flow field are illustrated. It was found that the converging- diverging channels destroy the boundary layer significantly and Nusselt number is found to be about 400% higher than those of parallel plate channels, whereas due to vortex formation, pressure drop increases also. Journal of Thermal Engineering Journal of Thermal Engineering 2018-06-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2634 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2634 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2634

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2635 2018-06-28T21:00:00Z 1

Parametric Analysis of Thermal Performance of Ranque-Hilsch Vortex Tube Kiran Devade, Ashok Pise Vortex Tube, Energy Separation, Cold Mass Fraction, Stagnation Point, L/D Ratio, Cold Orifice Diameter Vortex tube separates pressurized fluid into hot and cold fluid streams simultaneously. Geometrical and operational parameters affect this separation. The study deals with experimental investigations of effect of geometrical and operational parameters. L/D ratio (15, 16, 17 and 18), number of nozzles (2, 4 and 6), nozzle geometry (straight and Spiral), divergence angle (0, 2, 3, 4 and 5), valve angles (30 to 90 deg. in steps of 15 deg.) and cold orifice diameter (5, 6 and 7mm) are variables. For all the experiments, air is working fluid. Air is supplied at different pressures ranging from (200 to 600 KPa in steps of 100KPa). CMF variation is in the range from 0 to 1 for all geometries. The effects on energy separation were analyzed with respect to CMF and Mach number. The results are expressed in percentage rise and drop. Similarity relation is developed and results are compared with literature. Journal of Thermal Engineering Journal of Thermal Engineering 2018-06-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2635 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2635 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2635

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2605 2018-06-13T21:00:00Z 1

Thermo-Fluidic Parameters Effects on Nonlinear Vibration of Fluid-Conveying Nanotube Resting on Elastic Foundations Using Homotopy Perturbation Method M. G. Sobamowo, A. A. Yinusa Thermo-Fluidic Effects, Non-Linear Vibration, Slip Boundary Condition, Fluid-Conveying Nanotube, Homotopy Perturbation Method In this paper, effects of thermo-fluidic parameters on the nonlinear dynamic behaviours of single-walled carbon nanotube conveying fluid with slip boundary conditions and resting on linear and nonlinear elastic foundations under external applied tension and global pressure is studied using homotopy perturbation method. From the result, it is observed that increase in the Knudsen number, the slip parameter, leads to decrease in the frequency of vibration and the critical velocity while natural frequency and the critical fluid velocity increase as the in stretching effect increases. Also, as the Knudsen number increases, the bending stiffness of the nanotube decreases and in consequent, the critical continuum flow velocity decreases as the curves shift to the lowest frequency zone. As the change in temperature increases, the natural frequencies and the critical flow velocity of the structure increase for the low or room temperature while at high temperature, increase in temperature change, decreases the natural frequencies and the critical flow velocity of the structure. Further, it is established that the alteration of nonlinear flow-induced frequency from linear frequency is significant as the amplitude, flow velocity and axial tension increase. The developed analytical solutions can be used as starting points for better understanding of the relationship between the physical quantities of the problem. Journal of Thermal Engineering Journal of Thermal Engineering 2018-06-13T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2605 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2605 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2605

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2632 2018-06-27T21:00:00Z 1

Thermal Performance Analysis of Convective-Radiative Fin with Temperature-Dependent Thermal Conductivity in The Presence of Uniform Magnetic Field Using Partial Noether Method M. G. Sobamowo, A. O. Adesina Thermal performance; Convective-radiative fin; Partial Noether method; Temperature-dependent thermal conductivity; Magnetic field In this paper, thermal performance of convective-radiative straight fin with temperature-dependent thermal conductivity in the presence of uniform magnetic field is analyzed using partial Noether method. The exact analytical solution is used to investigate the effects of magnetic field, convective, radiative, thermo-geometric and thermal conductivity (non-linear) parameters on the thermal performance of the fin. The results reveal that as the magnetic, convective and radiative parameters increase, the temperature of the fin decreases rapidly and by implication, the rate of heat transfer through the fin increases. The study provides a platform for comparison of results of any other method of analysis of the problem with the results of the exact analytical solutions in this paper. Also, such an analytical tool is valuable as a design and optimization approach for large scale (not necessarily in size) finned heat exchangers where each fin/row are analytically analyzed and where the surrounding fluid is influenced by a magnetic field. Journal of Thermal Engineering Journal of Thermal Engineering 2018-06-27T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2632 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2632 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2632

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2599 2018-06-12T21:00:00Z 1

Analysis of the Effect of Propellant Temperature on Interior Ballistics Problem Celal Evci, Halil Işık Interior Ballistics, Heat Transfer, Stress Analysis, Experimental Verification This study investigates the effect of conditioning temperature of double base propellants on the interior ballistic parameters such as burning gas temperature, barrel wall temperature, pressure and stresses generated in the barrel. Interior ballistic problem was solved employing experimental, numerical and analytical methods with a thermo-mechanical approach. Double base propellants were conditioned at different temperatures (52, 35, 21, 0, -20, -35, -54ºC). The maximum pressure in the barrel and projectile muzzle velocity were measured for all the propellants by conducting shooting tests with a special test barrel using 7.62x51 mm NATO ammunition. VallierHeydenreich method was employed to determine the transient pressure distribution along the barrel. The temperature of burnt gases was calculated by using Noble-Abel equation. The heat transfer analysis was done using the commercial software ANSYS to get the transient temperature and stress distributions. Temperature distribution through the barrel wall thickness was validated using a FLIR thermal imager. Radial, circumferential and axial stresses and corresponding equivalent Von Misses stresses were determined numerically and analytically. The results of the analytical solution for stress analysis validated the finite element solution of interior ballistic problem. Increasing the initial temperature of the propellant resulted in higher temperature and pressure inside the barrel which in turn increased the stresses in the barrel. Journal of Thermal Engineering Journal of Thermal Engineering 2018-06-12T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2599 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2599 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2599

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2681 2018-09-28T21:00:00Z 1

Comparative Energy and Exergy Analysis of a Power Plant with Super-Critical and Sub-Critical Burhanettin Çetin, Erman Özen Thermal efficiency, Exergy efficiency, Sub-critical power plant, Ultra super-critical power plant The aim of this study that how to effect live steam parameters reheat and feed water preheater numbers on efficiencies of energy and exergy at coal-fired power plants. Moreover, two desuperheaters and a regenerative turbine are added USCPP (Case 3) to approach best results. Soma Power Plant (Case 1) consists of one reheat stage, two HPRHs and four LPRHs with one DEA. It is operated sub-critic and coal is used for a fuel. Live steam conditions of Soma Power Plant set at 13,92 MPa and 540 ?C, and the reheat steam is reheated to 540 ?C. Supercritical Power Plant (Case 2) consists of the same main components of Case 1. However, steam parameters of Case 2 are increased to 262.5 Bar and 600 ?C to determine impact of the steam parameters on power plant efficiencies. USCPP which consists of two reheat stages, four HPRHs, six LPRHs with one DEA is designed to generate live steam under nominal conditions of 30 Bar and 600 ?C. Besides, reheat steam are heated to 620 ?C. Simulations have been carried out Ebsilon Professional software and pressure drops at preheaters and reheats are also considered. Some assumptions are made in the analysis. The thermal and exergy efficiencies of USCPP increase by 9.241 and 8.06 percentage points compared with Soma power plant, respectively. The results of this study that live steam parameters which are increased from sub-critical values to super-critical values have enormous influence on energy and exergy efficiencies. Secondly, adding second reheat stage has positive impact to improve power plant efficiencies. Finally, augmenting feed water preheater number, adding two desuperheater and one regenerative turbine increase power plant efficiencies. However, optimum numbers of feed water preheaters are determined considering economic parameters. Journal of Thermal Engineering Journal of Thermal Engineering 2018-09-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2681 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2681 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2681

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2774 2019-03-13T21:00:00Z 4

Performance Predictions of Air-Cooled Condensers Having Circular and Elliptic Cross-Sections with Artificial Neural Networks Fatih Selimefendigil, Hakan Öztop Refrigeration, Elliptic, Computational Fluid Dynamics, Artificial Neural Network In this study, mathematical models of air cooled condensers with circular and elliptic cross-sections were developed and performances were evaluated with artificial neural networks. Air velocity, orientation angle and ambient temperature were used as the input to the neural network structure while heat transfer rate to the air was used as the output. The data sets were generated from high fidelity, computationally inefficient expensive three dimensional computational fluid dynamics simulations. It was observed that artificial neural network model can be replaced instead of computational fluid dynamics model and based on the mathematical model with artificial neural network, elliptic condensers perform better in terms of heat transfer compared to circular ones. Journal of Thermal Engineering Journal of Thermal Engineering 2019-03-13T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2774 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2774 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2774

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2638 2018-06-29T21:00:00Z 1

Thermodynamic Analysis of Basic and Regenerative Organic Rankine Cycles Using Dry Fluids from Waste Heat Recovery Esra Özdemir, Muhsin Kilic Energy, Exergy, Working Fluid, Organic Rankine Cycle, Regenerative Organic Rankine Cycle The organic Rankine cycle (ORC), which generates electric energy using low temperature heat sources, is a promising technology in energy production sector. The ORC, which uses an organic fluid with its lower boiling point and higher vapour pressure than water-steam as a working fluid. The thermal efficiency of an ORC showes the performance of system, depends on system compenents, working fluid and operating conditions. This paper presents an thermodynamics examination of basic ORC and regenerative ORC for waste heat recovery applications using dry organic fluids. R113, R114, R227ea, R245fa and R600a with the boiling points from -16 oC to 48 oC are selected in the analyses. The relationships between the ORC's performance parameters for basic and regenerative technologies and the properties of working fluids are evaluated based on various turbine inlet pressure values. Results show that regenerative ORC has higher thermal efficiency compared with basic ORC. Also, the thermal efficiency increases with the increment of the turbine inlet pressure for both basic ORC and regenerative ORC. Journal of Thermal Engineering Journal of Thermal Engineering 2018-06-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2638 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2638 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2638

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2557 2018-03-21T21:00:00Z 1

Solar Energy Control and Power Quality Improvement Using Multilayer Feed Forward Neural Network Rachid Dehini, Brahim Berbaoui MLFFN, Photovoltaic cells, MPPT, SAPF, harmonics current Oil, coal and gas continue to be the most demanded source of energy throughout the world along . In recent years, the alarming fall in amounts of fossil fuels and increase in atmospheric carbon dioxide composition have been seen on several occasions. These disadvantages of fossil fuels orientate the researchers toward renewable energy sources as a more durable long-term solution. The aim of this paper is to present a shunt active power filter (PAPF) supplied by the Photovoltaic cells ,in such a way that the (PAPF) feeds the linear and nonlinear loads by harmonics currents and the excess of the energy is injected into the power system. In order to improve the performances of conventional (PAPF) This paper also proposes artificial neural networks (ANN) for harmonics identification and DC link voltage control. The simulation study results of the new (SAPF) identification technique are found quite satisfactory by assuring good filtering characteristics and high system stability. Journal of Thermal Engineering Journal of Thermal Engineering 2018-03-21T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2557 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2557 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2557

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2684 2018-09-28T21:00:00Z 1

A Review of Single-Phase and Two-Phase Pressure Drop Characteristics and Flow Boiling Instabilities in Microchannels Mehmed Rafet Özdemir, Ömer Refik Sözbir Instability, Microchannels, Pressure Drop, Single-Phase Flow, Two-phase Flow This study presents a comprehensive review on single and two-phase pressure drop characteristics and flow boiling instabilities in microchannels to outline the discrepancies in the literature. The effect of mass flux, heat flux, experimental conditions, channel geometrical parameters (hydraulic diameter, aspect ratio etc.) was surveyed critically over a broad range of literature studies including the past and recent researches. Additionally, conventional and micro-scale pressure drop correlations are discussed. This study showed that the continuum theory is applicable for single-phase pressure drop applications with some considerations. Also, the two-phase pressure drop in micro-scale was found to have similar characteristics with conventional-scale channels. On the other hand, flow boiling instability is one of the important issues in microchannel heat exchangers. Flow boiling instabilities affect the system performance and may cause system failures. Therefore, unstable flow boiling conditions were identified in this paper for a reliable design of micro heat exchangers. Journal of Thermal Engineering Journal of Thermal Engineering 2018-09-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2684 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2684 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2684

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2637 2018-06-29T21:00:00Z 1

Exergo-Economic Analysis of Microchannels in Single-Phase Flow Mehmed Rafet Özdemir, Ömer Refik Sözbir, Mustafa Yılmaz Exergo-Economic Performance, Microchannels, Thermo-Economics, Single-Phase Flow With the increase of energy demand, many researchers tried to develop scientific approaches in order to design more efficient and environmentally friendly energy systems. Exergo-economic (thermoeconomic) analysis of a system or device is an efficient tool for evaluating the system in terms of the thermodynamic and economic aspects. In this parametric study, exergo-economic analysis of rectangular copper plain microchannels under single-phase flow conditions were investigated using de-ionised water. The exergo-economic performance was evaluated based on the relative cost difference and unit cost per product exergy tools. The channel aspect ratio effect on the unit cost per product exergy and relative cost difference was examined using three microchannel test sections with the same channel hydraulic diameter (Dh = 0.56 mm) and length (L = 62 mm) but different aspect ratios (ß = 0.5, 2.56 and 4.94) under single-phase flow conditions. The results showed that the exergo-economic performances of the three microchannel test sections decreased as the net heat input increased over the experimental range. Moreover, the exergo-economic performance of test section 2 (ß = 4.94) was found to be greater than the exergo-economic performances of test sections 1 and 3 (ß = 0.5 and 2.56) at fixed flow rate and fixed net heat input case. Journal of Thermal Engineering Journal of Thermal Engineering 2018-06-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2637 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2637 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2637

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2748 2018-12-29T21:00:00Z 4

Participating Media for Volumetric Heat Generation Layth Al-Gebory Participating media, Volumetric heat generation When an electromagnetic wave interacts with participating media (e.g. particulate media); the intensity of the radiation may be changed by the absorption, emission and scattering phenomena. Subsequently, the incident radiation will be attenuated and/or augmented under the effect of these phenomena. Light scattering and absorption by small particles are quite important in a wide range of applications such as meteorology, biomedicine, biophysics, astronomy, combustion, fire and flame, and solar thermal applications. Particulate media have been introduced as a working medium to improve the efficiency of thermal systems such as solar thermal power plants. The efficiency of the direct absorption solar thermal collectors (DASC) can be improved by using particulate media because of the unique thermo-optical properties, which in turn leads to enhance the thermal performance. The main objective of the present study is to investigate the effect of the participating media in the volumetric heat generation under the concept of photo-thermal energy conversion. Journal of Thermal Engineering Journal of Thermal Engineering 2018-12-29T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2748 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2748 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2748

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2478 2017-10-03T21:00:00Z 1

The Micro-Scale Modeling By Experimental Study in PEM Fuel Cell Tolga Taner PEM Fuel Cell; Water Production; Hydrogen Gas; Performance; Energy Efficiency This study posed parameters effects to the PEM fuel cell performance by an experimental work. The aim of this study is to investigate performance effects of PEM fuel cells and to optimize water conditions as well as fuel cell performance. Platinum-plated catalyzed anode performance was demonstrated for the micro-scale modeling by experimental study in PEM fuel cell. Therefore, time dependent voltage and current parameter changes were observed for the performance analysis in the experimental study. PEM fuel cell was enhanced by adjusting the anode plate, air feed pump and hydrogen fuel quantities. This study is to determine about optimizing some parameters (pressure, flow rate, voltage) for the fuel cell performance. The result of this study was found to be 2.62 x 10-7 [kg/s] average of water production and generated 42.5 [kJ] H2 energy. In conclusion, performance efficiency was found to be around 52%. These results demonstrated that water production was also very significant for the PEM fuel cell durability. PEM fuel cell energy efficiency increases while the mass flow is in a certain range and under pressure atmospheric conditions. Journal of Thermal Engineering Journal of Thermal Engineering 2017-10-03T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2478 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2478 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2478

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2743 2018-12-29T21:00:00Z 1

A CFD Investigation of Al2O3/Water Flow in a Duct Having Backward-Facing Step R. Ekiciler, E. Aydeniz, K. Arslan Forced Convection, Nanofluid, Backward-facing Step, Laminar Flow, Diameter of Nanoparticle Al2O3/water forced convection nanofluid flow was numerically studied in a duct with backward-facing step. Nanoparticle volume fraction was changed between 1%-5%. Diameter of nanoparticle was constant (dp=40 nm). The Reynolds number was increased from 100 to 500. The step and total height of the duct were 4.8 mm and 9.6 mm, respectively. The bottom wall, which was positioned after the step, was heated with 2000 W/m2 and the rest of the walls were adiabatic. Nusselt number, velocity profiles and friction factor were investigated in detail. It was obtained that Nusselt number increases with increasing nanoparticle volume fraction and Reynolds number. Journal of Thermal Engineering Journal of Thermal Engineering 2018-12-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2743 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2743 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2743

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2523 2018-01-15T21:00:00Z 1

Microwave Dehydration Modelling of Tincalconite Seyma Çoban, Berker Özkarasu, Fatma Tuğçe Şenberber, Azmi Seyhun Kıpçak, İbrahim Doymaz, Emek Moroydor Derun Tincalconite, Microwave, Dehydration, Modelling, XRD, Raman Boron is known element due to wide range of application areas. Microwave dehydration has more advantages than conventional dehydraion. Differ dehydraion mechanism, higher dehydraion rate and higher level of safety are some of this advantages. Furthermore, most of minerals give better result in microwave for temperature increase. Particle size, microwave power and sample mass are parameters which effect to dehydration directly. Structure of tincalconite is suitable for the investigation of dehydration behavior by microwave because of their five moles of crystal water. Tincalconite is a type of sodium borate mineral which has a white color, trigonal system and molecule formula of Na2B4O7•5H2O. Tincalconite contains 48.8% of boron oxide(B2O3) and 29.47% of structural water. In this study, dehydration behavior of tincalconite was studied with using microwave irradiation with the power level of 180 and 360 W. The kinetic parameters of reaction were determined by using the dehydration kinetic models of Lewis, Henderson and Pabis and Wang and Singh. Tincalconite and dehydrated tincalconite characterized by the techniques of X-ray diffraction (XRD) and Raman spectroscopy. According to the results obtained tincalconite was dehydrated successfully at the microwave power level of 360 W at 14 min, on the contrary at 180 W, only the 68% of the structural water was dehydrated. Among the models, which are applied only at 360 W, Wang and Singh model best fits the data with the coefficient of regression (R2) value of 0.9965. Journal of Thermal Engineering Journal of Thermal Engineering 2018-01-15T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2523 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2523 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2523

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2685 2018-09-28T21:00:00Z 1

Numerical Study of Milk Fouling Thickness in the Channel of Plate Heat Exchanger Amine S. Aouanouk, Abdelkader Mouheb, Rafik Absi Milk Fouling, Plate Heat Exchanger, Modeling Fouling phenomenon remains at the forefront of problems that concern manufacturers using heat exchangers. Despite the large number of studies carried out, the mechanism and the evolution of this phenomenon remain poorly understood. In the dairy industry, fouling is a very important parameter seen as it can affect the quality of food product. Studies carried out on this phenomenon during milk heat treatment have led to the conclusion that ?-lacotglobulin protein is the main precursor of fouling. Indeed, the thermal instability of this protein undergoes chemical reactions generating an aggregate that accumulates on the hot walls of heat exchanger. In this work, an attempt to model, numerically, milk fouling during pasteurization was carried out. Wall temperature and fouling thickness distributions were studied along the channel. This permits to determine a mathematical relationship between fouling thickness, wall temperature, wall longer and time. Journal of Thermal Engineering Journal of Thermal Engineering 2018-09-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2685 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2685 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2685

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2525 2018-01-19T21:00:00Z 1

Investigation of Infrared Drying of Pomegranate By-Products İbrahim Doymaz, Azmi Seyhun Kıpçak Infrared Drying, Pomegranate By-Product, Modelling, Effective Moisture Diffusivity, Activation Energy In the present study, infrared radiation drying, representative of the innovative drying method, was chosen to perform comparative study at different infrared power levels. Infrared drying of pomegranate by-products was dried at 88, 104, 125, 146 and 167 W power levels. The results showed that the infrared power has a significant effect on the drying characteristics of pomegranate by-products. Drying time was reduced from 270 to 60 min as the infrared power level increased from 88 to 167 W. The falling-rate period proved to be the main stage of infrared drying. Three thin-layer drying models (Aghbashlo et al., Jena & Das and Midilli & Kucuk) were fitted to the experimental data. The drying data (moisture ratio versus drying time) were successfully fitted to Aghbashlo et al. model. Fick’s law of diffusion was used to determine the effective moisture diffusivity, which varied between 3.296×10−9 to 1.431×10−8 m2/s. Activation energy was estimated by a modified Arrhenius type equation as 4.424 kW/kg. Journal of Thermal Engineering Journal of Thermal Engineering 2018-01-19T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2525 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2525 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2525

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2744 2018-12-29T21:00:00Z 1

Numerical Simulation of Natural Convection Melting in 2D and 3D Enclosures Mikhail A. Sheremet, Nadezhda Bondareva Natural Convection, Melting, Numerical Analysis, Square and Cubical Cavities Natural convection melting in 2D and 3D enclosures with a local heater is studied numerically. The present research is related to a development of effective cooling system for the electronic devices using the phase change material that is essentially important nowadays. The domain of interest includes vertical cold walls, adiabatic horizontal walls and a discrete heater of constant high temperature located on the bottom adiabatic wall. The cavity is filled with a phase change material (PCM) in solid state at the beginning of the process. During the heating from the heat source PCM is melting. Numerical solution of the present problem has been conducted using the dimensionless transformed variables such as stream function and vorticity for 2D cavity and vector potential functions and vorticity vector for 3D cavity with appropriate initial and boundary conditions. The developed numerical technique has been verified comprehensively. Obtained results have shown a potential of the used methods for 2D and 3D problems. It has been found that, melting process is more intensive in 3D case and the heat transfer rate at the heater is greater for 2D in comparison with 3D data. Journal of Thermal Engineering Journal of Thermal Engineering 2018-12-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2744 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2744 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2744

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2742 2018-12-29T21:00:00Z 1

Numerical Investigation of Effects of Working Conditions on Performance of Pem Fuel Cell Muhammet Ozdogan, Lütfü Namlı, Aydın Durmuş PEM fuel cell; working conditions; three-dimensional analysis In this study, the effects of the working pressure and temperature on the performance of the PEM fuel cell were investigated numerically. Non-isothermal, steady state and single-phase model was used to examine the behaviour of the proton exchange membrane (PEM) fuel cells in the three-dimensional condition. Three-dimensional single-cell model has been developed within FLUENT 6.3 software by utilizing the PEMFC module. The results of polarization (voltage) variation curves and current density distribution were given and compared with each other. According to the results obtained, by keeping humidification and cell temperatures in equilibrium, the performance of the cell improves with increasing the cell temperature. In addition, the current density of the cell increases with increasing operating pressure. Journal of Thermal Engineering Journal of Thermal Engineering 2018-12-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2742 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2742 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2742

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2604 2018-06-13T21:00:00Z 1

A Hybrid Numerical/Experimental Study of the Aerodynamic Noise Prediction Beyza Alkan, Sevket Ozgur Atayılmaz Aeroacoustics, computational fluid dynamics, noise sources, SAS, turbulence An accurate noise prediction is important in order to reduce noise emission significantly and to prevent expensive after-design treatments. This study aims to examine the aerodynamics and aeroacoustics performance of an open system consisting of an axial fan and a heat exchanger where hybrid method incorporating CFD (Computational Fluid Dynamics) and CAA (Computational Aeroacoustics) is used to predict the noise behavior. The hybrid model method used consists of three steps. Firstly, the flow is computed by means of flow-computed fluids and the pressure fluctuations are obtained. This is followed by the acquisition of acoustic signals from these fluctuations and the attainment of a sound pressure level approach with the FW-H (Ffowcs Williams & Hawkings) model. Unsteady flow field of the air channel case was obtained by using different turbulence models. The SAS model is capable of resolving largescale turbulent structures without the time and grid-scale resolution restrictions of LES (Large Eddy Simulations), often allowing the use of existing grids created for URANS simulations. For this reason, two different turbulence models, namely URANS (Unsteady Reynolds Averaged Navier Stokes) model, SAS (Scale Adaptive Simulations) model have been applied. Acoustic sources were computed based on the pressure fluctuations and sound pressure level and frequency dependent graphics were plotted with Fast Fourier Transform. On the other hand, acoustic measurements were performed in a semi-anechoic chamber for both of them. When the experimental and numerical results were compared with the previously determined receiver points, the accuracy rate was obtained as SAS, URANS respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2018-06-13T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2604 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2604 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2604

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2741 2018-12-29T21:00:00Z 4

A Feasibility Study of Solar Energy - Techno Economic Analysis from Aksaray City, Turkey Tolga Taner, Ahmet Selim Dalkilic Renewable Energy, Solar Energy, Techno Economic Analysis, Energy This study posed a feasibility study of solar energy-techno economic analysis that was investigated for 20,000 m2 area of Aksaray city from Turkey. The result of a solar energy radiation production was found to be 1.65 million [kWh/m2 year]. The profit of solar energy plant was determined about 501,825 [$/y]. A simple payback period time was found to be 4.5 [y]. The aim of the study is to indicate building solar energy plant that can be efficiently for Aksaray city. Since a solar energy plant can be a feasible plant for Yapilcan village, Aksaray city that is near the power line local area network. These results figure out very efficient result for building solar energy plant to Yapilcan village, Aksaray city from Turkey. Journal of Thermal Engineering Journal of Thermal Engineering 2018-12-29T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2741 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2741 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2741

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2686 2018-09-28T21:00:00Z 1

The Effect of Blowing Direction on Heat Sink Performance by Thermal Imaging Mesut Abuşka, Seyfi Şevik, Volkan Altıntaş Heat Sink, Performance, Blowing Direction, Conical Pin Fin Heat sinks (HSs) are designed for the mechanical, electrical and electronic components that generate heat in considerable amount. For this purpose, an aluminum conical pin fin heat sink is designed. Aluminum conical pin-fins geometry has been experimentally investigated for the blowing direction (pushing or pulling) which is the energy efficient option for the heat sink. The heat sink was tested at the same fan power for pushing and pulling conditions for 25, 50, 75 and 100 W resistance heater power. Designed aluminum conical pin fin heat sink can be easily used in heat sweeping processes. It has found that pushing configuration of the fan is more efficient for this design. Journal of Thermal Engineering Journal of Thermal Engineering 2018-09-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2686 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2686 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2686

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2484 2017-11-14T21:00:00Z 1

Thermodynamic Analsysis of a Fluidized Bed Coal Combustor Steam Plant in a Textile Industry Atakan Tantekin, N. Filiz Özdil Energy, Exergy, Fluidized Bed The examinations of first and second laws of thermodynamics are performed on a 6.5 MW power plant, established in Adana, Turkey. The equipment for the investigated plant can be aligned as a fluidized bed coal combustor (FBCC), a heat recovery steam generator (HRSG), an economizer (ECO), fans, pumps, a cyclone and a chimney. Whole parts of equipment are investigated separately and energetic and exergetic inspections are enforced for whole parts of the plant. The maximum exergy destruction rates in the plant are obtained for the FBCC, HRSG and ECO with 95%, 3% and 1% of the whole system, respectively. Higher excess air in the system induces heat losses, especially in the FBCC component by virtue of the rising in mass flow rate of the flue gas. This situation can be considered as one of the primary reasons of irreversibility. Additionally, higher excess air induces the decrement of combustion efficiency in FBCC. Therefore, this value and adverse effects on combustion efficiency can be decreased by reducing the flow rate of air. Journal of Thermal Engineering Journal of Thermal Engineering 2017-11-14T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2484 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2484 Journal of Thermal Engineering, Year:2017, Vol:3, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2484

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2527 2018-01-21T21:00:00Z 1

Performance Assessment of a Cogeneration System in Food Industry N. Filiz Özdil, Atakan Tantekin, Arzu Pekdur Cogeneration, Energy, Exergy, Thermodynamic Analysis, Food Industry. Extensive analysis of the thermodynamics first and second laws is performed on a 14.25 MW cogeneration plant in Adana, Turkey. In this study, thermodynamic performance assessments are evaluated for the most important parts of the system. The obtained outcomes indicate that major exergy destruction happens in boiler, which is 42% of the whole system irreversibility. Moreover, the economizer and chimney have also considerable irreversibilities which are 29% and 25%, respectively. The energy efficiencies of the chimney, economizer and boiler are calculated as 61.68%, 66.03%, 79.91%, respectively. On the other hand, the exergy efficiencies of chimney, economizer and boiler are calculated as 96.56%, 30.27% and 71.94%, respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2018-01-21T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2527 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2527 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2527

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2747 2018-12-29T21:00:00Z 1

Analytical Decomposition Solutions for Heat tranfer on Straight Fins with Temperature Dependent Thermal Conductivity and Internal Heat Generation Akinbowale Akinshilo Fins, Temperature Dependent Viscosities, Convection, Heat Generation, Adomian Decomposition Method This paper analyses heat transfer across straight convecting fins with temperature dependent thermal conductivity and internal heat generation using the Adomian decomposition method (ADM). The ADM is the preferred analytical scheme adopted to provide approximate solutions to nonlinear equations arising from the dependence of thermal conductivity and heat transfer coefficient on temperature distribution. The effect of parameters such as internal heat generation, thermo geometric and thermal conductivity on the temperature profile and heat flux is studied. Where results reveal that thermo geometric parameter and thermal conductivity causes a significant increase in heat transfer across fin base. This study provides useful insight to fins operational performance in applications such as radiators, boilers, refrigeration devices, oil pipelines amongst others. Comparison of solutions with existing works in literature forms good agreement. Journal of Thermal Engineering Journal of Thermal Engineering 2018-12-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2747 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2747 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2747

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2528 2018-01-22T21:00:00Z 1

The Effect of Cooling on Mechanical and Thermal Stresses in Vascular Structures Erdal Çetkin Vascular, Cooling, Thermal Expansion, Smart Features Here, we show how the vascular channel configuration and its shape affect the mechanical strength which is simultaneously subjected to heating and mechanical load. The material properties were defined as functions of temperature. The effect of channel cross-section on the coolant mass flow rate, peak temperature and peak stresses are documented. The results show that the resistances to flow of stresses and fluid is minimum with the circular channels while the resistance to the heat flow is the smallest with semi-circular channels. In addition, morphing the vascular design provides almost the smallest resistance to the heat flow with circular channels (0.3% difference in the peak temperature). This shows that even the convective resistances are the smallest with circular-cross section, overall thermal resistance is smaller in semi-circular design for the fixed fluid volume. The peak stress is smaller with hybrid design than the parallel designs for the entire pressure drop range. In addition, the effects of mechanical load, heating rate and reference temperature on the stress distribution are also documented. Furthermore, the thermal and mechanical stresses are also documented separately, and then compared with the coupled solution cases. The chief result of this paper is that for a coupled system minimizing only one of the resistance terms is not sufficient, all the resistances considered simultaneously in order to uncover the best performing design. In coupled solutions, we documented the simulation results with temperature dependent material properties and the resistances to the heat and fluid flow is affected by the mechanical deformations. In addition, the results show that the designs should be free to vary, the unexpected designs can be the best performing designs for the given parameters and constraints. Therefore, the design parameters based on the experience does not always yield the best performing designs as the objectives and constraints vary. Journal of Thermal Engineering Journal of Thermal Engineering 2018-01-22T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2528 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2528 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2528

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2680 2018-09-28T21:00:00Z 1

Numerical Investigation of Cooling a Ribbed Microchannel Using Nanofluid Khadija Madani, Rejeb Ben Maad, Aissa Abidi-Saad Forced convection, heat transfer coefficient, microchannel, nanofluids, ribs, A 2-D numerical investigation was carried out to study the effect of spacing between ribs on nanofluid flow and heat transfer inside a horizontal micro-channel. Two identical ribs were placed at the lower wall of micro-channel with variable spacing between them. The alumina oxide nanaoparticles was suspended in water as based fluid at different volume fraction 0, 2 and 4%. The finite volume method was used to solve the continuity, momentum and energy equations. The effects of different parameters such as nanoparticles volume fraction, Reynolds number, and the spacing between ribs has been evaluated. The results showed that increasing nanoparticles volume fraction and Reynolds number significantly enhanced the heat transfer and the Poiseuille number. The presence of ribs improves the heat transfer. However, increasing the spacing between ribs leads to decrease the heat transfer rate. Journal of Thermal Engineering Journal of Thermal Engineering 2018-09-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2680 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2680 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2680

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5336 2021-02-27T21:00:00Z 1

Investigations on Heat Transfer Characteristics of Porous Type Copper Heat Sink with Bifurcations T. Prabhu Thangavel, C. Ajay Sekar Porous Type Copper Heat Sink, Laminar Flow, Turbulent Flow, Bifurcations, Characteristic Curves. The lotus type porous copper heat sink has a higher heat transfer capacity as compared to micro channel heat sink for same size. Many studies on this heat sink show that its heat transfer capacity can be further improved by improving design of heat sink. This study investigates the heat transfer and flow characteristics of porous heat sink with different designs of internal bifurcations under both laminar & turbulent flow and studies the effect of such bifurcations on heat transfer of heat sink. The results of heat sink with bifurcations are compared with that of heat sink without bifurcations which show that for case of both laminar & turbulent flow, the heat sink with bifurcation showed better thermal performance as compared to heat sink without bifurcations. Journal of Thermal Engineering Journal of Thermal Engineering 2021-02-27T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5336 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5336 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5336

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2501 2017-12-19T21:00:00Z 1

Numerical Simulation of Natural Convection in a Porous Cavity Filled With Ferrofluid in Presence of Magnetic Source Bengisen Pekmen Geridönmez Ferrofluid, Porous media, Natural convection, Radial basis functions, Magnetic Source In this study, numerical simulation of natural convection in a porous square cavity filled with Fe3O4-water is investigated. A magnetic source through the left wall of the cavity is also taken into account. Radial basis function based pseudo spectral (RBF-PS) method is applied. The effects of dimensionless parameters Darcy (Da), Hartmann (Ha), Rayleigh (Ra) numbers and solid volume fraction (\phi) are presented both in terms of streamlines, isotherms and vorticity contours and average Nusselt number through the heated wall. Convective heat transfer is inhibited with the rise of Ha, and with the decrease in Da while it is enhanced with the increase in \phi and Ra. Journal of Thermal Engineering Journal of Thermal Engineering 2017-12-19T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2501 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2501 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2501

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2606 2018-06-13T21:00:00Z 1

Advanced Numerical and Experimental Studies on CI Engine Emissions M. Zafer Gul, Hasan Koten, Mustafa Yilmaz, I. Hakki Savci Experimental study, CI Engine, Emission, Optimization, Aftertreatment In these studies, three important works examined to get ultra-low emission for a single cylinder diesel engine. The first study was performed for single fuel and compression ratio (CR), intake and exhaust valve timings, mass flow rate were optimized for a range of engine speed. Then for the same engine injection parameters such as start of injection (SOI), injector cone angle, and split injection structures were examined to get optimum parameters for the diesel engine. In CR studies, different combustion chambers were tested according to injector cone angles and fuel-wall interaction. In the second study, in addition to the above studies, dual fuel compressed biogas (CBG) and diesel combustion were analyzed under different engine loads both experimentally and computationally. Optimized single fuel diesel cases were compared with CBG + Diesel dual fuel cases which employed port injection for CBG fuel. In dual fuel engine applications, CBG fuel and air mixture is induced from intake port and this air-fuel mixture is ignited by pilot diesel fuel near top dead center (TDC). In dual fuel engine mode, exhaust emissions reduced considerably especially in NOx and particulate matter (PM) because of methane (CH4) rate and optimized engine parameters. The third study is focused on aftertreatment systems to minimize residual exhaust emissions. The emissions of the diesel engines consist of various harmful exhaust gases such as carbon monoxide (CO), particulate matter (PM), hydrocarbon (HC), and nitrogen oxides (NOx). Several technologies have been developed to reduce diesel emissions especially NOx reduction systems in last decades. The most promising NOx emission reduction technologies are exhaust gas recirculation (EGR) system to reduce peak cylinder temperature that reduces NOx form caused by combustion and active selective catalyst reduction (SCR) system using reducing agent such as urea-water-solution for exhaust aftertreatment system. In this study, computational fluid dynamic (CFD) methodology was developed with conjugate heat transfer, spray, deposit and chemical reaction modeling then emission prediction tool was developed based on the CFD results with deposit prediction mechanism. CFD and deposit results were correlated with image processing tool in flow test bench. Journal of Thermal Engineering Journal of Thermal Engineering 2018-06-13T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2606 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2606 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2606

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2600 2018-06-12T21:00:00Z 1

Experimental Investigation of Monocrystalline and Polycrystalline Solar Modules at Different Inclination Angles Muhammad Bilal Chatta, Hafiz Muhammad Ali, Muzaffar Ali, Muhammad Anser Bashir Photovoltaic Modules, Module Efficiency, Fill Factor, Inclination Angle Photovoltaic modules have a potential market for off-grid applications in rural context with limited access to the electrical grid. For fixed photovoltaic systems, proper orientation of photovoltaic modules at specific conditions plays a significant role to have maximum performance. This paper presents the effect of different metrological parameters on the performance of photovoltaic modules at three different inclination angles (0°, 33.74° and 90°) with horizontal. Six 40W photovoltaic modules (three monocrystalline and three polycrystalline) were exposed to sunlight at three different inclination angles. Performance ratio, module efficiency, fill factor were calculated for photovoltaic module at different inclination angles and results presented. PV modules at 33.74° tilt angle received high solar radiation and showed high output power. As solar radiation increases, the radiation losses from the surface of the module increases and resultant decrease the module efficiency and increase the module temperature at high solar irradiance. During the winter months, the average efficiency of the monocrystalline PV module at 0° and 90° was 4% and 2% higher respectively than the 33.74° tilt angle. Similarly polycrystalline PV module showed 7% and 5% higher efficiency at 0° and 90° respectively than the 33.74°. Moreover, Fill factor of PV module at 33.74° tilt angle had the highest value as compared to other tilt angles. Journal of Thermal Engineering Journal of Thermal Engineering 2018-06-12T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2600 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2600 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2600

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2526 2018-01-19T21:00:00Z 1

Utilization of Basic Multi-Layer Perceptron Artificial Neural Networks to Resolve Turbulent Fine Structure Chemical Kinetics Applied to a CFD Model of a Methane/Air Piloted Jet Flame R. Laubscher, J. H. Hoffmann Computational Fluid Dynamics, Artificial Neural Networks, Machine Learning, Chemical Kinetics, Combustion, Eddy Dissipation Concept This work investigates and proposes an alternative chemistry integration approach to be used with the eddy dissipation concept (EDC) advanced combustion model. The approach uses basic multi-layer perceptron (MLP) artificial neural networks (ANNs) as a chemistry integrator for the reactions that take place in the fine structure regions created by the turbulence field. The ANNs are therefore utilised to predict the incremental species changes that occur in these fine structure regions as a function of the initial species composition, temperature and the residence time of the mixture in the fine structure regions. The chemistry integration approach for the EDC model was implemented to model a piloted methane/air turbulent jet diffusion flame (Sandia Flame D) at a Reynolds number of 22400. To prove the concept, a five-step methane combustion mechanism was used to model the chemical reactions of the experimental flame. The results of the new approach were benchmarked against experimental data and the simulation results using the standard integration approaches in Fluent. It was shown that once the ANNs are well-trained (in-sample error minimised as best possible), it can predict the species mass fractions with relative accuracy in a manner that is both time and computer-memory efficient compared with using traditional integration procedures. Journal of Thermal Engineering Journal of Thermal Engineering 2018-01-19T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2526 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2526 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2526

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/4064 2020-04-22T21:00:00Z 1

Differential Transformation Method for Analysis of Nonlinear Flow and Mass Transfer Through a Channel Filled with a Porous Medium Sobhan Sobhan Mosayebidorcheh, M. Vatani, T. Mosayebidorcheh, M. Hatami, D. D. Ganji Chemical reaction; Porous channel; Boundary value problem; Differential Transformation Method (DTM). In this paper, mass transfer and chemical reaction effects on laminar viscous flow through a porous channel with moving or stationary walls are studied. The governing partial differential equations of the physical problem are transformed into a set of coupled nonlinear ordinary differential equations using similarity transformation. The coupled nonlinear ordinary differential equations are solved using differential transform method (DTM). The results obtained through the approximate analytical method are compared with the results of numerical method and high accuracy of the present approximate analytical solution is observed. The valuable achievement of the present study is imbedding a precise and efficient analytical method for the flow of viscous fluid in a porous channel with a chemical reaction. Also, the effects of some pertinent parameters such as Reynolds number, Darcy number, Schmidt number and suction/injection parameter on velocity components, heat transfer, concentration, and Sherwood distribution are presented in this work. Journal of Thermal Engineering Journal of Thermal Engineering 2020-04-22T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4064 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4064 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4064

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2519 2017-12-27T21:00:00Z 1

Effect of Time Horizon on Wind Speed Prediction with ANN Şaban Pusat, Mustafa Tahir Akkoyunlu Wind Energy; Wind Speed Prediction; Artificial Neural Network; Time Horizon Proper utilization of renewable energy sources in electricity production is inevitable due to the environmental concerns and global warming fight. Therefore, predictability of renewable electricity is a very significant issue for a long time. Main aim of this study, different from the literature, is to investigate the change of wind speed prediction errors for different time horizons. Different prediction time horizons (10, 30, 60, 90 and 120 minutes) were used, and the results were compared through the error measures and the regression values. The mean squared errors and the regression values vary between 0.819 and 5.570, and between 77.8% and 97.1%, respectively. The prediction error changes almost logarithmically, and the rate of change decreases with the increasing time horizon. A new analysis approach was proposed to see the change of the prediction error with time horizon. The equation, y = 1.5413ln(x) - 2.7428, representing the change of the mean squared error with time horizon was obtained. Journal of Thermal Engineering Journal of Thermal Engineering 2017-12-27T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2519 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2519 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2519

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2746 2018-12-29T21:00:00Z 1

Thermodynamic Performance Analysis of Gas Liquefaction Cycles for Cryogenic Applications C. Yilmaz, T. H. Cetin, B. Ozturkmen, M. Kanoglu Cryogenic cycles, Linde-Hampson, Claude, Kapitza, J-T expansion, thermodynamic analysis. In this paper presents an analysis of the thermodynamic cycles the most commonly used for the liquefaction of gases in order to evaluate and compare their performance under given working conditions and system component efficiencies. The cycles considered are simple Linde-Hampson cycle, precooled Linde-Hampson cycle, Claude cycle, and Kapitza cycle. First and second law relations are investigated for each cycle and performance parameters are evaluated. Thermodynamically performances criteria are compared of cycles with respect to the each other. Cycles are model in the computer environment and analyzed with Engineering Equation Solver (EES) software program. Cycles of the liquefaction fractions, coefficient of performances and second law of efficiencies are calculated for the liquefaction of different gases. Second law efficiencies are calculated as 13.4%, 21.8%, 62.9%, and 77.2% for simple Linde-Hampson cycle, pre-cooled Linde-Hampson cycle, Claude cycle, and Kapitza cycle, respectively. Claude and Kapitza cycles give better performance but simple and precooled Linde-Hampson cycle has the advantages of the simplicity of their setup. Journal of Thermal Engineering Journal of Thermal Engineering 2018-12-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2746 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2746 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2746

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2520 2017-12-29T21:00:00Z 1

Effect of Hydrogen Addition at Different Levels on Emissions and Performance of a Diesel Engine Yasin Karagöz CI Engine, Diesel, Hydrogen, NOx, Smoke, Performance, Emissions The ratio of diesel vehicles in vehicle park and also the number of diesel vehicles sharply increase in the world. Advantages of diesel engines can be stated as high efficiency, low fuel consumption etc., on the other hand high amount of oxides of nitrogen caused by high compression ratio of diesel engines should be noted as its disadvantage. Moreover, a high amount of smoke emission is formed due to combustion characteristics of diesel engines. Both NOx and smoke are really hazardous for the environment. Stringent emission regulations force diesel engines to exhaust less NOx and smoke emissions. Thus, diesel engines require advanced after - treatment systems. The catalyst materials in after - treatment systems are really expensive. In this study, different levels of hydrogen [0%, 40% and 75%] on energy basis of total fuel were introduced into intake manifold of engine. Brake thermal efficiency of the engine improved with increasing percentage of hydrogen. CO, THC and smoke emissions are significantly decreased by using hydrogen as additional fuel. Especially, a novel decrease on smoke emission [up to 70.7%] is obtained. However, particularly during 75% hydrogen addition, the dramatic increase in NOx emissions could not be prevented. Journal of Thermal Engineering Journal of Thermal Engineering 2017-12-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2520 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2520 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2520

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5138 2020-07-04T21:00:00Z 1

Optimum Parametric Analysis Based on Thermodynamic Modeling of a Compression Absorption Cascade Refrigeration System Naushad Ansari, Akhilesh Arora, Samsher Gautam, Manjunath K Absorption, Compression, COP, Generator, Cascade Condenser, Exergetic Efficiency In the present study a cascade refrigeration system (CRS) comprising of a vapor compression refrigeration (VCR) system in the low temperature (LT) stage and a single stage vapor absorption refrigeration (VAR) system in high temperature (HT) stage is analyzed. The scope of this work focuses on the effect of different parameters on the performance of the CRS with the help of a mathematical model. The energy and exergy analysis of the CRS is carried out with CO2 and NH3 as refrigerants in the VCR stage and the pair of H2O-LiBr fluids in the VAR stage. It is observed that COP and exergetic efficiency of the CRS reduce with increase in cascade condenser temperature with CO2 as a refrigerant in VCR stage whereas with NH3 as a refrigerant in VCR stage, the COP increases with increase in cascade condenser temperature, it attains a maximum value and then decreases. Journal of Thermal Engineering Journal of Thermal Engineering 2020-07-04T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5138 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5138 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5138

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2530 2018-01-31T21:00:00Z 1

Computational Fluid Dynamics Analysis of Flow and Combustion of a Diesel Engine Mahmut Abay, Üner Çolak, Levent Yüksek Diesel engine, Computational Fluid Dynamics, Exhaust Gas Recirculation, NOx, Soot Efficient usage of fossil fuels and reduction of CO2 emissions are very important priorities for the automotive industry. Without increasing contributions from diesel engines and newer diesel technologies, it would not be possible to successfully meet fuel consumption and CO2 emission reduction targets. Therefore, new regulations and applications have been put into action to address exhaust gas emission problems. Some exhaust gases have become prominent with regard to strong effects, such as NOx and soot. NOx contributes to acid rain, which has strong effects on the ozone layer. In this study, flow and combustion characteristics of a diesel engine are investigated by using Computational Fluid Dynamics (CFD). Whole engine components are modeled and analyses are performed for all engine speeds. Calculated crank angle dependent pressure and temperature values are used as boundary condition for reactive 3D CFD simulations. Reactive CFD simulations are performed with 45° sector geometry for the period that both valves are closed. In reactive simulations, RNG k-? and Standard k- ? models are used to characterize turbulence flow field. A lagrangian approach is used for two-phase flow computations to simulate the liquid fuel injection. Commercially available CFD code Forte Reaction Design and its sub-module Chemkin are used for three dimensional reactive simulations, moving grid generation and problem setup. Predicted in-cylinder pressure and apparent heat release rate are validated with experimental results. NOx and Soot formations as a result of combustion process are also investigated. Optimum level of NOx and Soot formation happen with 8.5% EGR usage. Journal of Thermal Engineering Journal of Thermal Engineering 2018-01-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2530 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2530 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2530

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3825 2019-06-24T21:00:00Z 1

Thermo-environmental analysis and Multi-Objective Optimization of performance of Ericsson Engine Implementing an Evolutionary Algorithm Mohammad Hossein Ahmadi, Fathollah Pourfayaz, Mohammad Hossein Jahangir Evolutionary Algorithms, Decision-Making, Thermodynamic Analysis, Multi-Objective Optimization, Entropy Generation, Ericsson Engine This paper makes attempt to optimize a high-temperature differential Ericsson engine with several conditions. A mathematical approach based on the finite-time thermodynamic was proposed with the purpose of gaining thermal efficiency, the output power and the entropy generation rate throughout the Ericsson system with regenerative heat loss, finite rate of heat transfer, finite regeneration process time and conductive thermal bridging loss. In this study, an irreversible Ericsson engine is analyzed thermodynamically in order to optimize its performance. In addition, three Scenarios in multi-objective optimization are presented and the results of them are assessed individually. The first strategy is proposed to maximize the Ecological function, the thermal efficiency and the Exergetic performance criteria. Furthermore, the second strategy is suggested to maximize the Ecological function, the thermal efficiency and Ecological coefficient of performance. The third strategy is proposed to maximize the Ecological function and the thermal efficiency and Dimensionless ecological based thermo-environmental function. Multi-objective evolutionary algorithms based on NSGA-II algorithm was applied to the aforementioned system for calculating the optimum values of decision variables. Decision variables considered in this paper including the regenerator’s effectiveness, the high-temperature heat exchanger’s effectiveness, the low-temperature heat exchanger’s effectiveness, the working fluid temperature in the low-temperature isothermal process and the working fluid temperature in the high-temperature isothermal process. Moreover, Pareto optimal frontier was achieved and an ultimate optimum answer was chosen via three competent decision makers comprising LINMAP, fuzzy Bellman-Zadeh, and TOPSIS approaches. The results from scenarios shown that third scenario is the best scenario. Journal of Thermal Engineering Journal of Thermal Engineering 2019-06-24T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3825 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3825 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3825

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2776 2019-03-13T21:00:00Z 1

CFD Analysis of Laminar Forced Convective Heat Transfer for TiO2/Water Nanofluid in a Semi-Circular Cross-Sectioned Micro-Channel Hüseyin Kaya, Recep Ekiciler, Kamil Arslan CFD, Semi – Circular Cross – Sectioned Micro – Channel, Forced Convection, Nanofluid In this study, forced convection flow and heat transfer characteristics of TiO2/water nanofluid flow with different nanoparticle volume fractions (1.0%, 2.0%, 3.0% and 4.0%) in semi – circular cross – sectioned micro – channel was numerically investigated. Nusselt number and friction factor have been evaluated. The three - dimensional study was conducted under steady state laminar flow condition where Reynolds number changing from 100 to 1000. CFD model has been generated by using ANSYS FLUENT software based on finite volume method. The flow was under thermally developing flow condition. Uniform surface heat flux boundary condition was applied at the bottom surface of the micro – channel. The average and local Nusselt number and Darcy friction factor values were obtained using numerical results. Also, the effects of using nanofluid on local values of Nusselt number and Darcy friction factor were investigated. Numerical results indicate that the increase of nanoparticle volume fraction of nanofluid, the Nusselt number increases; however, there is no significant variation in Darcy friction factor. Journal of Thermal Engineering Journal of Thermal Engineering 2019-03-13T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2776 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2776 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2776

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2584 2018-03-30T21:00:00Z 1

A Review of Flow Boiling in Mini and Microchannels for Enhanced Geometries Alican Cebi, Ali Celen, Aydin Donmez, Yakup Karakoyun, Pinar Celen, Mehmet Salih Cellek, Ahmet Selim Dalkilic, Tolga Taner, Somchai Wongwises Refrigeration; alternative refrigerants; boiling; evaporator; minichannel; microchannel Flow boiling researches in enhanced geometries practiced recently have been summarized in this review. Classical approximations in macroscale flows have not applied to the flows with small hydraulic diameters, so, this subject has been paid attention by the researchers. Application areas of these structures are increasing continuously due to cooling need in small confined spaces. The related studies have been reviewed in a chronological manner and their parameters have been given in a table in order for the researchers to observe the scientific duration regarding the progresses on this subject. Almost all papers on this subject have been produced after 2000, therefore, this subject is considered as an actual one to improve and worth to study in the literature. This study can not only be evaluated as the beginning argument for the researchers involved in flow boiling process in mini and microchannel, but it also consists of new works on the investigated subject. Journal of Thermal Engineering Journal of Thermal Engineering 2018-03-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2584 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2584 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2584

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2601 2018-06-12T21:00:00Z 1

Power Generation from Combusted “Syngas” Using Hybrid Thermoelectric Generator and Forecasting the Performance with ANN Technique Appadurai Anitha Angeline, Jayaraj Jayakumar, Lazarus Godson Asirvatham, Somchai Wongwises Pongamia, ANN, Hybrid, Performance Parameters, Synthetic Oil, Thermoelectric Generator, Cost Analysis. The combustion of “syngas”, obtained through gasification of Pongamia de-oiled seed cake, is done to produce higher energy biomass waste heat for generating power using hybrid thermoelectric generator (TEG). An experimental set-up is fabricated using synthetic oil (Therminol-55) as the heating fluid by employing water and air-cooled methods on the cold side of hybrid TEG unit. The hot side temperature is varied from 200 - 250 ºC while the coolant temperature is maintained constant at 30oC for both water and air respectively. Results showed that an enhancement in electric power of 22.27% is obtained when water is used on the cold side of the TEG at a constant hot side temperature of 250 ºC. In addition, simulation results for the above mentioned conditions using artificial neural networks (ANN) tool in MATLAB also agreed well with the sample experimental results. The performance parameters such as open circuit voltage and maximum output power are forecasted using ANN upto the maximum possible hot side temperature of 350 ºC. Further, the financial evaluation of Biomass gasified-thermoelectric system ($0.0018/kWh and in terms of Indian currency is ? 0.0676/kWh) is found to be almost negligible when compared with that of the other available renewable energy technologies. Journal of Thermal Engineering Journal of Thermal Engineering 2018-06-12T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2601 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2601 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2601

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3818 2019-06-23T21:00:00Z 1

Thermodynamic Performance Analysis of Dedicated Mechanically Subcooled Vapour Compression Refrigeration System Shyam Agarwal, Akhilesh Arora, Bharat Bhushan Arora VCR, Subcooling, COP, R1234ze, R1234yf, Exergetic Efficiency, Dedicated, R134a In this work, the thermodynamic analysis of dedicated mechanically subcooled vapour compression refrigeration system is presented. A software based computer program in EES has been formulated for computation of the performance results. The effect of varation of degree of subcooling (5-30oC), evaporator temperature (-20 to 10oC) and condenser temperature (30-50oC) has been investigated for energetic and exergetic performance of the system. The analysis of the system has been carried out using zero ODP and very low GWP (1 to 4) refrigerants viz.HFO-R1234ze and R1234yf to compare the performance of HFC-R134a. The results depicts that the COP and exergetic efficiency of dedicated subcooled VCR cycle are better than that of simple VCR cycle. Refrigerant R1234ze performs better than R1234yf and comparable to R134a. Journal of Thermal Engineering Journal of Thermal Engineering 2019-06-23T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3818 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3818 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3818

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3861 2019-09-21T21:00:00Z 4

The Influence of Temperature on Dispersion of Particles on Liquid Surfaces Sathish K. Gurupatham, Valmiki Sooklal, Ashton Hensen, Michael Conner, Max Sayedzada, Daniel Shah Adsorption, Surface Tension, Particle Dispersion Fluid–Liquid Interface, Capillary Force, Viscous Drag It was shown recently that small particles and powders spontaneously disperse on liquid surfaces when they come in contact with the interface for the first time (Figure 2). This happens due to the combined effect of the capillary force, buoyant weight of the particle and the viscous drag that the particles experience when they encounter the liquid surface. The particles undergo oscillations normal to the interface before they come to the equilibrium position on the interface. These oscillations, in turn, induce a flow on the interface which disperses the particles radially outward. This phenomenon has a significant role in the pollination of sea plants such as “Ruppia ” in which the formation of “pollen rafts” is the first step which results from the spontaneous dispersion of their pollens on the water surface. This work investigates, experimentally, the influence of temperature of the liquid on which this dispersion occurs. It was observed that the frequency of oscillations of the particles decreased with the increase in the temperature of the liquid. It is because the magnitude of capillary force that the particle experiences also decreased when the temperature of the liquid increased. Journal of Thermal Engineering Journal of Thermal Engineering 2019-09-21T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3861 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3861 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3861

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2687 2018-09-28T21:00:00Z 1

CFD Simulation of Thermo-Aeraulic Fields in a Channel with Multiple Baffle Plates Y. Menni, A. Azzi, C. Zidani Computational Fluid Dynamics, Heat Transfer, Friction Loss, Thermal Enhancement Factor, Shell-and-Tube Heat Exchangers, Renewable Energy, Solar Air Collectors In this paper, the steady turbulent forced-convection flow of air through a constant temperature-surfaced rectangular cross section channel, where four baffle plates were placed in opposite walls, is numerically investigated using commercial fluid dynamics (CFD) technique (FLUENT 6.3 and GAMBIT 2.3). The geometry of the problem is a simplification of the geometry of baffle plates found in shell-and-tube heat exchangers. The aspect ratio of channel width-to-height, channel length-to-hydraulic diameter, baffle spacing-to-channel height ratio, and blockage ratio of baffle height-to-channel height are fixed at W/H = 1.321, L/Dh = 5.137, Pi/H = 0.972, and h/H = 0.547, respectively. The channel flow model is governed by the Reynolds averaged Navier-Stokes (RANS) equations with the k-? turbulence model and the energy equation. The simulation runs were carried out for different values of Reynolds numbers at constant wall temperature condition along the top and bottom walls. In particular, stream function, axial velocity, dynamic pressure, turbulent kinetic energy, turbulent viscosity, and temperature fields as well as dimensionless axial velocity profiles were obtained. The comparisons between the numerical and experimental data in the axial velocity profiles show reasonable agreement. The CFD results show that the air flow is characterized by strong deformations and large recirculation regions. Journal of Thermal Engineering Journal of Thermal Engineering 2018-09-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2687 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2687 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2687

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2602 2018-06-13T21:00:00Z 1

Development of Semi-Continuous Solar Powered Adsorption Water Chiller for Food Preservation Hitesh Bhargav, Bharat Ramani, V. Siva Reddy, Feng C. Lai Solar Energy, Adsorption Refrigeration, Food Preservation, ACF-Methanol Solar powered adsorption refrigeration systems has been preserved the food for the national requirement and in addition protected the environment. In this research article, the design and development of semi-continuous solar powered Adsorption water chiller for food preservation are presented. The design of the main components includes an adsorber bed, a condenser, an expansion device and an evaporator are performed by using heat transfer correlations. The outcomes of design were presented and discussed .The cooling produced in 10 kg of water is 554 kJ in 6 hours for the water flow of 170 kg/hour, 25° C condenser temperature and 65° C adsorber temperature .The fluctuation in system pressure is observed in the range of 30 kPa to 80 kPa for desorption and adsorption process during experimentation. The chiller performance is tested and compared with the earlier adsorption chiller. The comparison showed that proposed chiller has higher specific cooling power (SCP), low cycle time and low generation temperature due to activated carbon fiber-methanol pair and effective design of system. Journal of Thermal Engineering Journal of Thermal Engineering 2018-06-13T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2602 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2602 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2602

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2781 2019-03-14T21:00:00Z 1

Numerical Analyses on the Prediction of Nusselt Numbers for Upward and Downward Flows of Water in a Smooth Pipe: Effects of Buoyancy and Property Variations Ahmet Selim Dalkılıç, Alican Çebi, Ali Celen Natural Convection, Single Phase Flow, Buoyancy and Property Variation, Friction Factor, Nusselt Number In this paper, an artificial neural network (ANN) was employed to analyze and investigate the buoyancy and property variation effects calculating Nusselt numbers during the upward and downward flow of water in a smooth pipe. Available data in the literature (Parlatan et al.) has been used in the analyses to show ANN’s success ratio of predictability on the measured pipe length’s averaged Nusselt numbers (Nuavg) and forced convection’s Nusselt numbers (Nuo). Mixed convective flow conditions were valid for Reynolds numbers ranging from 4000 to 9000 with Bond numbers smaller than 1.3. Dimensionless values of Reynolds number, Grashof number, Prandtl number, Bond number, Darcy friction factor, isothermal friction factor in forced convection, ratio of dynamic viscosities, and a Parlatan et al.’s friction factor were the inputs while Nuavg and Nuo were the outputs of ANN analyses. All data was properly separated for test/training/validation processes. The ANNs performances were determined by way of relative error criteria with the practice of unknown test sets. As a result of analyses, outputs were predicted within the deviation of ±5% accurately, new correlations were proposed using the inputs, and importance of inputs on the outputs were emphasized according to dependency analyses showing the importance of buoyancy influence (Gr?T) and the effects of temperature-dependent viscosity variations under mixed convection conditions in aiding and opposing transition and turbulent flow of water in a test tube. Journal of Thermal Engineering Journal of Thermal Engineering 2019-03-14T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2781 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2781 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2781

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2603 2018-06-13T21:00:00Z 1

Application of Nanotechnology to Improve the Performance of Tractor Radiator Using Cu-Water Nanofluid R.Ravisankar, V.S.K.Venkatachalapathy, N.Alagumurthi Heat Transfer enhancement, Nanofluid Cu/water, Tractor Radiator This paper gives the performance improvement of tractor radiator by Cu/water nanofluid through the mechanism of nanotechnology. It was found that the use of the nanofluid in heat transfer field can play a crucial role in increasing the efficiency of equipment. Miniaturization and increased operating speeds of heat exchangers warranted the need for new and innovative cooling concepts for better performance. The nano materials and its suspension in fluids as particles have been the subject of intensive study worldwide. Tractor Engine cooling is an important factor for their performance in the intended application. Here the tractor engine radiator cooling is enhanced by nanofluid mechanism of heat transfer for its improved performance in agricultural work. The experimental and numerical investigation for the improved heat transfer characteristics of a radiator using Cu/water nanofluid for 0.025, 0.05 and 0.075% volume fraction is done with inlet temp of 50 - 60°C under the turbulent flow regime (8000 ? Re ? 25000). The overall heat transfer coefficient decreases with increase in nanofluid inlet temperature of 50 - 60°C. The experimental results when compared with numerical shows enhanced heat transfer coefficient. The results also proved that nanofluid is better heat transfer fluid than the base fluid water. Experimental results emphasize the enhancement of heat transfer due to the nanoparticles presence in the fluid. Heat transfer coefficient increases by increasing the concentration of nanoparticles in nanofluid. The nanofluids are projected as alternative cooling fluid in heat exchangers through its nano mechanism. Further researches are required to study the effect of nanotechnology to enhance the heat exchanger performance over the next several coming years. Journal of Thermal Engineering Journal of Thermal Engineering 2018-06-13T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2603 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2603 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2603

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2775 2019-03-13T21:00:00Z 4

Heat Transfer and Friction Characteristics of an Array of Perforated Fins under Laminar Forced Convection Afshin Ahmadi Nodooshan, Shekoufeh Mohammadi, Morteza Bayareh, Laminar Forced Convection, Perforated Fin, Nusselt Number, Reynolds Number, Thermal Performance Three-dimensional incompressible laminar fluid flow and heat transfer of a heated array of circular perforated fins are examined numerically. The Navier–Stokes and energy equations are solved by a finite volume method using the SIMPLE algorithm. The second order upwind technique is employed to discretize the momentum and energy equations. Computations were performed for a range of Reynolds numbers 100 ?Re ? 350. Thermal performance and effectiveness as well as friction coefficient of perforated and solid fins are determined for the optimum porosity. The results show that the average coefficient of friction reduces with increasing the Reynolds number and the number of perforations. The heat transfer rate increases with the porosity and the Reynolds number. It is found that perforated fin effectiveness decreases with the number of peroration at constant Reynolds numbers. Journal of Thermal Engineering Journal of Thermal Engineering 2019-03-13T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2775 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2775 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2775

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3819 2019-06-23T21:00:00Z 1

Multi-Objective Optimization of a R744/R134a Cascade Refrigeration System: Exergetic, Economic, Environmental, and Sensitive Analysis (3ES) Mohammad Mehdi Keshtkar, Pouyan Talebezadeh Cascade Refrigeration, Thermo-economic Optimization, Exergetic, Economic, Environmental, Sensitive Analysis This work presents the optimization of a two stage-cascade refrigeration system (TS-CRS), based on exergetic, economic, environmental, and sensitive analysis (3ES). R134a and R744 are considered as the refrigerants of high and low temperature circuits, respectively. Two single-optimization strategies including exergetic and economic optimizations and a multi-objective optimization are applied on the problem. In the first step, a comprehensive performance evaluation of different effective parameters, based on the genetic algorithm, used to indicate the optimum operative conditions in single objective strategies. In the next step, a multi-objective optimization is performed with considering a decision-making strategy based on the Pareto frontier using TOPSIS method. The higher exergetic efficiency and lower cost found in the exergetic and economic single-optimization, respectively. The multi-objective optimization results demonstrate that, the total system cost and the exergetic efficiency increase 28.6% and 99.5%, respectively, compared to the base design, and 46.6% higher energy can be saved in the compressors. Journal of Thermal Engineering Journal of Thermal Engineering 2019-06-23T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3819 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3819 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3819

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2765 2019-02-18T21:00:00Z 1

Performance Assessment of Phosphoric Acid Fuel Cell - Thermoelectric Generator Hybrid System with Economic Aspect Fatma Gul Celik, Emin Acıkkalp, Hasan Yamik phosphoric acid fuel cell,thermoelectric generator, hybridsystem, economic evaluation, EXCEM analysis Using fuel cells present considerable opportunity for alternative energy applications. Especially fuel cell hybrid system implementations can be used for obtaining efficient energy systems and economic evaluation is one of the important criterion for any system. Purpose of this paper is to evaluate phosphoric acid fuel cell (PAFC) - thermoelectric generator hybrid system with economic and thermoeconomic point of view. Firstly, basic equations of PAFC, thermoelectric generator and hybrid system are described. Secondly, basic performance parameters like power output, energy efficiency, exergy efficiency and exergy destruction rate are investigated. Finally, cost equations are set up to determine economic results of the considered system, in addition to that, these system are considered by using EXCEM analysis. According to results, the maximum total cost of the hybrid system is obtained j= 10900 Am-2, exergy loss ratio to capital cost (EC) of the hybrid system increases dramatically at j= 11000 Am-2. Maximum power density, maximum energy efficiency and of the hybrid system are 8735.340 Wm-2, 81.35% and 86.6% respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2019-02-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2765 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2765 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2765

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3987 2020-01-05T21:00:00Z 4

Experimental Study of Hydrocarbon R290 in Water Cooler Refrigeration System Chandrakishor S. Choudhari, S.N. Sapali Hydrocarbon, R290, Flammable Refrigerant, Water Cooler Environment friendly hydrocarbon R290 is one of the options for the next generation refrigeration systems. In warm climatic countries, water cooler is the widely used refrigeration application and R22 is the predominantly used refrigerant in these refrigeration systems. In accordance with international agreements, use of refrigerant R22 is to be stopped on urgent basis because of its environmental concerns, ozone depletion and global warming. This paper presents an experimental study on the performance of laboratory water cooler charged with environment friendly refrigerant R290. A laboratory water cooler of nominal cooling capacity 1.5 kW is developed. Pull down tests and energy consumption tests at condensing temperatures of 38°C, 43°C, and 48°C is conducted as per Indian standard IS1425 (Part 1): 2001. Performance parameters such as pull-down time, pressure ratio, discharge gas temperature, average compressor energy consumption, energy consumption over a period of 24 hours, coefficient of performance and performance parameter of the water cooler refrigeration system are measured. Observed performance parameters also proved the compatibility of mineral oil with refrigerant R290. The overall performance of the developed water cooler suggests refrigerant R290 as a better long- term alternative refrigerant for water cooler applications. Journal of Thermal Engineering Journal of Thermal Engineering 2020-01-05T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3987 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3987 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3987

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2777 2019-03-13T21:00:00Z 1

Geometry Effects on Thermohydraulic Behavior of Fluid Flow in a Square Enclosure with an Inner Circular Tube Akram Jahanbakhshi, Afshin Ahmadi Nodooshan, Morteza Bayareh Square Channel, Forced Convection, Numerical Simulation, Holder Rigid Plate, Reynolds Number Convective heat transfer in non-circular channels are of interest in many industrial applications. In the present work, fluid flow in the space between a square channel and a circular tube with different positions of the holder rigid plate is investigated numerically. The use of holder plates is applicable in industrial applications. Holder plates allow different flows with different thermal and hydrodynamic behaviors in a channel at constant Reynolds numbers. Six geometries selected to explore the effect of the position of holder plate on heat transfer rate. Results demonstrated that the plate position has significant effects on fluid flow behavior. It is found that hydrodynamic and thermal behavior affected by the plate position for different Reynolds numbers. ¬ For example, for the case that the circular tube is positioned in the center of the square channel with two inclined plates, average convective heat transfer outside and between the two plates is 344 (w/(m^2 k)) and 465 (w/(m^2 k)), respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2019-03-13T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2777 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2777 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2777

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3827 2019-06-26T21:00:00Z 1

Energy and Exergy Analysis of a Vapor Absorption Refrigeration System in an Intercity Bus Application Nazım Kurtulmuş, Mehmet Bilgili, Beşir Şahin Energy, Exergy, Intercity Bus Air-Conditioning, Vapor Absorption Refrigeration System, Water-Lithium Bromide A Vapor Absorption Refrigeration system driven by the exhaust gas waste heat received from the internal combustion engine of an intercity bus is modeled and analyzed for air-conditioning the intercity bus cabin under different operating parameters. Initially the hourly comfort cooling load of the intercity bus is calculated for a cooling season spanning five months between May and October in Turkey. After determining the capacity of heat source sufficiency for air-conditioning the intercity bus, energy and exergy analyses of the VAR system are conducted, then designed and compared with the vapor compression refrigeration system in respect to the effect of fuel consumption. The results show that approximately 4,488.774 kg/year of fuel can be saved by using the VAR system driven by an exhaust gas waste heat in an intercity bus. The maximum coefficient of performance (COP) of the VAR system is obtained as 0.78 at 5 a.m. in May, and the maximum total exergy destruction for the VAR system is obtained as 15.25 kW at 4 p.m. in July. Lastly, the specific time at which the highest total exergy destruction occurs through the VAR system is selected to investigate the effect of operating and environmental parameters on the VAR system. Journal of Thermal Engineering Journal of Thermal Engineering 2019-06-26T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3827 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3827 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3827

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3820 2019-06-23T21:00:00Z 1

Determination of Some Domestic Radiators’ Thermal Capacity Numerically Ahmet Selim Dalkilic, Ozgen Acikgoz, Ekrem Ekici, Somchai Wongwises Radiator, Heat Transfer, Natural Convection, Radiation, ANSYS Free convection and radiation comprise the heat transfer mechanisms through which a hydronic household radiator conveys heat from its surface to air and surrounding surfaces. It should also be noted that their performance could be enhanced by improving surface geometries as well as increasing temperature levels. In the present study, heat transfer rates and convective heat transfer coefficients occurring through the investigated radiators, were numerically examined. To this end, radiators at two different dimensions having two different geometric shapes were drawn and analyzed in the program Ansys 17. The heat transfer rates obtained from the program were validated via radiator producer catalogues. Furthermore, the influence of parameters, such as water velocity in the radiators and thus mass flow rate, temperature difference between water inlet and outlet and also between radiator surface and surrounding air on convective heat transfer coefficient over radiator, were scrutinized. Journal of Thermal Engineering Journal of Thermal Engineering 2019-06-23T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3820 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3820 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3820

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3826 2019-06-25T21:00:00Z 1

A Proper Selection of Hot and Cold Utilities in a Plant Containing Multiple Heat Exchanger Networks Fathollah Pourfayaz, Alibakhsh Kasaeian, Mohsen Mehdizadeh Fard Practical Pinch Analysis, Heat Exchanger Network, Hot and Cold Utilities, Appropriate Placement Principle In this paper, the hot and cold utilities of a complex natural gas refinery containing multiple heat exchanger networks (HENs) were properly selected. Following using pinch analysis for designing the HENs of the natural gas refinery, this selection could be done by considering available utilities in the plant under consideration. The plant network was divided into the five heat exchanger networks for better and precise estimation of utility requirements in each smaller network. By comparing the type and temperature level of the utility required in each network, the best utility could be selected, in order to use as the heating and cooling media in the plant network with a considerable reduced operating cost of the system. The results show that in the new network design, there was about 38 and 100% reduction in cooling air and BFW respectively, but 45% increase in cooling water, as cold utilities and almost 64.4, 30.0, 90.9 and 100% reduction in HP steam, LP steam, hot flue gas and electric heater as hot utilities, respectively relative to the existing network. Journal of Thermal Engineering Journal of Thermal Engineering 2019-06-25T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3826 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3826 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3826

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3994 2020-01-07T21:00:00Z 1

Optimization of Micro Gas Turbine by Economic, Exergy and Environment Analysis Using Genetic, Bee Colony and Searching Algorithms Amin Vafaei, Mehdi A. Aliehyaei Micro Gas Turbine, Exergy, Air Pollution, Optimization, Genetic, Honey Bees, Ant Colony In this paper it was dealt with optimization of micro gas turbine with natural gas fuel in four forms of simple, with recuperator, combined heat and power (CHP) and CHP with recuperator. Target function included energy and exergy efficiencies and electricity cost by considering effects of environmental pollution. Optimization procedures were genetic, bee colony and searching algorithms. Results showed that optimum air fuel ratio calculated by searching method for micro gas turbine with above-mentioned cycles were 1.7, 1.3, 1.6 and 2.3 respectively. By applying Genetic algorithm, optimum air fuel ratios were 1.40, 1.21, 1.42 and 1.82 respectively. At these points energy efficiency obtained as 29, 34.4, 39.4 and 38.2 %, second law efficiency obtained as 61.4, 74.9, 85.4 and 57.2 %, electricity cost obtained as 0.102, 0.086, 0.075 and 0.029 US$/kWh respectively. By using bee colony algorithm, optimum air fuel ratios were 1.36, 1.13, 1.32 and 1.61 respectively. At these points, energy efficiency equalled to 28.2, 34.3, 40.5 and 35.6 %, second law efficiency equalled to 60.9, 75.67, 81.80 and 56.65 %, electricity costs equalled to 0.105, 0.087, 0.073 and 0.03 US$/kWh respectively. Among these methods, Genetic algorithm was selected as best method because of best answer in optimization. Journal of Thermal Engineering Journal of Thermal Engineering 2020-01-07T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3994 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3994 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3994

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3906 2019-12-01T21:00:00Z 4

Energy Potential from Municipal Solid Waste (MSW) for a Developing Metropolis Akinbowale Akinshilo, Joseph Olofinkua, O. Olamide, A. Asuelinmen Solid Municipal Waste, Site Selection, Waste Forecast, Energy Recovery Potential, Lagos Metropolis In many developing cities around the world, the shortage of energy and environmental degradation are currently two vital issues affecting sustainable development. The migration of people from villages to one of Africa’s rapidly growing city Lagos, Nigeria has led to the generation of thousands tons of municipal solid waste (MSW) daily, which is one of the important contributors to environmental degradation. Harnessing the useful potential of MSW for power generation adopting the incineration technology will enhance the intermittent power supply and also help with waste management, which has threatening effect on the populace. Therefore this paper focuses on energy stored in waste generated and the power potential of this MSW through an energy recovery method to generate other forms of energy for use has an alternative energy. From the waste characterization exercise, the main components of the Lagos MSW were found to be food, metal and plastic; making the average moisture content of the MSW high. It was illustrated from analysis that a high power potential of over 10,000 MW can be obtained adopting the incineration process, starting with data from 2016 with an exponential increase over the years. Journal of Thermal Engineering Journal of Thermal Engineering 2019-12-01T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3906 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3906 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3906

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/4015 2020-03-30T21:00:00Z 1

Entropy Generation in MHD Flow of Viscoelastic Nanofluids with Homogeneous-Heterogeneous Reaction, Partial Slip and Nonlinear Thermal Radiation Mohammed Almakki, Hiranmoy Mondal, Precious Sibanda Nanofluids; Viscoelastic Fluid; Homogeneous--Heterogeneous Reactions; Nonlinear Thermal Radiation We investigate the combined effects of homogeneous and heterogeneous reactions in the boundary layer flow of a viscoelastic nanofluid over a stretching sheet with nonlinear thermal radiation. The incompressible fluid is electrically conducting with an applied a transverse magnetic field. The conservation equations are solved using the spectral quasi-linearization method. This analysis is carried out in order to enhance the system performance, with the source of entropy generation and the impact of Bejan number on viscoelastic nanofluid due to a partial slip in homogeneous and heterogeneous reactions flow using the spectral quasi-linearization method. Various fluid parameters of interest such as entropy generation, Bejan number, fluid velocity, shear stress heat and mass transfer rates are studied quantitatively and their behaviors are depicted graphically. A comparison of the entropy generation due to the heat transfer and the fluid friction is made with the help of the Bejan number. Among the findings reported in this study is that the entropy generation has a significant impact in controlling the rate of heat transfer in the boundary layer region. Journal of Thermal Engineering Journal of Thermal Engineering 2020-03-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4015 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4015 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4015

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2778 2019-03-13T21:00:00Z 4

Study of the Effect of the Porous Plates on the Tank Bottom on the Boiling Process Morteza Bayareh, Amireh Nourbakhsh CFD, Porosity Coefficient, Boiling, Two-Phase Flow In the present study, the boiling process is simulated in a fixed-temperature tank using the ANSYS FLUENT commercial software. Eulerian method is used to simulate the condensation and evaporation processes. The effect of porous media on the boiling process is investigated. For this purpose, a porous medium with different porosity coefficients is placed on the bottom of the tank and its effect on the bubble dynamics and wall thermal flux is investigated. The simulation is carried out in two dimensions and is considered as unstable. The results show that the porosity coefficient of the porous medium affects the bubble dynamics. The process of phase change decreases by decreasing porosity. Also, the growth rate of the bubble phase in the tank increases with increasing the heat transfer coefficient of the porous medium. Journal of Thermal Engineering Journal of Thermal Engineering 2019-03-13T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2778 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2778 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2778

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2779 2019-03-13T21:00:00Z 1

Exergy Analysis of the Organic Rankine Cycle Based on the Pinch Point Temperature Difference Ali Husnu Bademlioglu, Recep Yamankaradeniz, Omer Kaynakli Organic Rankine Cycle, Exergy Analysis, Pinch Point Temperature, Refrigerant, Geothermal Source Organic Rankine Cycle (ORC) is a system that uses working fluids with hydrocarbon components instead of water and generates power from the heat recovery of different heat sources. In this study, the exergy analysis of a simple ORC, which produces electrical energy with the help a geothermal source (125°C), was performed. R123, R152a, R245fa and R600a were determined as the fluids to be used in the Cycle. In this analysis, which was carried out according to the pinch point temperature differences (5-20°C) in the evaporator, the exergy performance of the cycle components was evaluated for the geothermal resource unit flow rate and the variation of the exergy efficiency of the system was calculated. With the increase of the pinch point temperature difference in the evaporator, the decrease of the system’s exergy efficiency became maximal (11.7%) with the use of R152a as a refrigerant and the loss in the system’s exergy efficiency became minimal (9.03%) with the use of R123 as a refrigerant. Journal of Thermal Engineering Journal of Thermal Engineering 2019-03-13T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2779 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2779 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2779

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3821 2019-06-23T21:00:00Z 4

Parametric Analysis of Electrical Energy Production by Wind Energy for Bozcaada Burhanettin Çetin, Mehmet Doğukan Alpkaya Wind Power Plant, Economic Analysis, Electricity Production Cost, RETScreen In this study, the economic analysis of the wind power plant to be installed in Bozcaada district has been investigated. The aim of this study is to find the most economical wind turbine for Bozcaada and to analyze the electricity production cost for different economic and technical parameters such as interest rate, wind speed, hub height, capacity factor, etc. As a result, the developed model is solved by using RETScreen and Excel program, and then the effect of the studied parameters on electricity generation cost is investigated. The electricity production cost was found minimum for the Vestas V80-67M turbine. Consequently, Vestas V80-67M was preferred as the most suitable turbine for Bozcaada. Journal of Thermal Engineering Journal of Thermal Engineering 2019-06-23T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3821 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3821 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3821

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2768 2019-02-24T21:00:00Z 1

Effects of Kaolin Additions on Thermal Behaviors of Rigid Polyurethane Foams B. Aydoğan, N. Usta Rigid Polyurethane, Kaolin, Thermal Conductivity, Thermal Decomposition Thermal insulation is very important issue in many industrial applications and different materials are preferred to satisfy the thermal insulation depending on the applications. One of the most important properties of the thermal insulation materials is low thermal conductivity. In addition, the cost of the material is another important factor. Among the thermal insulation materials, rigid polyurethane foams are used in automotive, transportation and building sectors due to lower thermal conductivity. Although the thermal conductivity of the rigid polyurethane foam is lower than those of many other thermal insulation materials, other thermal insulation materials may be preferred in some applications due to their lower costs. Therefore, different natural inorganic minerals have been added as fillers into the foams, mainly to reduce raw materials costs. In this study, kaolin, which is a cheap natural inorganic mineral, was incorporated into rigid polyurethane foams in 5, 10 and 15 % in mass. Effects of kaolin addition on thermal decomposition and thermal conductivity of rigid polyurethane foams were investigated. The results revealed that the incorporations of kaolin into the foams slightly increased the thermal conductivities of the foams. However, it was found that kaolin addition enhanced the thermal stability of rigid polyurethane foams. Journal of Thermal Engineering Journal of Thermal Engineering 2019-02-24T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2768 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2768 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2768

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2636 2018-06-28T21:00:00Z 1

Comparison of Thermoeconomic Cost Calculation Methodologies for Dora II Binary Geothermal Power Plant Ceyhun Yılmaz Geothermal Power, Thermoeconomic Analysis, SPECO, MOPSA, Moran Methods This paper presents a comparison of the three thermoeconomic methodologies, SPECO (Specific exergy costing), MOPSA (Modified productive structure analysis) and Moran for an existing binary geothermal power plant in western Turkey. Exergy and exergoeconomic analyses of the Dora II binary geothermal power plant with 9543 kW net power output is carried out by using actual plant data to evaluate plant performances and thermoeconomic costs. The objective of the study is to perform the advantages and disadvantages of the presented thermoeconomic methods with respect to the one other using a binary geothermal plant data. The presented thermoeconomic methodologies are used to reveal and compare the cost flows and products interactions between the system components. The overall energy and exergy efficiencies of the plant are calculated to be 47.3% and 13.5%. The unit exergetic costs of electricity are calculated to be 0.0436 $/kWh for MOPSA method, 0.0367 $/kWh for SPECO method and 0.0355 $/kWh for MORAN method, respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2018-06-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2636 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2636 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2636

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3860 2019-09-21T21:00:00Z 4

Dynamic Performance Characteristics of a Thermoelectric Generator Ahmed S. El-Adl, M.G. Mousa, E.A. Abdel-Hadi, A.A. Hegazi Thermoelectric Generator (TEG), Seebeck Effect, Fins, Temperature of the TEG Sides, Power Output, Conversion Efficiency, Transient and Steady-State Performance The global energy and environmental issues are promoting the development of innovative energy solutions. Thermoelectric generators (TEGs) are regarded as a promising to be a potential alternative to conventional energy technologies. TEG is a device that converts thermal energy directly into electric power by exploiting Seebeck effect. In the present study, dynamic performance characteristics of a TEG is experimentally studied under different operating conditions. The effect of heat input and the influence of utilizing extended surfaces (fins) on both transient and steady state performance of a TEG are experimentally investigated. The variation in the temperature of the TEG hot side and cold side in addition to the power output is taken as a denotation of the performance characteristics. Input heat rate of 15.0 W, 17.5 W, 20.0 W, 22.0W and 25.0 W are applied to the TEG hot side, and natural air convection is the utilized for heat dissipation from the TEG module through the cold side. From experimentation, it is generally can be deduced that increasing the input heat rate provides higher temperature difference across the module sides leading to higher power output. Additionally using fins to aid heat dissipations enhanced the TEG performance by lowering the temperature of cold side and increasing the temperature difference across the module. Consequently, the results showed that under matched load conditions an average increase in power output of 194% and 200% could be achieved when increasing the input heat rate from 15.0 W to 25 W in case of without and with utilizing of fins to aid heat dissipation respectively. In addition, an average increase of 14.9% up to 17.3% in power output is achieved when utilizing fin to aid the heat dissipation of cold side. The maximum conversion efficiency achieved was 5.8% in case of utilizing the fins and for 25.0 W input heat rate. The experimental data obtained are compared with the available data from the literature, and excellent agreement is found. Journal of Thermal Engineering Journal of Thermal Engineering 2019-09-21T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3860 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3860 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3860

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2529 2018-01-23T21:00:00Z 1

Numerical Investigation of Blood Flow Features in Intracranial Saccular Aneurysms Hatice Mercan, Kunt Atalik Hemodynamics, Saccular Aneurysm, Wall shear stress, CFD This study aims to provide insight about how the hemodynamic factors change with artery curvature for a developing aneurysm during a cardiac cycle. The aneurysm is investigated in terms of the vortical structure and the shear stress along the curved artery wall for three developing stages (initial, intermediate and terminal stages), for three instances of a cardiac cycle (diastole end, systole peak and diastole start) and for three different vascular geometries. The stream function vorticity formulation is used with Newtonian constitutive relation. During the systole peak instance for all aneurysm stages, the central vortex squeezes the streamlines towards the distal neck of the aneurysm leading to maximum wall shear stress in the vicinity of the distal wall of the aneurysm. The radius of curvature of the artery and inertial forces increased the wall shear stress along the aneurysm wall. The wall shear stress changes direction and concentrates in the vicinity of the distal neck for all artery geometries. Secondary vortices are observed in the terminal stage during diastole end and diastole start instances for the straight arteries and lead to shear stress fluctuations along the wall. The observations of this study are discussed together with the relevant clinical and numerical literature. Journal of Thermal Engineering Journal of Thermal Engineering 2018-01-23T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2529 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2529 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2529

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3903 2019-12-01T21:00:00Z 1

Computational Aspects of Radiative Transfer Equation in Non-Orthogonal Coordinates Saad Mansoor Phonon Transport, Thin Film, Non-Orthogonal Coordinate, Equivalent Equilibrium Temperature Non-equilibrium energy transfer takes place for thin films when thermal disturbance is introduced. In this case, phonon transport inside the film governs the heat transport and temperature distribution in the film. In the present study an attempt is made to formulate and illustrate the phonon transfer in micro-scale silicon film of various shapes incorporating the non-orthogonal coordinate system. Successful application of the discrete-ordinates method to the solution of the equation for phonon radiative transport in non-orthogonal coordinates requires the application of various numerical techniques connected to the finite-difference method. The numerical solution of the equation for phonon transfer in non-orthogonal coordinate is introduced via adapting the discrete ordinate method. Phonon intensity distribution in the thin film is presented in terms of equivalent equilibrium temperature. It is found that film shape has significant effect on equivalent equilibrium temperature distribution inside the film. The validation study demonstrates that the code developed solving the equation for phonon transport is also applicable to the phonon transport in non-orthogonal coordinate system. Journal of Thermal Engineering Journal of Thermal Engineering 2019-12-01T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3903 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3903 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3903

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2782 2019-03-16T21:00:00Z 1

Operation of HVAC System for Energy Savings and Economic Analysis M. Kassas, W. M. Hamanah, O. Al-Tamimi, A. Sahin, B. S. Yilbas, C. B. Ahmed Air-Conditioning, Energy Savings, Variable Frequency Drives VFD, ON/OFF Cycle, Modeling In recent years, energy savings in air-conditioning (A/C) systems has become one of the hot topics of applied energy towards innovative management and efficient utilization of the operating systems. Achieving thermal comfort with minimum energy consumption is the main concern for innovative designing of an air conditioning system. The A/C system is one of the chief contributors to energy consumption in warm and hot environments. An innovative design of an A/C operating system is essential to satisfy a high thermal performance and maintain the desired thermal comfort level. The aim of this work is to introduce innovative design of an operating system to simulate and experiment the thermal performance of A/C units for two identical houses located in Dhahran area of Saudi Arabia. In this case, the thermal model for both houses has been developed incorporating two different air-conditioning operating systems. In the analysis, several physical properties and parameters, such as climate conditions and heat gain/loss, have been taken into account inside the house. Matlab/ Simulink software is used to simulate the ON/ OFF and the VFD air conditioning controller systems. LabView platform with the data acquisition is utilized for the experimental work to monitor the real time climate and electrical power data. Journal of Thermal Engineering Journal of Thermal Engineering 2019-03-16T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2782 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2782 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2782

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3907 2019-12-01T21:00:00Z 1

Unsteady MHD Micropolar Fluid in a Stretching Sheet over an Inclined Plate with the Effect of Non-Linear Thermal Radiation and Soret-Dufour H. Mondal, S. Mishra, P.K. Kundu, P. Sibanda Micropolar Fluid, Thermal Radiation, Non-Uniform Heat Source/Sink, Magnetohydrodynamics, Thermophoresis The effect of unsteady MHD flow of a micropolar fluid over an inclined plate with thermal radiation and non-uniform heat source/sink, non-linear thermal radiation, chemical reaction and convective boundary conditions has been investigated in the present study. A mathematical model is developed to set of Partial differential equations into non-linear coupled ordinary differential equations and then solved numerically by spectral relaxation method (SRM) with finite difference scheme which employs the Gauss-Seidel type of relaxation approach to linearize and decouple the system of differential equations and then Chebyshev pseudo-spectral method was used to solve the equations. The influence of various physical parameters are depicted graphically and analyzed in details. An excellent agreement of accuracy has found after comparing present work with previously published work. Journal of Thermal Engineering Journal of Thermal Engineering 2019-12-01T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3907 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3907 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3907

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2784 2019-03-24T21:00:00Z 1

Response Surface Based Optimization of Ribbed Isosceles Triangular Twisted Tape Heat Exchanger using Entropy Augmentation Generation Number with Al2O3 Nano Working Fluid K. Pavan Kumar, R. Siddhardha, Ramabhadri Raju, K. Sudheer Kumar Ribs, Isosceles Triangular Projections, Entropy Augmentation Generation Number , Non Parametric Regression, Genetic Algorithm, Micro Genetic Algorithm In this work, a combination of passive techniques like providing ribs on the duct surface, inserting twisted tapes were employed at different configurations and analysed using ANSYS Fluent 17.2. The enhancement is probed by placing ribs on the duct surfaces at various angles. Twisted tape inserts were used in conjunction with ribs on the duct and an output parameter, Entropy Augmentation Generation Number (EAGN) is analysed when having an Al2O3 nanofluid (?=3%) as working medium. In furtherance, tapes of isosceles triangular projections with variable configuration, such as rib angles (300<?< 900), Internal angle (300<ß<900) and projection distance (1mm< x< 5mm) were also inserted in place of plain twisted tape inserts to verify the enhancement promised by this alteration. As expected, rate of heat transfer due to the presence of isosceles triangle projections gave decent augmentation. Later Response Surface based optimization was employed with non-parametric regression and genetic algorithm to make an investigative search of all the modified parameters so as to suggest best blend of inputs for low Entropy Augmentation Generation Number. Optimum performance was obtained at rib angle of 300, projection distance of 2.1mm and Internal angle of 44.40 with entropy augmentation number value of 0.77. The performance of Genetic Algorithm was compared with Micro Genetic Algorithm; it shows that optimized result is obtained less than half the time using Micro Genetic Algorithm Journal of Thermal Engineering Journal of Thermal Engineering 2019-03-24T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2784 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2784 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2784

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3863 2019-09-21T21:00:00Z 4

Entropy Generation Rate in a Microscale Thin Film Saad Mansoor Phonon Transport, Non-equilibrium Heating, Thin Films, Entropy Generation Rate This paper presents a new formulation of the rate of entropy generation in thin films whose thickness is of the order of the mean-free-path or less. In this relation, an expression for the gradient of the equivalent equilibrium temperature is proposed that is a function of the gradient of the phonon intensity at any point inside the thin film. It is shown that the proposed expression reduces to the familiar gradient of the thermodynamic temperature in the diffusive limit. Furthermore, the new formulation is used to compute the entropy generation rate for the case of steady-state, one-dimensional heat transfer in a thin film by first solving the Equation of Phonon Radiative Transfer to determine the phonon intensity. These computations are performed both for the silicon and the diamond thin films, for a range of Knudsen numbers starting from the diffusive limit up until the ballistic limit. It is found that the entropy generation rate attains a peak value at Kn = 0.7 and decreases for other Knudsen numbers when non-equilibrium transport is adopted in the analysis. However, rate of entropy generation increases almost linearly for the equilibrium heating situation. This is true for both the silicon and the diamond thin films. Journal of Thermal Engineering Journal of Thermal Engineering 2019-09-21T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3863 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3863 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3863

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3822 2019-06-23T21:00:00Z 1

Statistical Analysis of Wind Speed Distribution with Sinop-Turkey Application N. Balpetek, E. Kavak Akpınar Wind Energy, Statistical Analysis of Wind Energy Potential, Weibull Distribution, Rayleigh Distribution, Sinop-Turkey In this study, the wind energy potential of the Sinop region was analyzed statistically by using the Turkish State Meteorological Station’s hourly wind speed data between the years of 2005-2014. The two- parameter Weibull and one-parameter Rayleigh probability distribution functions were used to determine the wind energy potential of the region. The probability distribution functions were derived from the cumulative function and used to calculate the mean wind speed and the variance of the actual data. The best way of representing the performance of the Weibull and Rayleigh distributions is to use the statistical parameters such as the correlation coefficient (R2), chi-square (χ2) and the root mean square error analysis (RMSE). The results of the study showed that Sinop has a mean wind speed of 3.36 m/s with a maximum value of 4.28 m/s in February of 2011, and a minimum value of 2.41 m/s in March of 2013, while the corresponding mean wind power density is approximately 33.31 W/m2 for the whole year. In general, it was determined the wind speed is higher during some winter and spring months, notably February and March, and is lower during the autumn months. The Weibull distribution function was found to be more appropriate than the Rayleigh distribution function. Journal of Thermal Engineering Journal of Thermal Engineering 2019-06-23T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3822 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3822 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3822

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2585 2018-04-09T21:00:00Z 1

Performance Analysis of a Diesel Engine within a Multi-Dimensional Framework Hasan Koten Diesel Engine; CFD; Emission; Performance. In this study, large-bore diesel engine combustion was modeled using development combustion model Extended Coherent Flame Models 3 Zones (ECFM-3Z). During this work, the study was made about an engine configuration with compression, spray injection, combustion and emission of the diesel engine. Prediction of in-cylinder combustion phenomenon, effects of turbulence levels, flow structures and emission modeling have an importance in designing efficient engines. Effects of in-cylinder flow structures, fuel injection and design parameters were investigated for the engine performance and emission results. The results agree broadly with experimental and computational studies. As a result, it is aimed to find out the flow structure, spray, combustion and emission characteristics of the large-bore diesel engine. In a precombustion chamber structure, it is seen that controlled combustion starts and then high-pressure gas mixture uniformly spreads into the main combustion chamber. Journal of Thermal Engineering Journal of Thermal Engineering 2018-04-09T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2585 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2585 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2585

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2783 2019-03-16T21:00:00Z 1

Thermoeconomic Analysis of a Water to Water Heat Pump under Different Condenser and Evaporator Conditions Bahri Aksu, Cüneyt Uysal, Hüseyin Kurt Water to Water Heat Pump, Condenser Cooling Water, Thermoeconomic Analysis, MOPSA. A thermoeconomic analysis of a water to water heat pump are performed under different condenser and evaporator conditions. Experiments are realized for different volumetric inlet temperatures of 14.4, 17 and 19 C and different volumetric flow rates of 50, 100, 150 lt/h for condenser cooling water. Same inlet temperatures with condenser cooling water are used for evaporator water inlet, while constant volumetric flow rate of 100 lt/h is used for each case. Modified Productive Structure Analysis (MOPSA) is used for thermoeconomic analysis. It is found that increases in inlet temperature and in volumetric flow rate cause to decrease in both the unit cost of heat delivered (ch ) and the unit cost of entropy generation (cs). As a result, in the case of Tin =14.4 and V= 50 lt/h, and values are obtained to be 0.0489 $/kWh and 0.0221 $/kWh, respectively, while and values are obtained to be 0.0385 $/kWh and 0.0175 $/kWh for Tin=19 and V= 150 lt/h, respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2019-03-16T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2783 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2783 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2783

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2766 2019-02-23T21:00:00Z 4

Selection Criteria for Fusion Reactor Structures Sümer Şahin Fusion Reactors, Structural Materials, Refractory Metals, Molten Salt, First Wall, Radiation Damage Fusion energy is the ultimate energy to cover Mankind’s energy needs forever. However, taming the fusion energy is the greatest technological challenge the humanity is facing. Development of structural materials to withstand against the extreme conditions in the course of fusion power plant operation is one of the toughest nuts to be cracked. A great number of structural materials have been investigated for fusion reactor applications, such as steels (austenitic stainless steels and ferritic/martensitic steels), vanadium alloys, refractory metals and alloys (niobium alloys, tantalum alloys, chromium and chromium alloys, molybdenum alloys, tungsten and tungsten alloys), and composites (SiCf/SiC and Carbon Fibre Composite CFC composites). Steels have extensive technological data base and significantly lower cost compared to other refractory metals and alloys. Ferritic steels and modified austenitic stainless (Ni and Mo free) have relatively low residual radioactivity. However, steels cannot withstand high neutron wall loads to build an economically competitive fusion reactor. Some refractory metals and alloys (niobium alloys, tantalum alloys, molybdenum alloys, tungsten and tungsten alloys) can withstand high neutron wall loads. But, in addition to their very limited technological data base, they have high residual radioactivity and prohibitively high production costs. A protective, flowing liquid zone to protect the first wall of a fusion reactor from direct exposure to the fusion reaction products could extend the lifetime of the first wall to the expected lifetime of the fusion reactor. In that context, a fusion-fission (hybrid) with a multi-layered spherical blanket has been investigated, which is composed of a first wall made of oxide dispersed steel (ODS, 2 cm); neutron multiplier and coolant zone made of LiPb; ODS-separator (2 cm); a molten salt FLIBE coolant and fission zone; ODS-separator (2 cm); graphite reflector. Calculations are conducted for a liquid wall with variable thickness, containing Flibe + heavy metal salt (UF4 or ThF4) is used for first wall protection. The content of heavy metal salt is chosen as 4 and 12 mol%. A flowing wall with a thickness of ~ 60 cm can extend the lifetime of the solid first wall structure to a plant lifetime of 30 years for 9Cr–2WVTa and V–4Cr–4Ti, whereas the SiCf/SiC composite as first wall needs a flowing wall with a thickness of ~ 85 cm to maintain the radiation damage limit. Journal of Thermal Engineering Journal of Thermal Engineering 2019-02-23T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2766 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2766 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2766

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3868 2019-09-26T21:00:00Z 1

Investigation of Lorentz Force Effect on Steady Nanofluid Flow and Heat Transfer Through Parallel Plates Akinbowale Akinshilo, Adeleke Ola Ilegbusi Steady Flow, Nanofluid, Horizontal Plates, Lorentz Force, Homotopy Perturbation Method In this paper Lorentz force effect on steady fluid flow and heat transfer of nanofluid is examined. The nanofluid is transported through horizontal parallel plates with magnetic flux of uniform density acting perpendicular to the plates. The effects of thermo-fluidic parameters such as Schmidt number, viscosity and magnetic parameter on flow and heat transfer are presented. Other important heat and mass transfer parameters such as Nusselt and Sherwood numbers practically relevant were also studied. Obtained results from analytical solutions shows quantitative increase of Magnetic parameter varied within the range of 1-4 depicts increasing temperature distribution. Also results when compared with past literatures forms good agreement. Therefore study provides a good emphasis for the advancements of Nano fluidics such as micro mixing, friction reduction, energy conservation, and biological samples. Journal of Thermal Engineering Journal of Thermal Engineering 2019-09-26T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3868 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3868 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3868

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3823 2019-06-23T21:00:00Z 4

Numerical Simulation and Analysis of Heat Transfer for Different Geometries of Corrugated Tubes in a Double Pipe Heat Exchanger M. Bayareh, A. Nourbakhsh Heat Exchanger, Surface Geometry, Heat Transfer, Nanofluid, Friction Factor In the present study, effect of different geometries of inner and outer tube surfaces on heat transfer of a double pipe heat exchanger is studied. Water-CuO nanofluid, that is assumed to be a single phase, flows in the outer tube. Two-equation standard ?-? turbulence model is used to model the turbulent flow. Simulations are done for different cases include convex, concave and smooth surfaces for inner and outer tubes at different Reynolds numbers. Results show that the maximum heat transfer corresponds to the convex-concave case in comparison with the smooth-smooth one. Heat transfer rate increases with the Reynolds number, but the slope of the increase for nanofluid is lesser than that for the pure fluid. It is demonstrated that the friction factor decreases with the Reynolds number, so the pressure drop decreases as the Reynolds number increases. Also, the simulations are done for two other nanofluids, water-ZnO oxide and water-SiO_2 dioxide with a volume fraction of 3%. It is found that water-CuO nanofluid flow leads to more heat transfer rate in a double pipe heat exchanger in comparison with the other nanofluids. Journal of Thermal Engineering Journal of Thermal Engineering 2019-06-23T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3823 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3823 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3823

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2586 2018-04-12T21:00:00Z 1

Exergo-Sustainability Analysis and Ecological Function of a Simple Gas Turbine Aero-Engine Yasin Şöhret Aircraft, Aviation, Exergy, Gas turbine, Sustainability Nowadays, many environmental issues are of concern as a result of conventional energy resources utilization in addition to a rise in energy costs dependent on the rapid consumption of resources. Therefore, sustainability is an important term for the utilization of energy resources. The aviation industry is known to be responsible for 3% of total CO2 emissions concerning global warming. This forces us to investigate the aviation industry, specifically gas turbine aero-engines. Gas turbine aero-engines, working according to the principles of thermodynamics, similar to other energy conversion and generation systems can be evaluated using the first and second laws of thermodynamics. Integrated employment of the first and second laws of thermodynamics, namely exergy analysis, is an effective method for performance evaluation. Additionally, exergo-sustainability also yields beneficial results. In the framework of the current paper, ecological function is defined for a simple gas turbine aero-engine, while exergo-sustainability assessment methodology is also explained. Exergy efficiency of the compressor, combustor, gas turbine and nozzle, as components of a gas turbine aero-engine, is found to be 91.58%, 57.41%, 97.96%, and 61.25%, respectively. On the other hand, the sustainability measures of the evaluated gas turbine aero-engine in order of exergy efficiency, waste exergy ratio, recoverable exergy rate, exergy destruction factor, environmental effect factor and sustainability index are calculated to be 0.28, 0.71, 0.00, 0.69, 2.45, and 0.40, respectively whereas the ecological function is found to be -8732.21 kW. Journal of Thermal Engineering Journal of Thermal Engineering 2018-04-12T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2586 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2586 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2586

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3993 2020-01-06T21:00:00Z 4

Performance and Ecological Objective Investigation of Two-State Irreversible Quantum Heat Engine Emin Acıkkalp, Mohammad Hossein Ahmadi Quantum Heat Engine, Irreversibility, Ecological Function This paper considers irreversible two-state quantum heat engine. Basic thermodynamic parameters including power output and energy efficiency are considered, besides ecological function. Ecological function gives someone a balance between power output and exergy destruction. The results show that ecological function have maximum (optimum) point for a and there is no optimum point for any parameter for x and y. All parameters are compared with each other and the most convenient operation conditions are recommended. Journal of Thermal Engineering Journal of Thermal Engineering 2020-01-06T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3993 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3993 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3993

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3996 2020-01-07T21:00:00Z 1

Thermal Analysis on Variable Thickness Absorber Plate Fin in Flat-Plate Solar Collectors using Differential Transform Method Jaideep Dutta, Balaram Kundu Absorber Plate, Analysis, DTM, Solar Collector, Variable Plate Thickness This article highlights a parametric investigation of the thermal analysis of variable thickness flat plate solar collector. Triangular profile of an absorber plate has been adopted from the point of view of saving in material. An approximate analytical model based on the Taylor series of expansion has been implemented for finding out the temperature distribution in the heat conduction direction of the absorber plate. Differential transform method (DTM) has been used to establish a new analytical formulation. The Modified Bessel’s function has been applied for the comparison of the results produced by DTM. The variation of several temperature dependent parameters is studied for knowing the dependency effect. The efficiency of absorber plate has been analyzed as a function of Biot number and the impact of aspect ratio on the plate performance has been highlighted. The present analytical approach has ability to determine the thermal performance of an absorber plate under an actual design condition with a minor modification of the analysis. The formulation of the present work is also suitable for the analysis of any shape of an absorber plate in flat-plate solar collectors. Journal of Thermal Engineering Journal of Thermal Engineering 2020-01-07T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3996 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3996 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3996

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3862 2019-09-21T21:00:00Z 4

Assessing the Impact of Passive Cooling on Thermal Comfort in LIG House Using CFD Nisha Netam, Shubhashis Sanyal, Shubhankar Bhowmick Thermal Comfort, LIG, CFD It has been observed that existing low income group (LIG) houses are inefficient to provide thermal comfort in Raipur, Chhattisgarh. This makes more dependency on cooling equipment to achieve thermal comfort which leads to more energy consumption. The objective of the present work is to investigate and enhance the thermal comfort of LIG house by passive cooling techniques. Different cases are considered in the present study are: effect of windows, green roof and green walls and shaded wall etc. on indoor temperature of LIG house for the day of 20th May 2016. Results concluded that at summer when the outside temperature is lower than the inside temperature, it reduces the room temperature but insufficient to provide thermal comfort. It is also concluded that providing green roof along with green walls enhance the indoor temperature of house. Journal of Thermal Engineering Journal of Thermal Engineering 2019-09-21T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3862 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3862 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3862

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2764 2019-02-18T21:00:00Z 4

A Review of General and Modern Methods of Air Purification Aditya Roy, Chetan Mishra, Sarthak Jain, Naveen Solanki Air purifier, PM 2.5, NOx emissions, Bio materials The air purifier industry has seen a growth in terms of demand and sales lately. All credit goes to massive industrialization in developing countries such as India and China. As a result, a lot of research has been focused into the various methods of purifying air. The most harmful of the pollutants are PM 2.5 particulates and NOx emissions. The aim has been to bring down the costs without compromising on efficiency as efficient air purification is an expensive deal. This article presents a study of the current scenario of the problems of air pollution. Severity of the issues have been highlighted. A compilation of the most common and significant methods of purifying air such as those employing the use of HEPA filters, electrostatic smoke precipitators, activated carbon and UV light has been presented and their use in air purifiers manufactured by OEMs has been mentioned. Some of the most modern methods of purifying air such as those using transparent PAN filters, photochemical materials, soy proteins and silk nanofibrils have been studied and reviewed. It has been found that these methods provide an attractive and economical pathway of filtering out PM 2.5 when compared to the conventional HEPA filters. Journal of Thermal Engineering Journal of Thermal Engineering 2019-02-18T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2764 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2764 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2764

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/4062 2020-04-22T21:00:00Z 1

Thermophysical Properties of Deep Eutectic Solvent-Carbon Nanotubes (DES-CNT) Based Nanolubricant Rashmi Walvekar, Amarpreet Singh, Mohammad Khalid, TCSM Gupta, Wong Wai Yin Deep Eutectic Solvent, Carbon Nanotube, Nanolubricant, Viscosity, Thermal Conductivity Lubrication is an important aspect when it comes to machinery and equipment in the industry where nanolubricants are extensively being explored as the future of lubricants. Nanolubricants are new engineered fluids which are dispersed with nanoparticles which aids in the interface movement by forming a protective layer hence reducing the wear and friction. Apart from reducing wear, lubricants also play a vital role in removing the heat generated due to friction. In this research, a new synthetic lubricant is formulated by mixing two or more components of hydrogen bond donors and halide salt that achieves lower melting points compared to individual components. In this study, Glycerol and Polyethylene Glycol 600 (PEG) acts as the HBDs with common salt of Choline Chloride (ChCl). The nanolubricants were synthesised via two step method by dispersing three different concentration of Functionalised Multi Walled Carbon Nanotubes (F-MWCNTs) of 0.01 wt%, 0.05 wt% and 0.10 wt% with the aid of ultrasonication. The stability of the suspensions were studied via optical microscopy and visual observation. The addition of F-MWCNT increased the resultant dynamic viscosity of the nanolubricant whereas the density was not much affected. Besides that, thermal conductivity showed positive enhancement for glycerol DES nanolubricant and negative enhancement for PEG DES nanolubricant. Thus, this study concludes that the thermophysical properties of DES base fluids and MWCNT have potential to be used as lubricants due to its enhanced physical properties. Journal of Thermal Engineering Journal of Thermal Engineering 2020-04-22T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4062 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4062 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4062

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3908 2019-12-01T21:00:00Z 4

Combustion Analysis of CI Engine Fuelled with Algae Biofuel Blends Mahesh Joshi, Sukrut Thipse Algae Biofuel, Performance, Combustion, Emission Algae-based biofuels are the most capable solutions to energy catastrophe and global warming for years to come due to its potentially high yield, higher growth rate, biodegradable, nontoxic, carbon neutral, low emission profile, use of non-arable land and non-potable water with less attention and resource consumption. A biofuel produced from chlorella algae oil through a transesterification process was used in this study. Experimental tests were performed on a single cylinder, four stroke, direct injection, naturally aspirated diesel engine at constant engine speed of 1500 rpm and compression ratio of 18 at various loading conditions to evaluate the performance, emission, and combustion characteristics using algae biofuel blends of 5%, 10%, 20%, and 30%, moreover the results are compared with those of standard diesel. The brake thermal efficiency showed decreasing trend (upto 5%) whereas specific fuel consumption (upto 7%) and exhaust gas temperature (upto 3%) showed increasing trend for algae biofuel blends compared to diesel. Reduction in hydrocarbon (upto 28%) and carbon monoxide (upto 22%) emission was noted for algae biofuel blends along with a marginal increase in NOx (upto 13%) emissions. Also, algae biofuel blends showed almost comparable combustion results compared to conventional diesel, however, the blends confirm shortened ignition delay due to their earlier start of combustion. From this study, we can conclude that small fraction by volume (20%) of algae biofuel addition with diesel has exhibited satisfactory results and could be used as a good substitute for petrodiesel fuel. Journal of Thermal Engineering Journal of Thermal Engineering 2019-12-01T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3908 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3908 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3908

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2753 2019-01-28T21:00:00Z 1

Experimental Investigation and Performance Optimization of a Cross Flow Heat Exchanger by Entropy Generation Minimization Approach T. Mohapatra, S. K. Rout Experimental investigation, Counter flow heat exchanger, Performance optimization, Exergy analysis, Taguchi method The exergy loss and performance optimization of a cross flow heat exchanger (CFHE) with air and hot water as working fluid have been experimentally investigated. Experiments are performed on various mass flow rates of hot water and air over a ranges of 0.015 kg.s-1 – 0.04 kg.s-1 and 0.117 kg.s-1 - 0.763 kg.s-1 respectively. To validate the results of the present study, they are compared with available data in literature through which a reasonably a good agreement is obtained between them. This study demonstrates the successful application of Taguchi approach for optimal design of the (CFHE). The effects of design parameters and two different operating conditions such as the fin pitch, the inside tube diameter and the mass flow rate of water and air on exergy loss are investigated. In the Taguchi experimental design method, exergy loss is considered as performance parameter and it is revealed that parameter combinations such as , , and resulted optimum performance. Contribution ratios of each parameter on exergy loss are assessed. Mass flow rate of air is determined to be the most effective parameter on exergy loss with a contribution ratio of 51.26 % followed by mass flow rate of hot water, fin pitch, and diameter contribution ratios of 35.91 %, 7.02 % , 5.79 % respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2019-01-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2753 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2753 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2753

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3983 2020-01-05T21:00:00Z 1

Numerical Investigation of Laminar Mixed Convection in a Square Cross-Sectioned Cylindrical Annular Enclosure Osman Turan Mixed Convection, Rotating Wall, Richardson number, Cylindrical Enclosure, Annular Enclosure Steady-state laminar mixed convection of Newtonian fluids in a square cross-sectioned cylindrical annular enclosure with rotating inner wall and heated top cover has been numerically analysed based on axisymmetric incompressible flow simulations. Richardson number, Reynolds number and r_i/R effects on heat and momentum transport have been investigated for the range of Richardson number 0 ≤ Ri ≤ 1, Reynolds number 500 ≤ Re ≤ 2000 and 0.25≤r_i/R≤8 at a representative value of Prandtl number (i.e. Pr=1.0). A scaling analysis has been also carried out in order to elucidate the possible influences of Reynolds, Richardson and Prandtl numbers and r_i/R on the mean Nusselt number. It has been found that the mean Nusselt number (Nu) ̅ demonstrates a monotonically decreasing trend with increasing Ri whereas (Nu) ̅ increases with increasing r_i/R and Re which is consistent with scaling estimation. It is also observed that the flow pattern in the case of purely forced convection (i.e. Ri = 0) is significantly different from those in mixed convection (i.e. Ri> 0). In the case of Ri = 0 (i.e. purely forced convection), a one-cell flow structure with two small vortexes on the top corners is observed for r_i/R≤1, whereas a second cell appears in the flow field for r_i/R> 1 at Re = 1000. On the other hand, in the case of mixed convection (i.e. Ri> 0), two-cell and four-cell flow structures occur in the flow field depending on Ri and r_i/R for the range of Ri, Re and r_i/R considered here at Pr⁡=1.0. Based these observations, a flow regime diagram has been proposed here for mixed convection (i.e. Ri> 0) for the range of Ri, Re and r_i/R analysed in this study. Journal of Thermal Engineering Journal of Thermal Engineering 2020-01-05T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3983 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3983 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3983

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2679 2018-09-27T21:00:00Z 1

Experimental Examination of Heat Transfer Performance of the Heated Radiant Wall System Aliihsan Koca Radiant heating, Heat transfer coefficient, Radiant Wall heating In recent years, radiant heating systems have been catching more observation under favor of the many advantages such as; energy saving and thermal comfort. However, owing the fact that limited information on the system dynamics and the heat transfer characteristics of radiant systems, conventional systems are still preferred to radiant systems. Thereupon, radiant ceiling and floor systems are favored to wall systems. Also previous researchers have focused on radiant ceiling and floor systems instead of radiant wall systems. For this reason, a controlled climatic test set-up was built and detailed examinations were conducted. In this regard, to evaluate the heat transfer coefficients of the radiant wall panels, 10 different test cases were run using different supply water temperatures. On the basis of the obtained measurements, in the steady state, heat transfer coefficients, depending on the characteristic temperature differences and the heat transfer rates have been calculated. According to the results, the approximate mean values of 2.40, 5.49 and 8.29 W/m2K were evaluated, respectively for the convective, radiant and total heat transfer coefficients of radiant wall heating systems. Journal of Thermal Engineering Journal of Thermal Engineering 2018-09-27T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2679 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2679 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2679

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2587 2018-04-13T21:00:00Z 1

Development of a Cooling Die Used in Plastic Pipe Processing: Numerical and Experimental Analysis Zafer Gemici Plastic Pipe, Muff, Hot-forming, Cooling, Numerical and Experimental Analysis In this study, cooling of a plastic pipe-end during a hot-forming process that is one of the commonly used forming methods in plastic pipe production to get seal housing place (muff) was investigated numerically and experimentally. The aim of this study was development of a cooling die that has higher cooling performance and easier manufacturability. Cooling is supplied by the circulation of conditioned water in the channels located in the die in plastic production. The geometry of these channels and mass flow rate and temperature of the cooling water are the parameters affecting the quality of the formed region and process time. In the study, experimental analyses were performed, then numerical analyses were realised and validated with the experimental results for the existing die geometry. Continuity, momentum and energy equations were solved all together and heat transfer was investigated. After validating the model, a few different alternative die models were proposed and analysed to get an optimum which has highest cooling capacity and process ability. At the end of these studies, optimum alternative die geometry was determined. The channels in the suggested die were developed to increase the homogeneity of the cooling by changing the existing channel’s shape which can be produced by only longitudinal holes. A simple production method was also suggested for the new die to locate the channels following the circumference of the pipe, like conformal cooling channels. Additionally, aluminium material was also used to decrease the pipe temperature and die weight in the analyses. In conclusion, although cooling process time and mean temperature of the pipe-end were 30 secs and 43.9 oC respectively for the existing cooling die, these values were determined as 30 secs and 39.5 oC for the optimised aluminium die. If the temperature of the cooled pipe is taken as the same with the existing cooling, the cooling time decreases to around 20 secs for the suggested die. The weight of the die was reduced from 86.57 kg to 16.22 kg. Journal of Thermal Engineering Journal of Thermal Engineering 2018-04-13T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2587 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2587 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2587

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3995 2020-01-07T21:00:00Z 1

Economic and Environmental Impacts of Thermal Insulation Used in Different Duct Sizes Dileep Kumar, Sanjay Kumar, Bilawal Ahmed Bhayo, Khanji Harijan, Muhammad Aslam Uqali Optimum Insulation Thickness, Energy Saving, Life Cycle Cost Analysis and Environmental Analysis In this study, the economical and environmental impacts of insulation material are determined for different sizes of heating, ventilation and air conditioning (HVAC) duct. The optimum insulation thickness (OIT), energy saving (ES) and payback period (PP) for HVAC duct are estimated using LCC analysis. The analysis considers coal, natural gas (NG), liquefied petroleum gas (LPG), fuel oil (FO), bagasse, rice husk (RH) and geothermal as an energy source and the fibreglass as an insulation material. The results indicate the OIT and PP for an HVAC duct increase with the size of the duct while ES decreases. The maximum value OIT, ES and lower value PP among different sizes and energy sources is determined as 48.27mm for size A and NG, 84.91% for size E and LPG, and 0.2035year for size A and NG, respectively. Additionally, the environmental analysis results indicate emission of CO2, CO and SO2 decreases with insulation thickness. The maximum value of CO¬2 and CO emission is determined for size E and NG i.e. 40.9% and SO2 emission for size E and FO i.e. 38.33%, respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2020-01-07T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3995 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3995 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3995

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5220 2020-11-29T21:00:00Z 1

Mixed Convection in a Single-Walled Carbon Nanotube-Water Nanofluid Filled Partially Heated Triangular Lid-Driven Cavity Having an Elastic Bottom Wall Fatih Selimefendigil, Hakan Öztop carbon nanotube, nanofluid, flexible wall, mixed convection, simulation In this study, mixed convection of nanofluid filled triangular cavity with a partial heater and having an elastic bottom wall is analyzed with finite element method. Left vertical wall is partially heated while the inclined wall is kept at constant lower temperature. The bottom wall is flexible and inclined wall is moving at constant speed. Influences of Richardson number, elastic modulus of flexible wall, solid nanoparticle volume fraction on the convective heat transfer characteristics are analysed. It was observed that, lower values of Richardson number, elastic modulus of the flexible wall and higher values of nano-particle volume fraction resulted in higher local and average heat transfer enhancements. Average heat transfer enhanced significantly when solid particle volume fraction of nanoparticle was increased. Enhancements up to 121% were obtained at solid volume fraction of 0.04 as compared to pure water at Richardson number of 1. Effects of elastic modulus of the bottom wall were found to be marginal and at Ri=1, enhancements up to 2% were achieved by using a more flexible wall. Journal of Thermal Engineering Journal of Thermal Engineering 2020-11-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5220 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5220 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5220

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2763 2019-02-18T21:00:00Z 1

Drying Characteristics Investigation of Black Mulberry Dried Via Infrared Method Ibrahim Doymaz, Azmi Seyhun Kıpçak Drying, Black Mulberry, Infrared, Modelling, Effective Moisture Diffusivity, Activation Energy In this study, the drying characteristics of black mulberry were studied by using the drying method of infrared. Infrared power levels were selected between 50 and 104 W. The obtained drying data were applied to several drying models (Aghbashlo et al., Page, Parabolic, Wang and Singh and Weibull), which gave the high the coefficient of determination (R2) values. The best modelling method were selected based on the highest R2, and the lowest reduced chi-square (?2), and root mean square errors. Also, the effective moisture diffusivity was calculated using the Fick’s second law’s spherical coordinate approximation. The activation energies were calculated from the values of the effective moisture diffusivity with respect to mass over power levels. From the results it was seen that the Parabolic type of drying model best fits the data obtained with the R2 values between 0.997849 (104 W) - 0.999664 (62 W). The effective moisture values were obtained between 1.14?10-9 - 3.08?10-9 m2/s and increased as the infrared power level increased. The activation energy was calculated as 2.015 kW/kg. Journal of Thermal Engineering Journal of Thermal Engineering 2019-02-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2763 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2763 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2763

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2769 2019-02-24T21:00:00Z 1

Magnetohydrodynamic Flow in a Truncated Conical Enclosure Ali Bendjaghlouli, Brahim Mahfoud, Ameziani Djamel Axisymmetric, Asymmetric,Counter-rotation, Conical enclosure, Magnetohydrodynamic The effect of an axial magnetic field on the flow produced by counter-rotation of the top and bottom disks in a truncated conical enclosure filled with a liquid metal is studied. The governing Navier-Stokes, and potential equations are solved by using the finite-volume method. It was observed that the Reynolds number is increased, the axisymmetric basic state loses stability and giving an asymmetric mode m=1. It is also found that the primary thresholds Recr corresponding to the modes m=1 increase with increasing of the Hartmann number (Ha). Finally, stability diagram (Re-Ha) has been established according to the numerical results of this investigation. Journal of Thermal Engineering Journal of Thermal Engineering 2019-02-24T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2769 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2769 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2769

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2683 2018-09-28T21:00:00Z 1

Energy Consumption of Defrosting Process in No-Frost Refrigerators D. B. Özkan, F. Ünal Energy Consumption of Refrigerator, Defrosting Process, Energy Saving in Refrigerator Refrigerators have a high energy consumption because they consume energy throughout the day, and they are used in all residences and in most offices. Designing more efficient models and, thus, decreasing the energy consumption of refrigerators have become necessary, owing to the global energy scarcity. The purpose of this study was to decrease energy consumption and increase the efficiency of the defrosting process in no-frost refrigerators. The defrosting process plays an important role in the energy consumption of no-frost refrigerators. The amount of energy needed for defrosting and the time it takes are important factors for manufacturers in terms of energy performance. Recently, a theoretical correlation was developed as a function of the frost thickness, heat flux, and frost density for estimating the defrosting time of an evaporator fin surface. The melting time of the frost on the fin was calculated by a mathematical model, and compared to results that were obtained experimentally. The results were differ from the actual melting time as 4.7% . Journal of Thermal Engineering Journal of Thermal Engineering 2018-09-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2683 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2683 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2683

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3859 2019-09-21T21:00:00Z 1

Determination of Convective, Radiative, and Total Heat Transfer Characteristics over a Radiant Heated Ceiling: A Computational Approach Ozgen Acikgoz Ceiling Heating, CFD, Radiation, Convection In the present study, a computational investigation is carried out within a model room of which dimensions has also been given in international standards for experimental approaches. In accordance with the experimental standards, the analyses are realized at the room dimensions of (LxHxW= 4x3x4 m), and at the thermal boundary conditions of (Tc= 35 – 50oC), (Tw= 15 – 24oC), (Tf= 15 – 24oC). As a result of iterations conducted using a computational fluid dynamics package program code, each corresponding to a case study, convective, radiative, and total heat fluxes from radiant heated ceiling are obtained, and afterward using relevant reference temperature proposed in the literature, heat transfer coefficients pertaining to convection, radiation, and total heat transfer have been found. In conclusion, average heat flux values of 95.83 Wm-2 and 17.49 Wm-2 are gained through the examined radiant heated ceiling, by means of radiation and convection, respectively. This denotes that roughly 85% of total heat transfer from the ceiling arises through radiation that is very compatible with the relevant literature. Finally, spanning the entire different case studies, average convective, radiative, and total heat transfer coefficients of 1.1 Wm-2K-1, 5.4 Wm-2K-1, 7.6 Wm-2K-1 are acquired. Journal of Thermal Engineering Journal of Thermal Engineering 2019-09-21T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3859 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3859 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3859

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3911 2019-12-03T21:00:00Z 1

Second Law Analysis of Mixed Convection of Magnetohydrodynamic Flow in an Inclined Square Lid-Driven Enclosure Elif Büyük Öğüt Lid-driven Enclosure, Mixed Convection, Entropy Generation, Magnetic Field Second law of thermodynamics analysis is formulated for the case of laminar mixed convection in an inclined square lid-driven enclosure in the presence of magnetic field. Vertical sides of the enclosure moves upward when inclination angle is zero. Governing equations of flow and temperature in the form of stream function-vorticity formulation were solved numerically using the differential quadrature method. Governing parameters are: Richardson number (from 0.01 to 100), Prandtl number (from 0.1 to 1.0), inclination angle of enclosure (from 0? to 180?), Hartmann number (from 0 to 100) and magnetic field direction (0?). It is found that the inclination angle of enclosure is effective parameter on entropy generation especially for higher Richardson number (Ri > 1) due to domination of natural convection. However, Hartmann number is effective on both heat transfer and entropy generation for all values of Richardson and Prandtl numbers and it decreases the convective fluid flow and entropy generation. Journal of Thermal Engineering Journal of Thermal Engineering 2019-12-03T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3911 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3911 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3911

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3989 2020-01-05T21:00:00Z 1

Comparative Maximum Power Density Analysis of a Supercritical CO2 Brayton Power Cycle Asım Sinan Karakurt, Veysi Bashan, Yasin Ust Power Density, Supercritical CO2 Cycle, Brayton Cycle, Thermodynamics The supercritical CO2 (s-CO2) power cycle has been taking into account as one of the most effective alternatives for energy conversion because of its higher efficiency and smaller compressor and turbine sizes for many years. A plenty number of parametric and experimental studies for the different type of s-CO2 cycles have been accomplished in the literature. In this paper, a performance analysis based on a power density criterion has been carried out for a simple s-CO2 Brayton power cycle. The parameters which are obtained from analyzes were compared with those of a power performance criterion that is shown that design parameters at maximum power density give a chance to smaller cycle components and more efficient s-CO2 Brayton power cycle. Due to loses in the cycle, the power and thermal efficiency will reduce by a certain amount, however, the maximum power density conditions will still give a better performance than at the maximum power output conditions. The analysis exemplified in this paper may provide a reference for the finding of optimal operating conditions and the design parameters for real s-CO2 Brayton power cycles. Journal of Thermal Engineering Journal of Thermal Engineering 2020-01-05T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3989 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3989 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3989

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3909 2019-12-02T21:00:00Z 1

Comparison Study of Air and Thermal Oil Application in a Solar Cavity Receiver Alibakhsh Kasaeian, Reyhaneh Loni, Ezzatollah Askari Asli-Ardeh, Barat Ghobadian, Kazem Shahverdi Cavity Receiver, Mass Flow, Solar Irradiation, Thermal Oil, Air Nowadays, solar dish collector with a cavity receiver is accounted as an efficient and compact system for converting solar radiation energy into thermal energy. All of the incoming solar irradiation to the dish aperture area is concentrated at the dish focal point where the solar receiver is located. In the current study, the thermal performance of the dish collector with a rectangular cavity receiver was evaluated. Air and thermal oil were examined as the solar working fluids. The performance of the solar dish collector was evaluated at different values of the mass flow rate ranging from 0.002 to 0.06 kg/s as well as different solar irradiation ranging from 600 to 1200 W/m2. The results revealed that the collector efficiency improved with increasing the mass flow rate and solar irradiation. The thermal performance of the solar dish collector improved with the application of the thermal oil as the solar working fluid compared to the air in the investigated solar system. The results indicated the higher cavity surface temperature could be achieved by using air as the solar working fluid compared to the thermal oil. Journal of Thermal Engineering Journal of Thermal Engineering 2019-12-02T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3909 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3909 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3909

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3867 2019-09-24T21:00:00Z 4

Thermal Evaluation of Cavity Receiver using Water/PG as the Solar Working Fluid R. Loni, A. Kasaeian, E. Askari Asli-Ardeh, B. Ghobadian, G. Najafi Numerical modelling; cavity receiver; energy analysis; propylene glycol In this study, a parabolic dish concentrator with a cavity receiver was investigated. Water/ Propylene Glycol (PG) was used as the solar heat transfer fluid. Thermal numerical modelling was developed for prediction of the cavity receiver performance. The water/PG in different volume fractions (VF) of the PG was examined consist of 0%, 25%, 50%, and 55%. The working fluid inlet temperature is investigated in ranging 0oC to 100oC. The results revealed that the thermal efficiency and the cavity heat gain decreased by increasing the GP volume fraction. The pressure drop and pumping work demand decreased by increasing the working fluid inlet temperature as well as decreasing the PG volume fraction in the pure water. Consequently, the pure water had the lowest amount of the pressure drop among the investigated working fluids. The cavity surface temperature increased by increasing the working fluid inlet temperature as well as increasing the PG volume fraction in the pure water. Consequently, the application of the higher amount of PG is recommended for the Bryton cycle. Journal of Thermal Engineering Journal of Thermal Engineering 2019-09-24T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3867 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3867 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3867

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3910 2019-12-02T21:00:00Z 1

Evaluating Integration of Biomass Gasification Process with Solid Oxide Fuel Cell and Torrefaction Process H. Abbasi, F. Rahimpour, F. Pourfayaz, A. Kasaeian Solid Oxide Fuel Cell, Biomass, Gasification, Renewable Energy In the present study, the integration of a solid oxide fuel cell with the biomass gasification process in which the torrefied biomass produced in a torrefaction process is used as the feedstock has been investigated. This novel design gives the power generation system the advantage of eliminating the filtration of the fuel cell inlet gas. This is because of the absence of sulfur and its derivatives in the synthesized gas owing to the terrified biomass, as the feedstock of the gasification process. Moreover, the integration of the processes makes it possible to employ the heat recovery methods. Therefore, by using the high-grade thermal energies for preheating process flows, the presented design considers the maximum available heat recovery and minimum heat and mass losses. The optimum design is determined by the sensitivity analysis and then simulated using the ASPEN PLUS software and its performance has been studied. It was specified that in the optimum operation state, the gasifier outlet temperature and pressure are 950 °C and 5 bar, respectively. Also, the oxygen flow rate in the anode of SOFC and the combustion chamber are 3.03 and 0.81 kmol/h, respectively. Moreover, the results showed that the presented design causes an improvement in the performance of the fuel cell. The electrical efficiency and the overall efficiency of the system are determined to be in the range of 63-69% and 80-85%, respectively. Also, it was revealed that the presented design has the power generation capacity of 100 to 997 kW. Journal of Thermal Engineering Journal of Thermal Engineering 2019-12-02T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3910 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3910 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3910

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3824 2019-06-23T21:00:00Z 1

Cost Effective Operation of HVAC System under Thermal Disturbance O. Al-Tamimi, M. Kassas, W. M. Hamanah, B. S. Yilbas HVAC, Energy Consumption, Variable Frequency Drives VFD, ON/OFF Cycle, Cost Analysis Varying cooling load requirements in HVAC system become a major concern to many consumers because of the additional cost of electricity. The cooling load variation of HVAC system usually occurs when the domestic house door is frequently kept open for prolonged durations, which is particularly important in hot seasons. The present study, addresses a comparison of energy consumption due to the thermal disturbance during domestic house door keep opened for various duration when the Variable Frequency Driver (VFD) and ON/OFF controllers are installed in HVAC system. The experiments are carried out in two identical houses during six warm days in a hot season where the outdoor temperatures have similar patterns throughout the days. The energy response of HVAC system is analysed incorporating the thermal and the electricity consumption data because of the change of the indoor temperature during opening of the house main door. The cost analysis is carried out and it is extended to include several repeats of door opening durations. It is the first time demonstrated that the energy consumption for HVAC system increases dramatically when the house main door is kept opened for several times in a day. The energy consumption and additional cost increase significantly for the case when the period of the main door opening is extended. In this case, VFD A/C controller unit achieves more energy savings than that of ON/OFF A/C controller unit. Journal of Thermal Engineering Journal of Thermal Engineering 2019-06-23T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3824 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3824 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3824

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2770 2019-02-24T21:00:00Z 1

Method of Indirect Determination of Thermal Load Parameter Yurii Baidak, Iryna Vereitina Transformer, Thermal subsystem, Energy efficiency, Thermal load, Timing diagrams of temperatures An indirect method for determining the effectiveness of the transformers operating in a distribution network with variable load schedules, according to the parameter of their thermal load as a ratio of heat accumulated by transformer oil to the maximum permissible heat is proposed provided the thermal stability of the insulation. A mathematical model is developed which allows establishing analytically the forced temperature value and time invariable of heating or cooling on the section of the time dependence of the oil temperature, as well as an algorithm for calculating the amount of heat accumulated by the oil and the coefficient of heat transfer from the oil to the transformer tank is compiled. Approbation of the indirect method indicates that the divergence between the transformer oil heating time invariable which was obtained by solving the differential equation of thermal balance and calculated using the part of temperature dependence of its heating for two minutes, is 3.6%, and at determination of the forced temperature value - 0.8% Journal of Thermal Engineering Journal of Thermal Engineering 2019-02-24T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2770 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2770 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2770

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2771 2019-02-24T21:00:00Z 1

Thermoeconomic Analysis of Biogas Engines Powered Cogeneration System N. Doseva, D, Chakyrova Biogas engine, Cogeneration, Exergy, Thermoeconomics This study presents an analysis of an existing biogas engines-powered cogeneration system installed in Varna Wastewater Treatment Plant, Bulgaria using thermoeconomic method. The thermoeconomic analysis is conducted using three different groups of environmental conditions. The SPECO (specific exergy cost) method is applied to the system and cost balance equations are formulated for each component. The fuel F and the product P rules are used to obtain auxiliary equations. Moreover, in this paper, various thermoeconomic performance parameters such as the cost of exergy destruction, the relative cost difference and the exergoeconomic factor are determined. The obtained results show that the specific unit exergetic cost of the electrical power produced by the cogeneration system are found to be 30.0€/GJ = 0.11€/kWh, while the conducted thermoeconomic analysis based on energy delivers a result of 0.19€/kWh for the electrical work produced by biogas engines. In addition, the obtained results are compared to those seen in similar studies. Journal of Thermal Engineering Journal of Thermal Engineering 2019-02-24T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2771 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2771 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2771

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/4065 2020-04-22T21:00:00Z 4

An Investigation of Effect of Control Jets Location and Blowing Pressure Ratio to Control Base Pressure in Suddenly Expanded Flows Khizar Pathan, Prakash S. Dabeer, Sher Afghan Khan Area ratio, base pressure, blowing pressure ratio, Mach number, nozzle pressure ratio The drag force is an important factor in any projectile from road vehicles to rocket or aircraft. The total drag includes skin friction drag, wave drag and base drag. The base drag is the drag due to low pressure in the base region of the projectile. In case of suddenly expanded flows, due to sudden expansion of flow from nozzle into enlarged duct, the low pressure is created in the base region of enlarged duct which results in base drag and hence resultant thrust reduced. In this paper Computational Fluid Dynamic (CFD) approach is used to analyze the effect secondary air blowing holes called control jets to control base pressure in the base region of suddenly enlarged duct. The control jets are the secondary air blowing jets provided at different pitch circle diameters on base face of enlarged duct. The aim of the control jets is to increase the base pressure up to atmospheric pressure and hence reduces the drag. The nozzle is designed for Mach number 3.0. The CFD analysis is done for all the combinations of area ratios, nozzle pressure ratios and pitch circle diameters. Further analysis is done for different air blowing pressure ratios to optimize air blowing pressure. All the analysis results are compared with the help of graphs. By observing all the results it can be concluded that the control jets are very effective to increase base pressure. The air blowing pressure should be optimum to save energy and one can select optimum value by observing the results. Journal of Thermal Engineering Journal of Thermal Engineering 2020-04-22T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4065 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4065 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4065

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5222 2020-11-29T21:00:00Z 1

Characterization of Aerogel Based Thermal Insulation Blankets, Economics, and Applications for Domestic Water Heaters Emadeddin Y. Tanbour, Moh'd-Eslam Dahdolan, Mahmoud R. AlOmari, Oumar R. Barry High Performance Insulation, Aerogel Insulation Blankets, Thermal Insulation, High Efficiency Appliances, Thermal Conductivity, Economic Analysis of Alternative Insulation Materials One of the main ways to improve the performance of thermal systems is using better thermal insulation. Recent developments of high performance thermal insulation introduced thermal insulation blankets for low and moderately high temperature applications. One of the leading insulation technologies are aerogel based insulation blankets. Before studying the performance of thermal systems insulated with these materials, it is important to characterize these blankets under conditions similar to the operating conditions. In this study, thermal conductivity measurement experiments are done on Low Temperature High Performance Insulation (LTHPI) and High Temperature High Performance Insulation (HTHPI) blankets and their results will be discussed. Tests also conducted are scanning-electron-microscope (SEM) imaging to better understand the nano-structure and thermal conductivity test. Results in this paper show SEM images for Aspen®’s Spaceloft® and Pyrogel® XT-E blankets, and X-ray imaging showing the components inside the blankets’ aerogel to be Silicon, Oxygen, and Carbon. Thermal conductivity measurements were conducted for both LTHPI and LTHPI insulation materials. The thermal conductivity results confirm the results mentioned in the literature, showing that the thermal conductivity is 0.0159 W / (m.K) for LTHPI and 0.0188 W / (m.K) for HTHPI at 25 oC. It can be said that the tested blankets show a promising performance in thermal systems. This paper also demonstrates a comparison of utilizing high performance thermal insulation with current industry practice in domestic water heaters, and a discussion on its economic impacts for individual and national levels. This discussion shows that a minimum of 3.7 billion USA dollars can be saved annually by adjusting regulations to enforce water heater manufacturers to use HPI in their products. Keywords: Thermal Conductivity, Aerogel Thermal Insulation Blankets, Domestic Water Heaters, Economics of Aerogel Insulation, Aerogel Blankets Characterization, Scanning-Electron-Microscopy of Aerogel Blankets. Journal of Thermal Engineering Journal of Thermal Engineering 2020-11-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5222 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5222 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5222

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3986 2020-01-05T21:00:00Z 1

Thermodynamic Optimization of an Irreversible Regenerated Brayton Heat Engine Using Modified Ecological Criteria Ranjana Arora, Rajesh Arora Modified Ecological Function, Irreversible Brayton Heat Engine, Regenerators, Isothermal Heat Addition, Thermodynamic Optimization The modified configuration of regenerated Brayton heat engine along with supplementary addition of heat in its irreversible mode is thermodynamically investigated and optimized. The definite temperature differential between system/reservoir is the source of external irreversibility and the losses because of rubbing/friction in turbine/compressor, regeneration heat losses and losses due to pressure drop are the internal irreversibilities considered in this analysis. The difference of output power and the exergy destruction rate, termed as ecological function, is thermodynamically optimized. It is found that regenerative effectiveness plays a vital role in obtaining maximum possible ecological function whereas output power and 1st law efficiency predominantly depends on the cold side effectiveness in the system. It is also observed that the thermodynamic performance of proposed system/device is prominently depends on the efficiency of the turbine and consequently less dependent on compressor efficiency. The major outcome of this analysis is that with the inclusion of additional thermal heats at constant temperature conditions, various performance parameters i.e., output power (about 13%) and 1st law efficiency (about 9%) of the model get improved significantly in comparison with the conventional gas power plant. Moreover, the model investigated in this study yields lesser output power, first law efficiency and ecological function and exactly follows the results/outcomes presented in the available literature at α1=α2=1, which are the pressure recovery coefficients at two ends. Journal of Thermal Engineering Journal of Thermal Engineering 2020-01-05T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3986 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3986 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3986

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5216 2020-11-24T21:00:00Z 1

Experimental and Numerical Investigations of Solar Flux Density Distribution Over Flat Plate Receiver of Model Heliostat System Prakash Gadhe, Shivalingappa Sapali, Govind Kulkarni Central Receiver System, Ganged Heliostats, Peak Flux, Average Flux, SolTrace The flux density distribution and the temperature of the receiver are important parameters to assess the net thermal energy of any Solar Power Concentrator. In the present work, a heliostat field utilizing ganged type of heliostats for process heating application has been designed. A prototype model of the central receiver system consisting of ganged heliostats has been constructed and installed at Pune, Maharashtra, India. A thermocouple method was used to evaluate the total energy focused by the model heliostat system on a flat receiver. The flux density distribution was validated with the ray tracing simulation software ‘SolTrace’. The simulated flux density distribution was found to be in agreement with the measured one for a surface normal error of 10 milliradian. A heliostat field having 100 m2 total mirror area was designed in the north south cornfield layout. This heliostat field was simulated in ‘SolTrace’ software by considering the surface normal errors as 10 milliradian and the total energy gain was estimated. For the purpose of simulation to investigate the solar flux falling on the receiver, four days of the year were selected. It includes the March equinox, summer solstice, September equinox, and winter solstice. Journal of Thermal Engineering Journal of Thermal Engineering 2020-11-24T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5216 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5216 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5216

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3990 2020-01-06T21:00:00Z 1

A Practical Method for Determination of Economic Insulation Thickness of Steel, Plastic and Copper Hot Water Pipes Nuri Alpay Kurekci, Mehmet Özcan Heat Transfer Pipes, Optimum Insulation Thickness, Energy Saving, Thermo-Economic Analysis, Mathematical Modeling, Thermal insulation Hot water systems are being extensively used in residential as well as industrial contexts. Choice of insulation material’s thickness has a significant effect on total cost. The purpose of this study was to develop a simplified but accurate empirical method that allows to determine the optimum thicknesses of the insulation materials that are applied on the hot water pipes. In the first step, a comprehensive mathematical model was constructed for the calibration and validation purposes. Then, the heat transfer between the flow inside the pipe and the external environment was thermally modeled; followed by a calculation of fuel and insulation costs. After that, the total cost analysis method was applied in order to define the optimum insulation thickness. Later an empirical method was developed based on the mathematical model. Finally, the accuracy of the empirical method was tested, using a wide range of physical conditions as well as different insulation materials, pipe and fuel types. The standard optimum insulation thickness values were founded same for the all pipe types with the identical diameters. The heat losses can be reduced around 89, 88 and 83% by application of optimum insulation thickness to steel, copper and plastic pipes respectively. Larger pipes have higher net savings and lower payback periods. Fuel-oil is the least economic heating solution; therefore the application of insulation brings higher profits than the other fuels. Prediction accuracy of the empirical method is higher for the steel and copper pipes than the plastic pipes. An average matching rate of 91.4% indicated that the new method is a valid and time-saving alternative, which can be used in pipe insulation applications. Journal of Thermal Engineering Journal of Thermal Engineering 2020-01-06T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3990 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3990 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3990

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2773 2019-02-24T21:00:00Z 1

Design, Produce and Control of a 2-DOF Upper Lımb Exoskeletal Robot Ahmet Yavuz, Erhan Akdoğan, Mehmet Emin Aktan, Ahmet Taha Koru Biomechatronics, exoskeletal robot, rehabilitation, mechatronics design Exoskeletal robots are used as high-tech products in the military, health, and industrial applications. The integration of robots and humans offers new opportunities for the creation of new assistive technologies that can be used in biomedical, industrial and aviation applications. This paper describes the mechanical design, modeling, and simulation of 2 degrees of freedom (DOF) upper limb exoskeletal robot. The system can be used both for supporting a payload and for rehabilitation of upper limbs. A load cell was used to measure the applied load while two encoders were used to measure the shoulder and elbow joint angles. An electromyography system was developed to measure muscular activation. In this study, the simulation was done for PID position control but system hardware is applicable for force control. Journal of Thermal Engineering Journal of Thermal Engineering 2019-02-24T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2773 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2773 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2773

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2682 2018-09-28T21:00:00Z 1

Investigation of Natural Convection Heat Transfer at Constant Heat Flux Along a Vertical and Inclined Plate Sebiha Yıldız Natural convection, computer analysis, vertical and inclined plate, downward-facing surface, constant heat flux, air. It is a common phenomenon that the devices that are exposed to constant heat fluxes are cooled at natural atmospheric environments. However, it is required to know the surface temperature in these devices. In this study, the cooling of a plate (1 m in height and 1 m in width) which is oriented vertical, and also 20°- and 45°-inclined from the vertical (downward-facing surface), at the constant heat flux of 1000 Wm-2 at atmospheric natural convection conditions is investigated. The local temperature values at the vertical center of the plate are calculated using the correlation in Vliet [1]’s experimental study and computer analyses and compared to those results. The results show that the surface temperature values of the plate at the inclination angle of 45° are relatively higher than those of the plate at the vertical state and those of the 20°-inclined plate. Journal of Thermal Engineering Journal of Thermal Engineering 2018-09-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2682 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2682 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2682

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/4073 2020-04-29T21:00:00Z 1

The Stress Analysis on Two Different Adhesively Bonded T-Joints Via 3d Nonlinear Finite Element Method Elanur Çelebi Kavdır, Murat Demir Aydın T Adhesively Bonded Joints, Finite Element Method Adhesively bonded joints are formed in different configurations. T- adhesively bonded joint is one of these configurations and has an important position in industrial applications. The purpose of this study was to numerically study the stress distributions, strength, damage evolution of different T-joints with or without adhesive filling at the curvature of the L-shaped adherends under tensile load via 3D nonlinear finite element method. Here, type-I T-joint is the first model without adhesive filling at the curvature of the L-shaped adherends and type-II T-joint is the second model with adhesive filling at the curvature of the L-shaped adherends. In this study, FM73 and 3M 2214 adhesives and AA2024-T3 aluminum alloy adherends have been used to create two different T-joints numerically. Numerical analysis results have shown that the presence of filler adhesive has a direct influence on joint strength. It has also been observed that ABCD interface is the most critical region in terms of damage occurrence, while is AB and BC lines on the ABCD interface are the most critical lines. In addition, it was observed upon comparing the stress distributions of lines AB and BC that the shear and normal stress values decreased in lines AB and BC of the type-II T-joints. Therefore, it can be put forth that the strength of Type-II T-joints is greater in comparison with the strength of type-I T-joints and the use of a type-II T-joints is more suitable for loads which are close to the fracture load of the T-joints. Journal of Thermal Engineering Journal of Thermal Engineering 2020-04-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4073 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4073 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4073

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3997 2020-01-07T21:00:00Z 1

Effect of Magnetic Field Orientation on Nanofluid Free Convection in A Porous Cavity: A Heat Visualization Study Iman Zahmatkesh, Razieh Akhlaghi Ardekani Magnetohydrodynamics, Heatline, Porous Media, Nanofluid, Cavity Effect of magnetic field orientation on free convection of several water–based nanofluids in a square porous cavity is analyzed in this study. To this aim, the heatline visualization technique is implemented for the first time. Moreover, streamlines and isotherms are employed to present fluid flow and temperature distribution. The governing equations are transformed into a dimensionless form and then solved using the finite–volume method. Computations are undertaken for different orientations and magnitudes of the imposed magnetic field in circumstances with distinct Rayleigh numbers and the nanoparticles types and volume fractions. The corresponding results are presented in terms of dimensionless distributions of streamlines, isotherms, and heatlines as well as numerical values of the flow strength and the average Nusselt number. Inspection of the results demonstrates that increase in the magnetic field strength deteriorates the heat transfer rate. This effect, however, diminishes with rise in the magnetic field inclination angle. Journal of Thermal Engineering Journal of Thermal Engineering 2020-01-07T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3997 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3997 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3997

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2772 2019-02-24T21:00:00Z 3

Review on Post-Treatment Emission Control Technique by Application of Diesel Oxidation Catalysis and Diesel Particulate Filtration Caneon Kurien, Ajay Kumar Srivastava Catalysis, Emission, Oxidation, Soot, Regeneration The toxic nature of exhaust gases released by these engines has led to environmental concerns, affecting its sustainability. The exhaust emission from diesel engine includes carbon monoxide, nitrates, hydrocarbons and particulate matter. Soot particles contained in the particulate matter is also found to be carcinogenic in nature and also leads to various lung diseases. Diesel oxidation catalysis system involves oxidation of hydrocarbons, nitrates and soluble organic fraction. Diesel particulate filtration blocks the soot particles with the help of alternately plugged diesel particulate filter with porous walls. The regeneration of accumulated soot is one of the major challenges faced by automotive industries for effective implementation of diesel particulate filtration system. A detailed review on the challenges faced in the implementation of emission control techniques has been carried out in this study and it has been explored from the results of literature study that microwave based regeneration technique would be an effective technique. This paper provides a platform for understanding the working principle of post treatment emission control techniques and also on the role of regeneration in effective operation of Diesel Particulate Filter. Journal of Thermal Engineering Journal of Thermal Engineering 2019-02-24T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2772 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2772 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2772

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3998 2020-01-08T21:00:00Z 1

Flow Characterization of Multi-Phase Particulate Slurry in Thermal Power Plants Using Computational Fluid Dynamics Om Prakash, Rajesh Arora 3D CFD, Eulerian–Eulerian Two-Phase Model, Thermal Power Plants, Slurry Concentration, Pressure Drop The key issue associated with the thermal power plant is the disposal of ash-water slurry and the process of its transportation is accomplished using long length pipelines. The designing of such pipelines is a vital endeavor of researchers and designers globally. In this perspective, numerical simulation of 42 mm diameter three-dimensional slurry flow pipeline carrying high concentration of mono-dispersed fine ash particles has been carried out. The study is enunciated by employing Eulerian- Eulerian two-phase model with RNG k-ɛ turbulence model with the aim of visualizing and understanding the characteristics of the slurry flow behavior. The coal ash slurry concentration varies between 50% to 70% (by weight) for velocity ranges, 1-3 ms-1. The modeling is done using Fluent commercial software with the intention of predicting the characteristics of flow for 300 µm particle size. It is observed that pressure drop upsurges non-linearly with solid concentrations and slurry velocity across pipeline. The obtained results of predetermined pressure drop are analytically compared with the experimental results. Moreover, the results are also compared with that of Eulerian-Langrange model using SST K-ω turbulence model and it is found that RNG k-ɛ turbulence model yields more accurate and desirable results. Journal of Thermal Engineering Journal of Thermal Engineering 2020-01-08T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3998 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3998 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3998

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/4012 2020-03-29T21:00:00Z 1

Investigation of Waste Heat Energy in a Marine Engine with Transcritical Organic Rankine Cycle İbrahim Kaya, Asım Sinan Karakurt, Yasin Üst Waste Heat Recovery, Transcritical Organic Rankine Cycle, Energy The increasing of fuel prices and global energy demand and enactment of new restrictive emissions regulations require more efficient and environmentally friendly engines to be designed. In this context, conversion of waste heat to useful energy is necessary to design more energy efficient vessel including using more efficient main engines and auxiliary engines. The aim of this study, thermodynamic characteristic of recovery of a ship's main engine waste heat is determined parametrically for waste heat recovery system (WHRS). Naturally, heat exchangers are used for waste heat recovery. Because of that reason, firstly shell–and–tube heat exchanger will be investigated parametrically. In order to make a more accurate calculation, it is important to reflect the pressure and enthalpy variations in the heat exchanger to the heat transfer calculations. After that the Transcritical Organic Rankine Cycle (TORC), which is recommended by many authors for the recovery of waste heat sources at low and medium temperatures, will be examined parametrically. The results show that increasing the number of pipes in the heat exchanger at a certain value may result in a decrease in system performance parameters that is The Net Power and Thermal Efficiency due to decreasing velocity of the mass flow in tubes. Moreover, The Net Power and Thermal Efficiency curves behaved differently with variable mass flow rate. Therefore, we will define performance parameter being important for WHRS. Journal of Thermal Engineering Journal of Thermal Engineering 2020-03-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4012 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4012 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4012

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/4053 2020-03-31T21:00:00Z 4

On the Turbulent Prandtl Number in Stably Stratıfıed Turbulence by Second Order Models Saida Naifer, M.Bouzaiane Prandtl Number, Stably Stratified Turbulence, Second Order Modeling The aim of this work is to investigate the behavior of the Turbulent Prandtl number by second order modeling of a stably stratified homogeneous sheared turbulence. By analytic solutions, we have confirmed the asymptotic equilibrium behavior of the turbulent Prandtl number. Then two between the most second order models of turbulence; the Classic Launder-Reece-Model and the sophisticated Craft Launder model are retained. A non dimensional form of transport equations have been obtained when non dimensional parameters are introduced to substitute second order moments. A numerical integration using the fourth order Runge kutta method has been conducted for different values of the gradient Richardson number Ri. In comparison with direct numerical simulation result’s of Shih et al. the obtained results by the Craft Launder model has shown for the turbulent Prandtl number the best agreement at moderate values of gradient Richardson number 0.15 < Ri < 0.28. The classic model has shown a great default for the different values of Ri. No any concordance with retained results of DNS has been obtained by this model. We show also that prediction of this model can be improved by introducing variation and optimization of model constants. Journal of Thermal Engineering Journal of Thermal Engineering 2020-03-31T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4053 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4053 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4053

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/4051 2020-03-31T21:00:00Z 3

Analysis of Nearly Zero Energy Residental Building in Muscat Hafiz Zafar Sharif, Abdul Mutalib Leman, Aissa Nasser Krizou, Mohammad Tala’t Ahmed Al-Tarawne, Muthuraman Subbiah, Muna Al-Farsi Zero Energy Buildings, Energy Consumption, Eco House, Energy Balancing The building sector is the largest consumer of the primary sources of energy worldwide. The most commonly used primary sources of energy to generate electricity are oil, coal, peat, shale, natural gas, nuclear, hydro, renewables, biofuels, and waste. The energy demand by the building sector is about 40% of the world’s energy production.Net Zero Energy Buildings (NZEBs) is the best solution recommended by the energy experts to reduce substantial pressure on primary sources of energy contributed by the building sector. There is a marginal gap between estimates made during the design stage and actual energy performance of residential buildings, primarily due to lack of understanding of the factors affecting energy use and whole building simulations software limitations. The purpose of this research work was to conduct a comparative analysis of a predicted versus actual energy consumption of prototype Net Zero Energy Building (NZEB) constructed at Higher College of Technology, Muscat. Hourly Analysis Program (HAP V4.2) was used to predict energy demand of NZEB at HCT and same size regular house in Muscat. PVWatts calculator was used to determining possible power generation by the PV system installed on the roof in the form of a canopy. The constructed house was tested for a period of one month to perform multiple tasks as per competition requirements in which one of the major tasks was to produce onsite energy production by PV panel’s equivalent to the energy consumed by the house.The actual energy consumption results were compared with the simulated result and observed that actual energy demand of house was approximately 20% lower than that predicted by the simulation tool. The comparison of simulation results between NZEB and regular house indicated 61.2% less energy demand of NZEB, mainly due to less HVAC load. The simulation result for BEI of NZEB showed87.20 kWh/m2/year as compare to 225.1 kWh/m2/year for same size regular house. The simulated result obtained from PVWattscalculator for competition period and actual production of installed PV system at the top roof showed a minor deviation of 0.73% only. It is also observed from the results during the competition period house exported 1221 kWh energy to grid. Journal of Thermal Engineering Journal of Thermal Engineering 2020-03-31T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4051 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4051 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4051

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/4009 2020-03-26T21:00:00Z 1

Effects of Thickness and Camber Ratio on Flow Characteristics Over Airfoils İlyas Karasu, Halil Hakan Açıkel, Kemal Koca, Mustafa Serdar Genç Camber Ratio, Thickness, Laminar Separation Bubble, Onset of Transition, Low Reynolds Number This study ensures experimental and numerical investigation of different airfoils to observe and understand how camber ratio affects the flow characteristics over surface of different airfoils. Experimental results in the previous studies were used while the numerical study was performed for present investigation. Reynolds numbers based on the airfoil chords were 1x105 and the angle of attack of 8°. Instantaneous voltage output data were used in order to detect transition location for NACA 4412, oil surface visualization experiments were presented for NACA 2415. In the numerical analysis, values of u/U? and turbulent kinetic energy were presented for NACA 4415 airfoil. The experimental results denoted that the change of camber ratio and thickness significantly affected the flow phenomenon such as boundary layer separation or formation and progress of the laminar separation bubble. The long bubble was clearly observed with accumulation of pigments at oil-flow measurement experiment. By increasing the camber ratio with the use of NACA 4412 airfoil, the long bubble turned into the short bubble. Briefly, not only the progress and formation of laminar separation bubble was being affected, but also the onset of transition point was obviously influenced by changing of camber ratio. Journal of Thermal Engineering Journal of Thermal Engineering 2020-03-26T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4009 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4009 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4009

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2689 2018-10-02T21:00:00Z 1

Exergetic Efficiency Analysis of a Combined Power Plant of a Container Ship Yalçın Durmuşoğlu, Gazi Kocak hipping, Energy Efficiency, Exergy, Combined Power System Energy problems in the world require more efficient use of energy. Thus, in recent years there has been a significant increase in scientific studies on energy efficiency. Approximately 80% of world trade is carried by sea. Therefore, transportation of such a big volume requires large-scale energy consumption. For this reason, energy efficiency is very important in the maritime sector. Therefore, International Maritime Organization which is the authority on maritime transport in the world, executes obligations and recommendations for energy efficiency and environmental pollution issues. An important method of scientifically measuring energy efficiency is exergy analysis. It is observed that the performance analysis by exergy method is not applied to the shipping sector sufficiently, so this paper is tried to fill this gap in maritime area. In this article, the performance of the combined power system of a container ship is analyzed by the exergy method. According to the obtained results, the total exergy efficiency of the system is observed to be 49%. Journal of Thermal Engineering Journal of Thermal Engineering 2018-10-02T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2689 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2689 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2689

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5142 2020-07-07T21:00:00Z 1

Feasibility of Glycerin/Al2O3 Nanofluid for Automotive Cooling Applications Kondru Gnana Sundari, Lazarus Godson Asirvatham, Joseph John Marshal, Emerald Ninolin, Surekha B. Nanofluid, Glycerin, Radiator, Convective Heat Transfer Coefficient, Automotive Cooling In this paper, the feasibility of glycerin/Al2O3 nanofluid for automotive cooling applications is experimentally studied. The test setup includes an engine model and a car radiator and the heat transfer characteristics at required operating conditions are analyzed under laminar flow conditions. Three different concentrations of nanofluids such as 0.05, 0.1 and 0.15 vol. % are used and the enhancement in the heat transfer coefficient is 62% when 0.15% volume concentration of nanoparticles are added to the base fluid (glycerin) at a constant heat flux of 6919 W/m2. The effectiveness of the radiator cooling system increases along with negligible increase in pumping power with increase of volume concentration. The addition of nanoparticles in the base fluid enhances the absorption capacity of the radiator coolant leading to the increase in the effectiveness. Results have also indicated that the nanofluids are mainly dependent on particle concentration, flow rates, and temperature. Hence, it is suggested that nanoparticle suspended coolants are promising and efficient for automotive cooling applications. Journal of Thermal Engineering Journal of Thermal Engineering 2020-07-07T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5142 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5142 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5142

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2607 2018-06-24T21:00:00Z 1

The Effect of System Parameters on the Condensation Performance of Heat Pump System Using R290 Samet Hocaoğlu, Derya Burcu Özkan Heat Pump, Hydrocarbons, Propane, R290, F-Gas Regulation, GWP, ODP Since global warming has reached critical levels, limitations have been placed on the use of certain fluoride-containing refrigerants by F-Gas regulations. The EU F-Gas Regulation has introduced quotas for the use of refrigerants with a global warming potential(GWP) greater than 150. Hydrofluorocarbons(HFCs) from restricted refrigerants are widely used in heat pump systems. Considering the environmental impact of these refrigerants, it is important to look for long-term alternatives to comply with F-gas regulations. Hydrocarbon(HC) refrigerants are shown as suitable alternatives for heat pump applications. R290 as a HC refrigerant is a potential refrigerant suitable for existing HFCs systems due to zero ODP and low GWP. In heat pump systems, there are many system components or parameters that are effective in condensing the air passing through the evaporator. It is very important to know how these elements affect the condensation performance in different design situations. In this study, the effect of different parameters such as capillary length, charge amount and evaporator tube volume on the condensation performance of a R290 hydrocarbon refrigerant heat pump was investigated by the experimental design approach. The experimental results obtained was compared with the theoretical model. It has been determined that the most effective parameter on the condensation performance is the capillary tube length with the effect of 35%. Journal of Thermal Engineering Journal of Thermal Engineering 2018-06-24T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2607 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2607 Journal of Thermal Engineering, Year:2018, Vol:4, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2607

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/4054 2020-03-31T21:00:00Z 1

Optimization of the Variable Refrigerant Flow Systems by use of Genetic Algorithm and Energy, Exergy, and Economic Analysis for Three Coolant Fluids Masoud Lotfihrejrandoost, Ali Behbhani, Mehdi Aliehyaei Exergy, Evaporator, VRF, COP, and Cost. The current study aimed at investigation of the Variable Refrigerant Flow (VRF). Energy, exergy, and economic model for R11, R22, and R134a refrigerants. The genetic algorithm was used for optimization of the cycle. The objective functions in the current study were the second law efficiency and cooling cost. The cooling cost was a new economic function that was defined in this paper for the first time. Results showed that the highest Coefficient of Performance (COP) and second law’s efficiency as well as the lowest cooling cost and exergy loss belonged to the refrigerant R134a, and second and third to it were R11 and R22. The optimum values of condenser pressure and evaporators 1, 2, and 3 for the refrigerant R134a were 799.7, 706.2, 925.2, and 23122 (kPa), and the mass discharge of the evaporators 1 and 2, was 0.1 and 0.072 (kg/s). Journal of Thermal Engineering Journal of Thermal Engineering 2020-03-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4054 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4054 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4054

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/4063 2020-04-22T21:00:00Z 1

Optimization of a New Configuration of Power Tri-generation Cycle by the Use of a Multi-Purpose Genetic Algorithm Bardia Eftekhari, Mehdi Aliehyaei Tri-generation Cycle, Steam, ORC, Exergy, Genetic, Objective Function In the current study, a new configuration of power tri-generation cycle was suggested. In this cycle, the energy of hot gases output from the gas cycle in the heat recovery steam generator (HRSG), and the waste energy of the condenser in the steam cycle were recovered in the Organic Rankine Cycle (ORC). After the energy, exergy, and economic modeling of the cycle, the optimization of this cycle by the use of multipurpose genetic algorithm was performed. The objective functions were the electricity cost and the second law efficiency of thermodynamics. The variables chosen for optimization were the air to fuel molar ratio, the compression, and expansion ratio of the compressor and turbine of the gas cycle, the mass flow rate of water steam and refrigerant in steam cycles and ORC, the Pinch points between the gas cycle and steam, and steam cycles and ORC, and the maximum temperatures of the steam and ORC cycles. The optimization results showed that by choosing the optimal values of variables, the efficiency of the first and second thermodynamic laws, and the produced entropy would be 67.3%, 68.9%, and 3342.5kW/K. Also, the generated electricity cost was reduced to 0.049 US$/kWh. Journal of Thermal Engineering Journal of Thermal Engineering 2020-04-22T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4063 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4063 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4063

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/4008 2020-03-26T21:00:00Z 1

Analyzing the Impact of Temperature on Axoplasmic Fluid Properties Defining Neuronal Excitation Suman Bhatia, Prabha Sharma, Phool Singh, Pramod Bhatia Axoplasmic fluid properties, Temperature Dependency, Neuronal Excitation Axoplasmic fluid properties for neuronal excitation have been investigated with respect to temperature. Density, mass fraction of ions and rate of addition of ions are the parameters considered for characterizing axoplasmic fluid properties. The behavior of these parameters has been analyzed with respect to the changes in temperature ranging from -5 degree Celsius to 35 degree Celsius. The temperature has been defined using Q10of3 coefficient as done in the Hodgkin-Huxley model. The trend of these parameters at different temperatures has been depicted along the axonal length represented through x-axis of the graphs. The conduction velocities of above said parameters have also been recorded at different temperatures. The range [-5,35] degree Celsius has been increased by 20 degrees, 10 degree on the lower side and 10 degree on the upper side of the range [-5,25] degree Celsius and it is found that temperature dependency using Q10of3 coefficient for said parameters is valid only in the temperature ranging from 5 degree Celsius to 25 degree Celsius as it is for membrane voltage in Hodgkin-Huxley model. These findings strongly support the obtained results and also suggest obtaining the temperature coefficient value which is applicable for wider range of temperatures impacting neuronal excitation. Journal of Thermal Engineering Journal of Thermal Engineering 2020-03-26T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4008 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4008 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4008

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2745 2018-12-29T21:00:00Z 4

Design, Development and Fabrication of a Mist Spray Direct Evaporative Cooling System and Its Performance Evaluation Avinash Deshmukh, Shivalingappa Nagappa Sapali Mist Nozzle; Evaporative cooling, Spinning Disc atomization In today's essential commodities, air conditioning system is one of the major energy consuming elements. Nowadays evaporative cooling systems are mostly preferred as an alternative to compressor-based air conditioned systems. It is reported that evaporative cooling systems consume 60 - 70 % less energy compared to compressor-based air conditioning systems. In this paper, performance analysis of a mist evaporative cooler is carried out experimentally. The performance parameters such as, drop in temperature, cooling capacity, saturation efficiency, the coefficient of performance are evaluated with respect to various ambient conditions and with a varied mass flow rate of air. Experimental data used to develop an empirical correlation to predict the temperature of cooled air by linear regression analysis. Predicted temperature of cooled air temperature by empirical correlation is validated through experimentation, and are good in agreement with experimental values. Journal of Thermal Engineering Journal of Thermal Engineering 2018-12-29T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2745 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2745 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2745

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5224 2020-12-09T21:00:00Z 3

An Overview of Recent Progress in Condensation Heat Transfer Enhancement across Horizontal Tubes and Tube Bundles Tayyaba Bano, Hafiz Muhamad Ali Condensation heat transfer, finned tube, Heat transfer enhancement, fluid The present paper presents a review of condensation heat transfer across smooth and enhanced horizontal surfaces due to its significance in refrigeration, air conditioning and heat pump applications. The emphasizes is on the recent understanding of experimental as well as the semi-empirical correlations to investigate the heat transfer phenomena during condensation associated with enhanced geometries. An effort has been made to submit free-convection condensation effects outside of single tubes and tube bundles with the influence of tube geometries, condensate retention and gravity on film condensation; however, comparison of forced convection is also presented. Alternative of conventional refrigerants in condensation process by low- global warming potential (GWP)refrigerants is addressed as well due to increase in atmospheric burden affected by hydroflourocarbons(HFCs) .Although many researchers have reviewed the condensation impact across enhanced surfaces, a few of them revised its behavior across pin finned tubes. The effects of geometry, surface wettability, and operating conditions on the location, amount and form of condensate film are discussed. Various theoretical models prediction with the new experimental data across pin fins is also revealed. This review is distributed into two main sections: the first section focuses on condensation across enhanced tubes, sub dividing the study into integral and pin finned tubes based on theoretical and experimental investigations. It covers the geometrical effects concerning three dimensional surfaces, fin density, fin spacing and fin thickness. The later part of the paper concentrates on condensation behavior across tube bundles incorporating the effects of fin density and refrigerant mixtures highlighting both theoretical and experimental knowledge. Recent research shows an agreement between theoretical and experimental models in the defined area; though, a considerable amount of work on semi-empirical correlation formulation is visible in the literature. The strength of this paper is the latest findings on condensation against different geometrical parameters of extended surfaces specifically across pin fin tubes and tube bundles. Finally, theoretical enhancement factors along with many heat transfer correlations are presented and recommendations are suggested for the future work. Journal of Thermal Engineering Journal of Thermal Engineering 2020-12-09T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5224 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5224 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5224

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5136 2020-07-03T21:00:00Z 1

Magnetic Field Effect on the Heat Transfer in a Nanofluid Filled Lid Driven Cavity with Joule Heating Mohammad Ali Taghikhani Magnetic Field, Nano-fluid, Lid Driven Cavity, Stream Function-Velocity, Joule Heating, Volumetric Heat Generation In this paper, the effects of magnetic field, Joule heating and volumetric heat generation on the heat transfer and fluid flow in a Cu-Water nanofluid filled lid driven cavity using enhanced streamfunction–velocity method are investigated. The cavity is heated by a uniform volumetric heat density and side walls have constant temperature. The top wall moves with constant velocity in +x direction, while no-slip boundary conditions are imposed on the other walls of the cavity. An inclined fixed magnetic field is applied to the left side wall of the cavity. The dimensionless governing equations are solved numerically for the stream function and temperature using finite difference method for various Richardson(Ri), Reynolds(Re), Hartmann (Ha), Eckert(Ec)numbers, magnetic field angle(?) and solid volume fraction of the nanofluid(?) in MATLAB software. To discretize the streamfunction-velocity formulation, a five point constant coefficient second-order compact finite difference approximation which avoids difficulties inherent in the conventional streamfunction–vorticity and primitive variable formulations is used. The stream function equation is solved using fast Poisson's equation solver on a rectangular grid (POICALC function in MATLAB) and the temperature equation is solved using Jacobi bi-conjugate gradient stabilized (BiCGSTAB) method. The heat transfer within the cavity is characterized by Nusselt number (Nu1). The results show that Nu1 is significantly increased by increasing Ri and ? and increasing the Reynolds number enhances convective cooling. The heat transfer within the cavity is decreased by increasing Hartmann number which improves conduction heat transfer and reduces Nu1. Joule heating has a negative effect on the convection within the cavity and convection is decreased by increasing the value of Ec. It can be investigated that Nu1 is decreased by increasing Ec due to the strong distortion effect of Joule heating on convection current of heat transfer. Journal of Thermal Engineering Journal of Thermal Engineering 2020-07-03T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5136 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5136 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5136

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3904 2019-12-01T21:00:00Z 1

Effect of The Geometrical Parameters in A Domestic Burner with Crescent Flame Channels for an Optimal Temperature Distribution and Thermal Efficiency Ramazan Şener, Mehmed Rafet Özdemir, Murat Umut Yangaz Combustion, CFD, Domestic Burner, Cooker, Emissions, Fuel Domestic cookers are common tools of house appliances in the world and they have significant share in global energy consumption. Therefore, a small amount of improvement in efficiency would result in a huge drop in total energy and resource activity. This study aims at presenting numerically the thermal efficiency of a domestic burner with crescent-shaped flame channels by changing the distance from the cooker to the burner head and the diameter of the burner. The energy efficiency parameter was evaluated analyzing temperature distribution along the bottom surface of the cooker and unburnt HC, CO and NO emissions. Simulations have been carried out with methane as fuel for three different diameter and distance parameters. The results showed that the temperature on the surface and the emission values of unburnt CO, NO and HC decreased with increasing the cooker diameter and distance parameter. Journal of Thermal Engineering Journal of Thermal Engineering 2019-12-01T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3904 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3904 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3904

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5073 2020-04-29T21:00:00Z 1

Optimization of Gas Turbine Power Plant by Evoloutionary Algorithm; Considering Exergy, Economic And Environmental Aspects Moein Shamoushaki, Mehdi Aliehyaei Gas Turbine, Exergy, Sensitive, Environmental, NSGA-II In this paper the exergy, economic and environmental analysis of Aliabad Katoul power plant as well as its multi-objective optimization have been done by NSGA-II algorithm. Two objective functions have been considered. The first objective function is the total cost rate and the second objective function is environmental impact cost. Optimization of objective functions has been done in two modes namely cycle with and without air preheater. The results showed that the existence of air preheater reduces both objective functions. So that in optimum point, for cycle without air preheater, the amount of total cost rate has been about 30% and environmental cost rate was about 33% higher than cycle with air preheater. Also, sensitive analysis of objective functions to fuel unit cost was conducted. At the lower environmental cost rate that the total cost rate was higher, sensitivity of Pareto solutions to the fuel unit cost was more than some parts of figure with smaller total cost rate. Also, exergy losses of various components were obtained that conclusions illustrated that combustion chamber has the maximum rate of exergy destruction (about 73%). Impact of ambient temperature variation on exergy losses and efficiency for different components was studied. The conclusions illustrated that with growing in ambient temperature, exergy efficiency of all parts decreased and exergy losses increased. Also, by rising the ambient temperature, exergy efficiency decreased, so that an increase in temperature from 293 Kelvin to 323 Kelvin, total exergy efficiency decreased from about 51% to 49%. Journal of Thermal Engineering Journal of Thermal Engineering 2020-04-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5073 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5073 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5073

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/4071 2020-04-28T21:00:00Z 4

Numerical Investigations on Flow Characteristics of Sand-Water Slurry Through Horizontal Pİpelİne Usİng Computatİonal Fluıd Dynamics Shofique Ahmed, Rajesh Arora, Om Parkash 3D CFD modeling; Eulerian two-phase model; RNG K-epsilon model; Concentration distribution; Flow velocity distribution; Pressure drop; Slurry pipeline The study presents the numerical computational fluid dynamics (CFD) analysis of sand-water slurry flow with different sand particle sizes viz. 90µm, 125µm, 150µm, 200µm and 270µm having specific gravity of 2.65 through a 103 mm diameter, 5.5 m long horizontal pipeline for a high flow velocity of 5.4 m/s at various solid volumetric concentrations viz. 10%, 20%, 30%, 36% and 40%. Granular version of Eulerian two-phase model with dispersed particles along with RNG –epsilon approach has been utilized. Non-uniform structured mesh with a refinement near the wall boundary has been selected for discretizing the computational flow domain while Navier-Stokes governing equations are solved in FLUENT 14.0. The effects of the size of sand particles and solid volumetric concentrations on territorial concentration distributions, particle flow velocity and pressure drops have been studied and analyzed. Generalized mathematical correlation has been developed from the simulated results for calculating the consequences of the size of solid particles and solid volumetric concentration on pressure drop analytically. The simulated outcomes of pressure drop are validated with the experimental results. These outcomes will be very helpful in the setup of an experimental model for sand/water slurry flow pipelines in many industries viz. mining, construction, power generation etc. Journal of Thermal Engineering Journal of Thermal Engineering 2020-04-28T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4071 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4071 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4071

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/4006 2020-03-26T21:00:00Z 1

Experimental Analysis and Kinetic Modelling for Steam Gasification of the Turkish Lignites Ömer Güney, Ahmet Koyun Random Pore Model, Coal Gasification, Elevated Temperature, Porosity During the last decades, the importance of structural parameters has been increased because the models which have been developed using structural parameter can define the gasification process effectively. In this study, structural parameters, rates of conversion and activation energies of Zonguldak coal and Beypazari lignite have obtained. The samples of Zonguldak coal and Beypazari lignite used in this study have different characteristics. Pore dimensions, distribution of pores and surface areas were used as structural parameters. Suitable kinetic parameters were determined by fitting the gasification model to experimental data. The random pore model was used to define these kinetic parameters. The data were taken from experiments of Balci and Durusoy and the results obtained from Zonguldak coal and Beypazarı lignite pyrolysed in a vertical tube heated from outside by an inert gas and gasified with steam at elevated temperatures (between 700 °C and 1000 °C) were used in the model. Journal of Thermal Engineering Journal of Thermal Engineering 2020-03-26T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4006 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4006 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4006

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/4072 2020-04-28T21:00:00Z 1

Solar Hydrogen Production by Thermochemical Reaction: Development of A Packed-Bed Reactor D. Darfilal, C. Seladji, R. Bhandari Hydrogen; Packed bed; CFD; balls Solar water splitting is a promising process for the storage and conversion of sunlight power into clean-burning hydrogen gas, this paper present a CFD analysis of hydrogen production via a proposed packed bed thermo-chemical receiver/reactor system. The idea of this study is the use of packed bed of spherical ceramic particles coated with active redox ferrite materials. The first step is an endothermic reaction, nickel ferrite (NiFe2O4) dissociate thermally into nickel oxide (NiO), ferrous oxide (FeO) and oxygen at 1473 K, this reaction take place under 2 KW concentrated solar energy. The second is the hydrolysis step at 1073 K to produce hydrogen, the latter is recycled to the first step for a new production cycle. The CFD code solves the momentum, energy and species transport equations. The temperature fields of the reactor solid & fluid phases were attained using the local thermal non-equilibrium model (LTNE). Journal of Thermal Engineering Journal of Thermal Engineering 2020-04-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4072 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4072 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4072

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3894 2019-10-07T21:00:00Z 1

Emissions and Performance Characteristics of an SI Engine with Biogas Fuel at Different CO2 Ratios Yasin Karagöz Biogas, CO2, Methane, SI Engine, Emissions, Combustion Nowadays increasing emission regulations and environmental concerns have led to the use of alternative fuels in internal combustion engines. Biogas is an alternative fuel that can be produced with clean, green and natural resources. In this study, a single cylinder, four stroke SI engine was operated at stoichiometric conditions, 2800 rpm constant engine speed with biogas fuel at different ratios. As biogas fuel, methane (CH4) and CO2 were used during engine tests. Test results which were taken by using only gasoline were compared with the results obtained by using biogas fuel at different CO2 ratios (10%, 20%, 30% and 40% by volume). Although it was determined specific CO emissions decrease and THC emissions slightly increases with the increasing CO2 ratio, it is foreseen that the increase in THC emissions can be prevented by the use of three way catalytic converter. Although the NOx emissions increase with the use of biogas compared to gasoline, it was significantly reduced by the increased CO2 rate in the biogas fuel, the CO2's heat carrying capacity and reducing the O2 availability of the fuel. On the other hand, because of the high cost of purification process of biogas and after-treatment equipments, it is foreseen that use of biogas at high ratio of CO2 in SI engines will be advantageous in terms of NOx emissions. Journal of Thermal Engineering Journal of Thermal Engineering 2019-10-07T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3894 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3894 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3894

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/4067 2020-04-26T21:00:00Z 4

Portable Solar Drying System with Inbuilt PV Module for Standalone Forced Convection Operation V. Siva Reddy Solar Dryer, PV Thermal, Forced Convection, Cost Economics A portable solar drying system with inbuilt PV module has been designed, fabricated and installed at Rajeev Gandhi Memorial College of Engineering & Technology, Nandyal, Andhra Pradesh. It is having a 1.1304 m2 absorber area and 3 m2 drying area. The dryer could accommodate 10 numbers of trays of size 0.3 m2). The brushless direct current (BLDC) motor fans of two 3 W capacity were operated directly from the energy generated by the PV panel of 10 W capacity installed in the solar dryer. As a part of the single batch load test performance analysis was tested using 3 kg of freshly harvested Fenugreek, Spinach, Chilli. After 6 h drying, 75 to 90 % of moisture has been removed where the solar radiation intensity measured was between 600-800 W/m2. Thus it is concluded that besides decreasing the overall transportation costs, the solar dryer with on-site efficient drying capability of food crops is highly beneficial in reducing the damage of produce and could retain sufficient nutrients. Journal of Thermal Engineering Journal of Thermal Engineering 2020-04-26T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4067 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4067 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4067

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5134 2020-07-03T21:00:00Z 4

Exergy Analysis of the Cross Current Cooling Tower Nandkumar Rawabawale, Shivalingappa Sapali Evaporative Cooling, Cross Current, Cooling Tower, Exergy The cold water needs to be circulated through the steam condenser of a thermal power plant in order to carry out the waste latent heat of condensation from steam. The hot water leaving condenser needs to be cooled in order to re-circulate it through condenser. Hence the hot water is passed through a cooling tower to reject waste heat to the ambient air through convection and mass transfer. The augmented cost of energy and scarceness of water has made researchers to focus on performance investigation of cooling tower as energy conservation opportunity. The thermal efficiency is generally used to measure performance of cooling tower which is evaluated from properties of fluids. However this method is inefficient to investigate the major causes of irreversibility inside the cooling tower. Therefore, an exergy investigation is initiated to synchronize with the energy investigation of cooling tower. This research paper includes the investigation of the thermal performance of cross current cooling tower through energy balance, mass balance and exergy correlations. The variation of fluid properties with flow direction of fluids and exergy loss within the cooling tower are examined and authenticated through test results. The outcomes of study have shown that the analytical exergy loss is lower than experimental exergy loss and the exergy loss varies with length and height of the cross current cooling tower. Further the influence of variation in size of cooling tower on exergy loss is evaluated analytically and found that the increase in length of cooling tower than the height reduces exergy loss by 8.18% improving thermal efficiency of cooling tower by 3.57%. Journal of Thermal Engineering Journal of Thermal Engineering 2020-07-03T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5134 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5134 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5134

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/4068 2020-04-26T21:00:00Z 4

An Investigative Methodology through Solid Modelling and Numerical Analysis for Designing a Thermo-Electric Generator System Ekansh Chaturvedi, Vijay Mamtani TEG, Seebeck Effect, FEM Analysis, Transient Heat Transfer, Charging Time This product development research project proposes a simplified novel methodology to design a thermo-electric generation (TEG) system. The iterative designs of complete assembly were prepared with the aid of Solidworks and the subsequent FEM analysis was aided by ANSYS fluent and transient thermal workbenches. The combustion chamber was subjected to a computational fluid dynamic study to generate flame profiles and to establish the temperature gradient distribution along the vertical length of inner surface of cylindrical chamber. The results of CFD analysis were then transported to the transient thermal workbench to calculate the charging time of whole system, which indeed founds the issues related to starting fuel efficiency of the system. A section model of the assembly was used to conduct the transient heat transfer analysis. The final results showed that after formation of a steady temperature gradient at the inner surface, the time required to completely charge up the system to achieve steady state came to be 30 minutes, which was found to be in good agreement with the operational constraints. Also, the temperature differences obtained between the hot and cold sides of TEG MARS modules were well within the safe limits. NOx emissions were also plotted and analysed. Journal of Thermal Engineering Journal of Thermal Engineering 2020-04-26T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4068 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4068 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4068

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/4055 2020-03-31T21:00:00Z 1

Multifluid Desciption of Rarefied Gas Mixture Flows Iman Zahmatkesh, Homayoun Emdad, Mohammad M. Alishahi Gas mixture; Kinetic theory; Rarefied flow; Multifluid model; Navier–Stokes equations In the present contribution attention is focused to extend the application of multifluid descriptions to rarefied conditions. To this aim, a multifluid Maxwell model and a multifluid Smoluchowski model are proposed for near wall behavior of the constituents of a rarefied gas mixture. Afterwards, multifluid balance equations in conjunction with these boundary conditions are solved for some slip flows of binary gas mixtures between parallel plates. The corresponding results are compared with those of a previously developed Navier–Stokes solver. Inspection of the results indicates that while the Navier–Stokes equations may lose their accuracy under high rarefaction, non–equilibrium features are properly captured by developed multifluid description. This successful method is thereafter utilized to discuss the consequences of velocity–slip, the tangential–momentum–accommodation coefficient, and mass disparity of the mixture constituents on the degree of non–equilibrium between the constituents of the gas mixtures between parallel plates. Journal of Thermal Engineering Journal of Thermal Engineering 2020-03-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4055 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4055 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4055

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/4052 2020-03-31T21:00:00Z 4

Performance Analysis of the Single Jet Air Curtain for Open Refrigerated Display Cabinet by Using Artificial Neural Network Vipin Kumar Titariya, Alka Bani Agarwal Air Curtain, Display Cabinet, Artificial Neural Network, Stability, Specific Cooling Load Low temperature is the key to maintain the high quality for chilled food. The single jet air curtain is used for doorways opening insulation in the current circumstances is an idealization of the single jet air curtain used in the supermarket open refrigerated display cabinets. Open refrigerated display cabinets are going through some of the changes in their thermal behavior and of its overall performance due to variations in air conditions like air curtain temperature, velocity, height/width ratio, deflection module, specific cooling load, stability, and thermal efficiency. A detailed experimental and comprehensive Artificial Neural Network Analysis of air conditions and energy transfer in an open refrigerated display cabinet is performed in this study. Numerical ANN predictions are 99.77% accurate and can be used to enable quick calculations and parametric analyses for the designing purposes of open refrigeration equipment that reduce the thermal infiltration of the Open Refrigerated Display Cabinet and increase the food safety. Journal of Thermal Engineering Journal of Thermal Engineering 2020-03-31T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4052 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4052 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4052

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/2767 2019-02-23T21:00:00Z 1

Effect of Different Levels of Hydrogen + LPG Addition on Emissions and Performance of a Compression Ignition Engine Yasin Karagöz, Hasan Köten Liquefied petroleum gas, LPG, LPG + H2, Common-rail Compelling emission regulations and diesel engines damage on environment have led researchers to work on alternative fuels such as LPG and hydrogen in recent years. Diesel engine costs are also increasing, especially on the increased costs of after-treatment equipment used in diesel engines. It is also known that diesel engines release NOx and smoke emissions, which are highly harmful to the environment and to the living health. The effect of the emissions of LPG + H2 (0%, 15%, 30% and 45%) with different energy contents at full load and same torque (70 Nm) at constant engine speed of 1200 rpm is investigated on CO, THC, NOx and Smoke emissions. From the results obtained, there was a slight increase in brake thermal efficiency, CO and THC emissions. However, significant improvement in NOx and smoke emissions has been achieved. The results show that using LPG + H2 in diesel engines, older technology and lower cost after-treatment equipment can be used, and that NOx and smoke emissions of diesel engines can be reduced significantly. Also, using small amount of hydrogen (20% of total gas mixture) and LPG, an important improvement can be achieved, and the harmful effects of diesel engines can be suppressed thanks to unique properties of hydrogen fuel. Journal of Thermal Engineering Journal of Thermal Engineering 2019-02-23T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2767 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2767 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=2767

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5209 2020-10-28T21:00:00Z 1

Comparative Assessment of The Emission Characteristics of First, Second and Third Generation Biodiesels as Fuel in A Diesel Engine Upendra Rajak, Prerana Nashine, Tikendra Nath Verma Compression ignition engine; biodiesel; emission; numerical The present study aims to investigate emission characteristics with the B20 blend level of first, second and third generation biodiesels. The engine, a naturally aspirated, single cylinder, diesel engine, was operated at 1500 rpm engine speed and at different engine loads with intervals of 25%. Also, the engine is analyzed by Diesel-RK mathematical tool and emission characteristics such as smoke, carbon dioxides (CO2), particulate matter (PM), nitric oxide (NO) and summary of emission (SE) were obtained. Numerical simulation is performed using pure diesel (D100), first, second and third generation B20 (80% diesel + 20% biodiesel). Results of reduction in emissions for biodiesel blend were found to be lower than diesel fuel as smoke (BSN) by 54.68% for jojoba, PM by 4.8% for coconut, 52.0% for jojoba and 7.1% for fish oil, NO by 38.2% for jatropha curcas, and SE by 8.8% for soybean, 12.9% for jatropha curcas and 8.8% for spirulina but carbon dioxides was found to be higher by 0.38% for rapeseed, 0.61% for fish oil. The blend of B20 shows a decrease in emissions at 1500 rpm with 100% engine load. The numerical results are verified against experimental results conducted under the same operating conditions. Journal of Thermal Engineering Journal of Thermal Engineering 2020-10-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5209 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5209 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5209

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5144 2020-09-02T21:00:00Z 3

Development of Passive Energy Source as Earth Air Pipe Heat Exchangers (Eaphe) System - A Review Mahendra Verma, Vikas Bansal, Kunj Bihari Rana Earth Pipe Heat Exchanger, Passive Energy, Air Velocity, Pipe Length, Thermal Conductivity of Soil. Diversity in living standards and population growth leads to increased global energy consumption. Human comfort always plays a vital role in using different means to reduce the effects of weather conditions. The building sector captures approximately 40% of the global energy and it is most commonly used for cooling and for heating of the space occupied due to the use of appliances such as room heaters or air coolers, air conditioners, etc. The use of these appliances contributes significantly to global warming, which is a very serious environmental problem. Passive energy sources are used widely to reduce the consumption of energy due to heating and cooling of the building. Earth air pipe heat exchanger is one of the passive cooling/ heating technology used for the indoor thermal comfort of the occupants. In this review article, various discussion has been done on the use of passive energy explained by the earth air pipe heat exchanger and various investigations conducted by authors under different conditions and parameters like air velocity, pipe depth, pipe length, etc. that the thermal conductivity of the soil is the key point to the efficient operation of the earth air pipe heat exchanger system and it is also necessary to maintain the thermal conductivity of the soil in the vicinity of the pipe in order to achieve better performance in operation. Journal of Thermal Engineering Journal of Thermal Engineering 2020-09-02T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5144 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5144 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5144

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/4069 2020-04-26T21:00:00Z 1

A Mathematical Model Featuring Time Lag and Decrement Factor to Assess Indoor Thermal Conditions in Low-Income-Group House Nisha Netam, Shubhashis Sanyal, Shubhankar Bhowmick Thermal Performance, Time Lag, Decrement Factor, Thermal Comfort Raipur, capital of Chhattisgarh state, India, is located at (21.18° N and 81.78° E). During summer season, the city experiences maximum temperature of 46 ºC. Residents resort to external cooling sources almost throughout the year for achieving thermal comfort. Therefore, thermal performance analysis of house is important to assess the temperature inside the house at different season. In present work, mathematical model of hourly temperature distribution in each room of the Low Income Group (LIG) house has been developed using time lag and decrement factor. A system of differential equations is derived and solved. The results obtained are validated with data collected onsite. The study is reported for three major seasons realized in Raipur. Deviation of room temperature from predefined thermal comfort has been calculated and reported for different season. The report reveals the lack of thermal comfort from the sets standards in post-monsoon and summer season. Journal of Thermal Engineering Journal of Thermal Engineering 2020-04-26T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4069 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4069 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4069

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/4066 2020-04-22T21:00:00Z 4

Monthly Design Data for Maximum Solar Radiation Falling on Collector Arrays in Baghdad City Ali Hussien Solar field designs; panel shading effect; solar collector arrays; mutual shading Increasing use of solar energy as a clean and free solution for energy demand necessitates proper use of its equipment, enhanced spatial planning and distribution of solar collectors, optimum directional facing and tilt angle to ensure maximum solar radiation falling, and decreasing as possible as the shading effects of panel arrays. Most existing references lack comprehensive data about shading effects that varied along the year and design of solar array. In the present work, enhanced theoretical design data of solar collector arrays were tabulated for each month in Baghdad. MATLAB program was used to calculate the maximum clear sky solar radiation per unit area per day. The tabulated data yields an economically saved design of solar field or rooftop collector systems. The results indicated that, the shading effect on panel arrays almost vanishes when the distance between two panel rows to panel height ratio is greater than 1 in summer and greater than 2 in winter. Journal of Thermal Engineering Journal of Thermal Engineering 2020-04-22T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4066 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4066 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4066

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/4070 2020-04-28T21:00:00Z 1

Effect of Dean Number on the Heat Transfer Characteristics of a Helical Coil Tube with Variable Velocity & Pressure Inlet Prerana Nashine, Subhaschandra Singh Thokchom,Upendra Rajak, Tikendra Nath Verma Dean number; heat transfer, friction factor, helical tubes; Nusselt number The heat transfer, friction factor, pressure difference, Nusselt number of a helical coil tube using variable pressure and velocity during inlet for various values of Dean number [ratio of coil diameter (D) to tube diameter (d)] has been studied using commercially available computational tool. A validation is performed using the computational tool through the experimental data and it was observed that the results are in good agreement. The helical coil of 0.3m diameter with four (4) turns of inner diameter 0.01 m with length 3.77 has been modelled, meshed and analyzed for both laminar and turbulent flows of constant wall temperature and heat flux. A grid independence test is also performed. The results show that increase in Dean number increases the heat transfer of the helical tube. The increases in pressure have less effect on heat transfer during laminar flow while adverse effect can be observed during turbulent flow. Journal of Thermal Engineering Journal of Thermal Engineering 2020-04-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4070 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4070 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4070

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5074 2020-04-30T21:00:00Z 4

Optimization of The Performance of Vapour Compression Cycle Using Liquid Suction Line Heat Exchanger Abdulkareem Sh. Mahdi Al-Obaidi, Ali Naif, Thabit Khalifa Al Harthi Coefficient of Performance, Liquid Suction Line Heat Exchanger, Subcooling, Vapour Compression Cycle One of the most commonly used refrigeration systems is vapour compression refrigeration system. As saving energy remains a challenge, researchers are putting a lot of efforts into finding efficient solution to improve the performance of vapour compression refrigeration systems. Mechanical subcooling and Liquid Suction Line Heat Exchanger (LSLHX) are approaches that have shown to improve the performance of Vapour Compression Cycle (VCC) systems. This experimental study is conducted to achieve two objectives. First objective is to optimize the heat source and heat sink water volumetric flow rate combination that results in the best performance. In order to evaluate the effect of using subcooling cycle and LSLHX cycle, different flow rate combinations are studied and analysed. Then, to optimize the heat source and heat sink water volumetric flow rate combination that outcome in the optimum performance. Second objective is to optimize the system performance through implementing subcooling and LSLHX. At the optimum water flow rates, the basic VCC performance of the designed system showed better performance compared to the published data. The system performance was improved by 10% at the optimum flow rate when solely subcooling was used while deteriorated by 47.5% at full LSLHX. Journal of Thermal Engineering Journal of Thermal Engineering 2020-04-30T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5074 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5074 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5074

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5310 2021-01-26T21:00:00Z 1

Flow Dynamics of Lid-Driven Cavities with Obstacles of Various Shapes and Configurations Using The Lattice Boltzmann Method Isac Rajan, D. Arumuga Perumal Lid Driven Cavity, Lattice Boltzmann Method, Circular Obstacle, Square Obstacle, Elliptic Obstacle This work implements the emerging computational technique namely the Lattice Boltzmann Method (LBM) to a fluid flow problem of single sided lid-driven cavities with various shapes of obstacles placed in it. The numerical methodology employs the Single-Relaxation-Time (SRT) model applicable to low Mach number hydrodynamic problem for incompressible flow regime. Three geometrical shapes of the obstacles considered are circular, square, and elliptic. Cavity with obstacles exhibited remarkable circulation zones and structures in contrast to the classical lid driven cavity. The flow mechanics and the vortex dynamics are studied for various values of Reynolds Number (Re = 100, 400, and 1000). Due to the introduction of the obstacles, a strong induced vortex forms close to the obstacles and its size changes interestingly with the variation of Reynolds number, which is captured by LBM. Further the study is extended to examine the vortex phenomena induced by changing the position of the obstacles within the cavity. It is observed that the flow structures change dramatically with little change in the position of obstacle inside the cavity which helps to identify position with enhanced mixing characteristics. Journal of Thermal Engineering Journal of Thermal Engineering 2021-01-26T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5310 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5310 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5310

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5284 2020-12-29T21:00:00Z 1

Mathematical Modelling, Simulation Analysis of a Photovoltaic Thermal System Mohammad Taghi Hajibeigy, Rashmi Walvekar, Aravind CV Photovoltaic Thermal, Electrical Energy, Thermal Energy, Heat Transfer, Photovoltaic Solar energy is one of the cleanest, environmentally friendly and abandoned available energy sources. While the photovoltaic (PV) module converts this free and available energy in the form of electrical energy, the efficiency of the PV module reduces as the temperature of the PV module rises above nominal value. The Photovoltaic Thermal (PVT) system removes the wasted thermal energy from the surface of the PV which is caused by the reflection of the sun's irradiance and stores it for the useful application, hence, maintain the electrical efficiency of the PV module. This paper analyses the heat response data collected from a PVT system, under normal conditions, with steady water acting as a coolant. Experimental and simulation values were compared and analyzed in this paper. The thermal response of the PVT system depends solely on the irradiation of sunlight. Therefore, the thermal energy output of the PVT system varies according to the solar irradiation. In this experiment, the PVT thermal response was measured via Thermocouple sensors mounted in each layer of the PVT system, which included solar panel, aluminum thermal plate, and heatsinks. A charge controller was connected to the output of the PV to regulate the charging process for a battery so that the electrical output can also be affected by the thermal response of the solar panel. The amount of solar irradiation was calculated based on the reading from the Pyranometer and the surface area of the PV. The setting of the Pyranometer and the thermocouples to measure the PV thermal value and the ambient temperature was set to ten seconds each, which was read using a data logger. The entire experiment is conducted in a constant condition such as constant ambient temperature and pressure to obtain fair data. Understanding the thermal transfer between each layer of the PVT system will help to increase the efficiency of the electrical and thermal output, from the study it was known that faster heat transfer maintains a steady temperature, this paper helps to design a PVT system with a better efficiency under a non-optimal condition. Journal of Thermal Engineering Journal of Thermal Engineering 2020-12-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5284 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5284 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5284

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5135 2020-07-03T21:00:00Z 1

Harnessing and Storing Solar Thermal Energy Using Phase Change Material (PCM) in a Small Flat Plate Collector Sathish Kumar Gurupatham, Govindasamy K. Manikandan, Fahad Fahad Phase Change Material, Latent Heat, Solar Energy In the recent past, the awareness to bring down the continuous increase in the level of greenhouse gas emissions has widely spread in many countries not only because of the stringent emission norms but also the rising fuel prices which have led to utilize renewable energy sources. When it comes to the different forms of renewable energy available, solar energy is considered to be the best option due to its abundant availability in nature. Still, there are a few hurdles to first get over when dealing with solar energy. For instance, the lack of effective technology has caused solar energy to be a costly endeavour and there are issues involved in the process of conversion of solar energy into useful forms of energy. Due to the recent developments in technology, the application of phase change materials (PCM) has become an attractive method to store solar energy. This paper addresses the novel method of transporting the solar energy from the location it was harnessed, to a location, it can be utilized, by using the phase change material, Erythritol (C4H8O4). Among various sugar alcohols, Erythritol is the one which is higher in latent heat, more thermally stable, non-toxic, inexpensive, and easily available. Journal of Thermal Engineering Journal of Thermal Engineering 2020-07-03T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5135 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5135 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5135

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5143 2020-07-07T21:00:00Z 1

A Techno-Economic Feasibility Study for Reducing the Energy Consumption in a Building: A Solar Energy Case Study for Bandar Abbas Shahin Bazarchi, Gholamreza Nabi Bidhendi, Iran Ghazi, Alibakhsh Kasaeian Building Energy Conservation; Techno-Economic Study; Solar Energy; EnergyPlus; TRNSYS In this work, 13 different solutions for the optimization of energy consumption of a building located in the tropical city of Bandar Abbas are studied out via the EnergyPlus and TRNSYS (Transient System Simulation Tool) commercial codes. Then, the suggested solutions are economically studied and the most economically viable ones are proposed. Ultimately, an energy efficient consumption scheme is put forward with the approach of solar energy utilization. Results reveal that 9 out of 13 studied solutions are techno-economically viable; and by implementing these solutions the energy consumption of the building could be decreased by 81% up to 165624.1 kWh as well as preventing 63022.66 kg of CO2 emission. Journal of Thermal Engineering Journal of Thermal Engineering 2020-07-07T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5143 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5143 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5143

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5210 2020-11-02T21:00:00Z 1

Thermodynamic and Environmental Comparative Investigation and Optimization of Landfill Vs. Incineration for Municipal Solid Waste: A Case Study in Varamin, Iran Amir Ghasemi, Mehrnoosh Moghaddam Waste to Energy, Exergy, Environmental Analysis, Landfill Plant, Incineration Plant, Multi Objective Optimization Waste to energy (WtE) introduces an appropriate solution for municipal solid waste (MSW) disposal and greenhouse gas emission reduction. In this study, for Varamin MSW management, a gas turbine plant with heat recovery unit that is fed by landfill gas (LFG) and combined heat and power (CHP) incineration plant is investigated and compared as two WtE systems to reveal the best plant effectively. Exergy and environmental analyses of two systems are performed. Moreover, the effects of key parameters as decision variables on the energy and exergy efficiencies are identified by sensitivity analysis of both systems. Multi-objective optimization of thermal and exergy efficiencies are then done by using Genetic Algorithm (GA) for each studied system. As a result, Furnace in incineration system and Combustion Chamber in landfill system have the most exergy destruction rate. Also, optimization results show that thermal and exergy effectiveness for landfill system are improved by 7.01% and 6.53% respectively; these values for incineration system are calculated to be 45.35% and 92.75% respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2020-11-02T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5210 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5210 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5210

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5223 2020-12-04T21:00:00Z 4

Development of an Efficient T-type Strainer with Its Performance Evaluation Gaurav Mahajan, Ram Subhash Maurya Porous Jump, CFD, Strainer, Porous Media, Pressure Drop Strainers are devices used in process industry to protect mechanical equipment from getting damaged due the impurities in process fluid. Hence, performance of a strainer has a direct impact on the performance of the process plant. Present work deals with a methodology to model a T-type strainer using CFD tools, investigating its performance, proposing more efficient model and investigating their performance. Numerical model compares well with the experimental data. Five modifications in the existing strainer are proposed by introducing additional punch plate ahead of meshing element. Another significant modification proposed is creating offset across strainer for inlet and outlet of flow. These arrangement increases the net pressure drop across strainer but significantly improves the flow distribution for longer life of the strainer. Increasing body size of strainer and hole of the punch plate is found to reduce the impact of increased pressure drop. These conclusions are important for improving and redesigning an efficient T-strainer. Journal of Thermal Engineering Journal of Thermal Engineering 2020-12-04T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5223 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5223 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5223

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/4010 2020-03-28T21:00:00Z 1

4E (Energy, Exergy, Economic and Environmental) Analysis of the Novel Design of Wet Cooling Tower Dileep Kumar, Tayaba Zehra, Awais Junejo, Sajid Ali Bhanbhro, Muhammad Basit Energy consumption; Water consumption; wet cooling tower; Energy Analysis; Exergy Analysis. This study aims to calculate the performance of the novel design of wet cooling tower (NDWCT) using first law (energy) and second law (exergy) of thermodynamics. Moreover, it determines the economic feasibility (cost savings and payback period) and sustainability of the NDWCT using life-cycle cost (LCC) and environmental assessment method. An appropriate mathematical model is developed and simulated in Engineering Equation Solver to calculate water savings, performance and payback period of additional investment. The simulation results have good agreement with the experimental outcomes (error 2.6%). Simulation results revealed that the NDWCT consumes 34.48% less water than the conventional wet cooling tower (WCT). The installation of heat exchanger improves the performance of WCT by 6% because consumption of water to air ratio increases. Moreover, the exergy destruction in the NDWCT is 1.23 MW lower than the conventional WCT. Additionally, heat exchanger costs k$30.7 to save annual fuel cost of k$72 which could be recovered within a payback period of 0.37 years. Lastly, the environmental assessment proves that the NDWCT relinquishes the particulate matters emission by 0.042 g/s. Journal of Thermal Engineering Journal of Thermal Engineering 2020-03-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4010 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4010 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4010

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3988 2020-01-05T21:00:00Z 1

Flow Performance Comparison along the Centerline in Straight and S-Shaped Diffuser Amit Sharma, Arun Gupta, Hardial Singh Coefficient of static pressure recovery, Coefficient of total pressure loss,S-shaped diffuser. In this paper of the S-shaped diffuser with area ratio (AR) 1.5, An experimental investigation was conducted to analyze the effect of the change in curvature of a straight-wall diffuser. During this study, a Straight diffuser was changed into a curved diffuser at different angles as their same upper and lower limbs (60/60, 90/90). Profile equations of diffusers were generated with the help of MATLAB/Simulink v2017a software. In this work centerline length is constant for all three profiles, Centerline length that’s utilized in the sector of circle and radius of curvature is calculated. S-shaped diffuser had a different unique angle with square inlet and a rectangular outlet. S-shaped diffuser CPR and CTL results compared with a straight walled diffuser with the different inlet velocity and Reynold’s Number. These outcomes from this research obtained the coefficient of static pressure gain and coefficient of total pressure loss for the three profile of the diffuser (Straight, 60/60, and 90/90 S-Shaped Diffuser). Journal of Thermal Engineering Journal of Thermal Engineering 2020-01-05T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3988 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3988 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3988

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5140 2020-07-04T21:00:00Z 1

Flow Boiling Heat Transfer Characteristics of Titanium Oxide/Water Nanofluid (Tio2/Di Water) in an Annular Heat Exchanger Shima Nakhjavani, Amin Abdolhossein Zadeh Annular Heat Exchanger, Flow Boiling, Titanium Oxide/Deionized Water Nanofluid, Thermal Performance, Bubble Formation In the present study, the thermal performance and heat transfer characteristics of titanium oxide/deionized water nanofluid inside an annular heat exchanger was investigated. A set of experiments was conducted to assess the influence of various parameters such as the inlet temperature of the nanofluid to the heat exchanger (333 K-363 K), the applied heat flux (5 kW/m2 to 110 kW/m2), 2000 < Reynolds number < 13500 and the weight concentration of the nanofluid (wt.%=0.05 to wt.%=0.15) on the heat transfer coefficient (HTC) and pressure drop of the nanofluid. Results showed that the increase in the flow rate and the applied heat flux can increase the HTC, while increasing the weight concentration of the nanofluid, initially increased the HTC such that the maximum enhancement in the HTC was 35.7% at wt.%=0.15 and Re=13500, however, over the time, the HTC of the nanofluid decreased. The reduction in the HTC was attributed to the formation of a continual sedimentation on the boiling surface after 1000 minutes of the operation. The inlet temperature of the nanofluid slightly increased the HTC, which was due to the enhancement in the thermo-physical properties of the nanofluid. The maximum enhancement in HTC due to increase of the inlet temperature from 333 K to 363 K was 4.2% at wt.%=0.15 and Re=13500. The bubble formation was also found to be a strong function of the applied heat flux such that with an increase in the heat flux, the rate of the bubble formation increased, which was also the main reason for the enhancement of the HTC at larger heat fluxes. Also, the pressure drop of the nanofluid increased with an increase in the fluid flow and the weight concentration of nanofluid. The maximum pressure drop was 9 kPa at wt.%=0.15 and Re=13500, which was 28% larger than that of measured for the base fluid. It was also found that a continual fouling layer of nanoparticles was formed on the boiling surface, which induced a thermal resistance against the boiling heat transfer. The fouling formation reduced the HTC of the nanofluid such that the maximum reduction in the HTC was 21.6% after 1000 minutes of the operation of the heater. Journal of Thermal Engineering Journal of Thermal Engineering 2020-07-04T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5140 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5140 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5140

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5141 2020-07-04T21:00:00Z 1

Multi Objective Optimization of Waste Heat Recovery in Cement Industry (A Case Study) Mostafa Mostafavi Sani, Alireza Noorpoor, Majid Shafipour Motlagh Exergy, Thermo-economic, Organic Rankine Cycle, Cement Industry, Genetic Algorithm Cement plants have the potential points to waste heat recovery. The method studied in this paper is based on the use of air quenching chamber (AQC) and suspension preheater (SP) Boilers which are installed at the output of the clean cooler and preheating stage respectively in Cement Plant. Due to the low temperature of the existed gases, three different fluids, water, R123 and R245fa are used as the working fluids and are evaluated in a similar cycle in terms of energy, exergy and the optimum parameters selection based on genetic algorithm. The results of this study showed that fluid R123 with optimized parameters leads to a 4% increase the total exergy loss and also will increase the production power from 5 MW to 9 MW. That is while in the case of water production power is increased from 4.8 to 5 MW is optimal state. Also the Results showed that the cost of produced electricity and exergy efficiency are lower in the case of organic fluid application in comparison with water as working fluid. Journal of Thermal Engineering Journal of Thermal Engineering 2020-07-04T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5141 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5141 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5141

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5139 2020-07-04T21:00:00Z 1

First and Second Law Evaluation of Combined Brayton-Organic Rankine Power Cycle Onder Kaska, Onur Bor, Nehir Tokgöz, Muhammed Murat Aksoy Brayton Cycle, Organic Rankine Cycle, Bottoming Cycle, Pinch Point Temperature, Waste Heat, Energy and Exergy Analysis In the present work, we have conducted thermodynamic analysis of an organic Rankine cycle (ORC) using waste heat from intercooler and regenerator in Brayton cycle with intercooling, reheating, and regeneration (BCIRR). First of all, the first law analysis is used in this combined cycle. Several outputs are revealed in this study such as the cycle efficiencies in Brayton cycle which is dependent on turbine inlet temperature, intercooler pressure ratios, and pinch point temperature difference. For all cycles, produced net power is increased because of increasing turbine inlet temperature. Since heat input to the cycles takes place at high temperatures, produced net power is increased because of increasing turbine inlet temperature for all cycles. The efficiency of the system is increased 11.7% by adding organic Rankine cycle as bottoming cycle to the BCIRR. The differences of pinch point temperature on ORC net power and efficiencies of ORC are investigated. In addition, exergy efficiencies of components with respect to intercooling pressure ratio and evaporator effectiveness is presented. Exergy destructions are calculated for all the components in ORC. Journal of Thermal Engineering Journal of Thermal Engineering 2020-07-04T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5139 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5139 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5139

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3991 2020-01-06T21:00:00Z 4

An Approach for Interface Condition of Phase-Change Heat Conduction in Curvilinear Coordinates Saad Bin Mansoor, Bekir Yilbas Phase Change, Interface, Tensor Analysis, Heat Transfer, Stefan Condition Phase change materials are vastly used in thermal engineering applications. The model studies reduce the experimental time and cost and gives insight into the physical process and and provides relation between the process outcomes and the influencing parameters on the process. One of the challenges in the model study related to the phase change problem is setting the appropriate boundary conditions across the phases. This is because of the fictitious definition of the mush zone across the phases. This situation becomes complicated when setting the boundary conditions across the odd geometric shapes. In this study, mathematical formulation of the condition for energy-balance at the interface of the phase changing is investigated using the curvilinear coordinate system without requiring the coordinate system. The proposed arrangement enables to create a curvilinear system via transformation equations from another curvilinear coordinate system. It also provides mathematical formulation of the interfacial boundary conditions across the phases. Journal of Thermal Engineering Journal of Thermal Engineering 2020-01-06T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3991 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3991 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3991

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5229 2020-12-23T21:00:00Z 1

Energy and Exergy Investigations of R1234yf and R1234ze as R134a Replacements in Mechanically Subcooled Vapour Compression Refrigeration Cycle Shyam Agarwal, Akhilesh Arora, Bharat Bhushan Arora LVHE, EDR, R1234yf, R1234ze, R134a, Exergetic Efficiency, VCR, COP The aim of present work is the evaluation of mechanically subcooled simple vapour compression refrigeration system on the basis of energy and exergy analysis, and compatibility of alternative low GWP and zero ODP HFOs R1234yf and R1234ze to replace HFC 134a. A computer program has been developed in Engineering Equation solver software to compute the system performance parameters such as COP, exergetic efficiency, total exergy destruction and exergy destruction ratio. The effect of degree of subcooling (5 to 30℃), evaporator temperature (-30℃ to 15℃), effectiveness of liquid vapour heat exchanger (0.2 to 1.0) and compressor efficiency (0.4 to 1.0) has been investigted on the performance parameters viz. exergy desturction, exergy destruction ratio (EDR) and exergetic efficiency of the system components. The results of current analysis highlight that the R1234ze is the best alternate refrigerant considered in the analysis and can replace R134a as the COP and exergetic efficiency of R1234ze are 1.87% and 1.88% more than that of R134a for 30℃ of subcoooling. However, R1234yf offers lower performance than R134a. The components condenser and evaporator are the sites of highest and lowest exergy destruction respectively for the refrigerants considered. Journal of Thermal Engineering Journal of Thermal Engineering 2020-12-23T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5229 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5229 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5229

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5287 2020-12-29T21:00:00Z 1

Thermodynamic Assessment and Optimization of a Novel Trigeneration Energy System Based on Solar Energy and MSW Gasification Using Energy and Exergy Concepts Amir Ghasemi, Ali Akbar Shayesteh, Amir Doustgani, Maryam Pazoki Energy, Exergy, Gasification, Solar Energy, MSW, Optimization The current study aimed at delving into the thermodynamic study of a trigeneration cycle based on biomass fuel, combined with an Organic Rankine Cycle (ORC) and an absorption chiller. Biomass fuel is purely produced from Municipal Solid Waste (MSW). Energy and exergy analyses were carried out using the solar collector employing optimized characteristics to provide the required thermal energy at the ideal condition to utilizing in the high-temperature gasification process having hot steam. For supplying electricity, heating and cooling power, a Rankine cycle including a turbine, a heater, and a single effect absorption chiller was considered. To solar energy exploitation, a parabolic trough solar collector and hot steam gasifier were utilized. ORC can efficiently recover low-grade waste heat due to its excellent thermodynamic performance. Based on the examinations, the effects of critical thermodynamic parameters on the exergy efficiency and optimization of the trigeneration cycle and ORC with R134a, as working fluid, was conducted to achieve the system optimization design from thermodynamic aspect through Genetic Algorithm (GA). In this study, exergy destruction and its percentage in the power generation process were calculated as well. Results indicated that the studied system has the potential to generate 11.2 kW electricity, 17.4 kW heating power, 15.3 kW cooling power with the energy and exergy efficiencies of 64.3 % and 52%. It was also revealed that the output power of this system is fixed on the constant amount of 11.2 KW, which is obtained from the microturbine and ORC turbine. Additionally, it was demonstrated that the most exergy destructions are for gasifier, compressor, and combustor respectively, containing 47 %, 26.3 % and 14 % of the destructions. Finally, the optimized performance of the system was determined using GA and exergy efficiency as an objective function. The optimized trigeneration energy system could yield the exergy efficiency of 4.4%. Journal of Thermal Engineering Journal of Thermal Engineering 2020-12-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5287 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5287 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5287

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/4011 2020-03-29T21:00:00Z 1

Optimization of a Small Scale Concentrated Solar Power Plant Using Rankine Cycle Ahlem Bouguila, Rachid Said Optimization, Renewable Energy, Solar Energy, Energy Etorage A system for the exploitation of the available energy of the sun is proposed in this paper. This system consists of a collector, a heat reservoir, a vapor generator, a set of direction control valves and a turbine. These components can be combined to form four closed different cycles in order to generate electricity or store heat in accordance of the outdoor environment. An optimization method is proposed to optimize the energy collected at the shaft of the turbine for a given input sun power. The method establishes a functional relationship between the optimal mass flow rate through the collector, the sun input power and the optimal collected power at the shaft of the turbine. A similar functional relationship is set up between the optimal temperature of the working fluid and the sun input power. The collected optimal energy is computed as a function of the sun input power for different temperatures of the vapor generator. The effect of the heat transfer coefficient and coefficient of radiation of Stefan-Boltzmann and the temperature of the vapor generator on the output optimal energy are investigated. Journal of Thermal Engineering Journal of Thermal Engineering 2020-03-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4011 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4011 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4011

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5214 2020-11-22T21:00:00Z 1

Investigation of Flow Characteristics and Vortex Formations of Lambda Wing at High Angles of Attack Mustafa Murat Yavuz Vortex Breakdown, Angle of Attack, Lambda Wing It is well known in literature that further stages of flow separation and vortex breakdown around wings can be able to cause stall of wings. These formations must be investigated carefully for new plane types. However, some limited studies are available, especially on lambda wing for high angles of attack. In this study, effect of angle of attack on flow characteristics and vortex breakdown around a lambda wing is investigated with a constant Reynolds number of 10000. Computational fluid dynamic analysis is used and results of high angles of attack of the wing are given up to 450 which are not available in literature. Open water channel simulation is used. Vortex breakdown initially begins at an angle of 170 and it almost reaches to tip of wing when angle of attack is equal to 250. Vortices get stronger at further increments of angle of attack and they become to nearly equal length of wing at 450. Rounding effect of leading edges is investigated for decreasing vortex magnitudes. Streamline, particle injection, iso-value of vortices and location of stagnation points are given and they are discussed in detail. Journal of Thermal Engineering Journal of Thermal Engineering 2020-11-22T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5214 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5214 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5214

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5137 2020-07-04T21:00:00Z 4

Experimental Studies on Pressure Drop Characterization of Curved Tube Sections in Laminar Flow Regime Vikram Kolhe, Ravindra Edlabadkar, Asmita Deshpande Pressure drop, Laminar flow regime, Friction factor In fluid metering technology, Coriolis Mass Flow Meter (CMFM) is the most prominent mass flow measuring instrument due to its high accuracy, repeatability, and fidelity. The meter works on the principle of Coriolis force generated due to change in momentum of fluid while flowing through a vibrating tube. In CMFM, a straight or curved tube section is used to measure the mass flow rate of flowing fluid. The performance of such devices is found to vary with the shape and size of the curved tube and also with the flow regimes. Especially, it has been reported to underpredict the flow rate than actual in laminar flow regime. In the recent past, few researchers had attempted to explain the phenomenon underlying the error in measurement with the help of secondary flow development in laminar regime. The present investigations attempt to highlight the phenomena with the help of pressure drops occurring in different sections of the tube. Therefore, characterization of hydraulic resistance of system with respect to flow rate is thought to be a fundamental aspect to enlighten the issues. In this regard, an extensive experimental investigation has been undertaken on pressure drop characteristics in four tube shapes widely used in commercial CMFM like U (Basic U and Narrow U), Omega, Delta and Diamond shape tubes in laminar flow regime. The results are expressed in terms of non-dimensional numbers to ease in generalization. Journal of Thermal Engineering Journal of Thermal Engineering 2020-07-04T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5137 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5137 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5137

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5149 2020-09-17T21:00:00Z 1

Performance Assessment of a Medium-Scale Turboprop Engine Designed for Unmanned Aerial Vehicle (UAV) Based on Exergetic and Sustainability Metrics Özgür Ballı Turboprop engine, Unmanned Aerial Vehicle, exergy analysis, sustainability analysis. This study presents an exergetic and sustainability analyses to assess the performance of a genuine medium scale turboprop engine (m-TPE) used on the Unmanned Aerial Vehicle (UAV). The exergy efficiency of the engine is obtained to be 17.24% whereas the exergy efficiencies of the compressor, the combustor, the gas generator turbine, the gas generator turbine mechanical shaft, the power turbine, the power turbine mechanical shaft and the exhaust duct are found to be 87.21%, 52.51%, 98.53%, 98.60%, 97.40%, 98.00%, and 94.29%, respectively. From the viewpoint of thermodynamics, the combustor is determined to be the bad factor on the engine performance among the engine components. According to overall engine analysis, the environmental effect factor, exergetic sustainability index, sustainable efficiency factor and ecological effect factor of m-TPE are found to be 4.8, 0.208, 1.208, and 5.8, respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2020-09-17T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5149 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5149 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5149

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5156 2020-09-24T21:00:00Z 1

Thermo-Hydraulic Performance Analysis of Parabolic Concentrating Solar Water Heater Amit Kumar Bhakta, S N Singh Solar Water Heater, Perforated Twisted Tape, Thermo-Hydraulic Performance, Pressure Drop, Heat Transfer This paper concerns the thermo-hydraulic performance analysis of a PCSWH (parabolic concentrating solar water heater) with placing the PTT (perforated twisted tape) in the absorber tube. The experiments are performed using water as testing fluid. In this analysis, the mass flow rate changes from 0.0326 kg/s to 0.0667 kg/s and Reynolds number ranges from 2100 to 4250 respectively. The analysis is based on the effect of porosity of the PTT and mass flow rate over the pressure drop and heat transfer enhancement during the flow into the absorber tube of the PCSWH. At last to guess the increment in pressure drop and enhancement of heat transfer the empirical correlations for friction factor and the Nusselt number have been formulated considering the turbulent effect caused by PTT inside the absorber tube. The major observations of this analysis are that PTT enhances the pressure drop and heat transfer and also both enhances with increasing porosity of the PTT. Journal of Thermal Engineering Journal of Thermal Engineering 2020-09-24T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5156 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5156 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5156

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5157 2020-09-24T21:00:00Z 1

Improvement of Thermal Energy Storage by Integrating PCM into Solar System Mouna Ben Zohra, Amine Riad, Abdelilalh Alhamany, Mohamed Sennoune, Mohamed Mansouri Phase Change Materials, PCM, Solar Heater, Energy Storage, Energy Production, Thermal Energy The solar heater is a system that generates hot water by converting solar energy to thermal energy. In these last few years, various ways have been developed to gather this natural energy. However, they can not be able to store the energy when the sun disappears. In this study, thermal system based on phase change materials that improves the hot water production and stores thermal energy is proposed. In order to describe phase change materials and considers the effects of inclination angle on the production and storing thermal energy a numerical study has been carried out using the ANSYS-Fluent software. In addition, details concerning the choice of calculation range, mesh size, boundary conditions and turbulence model have been provided. The numerical results have been compared with previous data that was very promising. Journal of Thermal Engineering Journal of Thermal Engineering 2020-09-24T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5157 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5157 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5157

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5282 2020-12-28T21:00:00Z 1

Forced Convection Coolig of Multiple Heat Sources Using Open Cell Metal Foams Ali Bousri, Abdelmalek Hamadouche, Samir Khali, Rachid Nebbali, M. Hassen Beji Numerical modeling, Heated metallic foam blocks, Laminar forced convection in the channel A numerical simulation is performed for heat transfer enhancement in a parallel-plate heat exchanger equipped with multiple metal foam blocks of various size. Localized heat sources are placed on the top wall of the exchanger in the location of the metallic foam blocks. The Brinkman-Forchheimer-extended Darcy model is used to characterize the flow field inside the foam region. Solution of the coupled governing equations for the composite fluid/ foam system is obtained using the finite volume method. In this study, the influence of the parameters such as the Darcy number, the Reynolds number and the arrangement of the foam samples on the hydrodynamic and thermal behavior of the flow are deeply analyzed. The results are reported for two different configurations containing four metal foam blocks mounted alternately on the top and bottom of the channel walls: (1) blocks are attached straightly to the channel walls and (2) blocks positioned at a precise distance from the channel walls . The obtained results show that the improvement of the cooling of the heat sources by forced convection is better in configuration (2). Journal of Thermal Engineering Journal of Thermal Engineering 2020-12-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5282 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5282 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5282

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5151 2020-09-18T21:00:00Z 1

Experimental Investigation of An Aluminium Thermosyphon at Normal Operating Conditions Sachin V. Mutalikdesai, Ajit M. Kate Thermosyphon, Filling Ratio, Mass Flow Rate, Surface Temperature, Total Thermal Resistance The paper presents experimental investigation of an aluminium thermosyphon charged with acetone as working fluid. The effect of filling ratio on steady state performance of thermosyphon is experimentally investigated. Experimentation is performed at three different ratios namely 30 %, 60 % and 100 %. The effect of heat input and mass flow rate of water is also investigated. The heat input is varied between 50 to 300 W and mass flow rate is maintained in the range 30 lph to 60 lph. A condenser section of thermosyphon is surrounded by two pass aluminium cooling block for effective condensation. The cooling block is design in such a way that water will absorbs maximum heat from working fluid in condenser section. The temperature at outer surface of thermosyphon is recorded with the help of temperature sensors. The temperature distribution at outer surface of evaporator and condenser observed to be almost uniform for all mass flow rates and filling ratios. The heat transfer limitations are not encountered for any of thermosyphon. The filling ratio has significant effect on outer surface temperature of evaporator. The surface temperature of evaporator increases by 20 % with increasing the filling ratio at 150 W heat input and 30 lph mass flow rate. The results also indicate that mass flow of cooling water has significant effect on total thermal resistance of thermosyphon at lower input. For 50 W heat input, minimum thermal resistance is recorded as 0.269 °C/W at 60 % filling ratio and 50 lph mass flow rate. While for a same heat input, maximum thermal resistance is recorded as 1.077 °C/W at 100 % filling ratio and 60 lph mass flow rate. Journal of Thermal Engineering Journal of Thermal Engineering 2020-09-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5151 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5151 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5151

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5217 2020-11-29T21:00:00Z 1

Parametric Study of The Non-Premixed Coal Combustion in Furnace for Heat Transfer and Emission Characteristics Satish Dewangan, Moode Praveen Kumar Naik, Vivek Deshmukh Non-premixed Combustion, Coal Combustion, Computational Fluid Dynamics, Combustion Modeling, Pollutant Emission, Nox Emission Steady state turbulent non-premixed combustion of pulverized coal has been modeled in the two dimensional furnace. Pulverized coal of three different types, low volatiles coal, medium volatiles coal and high volatiles coal, has been considered. The coal is injected through the center of the furnace and air is being supplied with two inlets (top inlet and bottom inlet) at different velocities. Taking the advantage of the symmetry only one half of the domain is considered. Results have been validated with the experimental data for furnace temperature distribution. Effect of variation of parameters such as top air velocity, bottom air velocity, air temperature, furnace wall temperature and mass flow rate of coal are discussed for all three different types of coal. Effect of these various parameters have been discussed upon peak temperature inside the furnace, heat transfer to/from the system to surroundings and emission of gases like compounds of NO, CO and CO2. The analysis has been carried out using Ansys-Fluent software. Journal of Thermal Engineering Journal of Thermal Engineering 2020-11-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5217 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5217 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5217

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5154 2020-09-23T21:00:00Z 1

A Combined Experiment-Simulation Study on Temperature Regime of Roller-Compacted Concrete Applying for Dam Construction Van-Lam Tang, Trong-Chuc Nguyen, Bulgakov Boris Igorevich, Ngoc-Anh Pham, Trong-Phuoc Huynh Dam, Roller-Compacted Concrete, Compressive Strength, Regression Equation, Response Surface, Contour Plot, Maximum Temperature, Thermal-Stress. Similar to most of the other developing countries, Vietnam has national programs for industrial waste recycling including fuel, ash, and slag. In which, fly ash (FA) has been used commonly as a pozzolanic additive in the roller-compacted concrete (RCC) mixture for the dam construction of hydropower projects. This usage allows reducing the concrete cost, the hydration heat, and the thermal cracking during the construction process of the RCC. In this study, the optimal concrete mixture and the maximum temperature of the RCC dam were determined using the experiment planning method, Matlab, Maple 13, and Midas Civil. In addition, the mathematical model has been used to adequately describe the influence of the intensity concreting (IC) and the initial temperature of the concrete mixture (ITC) on the temperature regime of the RCC dam. The calculation of the temperature regime during the construction of the RCC dam of 45 m high and 1 m thick in Vietnamese climate conditions was performed with considering the IC and the ITC. As the results, the maximum temperature of the RCC dam was determined depending on the IC and the ITC. Calculation found that at IC = 0.6 m/day and ITC = 20°C, the maximum temperature in the central dam zone reached 36.38°C after 1800 hours from the beginning of construction. The results of the present study further support the safe and durable construction of the RCC dam in the future. Journal of Thermal Engineering Journal of Thermal Engineering 2020-09-23T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5154 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5154 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5154

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5286 2020-12-29T21:00:00Z 3

Waste Heat Recovery Technologies: Pathway to sustainable Energy Development Sunday Olayinka Oyedepo, Babatunde Adebayo Fakeye Sustainable Energy, Sustainable Technology, Waste Heat Recovery, Low Grade Energy, Sustainable Development, Emissions The aim of this study was to review the significant of waste heat recovery technologies as means of achieving sustainable energy development. Most developing nations of the World are faced with the enormous release of industrial waste heat of low temperature grade to the environment. Unlike material waste that is clearly visible, waste heat can be difficult to identify and evaluate both in terms of quantity and quality. Hence, understanding the availability of waste heat, and the ability to recover it, offer great opportunity to reduce energy costs and associated environmental impacts. Utilizing low-grade energy from waste heat sources is considered to offer a significant contribution to improving overall energy efficiency in the energy-intensive industrial sectors. The concept of industrial waste heat is explained, potential sources of waste heat from industries are identified, and the technologies available for waste heat recovery are presented in this study. From the review study, it is shown that about 72% of the global primary energy consumption is lost after conversion, while 63% of the considered waste heat streams arise at a temperature below 100 °C in which electricity generation has the largest share followed by transportation and manufacturing industry. The results of this study reveals that considerable amount of waste heat can be technically and economically recovered through sustainable technologies with prospective capacity for the much desired sustainable energy development. Specifically, in-depth utilization of waste heat resources can effectively moderate the rate of depletion of the fossil fuels and sufficiently reduce toxic emissions to within acceptable limits that are compatible to the projected time of full deployment of renewable energy (RE) source. Journal of Thermal Engineering Journal of Thermal Engineering 2020-12-29T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5286 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5286 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5286

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5152 2020-09-20T21:00:00Z 1

Experimental and Numerical Investigation of Contaminant Control In Intensive Care Unit: A Case Study of Raipur, India Tikendra Nath Verma, Shobha Lata Sinha CFD; Ventilation Design; Simulation; Airborne Disease Proper ventilation is an important strategy in the practice of infection control. Hospitals are complex atmospheres that require ventilation for thermal comfort of patients as well as control of harmful pathogens infection emissions. The present study is performed on a hospital at Raipur (21.2514° N, 81.6296° E), India, to analyze the avoidance of airborne infections from the mouth of patient to protect the doctor and other patients in the intensive care unit (ICU) using Computational Fluid Dynamics (CFD) software FLUENT. Incense smoke is used to for capturing velocity field. Twenty seven (27) cases of simulation were executed using different air change per hour (ACH) (6, 9 & 12) and different inlet and outlet positions talking into account the constant inlet temperature (20 °C). The wall temperatures were taken out from ISHRAE handbook for Raipur region. The velocity vector and capturing the flow field were also performed experimentally. All three turbulence model (Standard, RNG & Realizable) predictions have shown to be in good agreement with the experimental data. It can be effectively employed to validate the extensively used k-ε model which was commonly used for ICU. Journal of Thermal Engineering Journal of Thermal Engineering 2020-09-20T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5152 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5152 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5152

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5211 2020-11-03T21:00:00Z 4

Predicting Boiler Efficiency Deterioration Using Energy Balance Method: Case Study in 660 MW Power Plant Jepara, Central Java, Indonesia Muhammad Sagaf,Saharul Alim,Cahya Wibisono,Amron Muzakki Boiler Efficiency, Deterioration, Energy Balance Method, linear regression This research aims to determine the deterioration of boiler efficiency in Tanjung Jati B Unit 3 and 4 coal-fired power plant with capacity 2x660MW in Jepara Central Java Indonesia using energy balance (indirect method) based on ASME PTC 4-2018. The deterioration of boiler efficiency per year estimated using linear regression. From the results of the research, it is found that the deterioration in boiler efficiency of unit 3 is 0.19% per year and unit 4 is 0.44% per year. Large heat losses that vary for each performance test are greatly influenced by the use of various coal properties. Journal of Thermal Engineering Journal of Thermal Engineering 2020-11-03T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5211 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5211 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5211

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5158 2020-09-24T21:00:00Z 1

The Effect of the Use of Different Cover Materials on Heat Transfer in Flat Solar Collectors Mesut Tekkalmaz, Çisil Timuralp, Zerrin Sert Thermal Radiation, Natural Convection, Different Cover Materials, Flat-Plate, Solar Collector In this study, combined thermal radiation and natural convection heat transfer from glass and plastic cover flat solar collectors is examined by varying tilt angle and cover materials. The flat-plate solar collector tilt angle is varied from 0º to 45º. The performance of glass, lexan, and acrylic cover materials is investigated. Numerical simulations have been performed for various solar collector thicknesses exposed to external ambient temperature and wind heat transfer coefficient. Continuity, momentum and the energy equations, along with the Boussinesq approach, are solved with the finite volume method using the SIMPLE algorithm. The cover temperature and the top loss coefficient are calculated for each cover material, collector tilt angle and bottom plate temperature, wind heat transfer coefficient and external ambient temperature. The flow and temperature field are obtained, and the mean convection and radiation Nusselt numbers are calculated for the bottom plate. The analytically and numerically computed glass cover temperatures are found to be in perfect agreement. The top loss coefficient of the plastic cover is lower than that of the glass cover. It is determined that with increasing heat input from the bottom plate, the top loss coefficient and the mean cover material temperature increase linearly. As the external ambient temperature increases, the top loss coefficient and the cover material temperature do not present any significant change. Journal of Thermal Engineering Journal of Thermal Engineering 2020-09-24T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5158 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5158 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5158

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5228 2020-12-19T21:00:00Z 1

Finite Element Solution of Hydromagnetic Mixed Convection in a Nanofluid Filled Vented Grooved Channel Mohammad Ali, Md. Abdul Alim, Syed Sabbir Ahmed Magnetic field, mixed convection, grooved channel, finite element method The mixed convection flow in a differentially heated grooved channel filled with water based nanofluid under the influence of external magnetic field has been analyzed numerically in this study. Nanofluid’s thermal conductivity model has been modified to develop a new physical problem and finite element method has been implemented to solve the dimensionless governing equations. Numerical simulations have been performed for different values of pertinent parameters. Fluid flow and temperature distributions have been exhibited in terms of streamlines and isotherms due to the variation of Richardson number, Hartmann number and concentration of nanoparticles in base fluid water. The results show that flow field and temperature distributions within the channel affected significantly with the effects of Richardson number, Hartmann number and concentration of nanoparticles. In addition, it is found that heat transfer rate increases and decreases respectively with the increase in strength of magnetic field which depends strongly on Richardson number. Moreover, heat transfer rate accelerates effectively for increasing volume fraction, Reynolds number and Richardson number. The present simulation has been validated by comparing the present results with other published works on the basis of special cases. Journal of Thermal Engineering Journal of Thermal Engineering 2020-12-19T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5228 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5228 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5228

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5212 2020-11-05T21:00:00Z 1

Numerical Investigation of Design Parameters Effects on Performance of Cooling System Designed for A Lithium Ion Cell Mohammad Alipour, Riza Kizilel Multilayer Cell, Thermal Management, Air-Cooling System, Water-Cooling System A 3D numerical approach using the Finite Element Method (FEM) is applied to model the thermal behavior of multilayer 20Ah LiFePO4/Graphite cell and to design a cooling system. A three-dimensional multilayer cell model with heterogeneous thermal properties for the various cell layers is developed to study the effects of design parameters on cooling performance of mini-channel aluminum plates. As design parameters, effects of channel width, a number of channel passes, inlet mass flow rate, and heat transfer medium were considered. Using the optimized parameters, cooling performance of water-cooling, and air-cooling systems were compared. The results showed that the designed cooling system provided good cooling performance in controlling the temperature rise and uniformity. Inlet mass flow rate was the main influential parameter in controlling the cooling performance. The optimum number of channel passes was found to be seven passes. Channel width mainly controlled the pressure drop and had minor effects on temperature. At higher discharge current rates, the water-cooling system showed better cooling performance in dropping the maximum temperature and making uniform surface and inner temperature profile. Moreover, pressure drop, and power consumption rates become significantly lower for water cooling system. Journal of Thermal Engineering Journal of Thermal Engineering 2020-11-05T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5212 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5212 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5212

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5145 2020-09-02T21:00:00Z 1

Enhancement in Thermo-hydraulic Performance of Microchannel Heat Sink with Secondary Flows of Leaf Venation Pattern Vinayak Gaikwad, Suhas Mohite, Swapnil Shinde, Mahesh Dherange Microchannel, Primary channel, Secondary flow, Enhancement factor A new microchannel heat sink (MCHS) design comprising of secondary channels which connect neighboring primary channels are numerically analyzed to study their thermo-hydraulic characteristics. The inclusion of secondary channels in the continuous walls results in disturbance of thermal and hydrodynamic boundary layers which leads to drop in boundary layer thickness. Number of such secondary channel on either side of main channel will cause the flow to be continuously in developing state. The new MCHS are tested for heat flux range of 65 Watt per sq.cm to 200 Watt per sq.cm and cooled by water flowing at Reynolds number ranging from 650 to 1300. Compared to conventional MCHS, the thermal performance of new MCHS is higher but at the cost of pressure drop. The overall enhancement factor of the new design which is a function of Nusselt number and pressure drop of enhanced MCHS and conventional MCHS is 1.4 to 1.85. Journal of Thermal Engineering Journal of Thermal Engineering 2020-09-02T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5145 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5145 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5145

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5221 2020-11-29T21:00:00Z 1

Numerical Investigation of the Blade Profile Effect on the Aerodynamic Performance of a Vertical-Axis Wind Turbine Darrieus H-Rotor Abdellah Boumehani, Belkheir Noura, Rabah Kerfah, Sofiane Khelladi , Ivan Dobrev Wind Turbine Darrieus, Rotor H Profile URANS, Aerodynamic Performance A thorough understanding of the various parameters that affect the vertical axis wind turbine performance and lifespan will make design this model of turbine not difficult task. This article presents a study of the blade profile effect on the aerodynamic performance of a vertical axis wind turbineDarrieus H-rotor. A complete series of simulations based on complete unstable URANS calculations are performed for a three-blade Darrieus wind turbine. Fluent’s software is used for the numerical solution. The aerofoils of blade chosen for testing were NACA 0012, 0015, 0018, 0021 and -60 pitch angle is taken as the reference case for comparison. In order to quantify the influence of the profile of the blade on the performance, the characteristics of the flow field around the rotor of the different configurations are studied. For different values of the tip speed ratio, dynamic quantities, such as torque and rotor power, are presented and analyzed. Also in this investigation of the flow flied, two parameters are carefully investigated: mesh resolution and time step size. In the analysis, it appears that these parameters affect result accuracy. Finally, the numerical result shows that the variation of blade profile directly affected directly the power production. Journal of Thermal Engineering Journal of Thermal Engineering 2020-11-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5221 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5221 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5221

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5133 2020-07-03T21:00:00Z 1

An Integrated Model to Study the Effects of Operational Parameters on The Performance and Pollutant Emissions in a Utility Boiler Hamid Abroshan Non-Premixed Combustion, Burner, Excess Air, Deposition, Thermal Efficiency, NOx and CO Emission A gas fired tangentially boiler was modeled under full load conditions. Furnace was simulated by CFD and then was joint with two mathematical models to calculate heat transfer in the convective section, and metal temperature of waterwall tubes. Effects of changing the combustion excess air (0 to 20%) and burners tilt angle (-30° to +30°) were studied. Results showed that the boiler efficiency is optimum if excess air= 10% and the burners have a negative angle. However, these optimum settings cannot produce a superheated and reheated steam of 538 °C which is desirable. Indeed, a zero or positive tilt angle with 10% excess air, or a negative burner angle with 15% excess air lead to highest efficiency by considering the potential of generating superheated steam of 538 °C. In addition, CO emission in low excess air values growths by increasing the burner tilt angle. NOx emission in low and high excess air ratios is lower at positive burner angles while a moderate excess air (10%) needs a zero tilt angle to minimize NOx emission. Furthermore, a critical fouling thickness was computed, considering boiler's circulation ratio, in which the metal temperature of the waterwall exceeds the short overheating threshold. With a certain thickness of scale layers inside the tubes, a burner tilting equal to 0° or 30° postpones tube rupture. These results could be utilized by operating engineers to keep their utility boilers in the most efficient state and avoiding overheating and tube rupture. Journal of Thermal Engineering Journal of Thermal Engineering 2020-07-03T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5133 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5133 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5133

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5200 2020-09-28T21:00:00Z 1

Optimum Insulation Thickness for Cold Storage Walls: Case Study for Turkey Nuri Alpay Kürekçi Cold Storage, Optimum Insulation Thickness, Energy Saving, Thermo-Economic Analysis, Mathematical Modeling, Thermal insulation Cold storage have heat gain resulting from walls, roof, lighting, human, cooled products, and infiltration. The biggest of these gains is the heat gain through the walls. In this study, the optimum insulation thickness which should be used on the walls of cold storage was calculated. Calculations were made for 5 cities of Turkey (Izmir, Istanbul, Ankara, Sivas, and Erzurum) with different degree-day values. Extruded polystyrene (XPS), Expanded polystyrene (EPS), glass wool, rock wool, polyurethane were chosen as insulants to be used on the walls. Cooling degree-day values of the selected cities were calculated by using the average external temperature of the cities and the cold storage temperature (4, 0, -5, -10, -15, -20, -25 and -30°C). Calculations were repeated for different cold storage temperature values, and optimum insulation thicknesses that should be used for each temperature were found. In addition, energy savings and payback periods when optimum insulation thickness is used were also calculated. Journal of Thermal Engineering Journal of Thermal Engineering 2020-09-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5200 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5200 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5200

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5283 2020-12-28T21:00:00Z 1

Performance Evaluation of Parabolic Trough Collector with Receiver Position Error Ramesh Donga, Suresh Kumar, Abhay Kumar Parabolic Trough Collector, Receiver Position Error, MCRT Method, Finite Volume Method, Concentrated Solar Power In the present study, the effect of receiver position error on the optical and thermal performance of a parabolic trough collector (PTC) has been studied. Optical analysis of the PTC has been carried out by using Monte Carlo ray tracing (MCRT) method. The solar heat flux profile obtained from the optical analysis is coupled with the finite volume method (FVM) to study the thermal performance of the PTC. Simulations have been done for experimental SEGS LS2 solar collector used in Sandia National Laboratories. Syltherm 800 has been considered as heat transfer fluid (HTF). Receiver position errors in two directions i.e. along optical axis and lateral direction, have been taken. Results show that the receiver position error substantially influences the solar heat flux distribution and hence the temperature distribution on the absorber tube. The maximum circumferential temperature difference over the absorber tube increases up to by 199.7 K with receiver dislocation along the optical axis. The effects of the receiver position error on the optical efficiency and collector efficiency have also been studied. A maximum drop of 32% in the optical efficiency is observed when the receiver is displaced from the focus by 1.63% of focal length of the collector in both directions. The collector efficiency decreases by up to 14% when the receiver is offset by 1.63% of focal length of the collector along optical axis (away from the trough). Journal of Thermal Engineering Journal of Thermal Engineering 2020-12-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5283 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5283 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5283

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5225 2020-12-12T21:00:00Z 1

Numerical Analysis of Natural Convection in A Heated Room and Its Implication on Thermal Comfort A. Sibo Anthony, Tikendra Nath Verma Natural Convection, Turbulence Intensities, Air Velocity, Comfort Temperature, Operative Temperature A heated room is numerically analyzed to study thermal comfort. Cold air flowing in from the inlet gets heated by a heat source (placed just below the inlet), before being distributed throughout the room. The presence of the heat source and a high Rayleigh number causes the flow of air to be buoyant and turbulent. Two RANS based turbulence models, RNG k-ε and k-ω SST turbulence models are used to model turbulence and the Discrete Ordinate (DO) radiation model is used to model radiation heat transfer between different surfaces in the room. In order to account for buoyant air movement, air is approximated as a Boussinesq fluid. Parameters that affect comfort such as comfort temperature, operative temperature, turbulence intensity, velocity and the temperature difference between the head and ankle level are investigated. It is found that the comfort temperature and operative temperature predicted in this study have similar profiles irrespective of the turbulence models. Predicted values of turbulence intensity and velocity were low, which shows a low risk of drought in the occupied zone. The two RANS models give results similar to earlier studies that were performed with different turbulence and radiation models, proving their robustness and viability for a variety of flow problems. Journal of Thermal Engineering Journal of Thermal Engineering 2020-12-12T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5225 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5225 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5225

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5285 2020-12-29T21:00:00Z 1

CFD Numerical and Experimental Investigation of Two-Phase Flow Development After an Expansion Device in a Horizontal Pipe Raid Ahmed Mahmood, David Buttsworth, Ray Malpress, Ahmad Sharifian-Barforoush Two-Phase Flow, CFD Simulation, Expansion Region, Flow Patterns, Adiabatic Expansion, Two-phase Flow Development, Stratified Two-Phase Flow To optimize a vertical flash tank separator, the characteristics of the flow entering the separator are required to be known. A flash tank separator improves the performance of a refrigeration cycle by separating the liquid from liquid-gas flow and providing the evaporator with only liquid refrigerant. This technique improves the effective area and enhances the heat transfer coefficient in the evaporator. This paper investigates the influence of the inlet operating conditions to an expansion device, on the adiabatic two-phase flow development in a horizontal pipe downstream from the expansion device. This work also compares three dimensional numerical simulations and experimental observations for the two-phase flow development after the expansion device in the horizontal pipe. A general trend of the two-phase flow after the expansion device was gradually developed and the expansion length was identified at less than 200 mm from the inlet. The two-phase flow behaviour was recorded using a digital camera recording the flow behaviour at the upstream and downstream of the horizontal tube. The results revealed that an increase of the mass flow rate causes an increase in the void fraction and a reduction in the slip ratio in the developed region. The simulations underestimate the expansion length and the mean difference between the experimental data and the numerical results is 8 %. Journal of Thermal Engineering Journal of Thermal Engineering 2020-12-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5285 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5285 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5285

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5276 2020-12-25T21:00:00Z 1

A Theoretical Investigation on the Evaporative Heat Transfer of Co2 in Smooth and Microfin Tube Pınar Alataş, Derya Burcu Özkan Carbon Dioxide, Evaporation, Smooth Tube, Microfin Tube, Heat Transfer Coefficient Nowadays, global environmental events such as thinning of the ozone layer and climate changes are increasing. These types of events are not only affecting all creatures living on the Earth, but also decreasing the quality of life. For this reason, natural refrigerants which are not harmful to environment, have been preferred in cooling systems. In this study, heat transfer coefficient of CO2 was investigated during the evaporation process in smooth tube and designed microfin tube. Features of the tube used in evaporator of these cooling systems directly affect to the heat transfer coefficient. The geometric parameters of the microfin tubes are an outer diameter of 9.52 mm, number of fins 50, apex angle of 38°, helix angle of 20° and fin height of 0.12 mm. Theoretical model was created on MATLAB environment. The heat transfer coefficient was investigated based on vapor quality. When theoretical results obtained for microfin tube were compared with experimental results, 6% approach was seen. A theoretical model was created for smooth and microfin tube by selecting heat flux as 10 kw/m^2 and mass flux as 380 kg/m2s and heat transfer coefficients in different evaporation temperatures were compared based on vapor quality. It has been concluded that heat transfer coefficients of microfin tube at 5°C, 0°C and -8°C were 52%, 44% and 34% higher than that of smooth tube, respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2020-12-25T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5276 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5276 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5276

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5280 2020-12-28T21:00:00Z 1

Analytical and Comparative Investigation of Particulate Size Effect on Slurry Flow Characteristics Using Computational Fluid Dynamics Om Parkash, Arvind Kumar, Basant Singh Sikarwar 3D Slurry Pipeline, Eulerian Two-Phase Model, Particulate Size, Slurry Concentration, Velocity Distribution, Pressure Drop The key issue associated with the industries is the transportation and dumping of solids particulates in the form of slurry at the desired place using long length pipelines. In this perspective, numerical simulation of three-dimensional horizontal slurry pipeline of 0.0549 m diameter using Eulerian two-phase model with RNG k-ɛ turbulence closure is carried out. The glass - beads solid particulates having density ( = 2470 kg/m3) and slurry concentration varies as 10% to 50% (by volume) for velocity ranges of 3-5 ms-1. The computational modeling is done using available commercial software ANSYS Fluent for 125µm and 440 µm particulate size at different velocity and concentration range to know their effect on slurry flow characteristics. It is observed that for chosen particulate size pressure drop increases with increase in velocity at all solid concentration range. The pressure drop in slurry for 440 µm solid particulates is found higher as compared to the pressure drop of 125 µm solid particulates slurry. The percentage change in pressure drop is also reported in the paper due to particulate size effect at all velocity and solid concentration. The obtained results of predicted pressure drop are analytically compared with the available experimental results of literature and are in synchronism with that. A parametric study is carried out with the aim of visualizing and understanding the solid particulate size effect on slurry flow characteristics. Finally, the results of settling solid concentration contour, velocity contour, concentration profiles, velocity profiles and vector representation of concentration/velocity were also predicted for chosen particulates sized slurry. Journal of Thermal Engineering Journal of Thermal Engineering 2020-12-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5280 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5280 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5280

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5240 2020-12-24T21:00:00Z 1

Effect of Exhaust Layout on the Indoor Thermal Comfort under Harsh Weather Conditions Ahmed Jawad Khaleel, Ahmed Qasim Ahmed, Hassan J. Dakkama, Wisam A.M. Al-Shohani Thermal Comfort, Exhaust Layout, Displacement Ventilation, CFD, Ventilation The inlet and outlet size, number and location have a significant influence on the thermal environment indoor and air distribution for the temperature and velocity. In this work, numerical and experimental studies were performed to examine the influences of the inlet and outlet distribution, number and location, on the air movement and temperature distribution indoor. Also, the separation of the amount of the extracted air has been investigated in this study. To provide a comfortable environment for the occupants, important factors such as air temperature distribution, thermal sensation and draft rate should be evaluated carefully. Therefore, in this paper the occupant’s thermal sensation and the air movement and temperature distribution were used as the main evaluation index. In this investigation, three cases study were used tested. The experimental work was performed under the Iraqi weather conditions which are hot and dry in summer. The finding showed that the indoor thermal environments were significantly influenced by the opening locations of the exhaust. Also it was found that the satisfied human thermal comfort was obtained when the exhaust diffuser installed relatively far away from the supply diffuser. In addition, the best results were found by separate the amount of the exhaust air and extracted from the two exhausts opening. This will give the supplied air the ability to distribute inside room perfectly. Also, in order to prevent the air short circuit, the exhaust opening should not be located at the wall in front of the supply opening. Journal of Thermal Engineering Journal of Thermal Engineering 2020-12-24T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5240 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5240 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5240

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5226 2020-12-12T21:00:00Z 1

Reduction of Energy Use in Industrial Facility Džana Kadrić, Nijaz Delalic, Berina Delalic Gurda, Milovan Kotur, Armin Skulj Energy Audit, Medium Size Bakery, Energy Savings, Energy Performance Indicator Energy saving potentials related to steam generation and its usage in the medium size bakery are analyzed and presented. Input data needed for the investigation are gathered through detailed energy audit. Four energy savings measures are analysed in detail: 1) change of heat generator for space heating and domestic hot water preparation from steam boiler to condensing boiler, 2) reduction of heat losses from steam and condensate distribution lines, 3) heat utilization of return condensate and 4) replacement of the old, low efficiency steam boiler with high-efficient one. Implementation of these measures will result in substantial reduction of energy costs, ranging from 2.900 to 26.200 € annually. Interaction of all measures is analysed through energy efficiency improvement scenario, whose implementation will ensure significant energy cost savings, estimated at 40.793 € annually, with simple payback period shorter than 4 years. Implementation of presented measures will improve facility’s energy efficiency, represented through reduction of annual energy performance indicators by 6,14 %. Presented analysis revealed that steam generation and its usage in the industrial facilities offer a substantial potential for reduction of energy use and energy related cost. Journal of Thermal Engineering Journal of Thermal Engineering 2020-12-12T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5226 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5226 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5226

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5277 2020-12-25T21:00:00Z 1

Performance Analysis of a Solar-Driven Ejector Air Conditioning System Under El-Oued Climatic Conditions, Algeria Mokhtar Ghodbane, Boussad Boumeddane, Ahmed Kadhim Hussein Solar Energy, Air Conditioning, Linear Fresnel Reflector, Ejector, Performance In order to understand the behavior and to determine the parameters of a solar-driven ejector air conditioning system at low or medium temperature; a dynamic model depends on the principles of conservation, the momentum mass and energy is developed. For this purpose, the thermodynamic characteristics of the liquid and vapor refrigerant were identified using the Engineering Equation Solver EES software. Linear Fresnel Reflector (LFR) has been used as a tool to convert solar energy into thermal energy. The water (R718) was used as a refrigerant. The performance of the ejector air conditioning system was compared as a function of the operating parameters of the subsystem. The thermal efficiency of the Fresnel linear concentrator was as high as 31%, and the overall thermal performance of the machine (STR) was as high as 19%. The results obtained during this study are very encouraging. This technique can be used for air conditioning in desert areas in southern Algeria, where fossil energy (petroleum, gas, etc.) is extracted and produced in various types. Journal of Thermal Engineering Journal of Thermal Engineering 2020-12-25T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5277 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5277 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5277

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5219 2020-11-29T21:00:00Z 1

Experimental and Computational Investigation of Flame Holders in Combustion Chambers at Different Thermal Loads Mohammed KH Abbas Alhumairi, Samir Gh. Yahya, Itimad D J Azzawi, Ahmed AAG Al-Rubaiy Premixed Combustion, Flame Stability, Flame Holder, Thermal Loads The effect on the dynamic stability of combustors with and without flame holders were investigated experimentally and computationally with thermal loads of 3, 5, and 9 kW. Three different cases were studied, large flame holder (LFH), small flame holder (SFH) and no flame holder (NO_ FH). Flame topology was investigated in these three cases. Moreover, lean propane–air premixed combustion were also considered for two models, turbulent flame speed closure (TFC) and coherent flame (CFM). These models were investigated using different turbulent kinetic energies and turbulence dissipation rates. Experiments were performed with mean inlet velocities of 16.5, 17, 29.2, 30.8, and 52.6 cm/s, excess air ratios (?) of 1.6, 1.65, 1.7, and 1.8. The results showed that the flame topology and location are more sensitive to the increase in the excess air ratios and thermal loads in the large flame holder than in the small flame holder. Heat transfers and species distributions caused by combustion are also investigated for the large and small flame holders; in both cases, flame stability was sustained, and the flame front position moved upward regarding to the flame holder region. Journal of Thermal Engineering Journal of Thermal Engineering 2020-11-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5219 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5219 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5219

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3864 2019-09-23T21:00:00Z 1

Numerical Analysis of Flame Characteristics and Stability for Conical Nozzle Burner Julanda Al-Mawali, Sam M Dakka Partially Premixed Flames, Flame Stability, Conical Burner, Aircraft Combustion Systems, Triple Reaction Zones, Mixing Length, Low Emissions The stability and the mean structure of methane partially premixed conical burner flames was investigated numerically using ANSYS Fluent. The study presents and discusses the stability curves of the partially premixed flame and maps the mean flame structure based on contours of mass fraction of O2, CO and temperature. From the data obtained, it can be concluded that both premixed and non-premixed flames are less stable than the partially premixed flames. An optimum level of partially premixing was found and the flames beyond this threshold were found to be less stable. This optimum level was found, when the ratio of the mixing length to the nozzle diameter is equal to 5. At this specific degree of partially premixing, the flame exhibited triple interaction reaction zones. It was found that with an increase of the angle of the cone of the burner, the air entrainment increases which, in turns breaks the stabilization core and hence cause a reduction in the flame stability limit. The main role of the cone is to provide a protection from the surrounding environment at early phase of the reaction near the jet exit where turbulence with high intensity was observed. Journal of Thermal Engineering Journal of Thermal Engineering 2019-09-23T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3864 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3864 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3864

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5466 2021-10-18T21:00:00Z 4

Thermodynamic investigations on 227 kWp industrial rooftop power plant Ranjana Arora Industrial Roof Top Solar Photovoltaic (PV) Power Plant, CUF, Performance Ratio (PR), Array Yield With the growing demand of energy along with scarcity of natural resources and drastic fluctuations of the climate change implications, there has been a constant effort of mankind to switch towards renewable energy sources. Among various renewable energy systems, solar photovoltaics (SPV) has emerged out as an evident choice for the range of applications from commercial to residential end users. The performance of the SPV power system needs to be monitored, so that the plant can be operated efficiently and maximum electrical output can be generated out of it. For performance assessment, capacity utilisation factor (CUF) has been considered the parameter for monitoring of the SPV power plant. CUF is monitored for the industrial roof top SPV power plant and compared with the other CUF data available in the literature. In the present work, an effort has been made to monitor the CUF parameters, performance ratio (PR) and energy generation units for a 227kWp SPV industrial rooftop power plant. It has been found that due to certain losses, the CUF is found to be lower than the ability of the system. The various technical causes of low CUF along with their remedial actions are proposed in view of improving CUF and overall efficiency of the system. Journal of Thermal Engineering Journal of Thermal Engineering 2021-10-18T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5466 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5466 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:7 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5466

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5352 2021-02-28T21:00:00Z 1

Comparison Study Between Theoretical Analysis and Artificial Neural Network of the Capillary Tube Basim Freegah, Ammar A. Hussain, Ahmed Ramadhan Al-Obaidi Capillary Tube, Refrigerant Cycle, Physical Properties of Refrigerant, ANN Technique The main purpose of expansion devices is reduced the higher pressure of the working fluid from the condenser pressure to the evaporator pressure. There are several kinds of expansion devices, one of these types is capillary tube which is common utilized in small size refrigeration systems. In this work, the effect of the diameter of capillary tube and mass flow rate of the refrigerant on the physical properties of the refrigerant within the capillary tube have been conducted. Moreover, an artificial neural network (ANN) technique has been utilized in order to clarify the possibility of applying this theory to the effect of such parameters on the results of the capillary tube. The study has been shown that there is a very good agreement between experimental and numerical results. The diameter and mass flow rate have impact on the length of the capillary tube, increase diameter leads to increase the capillary tube length while increase mass flow rate leads to decrease the length. Furthermore, the results shown that ANN technique can be employed to study the effect of such as parameters that considered in this on length of capillary tube. So, it can be using latter technique with accuracy 95%. Journal of Thermal Engineering Journal of Thermal Engineering 2021-02-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5352 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5352 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5352

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5311 2021-01-26T21:00:00Z 4

Numerical Analysis of Heat Transfer in Multilayered Skin Tissue Exposed to 5G Mobile Communication Frequencies Jagbir Kaur, Suyeb Ahmed Khan millimeter waves, bioheat transfer, multilayered skin tissue, 5G mobile phones Rapid growth in wireless communications has triggered the advent of 5G mobile communication systems. The use of millimeter waves (30-300 GHz) in 5G system has generated global concern about its biological safety. In present paper, we have numerically analyzed the heat transfer in a 3D multilayered skin tissue exposed to 5G frequencies. The numerical scheme comprises coupling of solution of Maxwell's equation of wave propagation within tissue to Pennes’ bioheat equation. Temperature variations are analyzed at 28 GHz, 38 GHz, and 60 GHz. Additionally, electric field and specific absorption rate distribution are also studied. Highest values of electric field and specific absorption rate are estimated in epidermis layer of skin tissue. For all considered frequencies, highest transient temperature (37.36°C) is predicted in subcutaneous fat layer of the skin. However, the steady state temperature is nearly same as core body temperature (37°C). The results show that 5G mobile phones do not cause any thermal damage to the skin tissue and can be considered safe. Journal of Thermal Engineering Journal of Thermal Engineering 2021-01-26T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5311 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5311 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5311

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3866 2019-09-24T21:00:00Z 1

Energy and Exergy Analysis of a Domestic Refrigerator: Approaching a Sustainable Refrigerator Niyaj Shikalgar, S.N. Sapali Refrigerator, Water cooled Condenser, Hot wall Condenser, Energy, Exergy In the perspective of reducing the household energy consumption, current research in conventional refrigeration is concentrating on introducing innovative designs and enhancing the energy efficiency of components. The energy and exergy analysis methods help to localize exergy losses in the refrigerator and to develop means to reduce them. In this research work to operate the refrigeration system at low condensing pressure the hot-wall air cooled condenser is replaced by box type shell and tube water-cooled condenser. The investigation is carried according to ISO 15502:2005 refrigerator test guidelines. Besides the coefficient of performance of a refrigerator with BSTWC, exergy efficiency, exergy loss in all components of the domestic refrigerator has been experimentally studied. The experimental results show that COP is increased by 18-20% and the improvement in exergy efficiencies of the refrigerator with BSTWC unit is found to be 6.89% to 9.13% which is more than results of a conventional refrigerator. The exergy losses caused by compressor and condenser are found to be 21 %. The per day energy consumption of a refrigerator with a water-cooled condenser reduces by 17% in comparison with conventional refrigerator. The irreversibility of the proposed system is 34 % less than that of the conventional system under similar operating conditions. The total equivalent warming impact(TEWI) of refrigerator working with BSTWC is 16% lower than that the refrigerator with HWAC condenser. The utilization of BSTWC in household refrigerators enhances energy efficiency. Journal of Thermal Engineering Journal of Thermal Engineering 2019-09-24T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3866 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3866 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3866

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5306 2021-01-22T21:00:00Z 1

Prediction Sulphuric Acid and Water Vapour Dew Point Temperatures of Flue Gases and Combustion Analysis for Solid Fuels in Turkey Meryem Terhan Solid Fuels, Combustion Analysis, Acid Dew Point Temperature, Heat Recovery from Flue Gas, Air Preheater In the study, the combustion analysis is examined for the solid fuels in Turkey. The principal aim of the analysis is determined the limits and obstacles in the design heat exchanger to avoid the corrosion risk on the heat exchanger surfaces in the latent heat recovery applications from waste flue gas. To do this, in which regions of the heat exchanger the flue gas temperature reached to the sulphuric acid and water vapour dew point temperatures are required to predict. In order to predict the condensing zone, an air preheater for the coal-fired boiler in a heating system is designed using finite difference method. Designed the air preheater is consists of the counter-cross flow, Ushaped stainless steel tube bundle. The tube is discredited 200 cells to one-dimensional during the flow. The heat transfer rates, the flue gas and air inlet and outlet temperatures, surface temperatures of the tube wall, the mole fractions of water and sulphuric acid vapour, the other non-condensing gases in the flue gas are calculated in each discrete cell. According to the results of the study, while the dew point temperature of the water vapour changes over the range 30-40 °C, the acid dew point temperature waves to 125 °C from 140 °C for the coal types mined in Turkey. Journal of Thermal Engineering Journal of Thermal Engineering 2021-01-22T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5306 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5306 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5306

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5338 2021-02-27T21:00:00Z 1

Analysis of A Hybrid Cascaded Latent/Sensible Storage System for Parabolic-Trough Solar Thermal Plants Mubarak D. Muhammad, Ossama Badr Latent Heat Storage, Sensible Storage, Parabolic-trough Solar Thermal Power Generation Dymola, Modelling and Simulation The molten-salt two-tank system is the state-of-the-art thermal storage technology employed in the more mature parabolic-trough solar thermal power generation using synthetic oil as the heat-transfer fluid (HTF). This storage technology requires high storage-material inventory, making it very expensive. The use of latent-heat storage (LHS) system offers smaller storage size and material inventory. However, such a storage system faces two challenges: there are limited number of commercially-available phase-change materials (PCMs) are suitable in the operating temperature range; and these materials have very low thermal conductivities. The use of finned tubes, nevertheless, can overcome the later shortcoming. In this study, the analysis of a hybrid storage system, consisting of a three cascaded finned-tube LHS stages and a sensible concrete tube register stage, was carried out through modelling and simulation. A procedure for the design of the finned-tube cascaded LHS stages was developed. For a typical 50 MW parabolic-trough solar thermal power plant, the dimensions of a storage system with 6 hour of operation at full load were obtained. The three-stage cascaded LHS sub-system provides 45.5% of the total storage capacity of the entire system and has a volumetric specific capacity of 54% greater than that of the two-tank system. The volumetric specific capacity of the entire storage system is 9.3% less than that of the two-tank system. Journal of Thermal Engineering Journal of Thermal Engineering 2021-02-27T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5338 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5338 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5338

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5335 2021-02-27T21:00:00Z 1

Multi-Objective Particle Swarm Optimization of The K-Type Shell and Tube Heat Exchanger (Case Study) M. Nadi, Mehdi Aliehyaei, A. Ahmadi, O. E. Turgut Cryogenic, Heat exchanger, Optimization, Objective This paper investigated optimization of two objectives function include the total amount of heat transfer between two mediums and the total cost of shell and tube heat exchanger. The study was carried out for k-type heat exchanger of the cryogenic unit of gas condensates by multiple objective particle swarm optimization. Six decision variables including pipe pitch ratio, pipe diameter, pipe number, pipe length, baffle cut ratio, and baffle distance ratio were taking into account to conduct this simulation-based research. The results of mathematical modeling confirmed the actual results (data collected from the evaporator unit of the Tehran refinery’s absorption chiller). The optimization results revealed that the two objective functions of heat transfer rate and the total cost were in contradiction with each other. The results of the sensitivity analysis showed that with change in the pitch ratio from 1.25 to 2, the amount of heat transfer was reduced from 420 to 390 kW about 7.8%. Moreover, these variations caused reduction in cost function from 24,500 to 23,500 $, less than 1%. On the other hand, an increase in pipe length from 3 to 12 meters, the heat transfer rate raised from 365 to 415 kW by 13.7%, while the cost increased from 20,000$ to 24500$ about 22%. Journal of Thermal Engineering Journal of Thermal Engineering 2021-02-27T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5335 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5335 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5335

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5339 2021-02-27T21:00:00Z 1

Numerical Investigation of Heat Transfer Water-Cooled Roof in an Electric Arc Furnace Mamdouh El Haj Assad, Khalil Khanafer, Ehab Bani Hani, Bashria Yousef Electric Arc, Furnace, Heat Transfer, Temperature One of the major problems in electric arc furnace is the high temperature which results in thermal stresses and cracks within the material of the furnace surrounding walls. An effective cooling technique is needed to avoid such problems. For this purpose, a novel roof configuration of an electric arc furnace is used to provide efficient cooling to reduce the temperature in the roof material. The roof consists of two solid materials, namely, copper and alumina brick. The roof cooling is achieved by a water circulation within the roof. A numerical model using finite element method was implemented to solve the heat conduction equation with the complicated boundary conditions to find out the effects of using brick material with geometrical size variations for different values of thermal conductivity on the temperature distribution within the roof. The results showed that the decrease in brick material thermal conductivity resulted in a significant decrease in the top surface temperature of the furnace roof. The results showed that rectangular brick material is the best option in the roof to keep it at low temperature. Journal of Thermal Engineering Journal of Thermal Engineering 2021-02-27T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5339 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5339 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5339

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5320 2021-01-30T21:00:00Z 1

Aerodynamic Study of Slotted Flap for NACA 24012 Airfoil by Dynamic Mesh Techniques and Visualization Flow Emad Qasem Hussein, Haider Nadhom Azziz, Farhan Lafta Rashid Aerodynamic Characteristic, Slotted Flap, Dynamic Mesh, CFD, Angle of Attack Slotted flap is one of high lift devices. It considered as a moving part of the airfoil which is used as a control instrument in a form of elevator, rudders and ailerons. The main focus of work is to investigate the effect of flap chord, gap and overlap on aerodynamic characteristic of NACA 24012 airfoil. The model was tested with 20% C, 30% C and 40% C single slotted flaps at zero angle of attack. The dynamic mesh and user defined function is applied to control the flap distance with respect to wing at any position. The simulation was done by solving the governing equations (Continuity, Reynolds Averaging Naveir- Stokes and Energy Equation) in 2-D using Fluent analysis at Reynolds number of 3.1x〖10〗^6. Based on the results presented, larger increment of lift coefficient is obtained with the larger flap chord, but this increase is accompanied by a drag penalty. Furthermore, the loss of lift coefficient associated with larger extending flap at 3% C had a very detrimental effect on the attainable lift coefficient. The simulation result also shows that an optimum gap is 1% C in order to derive the maximum lift capability from the flap model. The code is validated against field measurements to show how close the CFD model simulates the reality. Journal of Thermal Engineering Journal of Thermal Engineering 2021-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5320 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5320 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5320

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5227 2020-12-17T21:00:00Z 1

Review Enhancement of Thermal Conductivity and Heat Transfer using Carbon Nanotube for Nanofluids and Ionanofluids Ali Alshareef,E.N. Tugolukov Enhancement, Thermal conductivity, Carbon nanotubes, Heat transfer, Convection, Nano fluid This paper attempts to present a clearer picture, a detailed and up to date review of the heat transfer enhancement and thermal conductivity improvement for conventional fluids by adding carbon nanotubes or hybrid carbon nanotubes in the base fluid to obtain nanofluids or ionanofluid. Carbon nanotubes have attracted the interest of different researchers because of their high thermal conductivity that exceeds other equivalent types of nanoparticles. In view of this, the effect of different key factors like concentration, temperature and shape type of nanoparticles on the thermal conductivity improvement in nanofluids were reviewed. Moreover, the effect of surfactant stabilizers on the carbon nanotubes nanofluids distribution was evaluated. The results that have been obtained from the valuable studies have been analyzed and some gaps have been found that need to be re-reviewed by the researchers. Journal of Thermal Engineering Journal of Thermal Engineering 2020-12-17T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5227 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5227 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5227

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5332 2021-02-25T21:00:00Z 1

Thermal Design, Analysis and Test Validation of TURKSAT-3USAT Satellite Murat Bulut, Nedim Sözbir 3U CubeSat, Low Earth Orbit, Thermal Design, Thermal Analysis, Thermal Test. When CubeSat projects are a useful means by which universities can engage their students in space-related activities. TURKSAT-3USAT is a three-unit amateur radio CubeSat jointly developed by the Space Systems Design and Test Laboratory and the Radio Frequency Electronics Laboratory of Istanbul Technical University (ITU), in collaboration with TURKSAT, A.S. company as well as the Turkish Amateur Technology Organization. It was launched on April 26, 2013 as a secondary payload on a CZ-2D rocket from China’s Jiuquan Space Center to an altitude of approximately 680 km. The mission of the satellite has two primary goals: (1) to voice communication at Low Earth Orbit (LEO) and (2) to educate students by providing hands-on experience. TURKSAT-3USAT was designed to sustain a circular, near sun-synchronous LEO, and has dimensions of 10 x 10 x 34 cm3. Within the course of this paper, TURKSAT-3USAT’s thermal control will be addressed. TURKSAT-3USAT’s thermal control model was developed using ThermXL and ESATAN-TMS software. Using this model, temperature distributions of the CubeSat when subjected to various experimental conditions of interest were computed. Using a thermal vacuum chamber (TVAC), thermal cycling and bake-out testing were carried out on the flight model to verify the thermal design performance and check the mathematical model. Based on thermal analysis results, the temperature of equipment was within the allowable temperature range except for the batteries that were between 42.56 oC and -20.31 oC. Heaters were used for the batteries in order to maintain the batteries’ temperature within the allowable temperature range. Journal of Thermal Engineering Journal of Thermal Engineering 2021-02-25T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5332 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5332 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5332

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5351 2021-02-28T21:00:00Z 1

Experimental Investigation on Thermal Behavior of Hybrid Single Slope Solar Still Anshika Rani, Ravi Kant, S. Suresh, Anil Kumar Single Slope Solar Still, Natural Convection, Forced Convection, Internal Heat Transfer Coefficient, External Heat Transfer Coefficient Solar energy is one of the most common and eco-friendly non-conventional types of energy source which is having various applications like purification of saline water. The experimental study of the present research work has been performed at the M.A.N.I.T, Bhopal M.P, India (latitude: 23°12′ 51″ N, longitude: 77° 25′ 0″ E) in the month of January 2018. The investigation has been performed on single slope solar still coupled with a flat plate solar collector to examine the thermal behaviour of the solar system and results have been presented in natural and forced convection mode. The overall efficiency reached up to 9.86% in natural mode where as 16.70% in forced mode. Therefore, forced mode solar still option is better and preferred. Journal of Thermal Engineering Journal of Thermal Engineering 2021-02-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5351 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5351 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5351

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5340 2021-02-27T21:00:00Z 1

Physical Effects of Variable Fluid Properties on Gaseous Slip-Flow Through A Micro-Channel Heat Sink Rajan Kumar Micro-convection, Variable Fluid Properties, Nusselt Number, Slip-Flow Physical effects induced in micro-convective gaseous slip-flow due to variation in fluid properties are numerically examined in this paper. The problem is particularly simulated for slip-flow through a micro-channel heat sink (MCHS) having constant heat flux supplied from the wall under hydrodynamically and thermally fully developed flow (FDF) conditions. It is observed that the Nusselt number (Nu) for slip-flow is significantly higher than the no-slip-flow condition and Nu is significantly affected due to variable fluid properties (VFP). Four different cases of VFP are studied in order to investigate their effects individually. Pressure and temperature dependent density (?(p, T)) variation flattens the axial velocity profile in radial direction (u(r)) profile which promotes faster moving particles close to the wall which considerably enhances Nu. The incorporation of temperature dependent viscosity (µ(T)) variation marginally enhances Nu along the flow. Incorporation of temperature dependent thermal conductivity (k(T)) variation highly augments Nu due to higher ? and higher k fluid near to the wall and the incorporation of temperature dependent specific heat at constant pressure (Cp(T)) variation reduces Nu due to lower k fluid near to the wall. The investigation also shows that the pressure drop significantly deviates from no-slip to slip condition. Furthermore, the effects of VFP on the gauge static pressure drop (?pg) and slip velocity are also examined. The incorporation of µ(T) and k(T) variations trivially affects the ?pg and slip velocity. However, the incorporation of Cp(T) variation significantly affects the ?pg and slip velocity. Journal of Thermal Engineering Journal of Thermal Engineering 2021-02-27T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5340 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5340 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5340

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5355 2021-03-02T21:00:00Z 1

A Method to Predict Fouling on Multi-Storey Building Mounted Solar Photovoltaic Panels: A Computational Fluid Dynamics Approach Kudzanayi Chiteka, Rajesh Arora, S. N. Sridhara Solar Photovoltaics, Dust Deposition, CFD Simulation, Installation Configuration, Empirical Modelling The influence of installation and environmental parameters on dust particle deposition behavior on solar photovoltaic collectors were investigated using Computational Fluid Dynamics (CFD) simulation. Parameters including tilt, height of installation, dust particle size and wind speed were investigated. Modeling of wind flow on the building and the photovoltaic array was achieved using the Shear Stress Transport k-ω turbulence model. The discrete phase model was adopted for dust motion prediction and a model was developed to assess the impact of dust accumulation on the performance of the photovoltaic array. The study revealed that rooftop installations have less dust deposition unlike the ground-mounted installations. The wind flow characteristics on rooftop installations are greatly affected by the building while on ground mounted installations wind flow is only influenced by the tilt of the solar photovoltaic collector. Different tilt angles, wind speeds and particle sizes had different deposition characteristics. The lower impact velocities experienced on ground mounted Photovoltaic (PV) arrays resulted in more deposition for smaller sized (10µm) dust particles compared to the larger sized (50µm and 150µm) particles. On rooftop installations, dust particle size of 150µm had the most deposition at a velocity of 5m/s and hence it resulted in a 22.61% reduction in solar photovoltaic efficiency while the least reduction in efficiency of 1.32% was recorded at 15m/s and 10µm size dust particles. The tilt angles of 0o and 22.5o had large sized turbulent eddies compared to the tilt of 45o. The study revealed that ground mounted photovoltaic arrays had more dust deposition compared to rooftop mounted photovoltaics. Journal of Thermal Engineering Journal of Thermal Engineering 2021-03-02T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5355 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5355 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5355

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3902 2019-12-01T21:00:00Z 1

Bioheat Equation with Fourier and Non-Fourier Heat Transport Laws: Applicability to Heat Transfer in Human Tissues Natalya Kizilova, A. Korobov Pennes Bioheat Equation, Non-Fourier Heat Transport Laws, Heat Transfer in Biological Tissues, Mathematical Modeling The paper is dedicated to mathematical problem formulations for the heat propagation in biological tissues based on the Fourier and non-Fourier laws at different boundary conditions. The heating of the tissues is provided by external heat sources like low intensity lasers or light-emitting diodes which are widely used in contemporary medical care. Numerical computations on the standard Pennes bioheat equation with Fourier heat conduction give the temperature curves for both heating and thermal relaxation processes that do not correspond to the in vivo measurement data on human skin tissue. It is shown the modified bioheat equation based on the Guyer-Krumhansl heat conduction with correct formulation of the boundary conditions produces realistic temperature curves when the distributed heat sources and sinks in the tissue are accounted for. The former corresponds to the metabolic heat and temperature dependent chemical reactions, while the latter is provided by the heat convection with blood microcirculation system. The proposed model gives realistic two time temperature curves. The perspective applications of the novel mathematical formulation are discussed. Journal of Thermal Engineering Journal of Thermal Engineering 2019-12-01T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3902 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3902 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3902

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5326 2021-02-12T21:00:00Z 4

Convective Heat Transfer and Fully Developed Flow for Circular Tube Newtonian and Non-Newtonian Fluids Condition Ahmed Shkarah Non-Newtonian Fluids, Convective Heat Transfer We represent a conceptual scrutiny for completely organized convective heat transfer ring within the circular pipeline with power law liquids by means of realizing that the heat diffusivity has been a temperature gradient. The investigative resolution is availed and the behaviour of the heat transfer is inspected under a persistent thermic flux frontier condition. It has been demonstrated that the Nu stubbornly relies upon the power-law index n value. The Nu (Nusselt number) recognizably gets reduced in a range of n from 0 to 0.1. Nonetheless, for n greater than 0.5, there is a monotonic decrement in the Nu with the incremental n, and for n greater than 20, values of the Nu have approached a constant. Journal of Thermal Engineering Journal of Thermal Engineering 2021-02-12T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5326 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5326 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5326

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5350 2021-02-28T21:00:00Z 1

Performance of Rectangular Pin-Fin Heat Sink Subject to an Impinging Air Flow Adil Abbas Mohammed, Saad Abdulwahab Razuqi Forced Convection, Heat Transfer, Heat Sink, Rectangular Fins, Heat Flux, Numerical Analysis The heat sink is used to enhance heat rejection from heated surface to air. The seize and the geometry of the heat sink with the shape of the extended surfaces have a great influence on the heat transfer coefficient. The first step to get the optimal design is to predict the heat transfer by conduction in solid walls of heat sink and then by convection between the solid and air flow. The purpose of the present study is to predict the effectiveness of closely spaced parallel rectangular fin array arrangement. The electronic processor was represented by the copper heat sink base with thermal conductivity of 401 W/m.K. The 72 fins with the geometry above mentioned were exposed to heat transfer with conduction and convection along all the boundaries except the bottom from which heat flow toward air flow domain. Mesh generation at a specific cells, number of element and number of nodes were taken under temperature difference validation. The experiments were done under impinging air flow rate with Reynolds number ranged between 4000-16000. The flow was turbulent so the k-Ԑ turbulence model needed to simulate mean flow characteristics. Constant heat fluxes boundary conditions were proposed with range between 10000-70000 kW/m2. The Results of temperature contour lines depicted a heat trend from the hot base through the extended surfaces to the fin tips. The fins were aligned in the core of heat sink showed higher temperature gradient compared with the fins existed in lines surrounded the core. The thermal resistance decreased as the Reynolds number increased and the Nusselt number increased as the Reynolds number increased and also when the heat flux increased. The Reynolds number depicted increasing as the Nusselt number increased and so the heat rejected from the heat sink base increased. There is a good agreement between the experimental and simulating results at error percentage not exceed 2%. Journal of Thermal Engineering Journal of Thermal Engineering 2021-02-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5350 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5350 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5350

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5341 2021-02-28T21:00:00Z 1

Numerical Study of Turbulent Heat Transfer in a Horizontal Channel Provided with Square Blocks: Effect of the Inter Blocks Spacing Kamal Amghar, Abdelkader Filali, Mohamed Ali Louhibi, Hicham Bouali, Najim Salhi, Merzouki Salhi Turbulent Flow, Heat Transfer, Numerical Solution, Square Blocks, Blocks Spacing, Channel, Finite Volume Method. In the present paper, numerical simulation is carried out to investigate turbulent flow structure and heat transfer analysis in a two-dimensional horizontal plane channel, contains square blocks arranged in tandem or side by side arrangement. The k-ε model is used to describe turbulence phenomena, and governing equations are solved by a finite volume method, with SIMPLEC algorithm is applied for the coupling of the velocity-pressure variables. The power-law scheme is used for the discretization of the convective terms in the momentum equations. Presented results illustrates the effect of the transverse (GT) and longitudinal (GL) spacing between the blocks on flow structure and heat transfer for a wide range of Reynolds number (104≤ Re ≤5×104). Numerical results show a very good agreement in comparison with available data in the literature. Journal of Thermal Engineering Journal of Thermal Engineering 2021-02-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5341 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5341 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5341

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3992 2020-01-06T21:00:00Z 4

Comparative Analysis of Cascade Refrigeration System Based on Energy and Exergy Using Different Refrigerant Pairs Vipin Kumar, Munawar Nawab Karimi, Sandeep Kumar Kamboj Cascade Refrigeration System, High Temperature Circuit, Low Temperature Circuit, COP In this study a comparative analysis on the basis of energy and exergy of cascade refrigeration system using different refrigerant pair, R13 for low temperature cycle (LTC) and R134a, R290 and R717 for high temperature cycle (HTC) has been done by mathematical simulation using Engineering Equation Solver (EES-V9.224-3D). The analysis of cascade refrigeration system has been carried out at different operating condition and result has been compared with effect of various operating parameters. The range of evaporator temperature of LTC is taken from -53oC to -70oC, which represents the most common operating condition in commercial applications. The range of condenser temperature of LTC is from -11oC to -2oC and evaporator temperature of HTC from -19oC to -10oC.Results show that the refrigerant pair R13-R717 is the best suitable refrigerant pair for proposed cascade refrigeration system in comparison to other used refrigerant pairs and R717 can be a interesting alternative refrigerant to R134a and R290 for high temperature cycle of cascade refrigeration system in commercial applications for energy and environmental reasons. Journal of Thermal Engineering Journal of Thermal Engineering 2020-01-06T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3992 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3992 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3992

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5325 2021-02-11T21:00:00Z 3

A Review on Pulsating Heat Pipes: Latest Research, Applications and Future Scope Chirag Dave, Prajwal Dandale, Kushagra Shrivastava, Nilesh More, Kavi Rahangdale, Dashrath Dhaygude Pulsating Heat Pipes, CFD, Thermal Resistance, Fill Ratio. Heat pipes have become popular as passive heat dissipation devices for many applications ranging from electronics to heat recovery in recent years. Pulsating Heat Pipe abbreviated as PHP is an exclusive category of a heat pipe which does have wick structure. It transfers heat between its evaporator and condenser sections due to the to and fro movement of working fluid caused due to the continuous change of phase taking place in it. Its operation involves combined hydrodynamic and thermodynamic effects causing the two-phase flow, making it difficult to fully understand it. Nevertheless, the PHPs have drawn the attention of investigators worldwide due to their simplicity in construction and a wide range of applications requiring high heat flux transfer. This review starts with a prologue of the attempts made by various investigators to explain the operation of PHPs through mathematical modeling. Later numerical simulations through Computational Fluid Dynamics of PHP performed by various investigators have been discussed. Review of latest experimental investigations performed on PHPs, is presented concisely in a tabular form. Novel concepts like the application of nanofluids, magnetic field and surfactant, applied for enhancing the performance of the PHPs have been discussed. At the end, applications of PHP and future scope have been discussed. Journal of Thermal Engineering Journal of Thermal Engineering 2021-02-11T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5325 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5325 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5325

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/4014 2020-03-29T21:00:00Z 1

Constrained GA PI Sliding Mode Control of Indoor Climate Coupled MIMO Greenhouse Model Khelifa Lammari, Fatah Bounaama, Boudjema Ouradj, Belkacem Draoui PI, Sliding Mode Control, Greenhouse, MIMO, Microclimate Model, Constrained Inputs, Coupled Dynamics High accuracy trajectory tracking with constrained inputs is challenging topic in greenhouse indoor environment control. This is due to nonlinearities and inputs/outputs coupling present in physical model of greenhouse. The objective of this study is about the problem of identification and control of a Multi-Input Multi-Output (MIMO) greenhouse process. Proportional Integral (PI) and sliding mode controllers (SMC) are used in conjunction so that estimated outputs tracks desired trajectories with good performance as near as possible in spite of coupled dynamics and outside disturbances climate. To reflect the practical aspect, the constraints of the process and control elements were taken into account .The results demonstrate the feasibility of PISMC control method. Simulation has been done in the environment of Matlab and Simulink, it shows that combined controllers are capable to manage successfully the microclimate of greenhouse. Journal of Thermal Engineering Journal of Thermal Engineering 2020-03-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4014 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4014 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4014

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5362 2021-04-04T21:00:00Z 1

Thermal Performance Investigation of a Hybrid Solar Air Heater Applied in A Solar Dryer Using Thermodynamic Modeling Ali Heydari, Mikaeil Forati, Seyyed Mahan Khatami Exergy, Hybrid air heater, Fluid properties, Efficiency Hybrid air heater is a device taking advantage of two or more energy sources directly or indirectly for heating air. This study aims to analyze energy and exergy for a hybrid air heater. It is assumed that no thermal gradient exists along glass thickness and one-directional variation of temperature is in flow direction and thermal capacity of glass, absorber plate, and thermal insulations are negligible. To avoid food oxidation in dryers, effects of heating fluid such as air, carbon dioxide, and nitrogen on temperature, heat transfer, and thermodynamic first and second law efficiencies are also investigated along with the effects of hybrid heating on the aforementioned parameters. The problem is solved using MATLAB software and invoking iterative method with convergence criterion of 0.0001 for temperature. Results indicate the positive effects of using carbon dioxide. Applying hybrid system is also shown to increase the efficiency of air heater. Journal of Thermal Engineering Journal of Thermal Engineering 2021-04-04T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5362 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5362 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5362

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5364 2021-04-12T21:00:00Z 1

Thermoeconomic Analysis and Multi-Objective Optimization of an Integrated Solar System for Hydrogen Production Using Particle Swarm Optimization Algorithm Sajjad Keykhah, Ehsanolah Assareh, Rahim Moltames, Abbas Taghipour, Hasan Barati Multi-objective Optimization, Integrated Solar Energy System, Hydrogen Production, PSO This study aims to investigate the hydrogen production process using an integrated system based on solar energy. The system includes an evacuated tube collector to absorb solar energy as input energy of the system. A parametric study was conducted in order to determine the main design parameters and evaluate their impact on the objective functions of the system. For identifying the optimum system conditions, multi-objective optimization was performed using particle swarm optimization (PSO) algorithm. The results of the parametric analysis indicate that an increment in the collector mass flow rate and the turbine inlet temperature, as well as a decrement in the collector area and the evaporator inlet temperature, leads to improve the system exergy efficiency. Furthermore, the optimization results demonstrate that the exergy efficiency of the system can be improved from 1% to 3.5%; however, this improvement in exergy efficiency leads to increase the system costs from 20$/h to 26$/h, both at optimum states. At the optimum point, the average values for other performance parameters affecting the objective function including total output power production, cooling capacity, and hydrogen production rate are obtained as 24.24 kW, 47.07 kW, and 218.56 g/s, respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2021-04-12T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5364 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5364 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5364

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5218 2020-11-29T21:00:00Z 1

Automotive Headlamp High Power Led Cooling System and Its Effect on Junction Temperature and Light Intensity Ramesh Kumar Chidambaram, Rammohan Arunachalam HPLED Cooling System, HPLED Junction Temperature, Headlamp Reflector Temperature, Halogen, Light Intensity Halogen bulbs are sources of light of headlamps of most of the vehicles running around the world. To get better night vision, vehicle owners want to replace the conventional halogen bulbs with HPLEDs without replacing the conventional headlamp assembly. Though High Power Light Emitting Diodes (HPLED) are efficient sources of light for replacing halogen bulbs, conventional headlamps are not designed for HPLEDs and so replaced HPLEDs will fail within a short duration due to poor cooling. The aim of this work is to develop a compact cooling system for a conventional headlamp assembly to accommodate HPLEDs. An air cooled system with a compact heat sink is proposed in this work. To decide the dimensions of the compact heat sink various heatsink sizes were modeled and simulated in ANSYS. For this study, a popular SUV's headlamp is chosen and complete tests were carried out in absence of external lights on a flat black surface for about 28 meters. The light intensity is measured in terms of lux for Halogen and HPLED's horizontal passing beam at various test points. For generating the same intensity of light, it was found from the experimental results that the HPLED consumes only one third of the energy supplied to halogen bulbs. With the proposed cooling system the junction temperature was reduced by about 25% when the cooling fan is operated at laminar flow conditions. On the other hand, the luminous intensity of the HPLED improved by about 30.9% due to the decrease in junction temperature. The HPLED headlamp reflector inner wall temperature is found to be 49 % lesser than Halogen bulb headlamp reflector inner wall temperature. Journal of Thermal Engineering Journal of Thermal Engineering 2020-11-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5218 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5218 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5218

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5363 2021-04-12T21:00:00Z 1

Numerical Investigation of Natural Convection with Heated Tubes in Tunnel Greenhouse Slatni Yassine, Djezzar Mahfoud, Messai Tarek Natural Convection; Bicylindrical Cordinates; Heating tubes; Tunnel Greenhouse; The Vorticity-Streamfunction Formulation; S.O.R Method. In this research, a numerical study was carried out on heat transfer by natural convection, in a closed tunnel greenhouse, in the range of the Rayleigh number (103?Ra?106). Were considered in the study, the number of heating tubes used (1?Nt?7), which were equidistant inside the greenhouse volume, when the bottom at an average temperature and cold Roof. The governing equations written in a bicylindrical coordinates, were discretized using the finite volume method and vorticity-stream function formulation; the resulting algebraic equations were solved using successive over relaxation method (S.O.R). First, the effect of the Rayleigh number on heat transfer was examined for a fixed number of tubes as reference (Nt=3) and the number of tubes was varied to investigate the influence on heat transfer in the greenhouse. Finally, The results obtained were summarized in the form of isotherms and streamlines, and for the average Nusselt number profile; in addition to the horizontal and vertical velocities and temperatures. However, in the reference case, for low Rayleigh numbers, the heat transfer is dominated by pure conduction.With the increase of the Rayleigh number and the number of tubes Nt, the natural convection becomes more dominant and the heat transfer increases, and in general the heat transfer increase with the increasing number of tubes. Journal of Thermal Engineering Journal of Thermal Engineering 2021-04-12T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5363 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5363 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5363

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3985 2020-01-05T21:00:00Z 1

A Comment on Unsteady–Periodic Flow Friction Factor: An Analysis on Experimental Data Gathered in Pulsatile Pipe Flows Melda Ozdinc Carpinlioğlu Time-Average Friction Factor, Time-Average Reynolds Number, Womersley Number, Multiplication Element, Modified Friction Multiplier = C In 1940’s, Schultz- Grunow proposed that time-average value of friction factor, λ_u,ta was similar to its corresponding steady state value, λ for the presence of gradual and slow oscillations in pulsatile flows. A recent approach was available for low frequency pulsatile flows through narrow channels in transitional and turbulent regimes by Zhuang et al, in 2016 and 2017. In this analysis; extensive experimental data of λ_u,ta in fully laminar and turbulent sinusoidal flow are processed in the measured time-average Reynolds number range of 1390 ≤ Re_ta ≤ 60000 disregarding the transitional regime. The ranges of dimensionless frequency-Womersley number, √(ω') and oscillation amplitude, A_1 are 2.72 ≤ √(ω') ≤ 28 and 0.05 ≤ A_1≤ 0.96 respectively. A multiplication element is defined as Mel = Re_ta×√(ω^'). A modified friction multiplier, λ_(Mel ) which is similar to the conceptual parameter of Zhuang et al’s friction factor ratio C ( λ_Mel = λ_(u,ta)/λ ) is also referred. The correlation of λ_Mel = λ_Mel (Mel) is dependent on flow regime and the magnitude of Re_ta for the range of √(ω^') > 1.32. The proposal of Schultz-Grunow is verified irrespective of the oscillations in turbulent regime since the magnitude of λ_Mel = 1 is observed for turbulent flow cases with Re_(ta ) ≥ 35000. In laminar regime the magnitude of Re_(ta ) is governing the fact. The magnitude of λ_Mel varies in 0.589 ≤ λ_Mel ≤ 28.125 for Re_(ta ) ≤ 5000 while λ_Mel = 1 is obtained for Re_(ta ) > 5000. The graphical representation of λ_Mel = λ_Mel (Mel) can be considered as a counterpart of Moody Diagram in pulsatile fields for a significant practice. Journal of Thermal Engineering Journal of Thermal Engineering 2020-01-05T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3985 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3985 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3985

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5321 2021-01-31T21:00:00Z 1

Effect of Dye Concentration on Patterned Luminescent Solar Concentrator G. Gopi, T.J. Sarvoththama Jothi‬, S. Kumaravel Patterned LSC, Perylene Dye, Monte-Carlo Simulation, Dual Waveguide, PV Cell The present paper investigates the Luminescent Solar Concentrator (LSC) with single and dual waveguide coated with perylene dye of various concentrations. Monte Carlo simulations are carried out to assess the efficiency of the LSC with the waveguide areas varying from 10 to 110 cm2, and the dye concentration varying from 30 to 800 PPM. The percentage of dye area coated in the waveguides is varied from 20 to 80%. Results indicate that the LSC efficiency increases with dye concentration up to a particular value, and thereafter shows a decreasing trend. Further, LSC efficiency is found to be increasing with a decrease in waveguide size. Experimental and simulation results indicate the maximum efficiency at the dye coverage area of 50%. Simulation results indicate the maximum LSC efficiency of around 9%, while the same is around 6% when examined experimentally. Journal of Thermal Engineering Journal of Thermal Engineering 2021-01-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5321 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5321 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5321

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5370 2021-04-29T21:00:00Z 1

Effect of Aligned Magnetic Field and Inclined Outer Velocity in Casson Fluid Flow Over a Stretching Sheet with Heat Source Renu Devi, Vikas Poply, Mani Mala Casson fluid, Aligned magnetic field, Outer velocity, Oblique flow, Heat source. The purpose of this study was to assess the effect of the inclined outer velocity on heat and flow transportation in boundary layer Casson fluid over a stretching sheet. The flow is adopted to have non-orthogonal magnetic field with heat generation in the uniform manner on stretching surface. It has been taken that in both the directions along the x-axis, the sheet is stretched. By applying similarity transformations, the governing equations representing the heat and flow transportation are converted to ordinary differential equations. Runge-Kutta Fehlberg approach was adopted to solve numerically the moulded differential equations with the help of shooting technique. The flow is also governed by the heat source parameter, Casson fluid parameter, magnetic parameter, Prandtl number, aligned angle of magnetic field and the impinging angle parameter. The results revealed that velocity decreases with an increase in Casson fluid parameter, magnetic parameter and aligned angle of magnetic field for the case of outer velocity parameter less than one while velocity increases for the case of outer velocity parameter greater than one because of the inverted boundary layer formation for velocity profile in second case. Also, the fluid temperature increases (for the case of outer velocity parameter less than one) and temperature decreases (for the case of outer velocity parameter greater than one) with an increase in Casson fluid parameter, impinging angle parameter and aligned angle parameter. The results indicate that outer velocity and aligned magnetic field has a significant impact on fluid temperature and velocity. The behaviour of emerging fluid parameters on fluid temperature and velocity are depicted graphically and their effect on local Nusselt number (〖Nu〗_x ) and skin friction coefficient (C_f ) are represented by tables. The finding of this study may serve as to control the rate of heat transportation and fluid velocity in many manufacturing processes and industrial applications to make the desired quality of final product. Acceptance of the extant technique used in current study is correlated with the existing outcomes in the literature. Journal of Thermal Engineering Journal of Thermal Engineering 2021-04-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5370 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5370 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5370

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5379 2021-05-01T21:00:00Z 1

Numerical Investigation of Horizontal Magnetic Field Effect on The Flow Characteristics of Gallium Filled in A Vertical Annulus Vahid Ahmadpour, Sajad Rezazadeh, Iraj Mirzaei, Amir Hossein Mosaffa Magnetic Field, Lorentz Force, Electric Field, Natural Convection, Annulus In the present numerical study, the effect of an external horizontal magnetic field on the natural convection of an electrically conducting molten metal (gallium) inside a vertical cylindrical crucible has been investigated. The effect of the external magnetic field is evaluated on the flow pattern and also the temperature field of molten gallium in the mold with an aspect ratio of A=1.0 and a radii ratio of λ=3.0. A series of simulations are carried out for Hartmann numbers of 0, 22.5, 112, and 167 and Rayleigh numbers of 104, 105, and 106. The obtained results show that for a given Rayleigh number, increasing the Hartmann number suppresses convection flows in all directions with different intensities. Moreover, it was found that the employed horizontal magnetic field leads to vanishing the axisymmetric pattern of flow structures. This is due to the formation of Roberts and Hartmann layers near the walls parallel (0° and 180°) and normal (90° and 270°) to the magnetic field, respectively. Additionally, it is found that the presence of the magnetic field results in the reduction of convection heat transfer. This reduction is lower in the 90° and 270° directions due to the development of Roberts layers near the walls parallel to an external magnetic field. Finally, the numerical results have been validated against the published reliable data. Journal of Thermal Engineering Journal of Thermal Engineering 2021-05-01T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5379 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5379 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5379

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5374 2021-04-30T21:00:00Z 4

Parametric Effects on the Performance of an Industrial Cooling Tower Timothy Bamimore, Samuel Enibe, Paul Adedeji Cooling Tower; Natural Draft; Parametric Modelling; Poppe Model Sensible and latent heat rejection from heat engines is of high necessity for system efficiency and continuous production. The cooling tower is one of the major heat-exchanging systems used for cooling industrial heat systems by intimately mixing hot water with cooling air. Optimal operating conditions and parameters of the system are highly essential for its effectiveness and efficiency. This study used the Poppe model to evaluate selected thermodynamic relations of a rectangular counter-flow industrial cooling tower of a steel rolling mill using the system’s inlet and outlet data as initial conditions. The effect of increasing the water temperature on the air moisture content, Merkel number, and specific enthalpy was studied across the fills of the cooling tower. Air moisture content, Merkel number and specific enthalpy of the system increase with increasing water temperature. However, while other variables reach a stationary point at half the nodal segments, the specific enthalpy increases across the fills in the system. It was concluded that the use of nano particles with high heat removal rate could increase the efficiency of the system. Also, an increase in the quantity of the makeup water of a force draft system is recommended towards increasing the system efficiency. Journal of Thermal Engineering Journal of Thermal Engineering 2021-04-30T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5374 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5374 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5374

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5378 2021-04-30T21:00:00Z 3

Solar Absorption Cooling Systems: A Review Ali Abdulqader, Zamri Noranai, Ahmed İmran Solar Cooling, Absorption Cooling, Saving Power, Solar Power Reduction of the green-house effect can be obtained by reducing the emissions of CO2. One of the technologies that contributes to this purpose is using solar cooling systems. An example of such systems is Lithium Bromide Absorption Chillers-Driven by Hot Water (LiBr/H2O absorption chillers). These chillers are normally powered by solar collectors (ordinary plate or evacuate tubular), which are widely accessible. This paper includes a review of previous experimental and theoretical studies on the effect of single cooling absorption systems. In addition, new proposals regarding the design of the solar collectors, supporting systems for energy and cooling methods will be provided. Furthermore, the present paper also summarizes the major double influence of the cooling absorption systems, add to the two-stage and half-effect absorption coolers. The influence of double cooling absorption systems using solar power could be considered for the buildings with more cooling capacity requirements, but with structure of space restrictions. However, for these cases is important to consider the direct irradiation, which needs high levels. For dry regions with water shortage, half-absorption and two-stage absorption coolers are more suitable. Solar-powered cooling systems designs should follow and incorporate standard rules based on the characteristics of various areas in order to be applicable on a large scale. Journal of Thermal Engineering Journal of Thermal Engineering 2021-04-30T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5378 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5378 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5378

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5317 2021-01-29T21:00:00Z 1

Magnesium Sulfate Heptahydrate as Phase Change Material in Double Slope Solar Still Mohan Khandagre, Bhupendra Gupta, Jyoti Bhalavi, Prashant Baredar Solar still, Desalination, Phase change materials, Magnesium sulfate heptahydrate, Productivity Solar still is best choice of utilizing freely available solar thermal energy to purify/desalinate muddy water. The driving force for this work is the inadequate availability of clean fresh water sources and the plenty of contaminated water available for probable conversion into potable water. Among various designs available, double basin passive solar still looks attractive for thermal applications in water prone and remote areas. This work presents experimental characterization of double slope solar still using phase change materials. This work aims to improve the performance (productivity of fresh water) using Mg2SO4.7H2O as phase change material (PCM). Different tests were conducted for varying mass of the PCM. For experimentation, two identical double slope solar stills (basin area of 0.5×0.5 m2) were designed, fabricated and tested for freshwater productivity. One is solar still (without PCM) and second with phase change material. A water depth of 5 cm was constant throughout the experimentation under climate conditions of Jabalpur (23° 10' N, 79° 59'E), Madhya Pradesh India. The results obtained indicate that daily distillate for solar still with Magnesium sulfate heptahydrate is higher as compared to solar still without PCM. The convective heat transfer coefficient increases during the discharging period of PCM The daily freshwater productivity of 1400, 1420 & 1400 ml/m2/day for solar still (without Mg2SO4.7H2O), while 1800, 1900 & 1960 ml/m2day for the solar still (with PCM) were recorded with addition of 0.5, 0.75 and 1kg of Mg2SO4.7H2O respectively. The overall thermal efficiency of the solar still with PCM was observed to be 64%, and for a solar still without the PCM, it was 47% while the other conditions kept constant. Journal of Thermal Engineering Journal of Thermal Engineering 2021-01-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5317 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5317 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5317

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/4013 2020-03-29T21:00:00Z 1

Investigation of Modified Ejector Cycle on Residential Air Conditioner with Environmentally Benign Refrigerant of R290 Kasni Sumeru, Mohamad Firdaus Sukri, Pratikto Pratikto, Apip Badarudin Air Conditioner, Ejector, R290, Modified Ejector Cycle, Entrainment Ratio, COP Improvement This paper investigates a modified ejector cycle (MEC) to further enhance the COP improvement of residential air conditioner (A/C), as compared to the standard ejector cycle (SEC). This paper also presents numerical and experimental studies of the MEC. Numerical approach of MEC performances was evaluated by using SEC cycle that had been developed by many researchers. In the experimental study of MEC, three motive nozzle diameters of 0.9, 1.0 and 1.1 mm were utilized. In addition, environmentally friendly refrigerant of R290 (propane) was used as a working fluid. The modeling results of residential A/C with the cooling capacity of 2.5 kW showed higher COP improvements of MEC than SEC for all entrainment ratios of the ejector. There was no COP improvement for SEC at a low entrainment ratio, whereas there are always COP improvements for all entrainment ratios for MEC. In addition, the experimental results showed the highest COP improvement of 16.67% was achieved with the motive nozzle diameter of 1.1 mm. Journal of Thermal Engineering Journal of Thermal Engineering 2020-03-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4013 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4013 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4013

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5377 2021-04-30T21:00:00Z 1

CFD Modelling of Slurry Pipeline at Different Prandtl Numbers Om Parkash, Arvind Kumar, Basant Singh Sikarwar 3D Horizontal Pipeline, Prandtl Number, Pressure Drop, Particulates Concentration, Velocity Distribution The present work shows the slurry flow characteristics of glass beads having density 2470 kg/m3 at different Prandtl number through a horizontal pipeline. The simulation is conducted by Eulerian two-phase model using RNG k-ε turbulence closure in available commercial software ANSYS FLUENT. The transportation of solid particulates has the settling behaviour in the slurry pipeline and that leads to the sedimentation and blockage of the pipeline resulting more power and pressure drop in the pipeline. Therefore, it is important to know the transport capability of the solid particulates at different Prandtl fluids to minimise the pressure loss. The fluid properties at four Prandtl numbers i.e. 1.34, 2.14, 3.42 and 5.83 is used to carry the solid concentration ranges from 30-50 % (by volume) at mean flow-velocity ranging from 3 to 5 ms-1 . The obtained computational results are validated with the published data in the literature. The results show that the pressure-drop rises with escalation in flow velocity and solid concentration at all Prandtl number. It is found that the suspension stability enhancement is considerable for lower range of Prandtl number and decreases for higher range of Prandtl number. Finally, glass beads concentration contours, velocity contours, concentration profile, velocity profiles and pressure drop are predicted to understand the slurry flow for chosen Prandtl numbers. Journal of Thermal Engineering Journal of Thermal Engineering 2021-04-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5377 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5377 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5377

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5213 2020-11-05T21:00:00Z 1

Environmental Impact of Using Generators in the University of Technology in Baghdad, Iraq Wahab K. Ahmed, Talib A. Abed, Ahmed Q. Salam, Khali S. Reza, Maitham T. Mahdiy, Miqdam T. Chaichan Iraq, Air Quality, PM, Electricity Generators, Noise, University of Technology The environmental impact of using large electrical generators in the University of Technology in Iraq is studied. These generators are utilised due to the lack of electricity from the national grid. The emissions are very high and exceed the acceptable limits set by the United States Environmental Protection Agency, the World Health Organization and Iraqi Standard No. 4950. The impact of switching to the use of photovoltaic cell systems, as what is done in the Energy and Renewable Energies Technology Center (ERETC), and the environmental impact of this transformation are also studied. Results show that when the generators are used, high concentrations of PM1, PM2.5 and PM10 are released, exposing students and staff to health hazards. The amounts of pollutants from SO2, H2S, NOx and volatile organic compounds are high due to the high sulphur content in Iraqi diesel fuel. Generator noise is extremely high that it could pose serious health risks to university staff and students. Furthermore, using the photovoltaic system considerably reduces PM1.0 and PM2.5 concentrations by 85.6% and 52.4%, respectively. The levels of CO2, CO, H2S and SO2 decrease by 60.5%, 49.6%, 91.7% and 95.3%, respectively. The noise inside ERETC is reduced by 29% compared with that in the external environment. Shifting towards the generation of photovoltaic electricity instead of using fossil fuel generators provides an immediate and appropriate treatment of Iraqi atmospheric pollution. Journal of Thermal Engineering Journal of Thermal Engineering 2020-11-05T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5213 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5213 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5213

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5322 2021-01-31T21:00:00Z 1

Three-Dimensional Simulation of a Turbulent Flow Around A Tapered Cube Dug in the Middle Lamia Benahmed, Khaled Aliane, Ali J. Chamkha Turbulent Flow, Tapered Obstacle, Hollow, Finite Volume, Turbulence Models, ANSYS -CFX To analyze the influence of the tapered form of the two upper vertices of a rectangular cube placed in channel and the impact of the insertion of hollow in the center of the obstacle, three-dimensional study was executed using K-? SST turbulence model. Different models of the form of the cube were presented to examine the features of the flow with a Reynolds number Re=4×104. The turbulence kinetic energy, 2D and 3D time averaged streamlines, trace-lines, stream wise velocity profiles, pressure profiles were obtained using the ANSYS CFX calculation code and the finite volume method were employed for resolving the governing equations. The streamlines showed in the model of the tapered cube with hollow a formation of another vortex downstream of the cube at the outlet of the hollow. For the stream wise velocity, there are two recirculation zones: one logarithmic zone due to the main flow, the other is a lower parabolic return zone due to the recirculation vortex. Journal of Thermal Engineering Journal of Thermal Engineering 2021-01-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5322 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5322 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5322

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5373 2021-04-29T21:00:00Z 1

A Systematic Graphical Method for Synthesis of Heat Exchanger Networks Mohammad Al-Mayyahi, Mohammad Fares, Nabeel Abbood Pinch Analysis, Energy Integration, Graphical Approach, Supply-Target Diagram, Heat Exchanger Network Heat exchanger networks (HENs) play a significant role in the energy conservation of any process industry. The HENs are used to maximize heat recovery by exchanging heat between hot and cold process streams. Therefore, the optimum design of HENs is extremely important to reach the maximum efficiency of energy systems. Many graphical methods have been developed during the last four decades for synthesizing of heat exchanger networks (HENs). However, most of these methods have only been evaluated for retrofitting design of HENs. In the grassroots design situation, these methods are often complicated and tedious. This paper introduces a new and simple graphical approach for HEN grassroots design. The new approach based on a single graph called Supply-Target Diagram (ST-D). The ST-D is formulated by plotting supply temperatures versus target temperatures of streams. Streams matching can easily be applied in the ST-D and splitting of streams is clearly visualized and evaluated. A case study is used to illustrate the application of the new graphical method for grassroots design of HENs. Journal of Thermal Engineering Journal of Thermal Engineering 2021-04-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5373 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5373 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5373

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5314 2021-01-29T21:00:00Z 1

An Experimental Study Optimization of a Photovoltaic Solar Pumping System Used for Solar Domestic Hot Water System Under Iraqi Climate Mahmoud Maustafa Mahdi, Ameer Abed Jaddoa Photovoltaic pumping system, Photovoltaic configuration optimization, Outdoor testing, Domestic hot water system. The performance of a photovoltaic solar water pumping system (PVSWPS) promising in a solar water heating system has been studied experimentally. The design of a photovoltaic array configuration can affect the performance of the (PVSWPS), the water pump characteristic, the flow rate of the water and the overall system efficiency. The aim of the present work is to determine an optimum photovoltaic array configuration that can supply a water pump with an optimal amount of energy. Three different photovoltaic array configurations have been tested (4S, 2S ×2P and 4P). The experiments have been carried out in a sunny day, light hours under the conditions of Iraq climate and for a constant head level of 6m. The results showed that the second photovoltaic array configuration (2P × 2S) is suitable to provide an optimal energy. Also, the second photovoltaic array configuration (2P × 2S) that powered the water pump delivered a maximum average water volume (2.298 m3) during the day among the three different configuration. Journal of Thermal Engineering Journal of Thermal Engineering 2021-01-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5314 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5314 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5314

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5376 2021-04-30T21:00:00Z 1

Influence of Relaxation Times on Heat Transfer in Human Head Exposed to Microwave Frequencies Jagbir Kaur, Suyeb Ahmed Khan Bioheat Transfer, Thermal Wave Model of Bioheat Transfer (TWMBT), Human Head, Microwaves, Relaxation Time The electromagnetic energy carried by microwaves interacts with human head and produces thermal changes within the head. Conventionally, Pennes’ bioheat transfer equation (BTE) is employed to investigate the thermal changes in biological tissues. Pennes’ equation assumes infinite speed of propagation of heat transfer, however, heterogeneous structures such as biological tissues exhibit relaxation times, which is the time required for accumulation of enough energy to transfer it to the nearest element. In present study, we utilized thermal wave model of bioheat transfer (TWMBT) which incorporates relaxation times to numerically predict temperature changes in six layers human head. Finite element based numerical simulation package COMSOL Multiphysics is employed for the thermal analysis. Numerical scheme comprises coupling of solution of Maxwell's equation of wave propagation within tissue to TWMBT. Temperatures estimated with various values of relaxation time are compared with that by Pennes’ equation. The results show that the transient temperature within human head estimated with relaxation time 10 s, 20 s, and 30 s can be up to 36%, 54%, and 66% lower than predicted by Pennes’ BTE respectively. At longer microwave exposure the influence of relaxation times becomes insignificant and the steady state temperatures predicted by TWMBT and Pennes’ BTE are identical. The findings suggest that inclusion of relaxation times in thermal analysis is of significant importance if the exposure duration is short. The effect of parameters such as microwave power and user age on the temperatures projected with different relaxation times is also investigated. Journal of Thermal Engineering Journal of Thermal Engineering 2021-04-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5376 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5376 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5376

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3865 2019-09-23T21:00:00Z 1

A Flow Channel with Nafion Membrane Material Design of Pem Fuel Cell Tolga Taner PEM Fuel Cell, Membrane, Gas Diffusion Channel, Cost Analysis, This study is about flow channels in the design of the PEM (Proton Exchange Membrane) fuel cell system. In the experimental study, different flow geometry, Nafion membrane, and bipolar plate gas diffusion channel designs are available. In some cases, the techno-economic analysis method is applied. Cost analysis for the design has also been made and compared with similar studies. It was obtained that the new flow channel design increased the PEM fuel cell performance. A unit energy cost was set to 42.6 [$/W]. When a similar system was implemented for a year, the annual energy cost was calculated to be 25.48 [$/y]. The aim of this study is to determine the cost-benefit analysis of PEM fuel cell with a combined flow channel design. In addition, the simple payback period was found to be 0.81 [y]. Thus, the PEM fuel cell was determined by the techno-economic analysis calculation, in which energy savings can be achieved by the flow channel design. Journal of Thermal Engineering Journal of Thermal Engineering 2019-09-23T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3865 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3865 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3865

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5330 2021-02-21T21:00:00Z 1

Thermal Numerical Investigation of a Small Parabolic Trough Collector Under Desert Climatic Conditions Mokhtar Ghodbane, Boussad Boumeddane, Ahmed Kadhim Hussein, Hafiz Muhammad Ali, Dong Li Parabolic trough solar collector; Thermal solar, Direct-normal solar irradiation; Pure water; Simulation This paper has examined the thermal behavior of a small parabolic trough collector in El-Oued region, Algeria. Pure water was adopted as a heat transfer conveyor under climatic conditions on 16 March 2018. The energy balance equations have been analyzed, simplified and then programmed with the MATLAB code, in order to track all the elements that influence the thermal behavior of studied device. A mathematical model of computation has been developed a model of numerical computation in which has been taken into consideration all the physical phenomena influencing the performances of the studied solar concentrator. The average optical efficiency of the device has reached 78.5449315 %, while the average value of thermal efficiency has reached 74.2935616%. It was also observed to produce a quantity of hot water steam at a stage of study with practical conditions available between 10:20 and 11:50. This paper also discusses the definition and identification of all-important parameters that directly affect the device performance. Among these important thermal elements is the overall coefficient of thermal loss, which has an average value of 5.956890411 W.m-2.°C-1. Journal of Thermal Engineering Journal of Thermal Engineering 2021-02-21T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5330 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5330 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5330

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5410 2021-08-01T21:00:00Z 1

Performance Comparison and Investigation of Two Different Renewable Energy Fueled Multigeneration Systems Ali Reza Noorpoor, Parisa Heidarnejada Biomass, Environmental assessment, Exergoeconomic, Exergy, Multigeneration, Solar In this study, comprehensive thermodynamic, exergoeconomic and environmental performance of two multigeneration systems fueled by biomass and solar energy is surveyed. The multigeneration system A utilizes municipal solid waste and solar energy to produce power, heating, cooling, fresh water and hydrogen which is considered to be located in the north of Iran with a moderate climate. Whereas, the multigeneration system B consumes bagasse and solar energy to supply power, heating, cooling, liquefied natural gas and fresh water which is assumed to be located in the south of Iran with a hot climate. The results of the study show that system B provides better performance from a thermodynamic viewpoint with energy and exergy efficiencies of 82.45% and 15.75%. Moreover, according to the outputs of exergoeconomic modeling, system B presents better performance because of lower capital cost. Finally, environmental profit is attained by accomplishing system B because of avoiding 1.14 million tons of NOx and 0.31 million tons of CO2 depletion to the atmosphere per year. In the end, through conducting a parametric study, the effect of key parameters on the thermodynamic, economic and environmental performances of two systems is discussed. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-01T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5410 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5410 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5410

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5367 2021-04-27T21:00:00Z 1

Performance Analysis of a Micro Heat Exchanger in Electronic Cooling Applications Mokrane Mahdi, Mourad Lounis, Mohamed Announ, Maamar Ouali, Med Ali Djebiret, Mahmoud Bourouis Cooling of Electronic Components, Micro Heat Exchangers, CFD To operate under normal conditions and depending on the technology used, the electronic components must be at a temperature below 80 to 85°C. Several cooling systems were investigated with the aim of improving the heat transfer process in this kind of applications. Single-phase liquid cooling systems, which mainly consist of a hot water-cooled micro-heat exchanger, provide an efficient approach to dissipate heat flows. In the present study, numerical and experimental investigations were carried out to study the characteristics of laminar flow and forced convective heat transfer in micro-channels. The inlet temperature of cooling water ranged from 25 to 65°C, the Reynolds number of water flow varied from 250 to 2000, and the electronic power supply component was set at 50, 80 and 120 W. The results showed that the micro heat exchanger was able to dissipate around 70 to 78% of the heat released by the electronic component. As regards the numerical results, it was observed that the inlet water temperature of 55ºC kept a heat source up to 80 W for a temperature source below the critical value of 80ºC. Journal of Thermal Engineering Journal of Thermal Engineering 2021-04-27T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5367 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5367 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5367

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5375 2021-04-30T21:00:00Z 1

An estimation Method for Greenhouse Temperature Under the Influence of Evaporative Cooling System Mohammad Hossein Shojaei , Hamid Mortezapour, Kazem Jafarinaeimi, Mohammad Mehdi Maharlooei Absolute Error, Fan and Pad, Heat and Mass Transfer, Mathematical Modelling TTemperature is one of the most important plant growth parameters that should be controlled in the greenhouses. The present study was aimed to assess the thermal behavior of a greenhouse with and without the fan and pad (FP) evaporative cooling system. A method was developed to approximate the greenhouse temperature based on the mass and energy balance equations. For this purpose, both of the fan and pad evaporative cooling system, and the greenhouse were studied. The results of the theoretical analysis were compared with those achieved by the experiments. Maximum deviations of 5.32, 5.56 and 4.53oC were observed between the theoretical and experimental temperatures of the inside air, the floor and the cover of the greenhouse without the cooling system, respectively. Whereas, the mean absolute error values associated with the predicted temperatures of the greenhouse with the FP system were ranged between 1.50 and 25.67%. Based on the obtained values for the correlation coefficient, root mean square error and mean absolute magnitude error, it was concluded that the models satisfactorily predicted the temperature of the greenhouse components. An air circulation system inside the greenhouse can be proposed to maintain the lumped condition even at the high temperatures, and lead to smaller errors. The results indicated that the inside air, the floor and the cover temperature of the greenhouse reduced by respectively 20.6, 13.0 and 20.6 oC when using the FP system with the air velocity of 4.4 ms-1 and the pad thickness of 6 cm. Journal of Thermal Engineering Journal of Thermal Engineering 2021-04-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5375 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5375 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5375

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5315 2021-01-29T21:00:00Z 1

Optical and Radiative Properties of Individual and Hybrid Nanosuspensions: The Effects of Similar and Dissimilar Particle Agglomerates on Thermal Radiation Layth Al-Gebory Radiative properties; particle agglomeration; nanosuspensions; dependent-independent scattering regimes. Nanosuspensions are proposed for use in improving the thermal efficiency of different thermal systems; including solar thermal power plants. Because of their excellent and unique thermo-optical properties, which are the basis of thermal transfer phenomena, they are used as working fluids in solar thermal collectors for photothermal energy conversion. However, particle agglomeration in nanosuspensions remains one of the most important challenges faced in terms of their usage. The purpose of this study is to investigate the particle agglomeration behavior of water-based {\rm Al}_2O_3 and {\rm TiO}_2\ individual and hybrid nanosuspensions and observe their effects on spectral radiative properties. Dynamic light scattering is used to measure the particle size distribution in nanosuspensions. The UV/Visible spectroscopy technique is used to obtain the light attenuation in the nanosuspensions. The results show that pH have significant effect on the particle agglomeration which in turn affects the optical and radiative properties involving individual and hybrid nanosuspensions. The hybrid nanosuspensions at pH=6 show the minimum particle agglomeration rate compared with the individual nanosuspensions. The effect of the different particle agglomerate size shows a considerable enhancement in the radiative properties specifically in the UV/Vis spectrum. Adjusting the pH value based on the isoelectric point of the nanoparticle is an efficient method when specific radiative properties are required for specific applications. Different regimes of the dependent/independent scattering can be obtained by changing the pH of a nanosuspension. Journal of Thermal Engineering Journal of Thermal Engineering 2021-01-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5315 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5315 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5315

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5318 2021-01-30T21:00:00Z 4

As A Potential Hydraulic Fluid: Corn Oil Behavior Characteristics Examination Mohammed Jabal, Abdulmunem R. Abdulmunem, Hussain Saad Abd Cooling fluid, Vegetable fluid, Viscosity, Friction coefficient, Wear diameter Low toxicity, high biodegradability, renewability and high viscosity index of the plant (vegetable) oils made it have immense potential to replace the mineral cooling fluids. This study aims to evaluate the wear and friction behaviour characteristics of the corn fluid as a renewable bio-fluid resource. Base on the ASTM G-99 standard, behaviour characteristics of fluid were examined in terms of kinematic viscosity, friction force, coefficient of friction, wear scar diameter, and flash temperature parameter. Each experiment was do during one hour and 800 rpm as a rotation speed of disk and under four different loads 5,10,15,20 kg using the ball on disk tester, the (Mobil hydraulic fluid 424) used as a mineral cooling hydraulic fluid sample for compared the results. Based on the results, it was found that under low loads (5 and 10kg) the performance of vegetable fluid (corn) is better than the mineral hydraulic fluid (463.38 & 469.84 μm under 5kg and 567.1&593.74 μm under 10 kg respectively), also the values of friction coefficient of vegetable fluids were lower under high load as in the case of normal load 20 kg., which was 0.0159 for the corn and 0.0230 for the mineral fluid. Finally, it is concluded that the corn fluid could be an alternative renewable working cooling fluid due to its adequate performance. Journal of Thermal Engineering Journal of Thermal Engineering 2021-01-30T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5318 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5318 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5318

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5380 2021-05-01T21:00:00Z 1

Enhancement the Solar Distiller Water by Using Parabolic Dish Collector with Single Slope Solar Still Mohammed R. Al_qasaab, Qahtan A. Abed, Wisam A. Abd Al-wahid Dual Axis, Parabolic Dish, Solar Still, Thermal Generation, Water Distillation Water desalination is the method of saltwater separating into two parts by using various types of energy. This paper offers an experimental work for solar distillation system to the production of drinking water by single slope solar still integrated with a parabolic dish. The result was compared with different solar still designs in the literature. The proposed solar thermal performance of the suggested solar still has been investigated to show its applicability in Iraq, Najaf (32.1No, 44.19Eo) during winter session (Nov., Dec., Jan.) 2018 - 2019. The assessment based on the effects of operational parameters, including solar irradiance, ambient temperature, wind speed, absorption wall temperature. A copper helical conical coil was used to compare steam condensation generated from the evaporator. The productivity of this study was 11.45 L.day-1, 8.2 L.day-1 freshwaters with and without coil condenser respectively, and average direct solar irradiance was 753.6 W.m-2. Comparison different types of solar stills, especially those that have used as concentrators of solar irradiance, with comparable periods of work time, indicate excellent performance. Also, this system can be considered acceptable because it can provide distilled water from the use of materials available in local markets and low cost, enough to cover the daily needs of water for at least two adults. Journal of Thermal Engineering Journal of Thermal Engineering 2021-05-01T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5380 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5380 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5380

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/4007 2020-03-26T21:00:00Z 1

Mathematical Modelling of Low Grade Thermal Energy Storage Using an Encapsulated Liquid Medium Law Torres Sevilla, Jovana Radulovic Thermal Energy Storage, COMSOL Multiphysics, Storage Material, Sensible Heat In the present study, we report the results obtained from numerical simulations of low grade heat storage. Four different fluid encapsulated materials were tested in four design types for their suitability as a small scale, low temperature thermal energy storage. This was done by analysing and evaluating the maximum temperature reached per sphere for three different positions inside the tank, which correspond to the top right, centre and bottom right sphere. The influences of the material properties and the inlet/outlet tank designs were analysed and evaluated based on the results. The heat transfer fluid was water and the storage materials selected were water, glycerol, MDM and MD3M. These were heated sensibly from an ambient temperature of 20°C to 90°C. The analysis shows that the materials with the highest relevant properties do not in fact charge the tank the fastest. Furthermore, the design of the inlet greatly affects the heating dynamics of the system, whereas changing the outlet design marginally affects the results. Journal of Thermal Engineering Journal of Thermal Engineering 2020-03-26T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4007 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4007 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4007

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5409 2021-08-01T21:00:00Z 1

Optimum Design Analysis of a Solar-Assisted LiBr/H2O Absorption System with a Flat-Plate Collector Rahul Roy, Balaram Kundu Absorber plate, LiBr/H2O Absorption System, Solar flat-plate collector, Operating condition, Optimization An analytical analysis has been presented to evaluate the performance of a solar assisted vapour absorption cooling system with a flat-plate absorber plate. The lithium bromide–water absorption cycle is used to obtain the cooling effect. The performance parameters, namely absorber plate efficiency, collector efficiency factor, heat removal factor, etc. have been determined with the variation of collector fluid inlet temperature. The cycle coefficient of performance (COP), system COP, refrigerating efficiency of cycle, and refrigerating efficiency of system are determined analytically. The maximum COP and cooling efficiency for both the cycle and the system have been found for an optimal collector fluid inlet temperature. The optimum design condition for the variation of different design parameters, such as, ambient temperature and thermal conductivity, has also been studied. Finally, the plate material is found to be a minimum at a particular collector fluid inlet temperature which is an optimum design condition to run the solar assisted vapour absorption system. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-01T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5409 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5409 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5409

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5408 2021-08-01T21:00:00Z 1

A Novel Tri-generation Energy System Integrating Solar Energy and Industrial Waste Heat Hamed Pourfarzad, Mohammad Saremia, Mohammad Reza Ganjali Energy Management, Cement Industry, Exergy, Energy Efficiency, Optimization Global warming has forced researchers to find an alternative for fossil fuels and to enhance the energy efficiency of processes in industries. Waste heat recovery has a significant potential to reduce fossil fuel consumption and energy performance enhancement. The study cycle is a tri-generation system, heating, electrical power, that can capture carbon dioxide gas. The system works with the solar energy and waste heat of the cement plant. In this study, a model for a completely new system has been developed based on renewable energies. Thermodynamic analysis for the energy system is performed, and the system is based on organic Rankine cycle, absorption chiller, solar energy, and waste heat recovery from the exhaust gases of the cement plant stacks. The results of the analysis showed that the energy and exergy efficiencies were calculated to be 35.78% and 12.77%, respectively, and the total exergy destruction was calculated 277327 kW. Also, the optimization result with the direct algorithm method with the objective function of exergy efficiency improved both efficiencies. In this optimization, the exergy efficiency reached 16.39% and energy efficiency was calculated 49.04%. The optimization with the objective function of total exergy destruction decreased the value to 216813 kW, which was significantly reduced from the base state of the system; while energy and exergy efficiencies were calculated to be 54.61% and 13.85%, respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-01T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5408 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5408 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5408

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5421 2021-08-02T21:00:00Z 1

Performance Analysis of Adsorption Refrigeration System using Silicagel/methanol Pair: Experimental & Analytical Approaches Palash Soni, Vivek Gaba Adsorption Refrigeration, Silica-gel/Methanol, Thermal Gravimetric Analysis, Exhaust Heat An adsorption refrigeration system working on silica-gel/methanol pair has been investigated analytically and experimentally. By applying the mass balance in the adsorber bed the mechanism of adsorption in thermal compressor with respect to time and bed length was determined. An experimental analysis was performed using Thermal Gravimetric Analyzer (TGA) to evaluate the mass transfer coefficient and optimum cycle time for silica-gel/methanol pair at different working temperature. The Diffusion coefficient Ds and Activation energy Ea for silica-gel/methanol pair were found 2.55×10-4 m2/s and 83.08 KJ/mol. Further, the effect of variation of regeneration temperature on the performance of the system in terms of COP and SCP was evaluated; the maximum average theoretical COP and SCP achieved by the system was 0.5 and 102 W/kg near about 127°C regeneration temperature. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-02T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5421 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5421 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5421

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5368 2021-04-28T21:00:00Z 1

Study of The Flow and Heat Transfer of a Viscoelastic Fluid Using Hybrid Neural Network-Particle Swarm Optimization (HNNPSO) Reza Mirzai, Mohammad Ghalambaz, Aminreza Noghrehabadi Ordinary differential equations (ODEs), Neural network (NN), Boundary layer, Viscoelastic fluid, Particle swarm optimization (PSO) Fluid flow and heat transfer of a second-order viscoelastic fluid in an axisymmetric channel with a porous wall for turbine cooling applications are studied. The nonlinear differential equations of the fluid flow and heat transfer arising from similarity solutions are computed employing a Hybrid Neural Network-Particle Swarm Optimization algorithm (HNNPSO). A trial function, satisfying the boundary conditions, as a possible solution for the governing equations is introduced. The trial functions incorporate a multi-layer perceptron neural network with adjustable parameters (the weights and biases). The Particle Swarm Optimization algorithm (PSO) is applied to find the adjustable parameters of the trial solution to satisfy the governing equations. Finally, comparisons are made between the results of the present method (HNNPSO) and the results of the fourth order Runge–Kutta method, finite difference method, and Variational Iteration Method. The results indicate that HNNPSO method conveniently produces a polynomial analytic solution with remarkable accuracy, and the accuracy of the solution improves as the number of neurons of the neural network increases. Journal of Thermal Engineering Journal of Thermal Engineering 2021-04-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5368 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5368 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5368

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5422 2021-08-02T21:00:00Z 1

Flow Behavior and Thermal Separation Mechanism on Vortex Tube Dedy Zulhidayat Noor, Heru Mirmanto, Joko Sarsetiyanto, Denny M.E. Soedjono Vortex tube, Flow field, Thermal separation, Numerical study Flow behavior and thermal separation mechanism on vortex tubes have been studied numerically. Rapid expansion indicated by high- pressure gradient near the inlet and the exit ports contributes to energy separation on the parallel and the counter flow vortex tubes. It creates a cooling process at the core region and drives an internal and rotational energy transfer to the peripheral region, then increases gas temperature at the periphery along with friction due to the presence of the confined wall. Static temperature is related to static pressure in such a way that low pressure leads to low static temperature at the same region inside the vortex tube. On the other hand, the high total temperature is found in the region with the low dynamic velocity. For both vortex tubes, the flow fields are mainly governed by the tangential velocity at the periphery and by the axial velocity at the core region. The maximum Mach number values based on the maximum tangential velocities in the inlet area for the counter and the parallel flow vortex tubes are 0.689 and 0.726 respectively, so both are compressible and subsonic flows. For the same size of geometry and boundary conditions, the parallel flow vortex tube has higher COP than the counter flow vortex tube i.e. 0.26 and 0.25, respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-02T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5422 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5422 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5422

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5382 2021-05-01T21:00:00Z 4

A Loop Thermosyphon for Liquid Cooled Minichannels Heat Sink with Pulsate Surface Heat Flux Kays A. Al-Tae’y, Ameer Abed Jaddoa, Hussain Saad Abd, Riad Adnan Kadhim Loop Thermosyphon, Natural Convection, Minichannels Heat Sink, Pulse Heat Flux, Single-Phase Flow, Ethylene Glycol The period operation of power electronic acts as switching element, where the power dissipated consists of pulses at certain duty cycle, the semiconductor temperature oscillates and varies as a waveform. In the present study, an experimental investigation was carried out for a loop thermosyphon order to evaluate the effect of pulsate surface heat flux on the single-phase buoyancy driven convection of ethylene glycol flow through a minichannels heat sink with hydraulic diameter 1.5 mm. An electric heater block is used to supply the heat flux to minichannels heat sink in a rectangle waveform. The study is done at different heat flux frequencies of 2.777×10-3 Hz, 8.333×10-4 Hz, 5.555×10-4 Hz and 4.166×10-4 Hz, while the heat flux amplitude (2 watt), Rayleigh number (1864) and duty cycle (50 %) are kept constant. The results revealed that for a range of the measured frequency for the complete power cycle and due to unsteady state operation conditions, the pulse heat flux pattern is close to a rectangle-wave, this generates the fluid outlet temperature pattern close to a triangle-wave. The fluid outlet temperature increases with the decreases of heat flux frequency and tends to reach to the fluid outlet temperature for a constant and continuous heat flux case. Due to closed-loop of thermosyphon, the fluid inlet temperature is changed in pattern like that the fluid outlet temperature change. Journal of Thermal Engineering Journal of Thermal Engineering 2021-05-01T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5382 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5382 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5382

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5415 2021-08-02T21:00:00Z 1

Effect of Viscosity on Entropy Generation for Laminar Flow in Helical Pipes Ravi Prattipati, Vamsi Krishna Narla, Srinivas Pendyala Exergy, Entropy, Helical pipe, Laminar flow, Viscosity Entropy generation for fully developed laminar flow in a helical pipe carrying high viscous fluid under constant temperature boundary condition is investigated analytically. This work focusses on geometrical, fluid and thermal aspects and their influence on irreversibilities in helical coils. The effect of viscosity on the irreversibilities and its influence on the operating parameters of helical coil are studied with second law of thermodynamics. The most commonly used relationships for estimating viscosity change due to temperature are selected for analysis. The entropy generation and avoidable exergy destruction in each case are presented. Bejan number is plotted for varying viscosities under different wall temperatures for both heat transfer to and from the fluid. Thermodynamic potential of improvement based on avoidable and unavoidable exergy destruction concepts showed that the potential of improvement for heating and cooling condition is considerable for a given operating condition in helical tubes. The selected model for estimating viscosity influences the optimum operating wall temperature. The optimum helical number is not affected by fluid properties and wall temperature. The heat transfer to pumping ratio is evaluated and it is found that the optimal value is influenced by the change in viscosity. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-02T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5415 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5415 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5415

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5434 2021-08-12T21:00:00Z 1

Effect of Fibrous Porous Material on Natural Convection Heat Transfer From a Horizontal Circular Cylinder Located in a Square Enclosure Hasan Shakir Majdi, Akeel Abdullah Mohammed, Amer Abdullah Mohammed, Laith Habeeb Natural Convection, Square Cavity, Porous Media A numerical simulation study was carried out to investigate a steady two-dimensional laminar natural convective heat transfer from a uniformly heated inner circular cylinder placed inside an air-filled square enclosure with a porous material. The enclosure’s side and upper walls were isothermal, while the bottom wall was adiabatic. All the numerical calculations were performed in the range of Rayleigh numbers between 103 and 107. The material porosity (ε), the solid to fluid thermal conductivity ratio (k_r), and Darcy number in the present study were 1.0, 0.5, and 0.01, respectively. The results showed that for Rayleigh numbers that are less than 106, the isotherms are almost parallel inside the three cold walls except for the corners of the adiabatic bottom wall. The rates of vertical velocity are higher than the horizontal velocity, especially at higher Grashof numbers. Also, the use of fibrous porous material with low thermal conductivity relative to the fluid thermal conductivity reduces the values of average Nusselt number, in addition to reducing the horizontal and vertical velocities along the horizontal axis. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-12T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5434 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5434 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5434

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5499 2021-11-20T21:00:00Z 1

Bio-Heat Transfer in Cancer Treatment Using Cryo-Freezing Method Erkan Kizilrmak, Oguz Turgut Bio-Heat Transfer, Cancer Treatment, Cryo-Freezing, Tumorous Tissue, Experimental Study The objective of this study is to investigate the effect of bio-heat transfer from large blood vessels on freezing region size of tumorous liver tissue using cryo-freezing method. Bio-heat transfer, one of the cancer treatment method, in tumorous tissue has been investigated experimentally using cryo-freezing method for vessels. Investigated parameters are the blood mass flow rate, the diameter of vessel, the number of vessel, and the location of tumorous tissue. Study is carried out for nine different blood mass flow rates varying from 10 g/min to 1200 g/min. Tissues without blood vessel, with single, double and branched vessels are used for the experimental study. Vessels with inner diameter of 2.4, 3.2 and 4.0 mm are used. Liver of beef is employed as a tissue. Refrigerant is the nitrogen protoxide gas. Results show that the number of vessel, the diameter of vessel, the location of tumorous tissue, and the blood mass flow rate affect the freezing region size. Freezing region size decreases with increasing in diameter of vessel, number of vessel and blood mass flow rate. The large blood vessel located near the tumorous tissue affects the freezing time to destroy the tumor. The desired freezing region obtained in tumorous tissue with vessel develops later than the tumorous tissue without vessel. Results indicate that a tumorous tissue about 23 mm may be destroyed in a short time using cryo-freezing method when nitrogen protoxide gas is used as refrigerant gas. Journal of Thermal Engineering Journal of Thermal Engineering 2021-11-20T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5499 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5499 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:8 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5499

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3901 2019-11-26T21:00:00Z 1

A New Approach For Evaluating the Rankine Cycle through Entropy Generation Asım Sinan Karakurt, Umit Gunes Rankine cycle, Entropy generation, Exergy density Increasing oil prices, the growing demand for energy, the adoption of new regulations for greenhouse gases and other harmful particulate emissions, as well as political instabilities and crises have necessitated the design of more efficient and environmentally-friendly plants. This paper presents a useful combination of mean cycle irreversibility (MCI) for thermodynamically optimizing the Rankine cycle using the MCI as the currently proposed criterion. The thermal irreversibilities and physical size of a system are evaluated together using the criterion that aims to minimize the ratio of the thermal irreversibilities or exergy destruction to a specified size that is characterized as the difference between the maximum and the minimum specific volumes of the cycle. The analyses consider the effects of different boiler-outlet or turbine-inlet pressures and temperatures, different condenser pressures, and different isentropic efficiencies on cycle performance. The results show that increasing the inlet temperature for a constant turbine-inlet pressure increases the MCI and increasing the turbine-inlet pressure at a constant inlet temperature decreases the MCI. With boiler pressure at 500 kPa, the boiler temperature increases from 500K to 600K, the MCI value increases nearly seven-fold, and thermal efficiency increases from 14% to nearly 16%. Also, the results show that the criterion gives more beneficial information to designers and engineers in terms of exergy destruction for designing more environmentally friendly and smaller thermal systems. Journal of Thermal Engineering Journal of Thermal Engineering 2019-11-26T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3901 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3901 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3901

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5416 2021-08-02T21:00:00Z 1

Parametric Investigation of Open-drive Scroll Expander for Micro Organic Rankine Cycle Applications Suhas Upadhyaya, Veershetty Gumtapure Scroll expander, Organic Rankine cycle, Semi-empirical model, Efficiency Organic Rankine cycles (ORC) are used to produce power from low temperature heat sources. In the low power output range (<10 kWe), scroll expanders are preferred. However, the performance of the ORC system is dependent on the expander efficiency. The present work focuses on the parametric investigation of open-drive scroll expander used for micro organic Rankine cycle. A 5 kWe expander was used and its built-in volume ratio was 3.5. R245fa was used as the working fluid. The analysis was carried out using a well known semi-empirical model available in literature. Effect of key parameters such as expansion ratio, shaft speed and expander inlet temperature on power output and expander efficiency was evaluated for four different cases. Results showed that, at inlet pressure of 10 bar, peak efficiency of 58% and 60% was achieved at shaft speeds of 1500 RPM and 2000 RPM respectively. It was also evident that, at higher shaft speeds, the increase in mass flow rate is not sufficient to counter frictional and mechanical losses within the expander. The analysis also indicated that, increasing the expander inlet temperature could have a negative impact on the expander efficiency as well as the overall performance of the ORC system, as the thermal energy dissipation is higher at higher inlet temperatures for all cases. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-02T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5416 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5416 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5416

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5413 2021-08-02T21:00:00Z 3

A Comprehensive Review to Study and Implement Solar Energy in Dairy Industries Alka Solanki, Yash Pal Dairy Industries, Energy Consumption, Renewable Energy, Refrigeration System, Solar Thermal Technologies, Triple-Effect, Vapour Absorption In this review, analysis of triple-impact vapour ingestion refrigeration framework involving of a high, medium and low temperature generator is characterized. This review suggests the solar power-related triple impact vapour retention refrigeration for heating and cooling applications in dairy industries that should be developed. In this review paper, investigates solar heat and cooling is practiced in dairy modern applications and with improved advancements and scaled down costs, the solar-powered energy guarantees to reduce power charges, builds countries' energy security through reliance on a special, unfathomable resource, redesigned practicality, limited defilement, cut down the costs of diminishing an unsafe barometrical deviation, and keeps oil subordinate costs lower than something different. The important source of heating is considered from solar-based by using different solar oriented heat advancements. The results indicate that the develop a solar power-related triple impact vapour retention refrigeration for heating and cooling applications in dairy industries. Different operating temperatures are measured during the implementing and to find an optimal condition for food processing in the dairy industry. Thus this observed study gives hands to develop an efficient renewable system for processing of dairy industrial operation using solar power respectively. By implementing renewable energy sources in the dairy industries promotes overall energy consumption and lower the total expenditure of the industrial processing respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-02T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5413 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5413 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5413

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5075 2020-05-08T21:00:00Z 1

Advancement of Solar Selective DLC Coating Using CAPVD for Solar Thermal Applications Ambati Sandeep, K. Archana, Sivakumar Ellappan, Dandu Mallesham DLC Multilayer Absorber Coating, Solar-Irradiation, Radiation Stable, High Hardness Metal nitride multilayer films display a unique combination of exceptional properties with respect to optical absorption, thermal emission, corrosion resistance, adhesion between coating and surface and high temperature withstand. Most considerable aspects of nitride coatings were economical, environmentally friendly and easy to develop. Similar to nitride thin films, to achieve a considerable absorption (α) -0.92 and low emission (Є) -0.08 along with chemical and radiation stable solar selective coatings, Diamond Like Carbon (DLC) thin films exhibit the desirable properties for Concentrated Solar thermal Power(CSP)applications. The main advantages of DLC films were high hardness, chemical and radiation stability and good control over the optical properties. To achieve above-mentioned properties, optimization of each layer of the DLC coating has needed. The main aim of this research is optimization of Cr-base layer using Cr-Target current 175A to get 125 nm thicknesses, optimise the AlSiN absorber layer by controlling the AlSi- target current 175A to maintain 35nm thickness. The sequence of the DLC coating layers was selected based on their relative thickness, which was optimize to get good solar selectivity (α/Є). Individual layers of the DLC solar coatings have unique properties to get overall required high absorbance and low emission along with chemical and radiation stability. These solar selective multi-layers (Cr/DLC/AlSiN) have deposited by using available Cathodic targets (Cr , AlSi & Ti) in Cathodic Arc Physical Vapor Deposition (CAPVD) and optimized parameters were mainly depend on the target currents to control over the thickness of the each layer, base pressure 1*10-5 mbar and deposition temperature 400°C. The DLC multilayer solar selective coatings were characterized using Ultraviolet Visible Near infrared (UV- Vis- NIR) spectrophotometer, Scanning Electronic Microscopy (SEM), Transmission Electron Microscopy (TEM) and Raman spectroscopy etc. Scratch test and corrosion tests have conducted for these absorber coatings testing. Journal of Thermal Engineering Journal of Thermal Engineering 2020-05-08T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5075 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5075 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5075

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5512 2021-12-08T21:00:00Z 4

Simulation of Turbulent Convective Heat Transfer of γ-Al2O3/Water Nanofluid in a Tube by ANN and ANFIS Models Roghayeh Nazari, Hossein Beiki, Morteza Esfandyari Nanofluids, Heat transfer coefficient, ANN, ANFIS, Prediction. In order to modeling and predicting heat transfer coefficient in nanofluids, artificial neural network (ANN) and Adaptive Neuro-fuzzy Inference system (ANFIS) were used in this study. In ANN and ANFIS, Input data are Reynolds number and nanoparticles volume fractions, and output data is heat transfer coefficient. Both of them could predict very well, and there is good agreement between experimental data and predicted data. In ANFIS coefficient of determination (R2), average relative error and mean square error for train data are 0.99, 8.9×10-5 and 6.5476×10-5, respectively, and for test data are one, zero and zero. According to results, by increasing the Reynolds number and volume fractions, the heat transfer coefficient increases. For base fluid in Re=16300, heat transfer coefficient is 10961.38 W/m2K, and for volume fraction 0.135, heat transfer coefficient is 13947.72 W/m2K, therefore, heat transfer coefficient of nanofluids increased 1.27 time compared to that of base fluid. Results obtained from ANFIS are reliable, and can be used in prediction. Also, for ANN, ARE, MSE and R2 value are, -0.003, 6.38264×10-5 and 0.99, respectively. So, there is good agreement between experimental data and ANN results too. According to errors, can conclude ANFIS is slightly better than ANN. Journal of Thermal Engineering Journal of Thermal Engineering 2021-12-08T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5512 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5512 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5512

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5417 2021-08-02T21:00:00Z 1

Enhancement of Household Refrigerator Energy Efficiency by Studying the Effect of Refrigerant Charge and Capillary Tube Length Santhosh Gugulothu Hydrocarbon, Refrigerant mixture, Capillary tubes, Pull-down time, Alternative refrigerant Experiments were carried out intially by considering pure R134a and hydro carbon refrigerant mixtures such as (R290/R600a) (HCM1 44/56, HCM2 50/50, HCM3 54/46, HCM4 64/36 and HCM5 74/26 wt%). Initially, tests are conducted at the atmospheric temperature of 300C in a domestic refrigerator system. The performance parameters such as pull-down time, desired effect, power consumption and running cost of the system are to be analyzed at different evaporator temperatures, the mass of refrigerant and varying length of capillary tubes. To evaluate the refrigeration effect, Power consumption and COP of the domestic refrigerator at various freezer temperatures (-9°C, -12°C &-15°C) were selected. Results report that out of all the alternative mixtures the amount of energy input was less consumed in the case of HCM1 at an minimal expansion length of 6.3 m. In case of HCM5 the least energy was consumed at a capillary length of 5.24 m whereas in the case of R134a it was at 3.3 m. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-02T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5417 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5417 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5417

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5334 2021-02-26T21:00:00Z 1

Optical Numerical Investigation of a Solar Power Plant of Parabolic Trough Collectors Mokhtar Ghodbane, Boussad Boumeddane, Ahmed Kadhim Hussein, Dong Li , S. Sivasankaran Solar Energy; Power Plants; Parabolic Trough Collector; Optical Investigation;Numerical Simulation. Going forward towards developing and improving renewable energies in Algeria is one of the main objectives of this study, especially, solar energy that is an exceptional and continuous source of energy. Algerian Sahara has a large area suitable for agriculture, but not connected to the electricity network. Therefore, the construction of solar power plants based on the solar energy concentration has been proposed for the electricity production, which is exploited in the rest of the economic sector of the Algerian state. Through the study conducted under real weather data for the day 16/03/2018, an optical characterization of a solar power plant of parabolic trough concentrator has been convoyedin El-Oued region, Algeria. The geometrical and the optical characteristics of studied reflector have been determined, such as the optical efficiency, the local concentration ratio, the cosine effect of the incidence angle, the optical losses at the ends of the receiver tube, the shading effect, the blocking effect, and the coefficient of incidence angle modifier and intercept factor. Matlab code has been used as a program for numerical programming. Of the most important results obtained, it was found that the optical efficiency has exceeded 77.22 %. As for the local concentration ratio, its maximum values is equal to 116.297 in the lower part of the receiver tube at the peripheral receiver angles “ß=270° and ß=90°", while the minimum values of this important coefficient were recorded at the top of the receiver tube. Journal of Thermal Engineering Journal of Thermal Engineering 2021-02-26T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5334 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5334 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5334

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5159 2020-09-24T21:00:00Z 1

Numerical Evaluation of Thermo-Hydraulic Performance Index of A Double Pipe Heat Exchanger Using Double Sided Louvered Winglet Tape R Thejaraju, KB Girisha, SH Manjunath, BS Dayananda Numerical technique, Louvered winglet tape, Thermo-hydraulic performance index, Slope angle The decade has witnessed great importance of numerical techniques for scientists and researchers in deciding the correctness, stability, and reliability of new designs. In the present study a numerical technique has been implemented to investigate the thermo-hydraulic performance of the Louvered winglet tape inside the tube section of the double pipe heat exchanger. The Louvered winglet tape has been examined with the slope angle of 50, 100, 150 and 210 to study their thermal characteristics. The Reynolds number 4000-30000 was examined on slope angle of 50, 100, 150 and 210 to study their flow characteristics in the turbulent domain. A smooth pipe was examined to evaluate heat transfer characteristics in terms of Nusselt number and friction coefficient over augmented tube with Louvered winglet tape. The results show a satisfactory performance of Louvered winglet tape over the smooth tube with a similar trend of friction factor, Nusselt number, and thermo-hydraulic performance index (THPI). The percentage of increment of the Nusselt number of the results is found to be 237.04%, 258.4%, 275.11%, and 289.72% when compared to smooth pipe with respect to slope angle of 50, 100, 150 and 210, respectively. The amount of increase in the friction factor in comparison with plain tube is 5.13, 6.73, 8.33, and 11.73 times of that of smooth pipe with respect to slope angle of 50, 100, 150 and 210, respectively. The Louvered winglet tape with slope angle 150 has shown to be promising with respect to higher THPI when considering with other slope angle of 50, 100, and 210. The maximum THPI of 1.85 was obtained for slope angle 150 at Re 12000. Similarly, the THPI values for other slope angle 50, 100, and 210 are 1.71, 1.78 and 1.69. In addition to better performance the Louvered winglet tape can be easily fabricated and adapted for a wide variety of heat transfer industries. Journal of Thermal Engineering Journal of Thermal Engineering 2020-09-24T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5159 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5159 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5159

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5423 2021-08-02T21:00:00Z 1

Experimental Investigation of a Scheffler Reflector for the Medium Temperature Applications Anil Kumar Energy efficiency, Performance evaluation, Scheffler collector, Solar, Thermal applications. This research problem reveals the experimental investigation at pressure of 1.5 bar and temperature of 120°C for the medium thermal applications utilizing the four Scheffler reflectors with 16 m2 surface area each. The Scheffler collector associated with absorber plate of mild steel of size, 0.45 m diameter and 0.025 m thick was assessed in the June 2018. The variation in solar beam radiation over the entire day was observed from 840 W/m2 to 1278 W/m2, while, the absorber plate temperature was recorded within the extent of 116°C to 195°C, however, maximum heating temperature was measured 129°C at the end use. The Scheffler collectors performed appropriately in the morning and evening time with substantial heat loss factor and lower optical efficiency factor. The energy efficiency of 59.28 % has been achieved which is higher as compared to the parabolic solar concentrator. The higher concentration ratio of Scheffler collector indicates it as an efficient substitute to replace the fossil fuels. The system is viable for more than 1600 kWh/m2 yearly solar potential while, the cost of heating is greater than 0.05 $/kWh for them. This paper concludes that the Scheffler reflector is the most promising solar technology for the medium temperature applications. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-02T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5423 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5423 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5423

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5411 2021-08-02T21:00:00Z 1

Convective Heat and Mass Transfer of Chemically Reacting Fluids with Activation Energy with Radiation and Heat Generation Poosappan Yesodha, Marimuthu Bhuvaneswari, S. Sivasankaran, Kaliannan Saravanan Heat Generation, Thermal Radiation, Activation Energy, Chemical Reaction. This study is to investigate the effect of chemical process by activation energy on heat transference and mass transference of a fluid by heat generation parameter (Hg) and radiation parameter (Rd). Attention has been given to the changes caused on the temperature by the flow in rotating frame by the heat generation parameter, Biot number and radiation parameter. The variation of velocity and concentration of fluid, which is chemically reacting, by the influence of the rotational parameter (ß) has been incorporated. Numerical solution of the system through resulting equations has been undertaken. Effects of different flow parameters are presented by graphs and tables. Results show that activation energy increases when there is an increase in concentration of the chemical species and that velocity decrease by the increase in porosity. With the raise of Prandlt number the temperature of the chemical system decreases. Numerical discussion on skin friction coefficients, Sherwood and Nusselt numbers has been done. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-02T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5411 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5411 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5411

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/3905 2019-12-01T21:00:00Z 1

Ship Emission Estimation for Izmir and Mersin International Ports – Turkey Araks Ekmekçioğlu, Uğur Buğra Çelebi, Kaan Ünlügençoğlu Shipping Emissions, Ports, Global Warming, Green Shipping Approximately 90% of the world trade is done by sea trade. The world maritime trade fleet is also increasing every year. Since ships use fossil fuels, they contribute to global climate change. It is very important for the environment and human health to calculate emissions in the port areas where ships do cargo operations. In this study, emissions analysis of the two important ports of Turkey’s is performed with using the buttom-up calculation method. In addition, hotelling periods of the vessels are monitored for both ports for 1 year period. As a result, total Nitrogen Oxide (NOx), Sulphur Dioxide (SO2), Carbon Dioxide (CO2), Volatile Organic Compounds (VOC), Particulate Matter (PM) and Carbon Monoxide (CO) emissions of İzmir Port are calculated as 900 tons/year, 589 tons/year, 45320.5 tons/year, 49.7 tons/year, 77.7 tons/year and 36.9 tons/year, respectively. Moreover, total NOx, SO2, CO2, VOC, PM and CO emissions of Mersin Port are calculated as 1998 tons/year, 1339 tons/year, 102330 tons/year, 114.5 tons/year, 178.5 tons/year and 82.5 tons/year, respectively. The amount of emissions of Mersin port, which has a higher number of movements, was higher than that of İzmir port. Journal of Thermal Engineering Journal of Thermal Engineering 2019-12-01T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3905 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3905 Journal of Thermal Engineering, Year:2019, Vol:5, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=3905

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5412 2021-08-02T21:00:00Z 1

Energy and Exergy Analysis of a Combined System: Cascade Organic Rankine Cycle and Cascade Refrigeration Cycle Rabah Touaibi, Hasan Köten, Fadhila Boudjema, Salma Selmane, Mohamed Hemis Organic Rankine cycle, Cascade refrigeration, Exergy analysis In this paper, a new combined system is proposed for recovering thermal energy at medium temperature using a cascade organic Rankine cycle to feed a cascade refrigeration cycle. Energy and exergy analysis is applied to the combined system to determine its performance using different working fluids under the same operating conditions taking into account the effect of some operating parameters and the selection of organic fluids on cycle performance. The pair of organic fluid (Toluene/R245fa) used for the cascade organic Rankine cycle and the pairs (R717/R744, R717/R23, R134a/R23) used for the cascade refrigeration cycles. The results show that the combined system function with the couple (R717/R23) for cascade refrigeration cycle gives better exergy efficiency 50.03% compared to other couples, 49.57 % for the couple (R717/R744) and 48.01 % for the couple (R134a/R23). The thermodynamic evaluation shows that the operating temperatures, such as the cascade organic Rankine cycle evaporation temperature and the cascade refrigeration cycle evaporation temperature influence the performance of the combined system. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-02T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5412 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5412 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5412

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5155 2020-09-23T21:00:00Z 1

Thermal Performance Analysis of Glazed and Unglazed Receiver of Scheffler Dish Dnyaneshwar Malwad, Vinod Tungikar Scheffler Dish, Glazed Receiver, Direct Steam Generation, Thermal Efficiency The impact of reradiation and convection losses from the receiver is substantial on the performance of solar parabolic dish concentrator. In this paper, an experimental and theoretical study to compare the performance of the glazed and unglazed receiver of Scheffler dish for direct steam generation is presented. Tempered glass cover is provided on aperture to reduce the reradiation and convection losses from the receiver. Improvement in the efficiency of the Scheffler dish is found due to suppressed heat losses from the receiver front surface. Overall heat loss coefficient, useful energy transfer rate to water, steam flow rate, and efficiency of the system with and without glass cover on the receiver are evaluated and compared. The average solar beam intensity during experimentation was 569 W/m2 and 600 W/m2 with the glazed and unglazed receiver respectively. The average temperature at the receiver with glazing is recorded as 425oC, even at low solar beam intensity in comparison with the unglazed receiver. Overall heat loss coefficient at the front surface of the receiver is reduced to 6.04 W/m2K. It has been observed that the Scheffler dish with a glazed receiver achieves thermal performance above 50.00% within the solar beam intensity range of 600-650 W/m2. The enhancement of 8.74% in the average thermal efficiency, with glass cover on the receiver is achieved. Journal of Thermal Engineering Journal of Thermal Engineering 2020-09-23T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5155 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5155 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5155

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5433 2021-08-08T21:00:00Z 1

Heat Transfer Analysis of Hybrid Active Solar Still with Water Flowing over Glass Cover M.K. Gaur, G.N. Tiwari, Pushpendra Singh, Anand Kushwah PVT collector, Thermal efficiency, Hybrid active solar still, Thermal modeling The aim of this research is to carry out the heat transfer analysis of PVT hybrid active solar still (HASS) at different water depth to obtain maximum output. Experimentation is performed for validation of thermal modeling with and without flowing water, having water depth of 0.15m in the solar still basin. During experimentation, water flows above the glass cover. Theoretically calculated values of basin water, basin liner, glass temperature and yield obtained using thermal modeling are very near to the experimental values having correlation coefficients 0.988, 0.981, 0.999 and 0.985 respectively. It is also found that thermal efficiency and daily exergy output increases by 4% and 8.2% respectively for this hybrid system whose glass cover is getting cooled by water flowing over it. Theoretical calculation for distillate output of the system was also calculated out for various climatic conditions of India using developed thermal modeling and it is found that proposed system gives higher annual yield of 2756.67 kg/m2 for the climate of Mumbai. The experimental uncertainty of the HASS is obtained as 14.82%. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-08T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5433 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5433 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5433

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5316 2021-01-29T21:00:00Z 1

Stabilization of Minority Carrier Lifetime in PERC Structured Silicon Solar Cell Veysel Ünsür : LID, light induced degradation, regeneration, minority carrier lifetime, PERC, Cz silicon wafers, hydrogenation, solar cells This paper reports on the regeneration of the minority carrier lifetime in PERC structured silicon solar cells. It is observed that minority carrier lifetime in the cells can degrade, recover and then stabilize with illumination level of ~1 sun (1000 W/m2) at 80oC. The exposure to ~1 sun illumination at 80oC enables the release of H from B-H bonds at ~1.3 eV energy to supplement the interstitial H in Si to passivate the B-O defects responsible for the minority carrier lifetime instability. Passivation of these B-O defects is therefore, dependent on temperature and time, hydrogenation and high carrier injection level. It was interesting to note that sequential process or single regeneration step led to same conclusion that minority carrier lifetime in a p-type PERC cell first degrades, due to B-O complexes, recovers and then stabilize with time. There is therefore, no need to degrade the cells in a separate step in order for regeneration to occur, because regeneration encompasses the three states: degradation, recovery and stabilization. Journal of Thermal Engineering Journal of Thermal Engineering 2021-01-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5316 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5316 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5316

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5278 2020-12-26T21:00:00Z 1

Multiscale Approach of The Equivalent Thermal Conductivity of Modified Foam-Filled and Non-Filled Hollow Brick and a Brick Wall Atheer Saad Hashim, Mushtaq F. Almensoury, Farooq Hassan Ali, Hameed Kadhem Hamzah, Mohammad Ghalambaz Hollow Clay Brick, PUF Foam, Multiscale Method, FEM, Equivalent Thermal Properties The energy loss through building components resulting in higher energy consumption, thus energy saving has become an essential aspect in design and comfort. This study aims to optimize the thermal insulation of red clay bricks used in the walls of buildings by using a multiscale method. The finite element approach in ABAQUS software has been used to simulate the bricks under different configurations and conditions. Due to cost and time challenges and difficulties in simulation and complex calculations, simplified and applicable equations have been derived to calculate thermal insulation properties. The results show that the paper’s brick design has a significant thermal conductivity reduction that could reach more than one-third of the other corresponding studies. The study goes to fill the hollow bricks by the insulation polyurethane foam (PUF) and comparing the results with air hollow bricks. Besides its other advantages, the outcomes reveal that using the PUF has a noticeable desired-influence in thermal insulation when considering the heat transfer by convection and radiation inside the air cavity of bricks. Journal of Thermal Engineering Journal of Thermal Engineering 2020-12-26T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5278 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5278 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5278

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5406 2021-08-02T21:00:00Z 1

Numerical Simulation on Performance Evaluation among Metal and Oxide Based nanofluids for Power Savings Application of a Circular Tube Md Insiat Rabby, Md Farzad Hossain, S.A.M. Shafwat Amin, A. K. M. Sadrul Islam Figure of merit, Volume fraction, Pumping power, Nusselt number enhancement ratio, Heat transfer coefficient enhancement ratio, Convective heat transfer. Advancement of heat transfer techniques is a challenge to the researcher in this era. Implementation of nanotechnology is one of the potential techniques which enhance the heat transfer rate in a significant amount. Subsequently, nanotechnology can reduce the requirement of pumping power. However, suspension of nanoparticle with liquid to produce a new working fluid called nanofluid which has better thermal and fluid dynamic properties in comparison to pure liquid is introduced as a typical nanotechnology technique in the heat transfer area. In this study, the thermal performance of two categories of nanofluids metal-based (Cu-water and Ag-water) and oxide-based (Al2O3-water, CuO-water, BeO-water) have been analyzed for laminar flow region of a circular plan tube which is fully developed under 2D control volume finite element method. For evaluating the performance among nanofluids, the Figure of Merits (FOM), pumping power, Nusselt Number enhancement ratio and Heat Transfer Coefficient ratio of base fluid and nanofluids have been calculated and compared among base fluid and nanofluids. The computational results show that in terms of Nusselt number and heat transfer coefficient, all nanofluids provide higher enhancement compared to pure water. Meanwhile, for this higher enhancement, nanofluids required significantly lower pumping power in comparison to pure water. Between the mentioned two categories of nanofluids, metal-based nanofluids provide the highest heat transfer enhancement and lowest pumping power requirement compared to oxide-based because of their higher thermal conductivity and other fluid and thermal properties. For clearing the enhancement of heat transfer rate over pumping power, a dimensionless number FOM has been calculated wherein metal-based nanofluids provide the highest value of FOM in comparison to oxide-based. In the meantime, the comparison between nanofluids also reveals that among all the nanofluids, metal-based Ag-water nanofluids provide the highest heat transfer and oxide-based BeO-water provide the lowest enhancement for heat transfer enhancement in terms of pumping power requirements. Lastly, the study concluded that suspension of metal-based nanoparticles with base fluid have better capability to save pumping power by providing the highest enhancement of heat transfer rate compared to oxide-based and base fluid. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-02T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5406 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5406 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5406

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5435 2021-08-12T21:00:00Z 1

Temperature-Dependent Particle Stability Behavior and Its Effect on Radiative Transfer in Water/SiO2 Nanofluids Layth Al-Gebory Nanofluids, Stability, Temperature, Radiative Transfer Radiative transfer is one of the methods of energy transport that includes in a wide range of applications and we feel it in our daily lives. Thermal radiation transfer plays an effective role in the utilization of renewable energy. The radiative and optical properties, as well as the nature of the radiative scattering, are the basic principles of the thermal radiation transfer. The unique properties of nanofluids offer the unmatched potential for use in energy utilization, the working temperature has a dominant effect on the stability and radiative properties of such type of suspensions. In this research, the radiative transfer (optical properties, the independent and dependent scattering, and radiative properties) in water/SiO_2 nanofluids are investigated; taking into consideration the effect of working temperature on the stability of the particles. The effect of the temperature on the stability ratio and particle agglomeration is determined by estimating the radius of gyration of particle agglomerates using the scaling law based on the stability (DLVO) method. The single-scattering approximation (SSA) is used to calculate the radiative properties in the case of independent scattering, while the quasi-crystalline approximation (QCA) is used for this purpose in the case of dependent scattering. The results show that the temperature has a significant effect on the stability of particles and radiative transfer in nanofluids. It was observed by comparing the results from the two approximation methods in the Rayleigh regime. Particle size affects the physical and scattering cross-sectional areas which give a general understanding of the scattering mechanism from small to large particles. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-12T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5435 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5435 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5435

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5436 2021-08-12T21:00:00Z 1

Experimental Study of Combustion of Low-Calorific Producer Gas From Small Scale Biomass Gasification Within Porous Burner Kanokkarn Jirakulsomchok, Thawatchai Wongchang, Karaboon Prasartthong Biomass, Combustion, Gasification, Porous Burner The aim of this experimental study is to investigate the combustion low-calorific producer gas within porous burner. The small scale downdraft biomass gasification for rural area was performed to produce gaseous fuel. Three types of wood in Thailand were used as raw materials to produce producer gas, i.e. Acacia-mangium, White popinac and Eucalyptus. The low heating values of producer gas were in the range of 3800-4232 kJ.kg-1 that are difficult to burn in conventional burner. Tapered and bilayer porous burners were used to overcome this limitation. The effects of air preheating modes, equivalence ratio and firing rate on thermal structure and pollutant emission were revealed. The results showed that the complete combustion with low emission of low-calorific producer gas was accomplished with low firing rate in the range of 2.8 – 3 kW. Both CO and NOx emission were less than 160 ppm for all of tests. The combustion within tapered porous burner emitted small CO emission nearly zero for all of equivalence ratios. The tar reduction was 99.5% by combustion within porous burner. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-12T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5436 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5436 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5436

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5575 2022-04-26T21:00:00Z 1

Comparative Exergy and Energy Analyses and Optimization of Different Configurations for a Laundry Purpose Hayder A. Dhahad, Hasanen M. Hussen, Wissam H. Alawee fossil fuels, renewable energy, Organic Rankin Cycle, exergy analysis, genetic algorithm Energy usually plays a critical role in the development of a country. With the gradual decrease of available traditional fuel reserves and air pollutions problems that is followed by using them, the need to replace alternative renewable and sustainable options to decrease our dependence on fossil fuels has drawn attentions. Biomass is a kind of reliable renewable energy that is used to derive combined heat and power systems that known as Organic Rankin Cycle (ORC). This paper presents of exergy analysis of three cycles which have been modeled by EES software for a laundry that needs 32 (kw) power and 2500 (kg/h) 65 (Co) hot water which hot water is our main goal in this study. in RC (gas fuel) and ORC ( biomass fuel) power which is produced provides part of electricity needed in the laundry but for Boiler Proving hot water (BPHW) the whole electricity needed is bought from grid. R245fa is a friendly environmentally organic fluid is used in ORC as working fluid. The result of this analysis shows for the same conditions the most exergy destruction occurs in boiler and the least in pump in three of cycles. It also shows the most efficiency of second law respectively is belong to RC, ORC, BPHW with 0.21%, 0.16%, 9% total efficiency respectively. Moreover, by utilizing EES software and genetic algorithm all of configurations has been optimized and compared. Journal of Thermal Engineering Journal of Thermal Engineering 2022-04-26T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5575 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5575 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5575

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5309 2021-01-25T21:00:00Z 1

Characterization of Synthesized Polymeric Blend Membranes Enhanced by Methyl Diethanolamine for Efficient CO2 Seperation Asim Mushtaq, Hilmi Bin Mukhtar, Azmi Mohd Shariff Carbon Dioxide, Methyl Diethanolamine, Polymeric Blend Membranes, Polysulfone, Polyvinyl Acetate The limited performance of pure glassy and rubbery polymeric membranes for natural gas purification are due to their intrinsic properties. Optimizing their properties by blending both polymers are expected to address the shortage. The foremost objective of this research is to synthesis enhance polymer blend membranes (EPBM) using glassy polysulfone (PSU) and rubbery polyvinyl acetate (PVAc) with the addition of amine for carbon dioxide (CO2) removal from methane (CH4). The EPBM were developed by varying the composition of PVAc ranging from 5 to 20 wt. % with 95 to 80 wt. % base PSU in dimethylacetamide (DMAc) solvent. The amines composition was added to the blend and kept at 10 wt. % over solvent. The findings showed good miscibility between PSU and PVAc blends and the original functional groups of polymers and amines were shown by FTIR with very few spectral peak shifts. The synthesized EPBM were found to have homogenous surfaces and a packed bed sphere structure as shown by FESEM images. Increasing the composition of PVAc from 5 to 20 wt. % has significantly reduced the glass transition temperature (Tg) of PSU from 185.09oC to 155.75oC. Journal of Thermal Engineering Journal of Thermal Engineering 2021-01-25T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5309 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5309 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5309

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5418 2021-08-02T21:00:00Z 3

A Review on Convective Heat Augmentation Techniques in Solar Thermal Collector using Nanofluid K.B. Deshmukh, S.V. Karmare Solar energy, Thermal performance, Nanofluid, PCM, Passive techniques Solar water heating system is convincing technology to convert solar energy into thermal energy. According to the survey, approximately 42% of refined crude oil is used in industrial and commercial applications for process heating. Fossil fuel is the main energy source that is depleting continuously. Solar energy is an environment-friendly energy source, which can full fill energy demand. Solar thermal collectors are most popular in domestic as well as industrial sectors for water heating due to its ease of operation and simple maintenance. Extensive work is going on to improve the thermal performance of solar thermal collectors using passive techniques. Passive techniques include the use of nanofluid, twisted tape, Phase Changing Materials. Active and passive techniques have a significant contribution to solar thermal collector thermal performance enhancement. This paper reviews the work carried out and current progress to enhance the thermal efficiency of solar water heaters using nanofluid. In addition to this, a detailed discussion and limitations of existing research have made, from this discussion, research gaps are identified and possible future modifications are suggested. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-02T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5418 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5418 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5418

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5281 2020-12-28T21:00:00Z 1

Natural Convection Heat Transfer Inside Horizontal Circular Enclosure with Triangular Cylinder at Different Angles of Inclination Akeel Mohammed Natural Convection, Heat Transfer, Circular Enclosure, Triangular Cylinder. Numerical simulation study by using Fluent CFD software has been carried out to investigate the steady. laminar natural convective heat transfer for air formed by heated inner equilateral triangular cylinder inside cold circular enclosure. The triangular cylinder was located at center of enclosure with four radius ratio RR=1.5, 2, 2.5, and 3; and four inclination angles, θ=0o (the base of triangle cylinder at bottom), 20o, 40o and 60o (the base of triangle at top). All numerical calculations were performed in the range of Rayleigh number extends from 103 to 107. The fluid and temperature fields were represented in the form of streamlines and isotherms. Results show that, As Rayleigh number increases, the streamlines become more concentrated next to the walls and the center of vortex displays upward towards the central plane of enclosure. Also, there is no effect for the inclination angle of triangular cylinder on the peak values of local Nusselt number along the inner surface of circular cylinder except the positions of these peaks due to turning of thermal plumes. Journal of Thermal Engineering Journal of Thermal Engineering 2020-12-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5281 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5281 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5281

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5438 2021-08-13T21:00:00Z 4

Effect of Air Fan Position on Heat transfer Performance of Elliptical Pin Fin Heat Sink Subjected to Impinging Air Flow Adil Abbas Mohammed, Saad Abdulwahab Razuqi Forced Convection, Heat Transfer, Heat Sink, Elliptical Fins, Heat Flux, Numerical Analysis Heat rejection from electronic components by heat sink is still a viable cooling solution. The optimal heat sink design enables higher heat transfer performance. The purpose of the present study is to predict the effectiveness of heat sink elliptical closely spaced fins subjected to impinging air cooling. The air fan is the main source of impinging air, then its position and direction with the heat sink take the main role in present work. Two positions of fan location are studied. The first position where the fan is outside the heat sink and the second case where the fan is existed in a cut out template. So there are one impinging air inlet with four transverse outlets and one axial exit opposite to the air flow inlet. Reynolds number were taken at a range 3400-16000, the flow was turbulent so k-Ԑ model turbulence model was used as our choice to simulate mean flow characteristics for turbulent flow conditions. The heat sink base was subjected to constant heat flux condition and proposed with range between 10000-40000 kW/m2 to keep the base temperature at a temperature around 100 oC. The Results of temperature contour lines depicted a variation from the base to the extended surfaces tips. The comparison between the two cases results showed high temperature difference in the case with the cut out template. Nusselts numbers indicated that the second case performed better in heat transfer than the first case. The experimental and numerical results showed a good agreement with a difference not exceeding 2%. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-13T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5438 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5438 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5438

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5516 2021-12-24T21:00:00Z 1

Heat and Mass Transfer in Stagnation Point Flow of Cross Nanofluid Over a Permeable Extending/Contracting Surface: A Stability Analysis H. Thameem Basha, R. Sivaraj Dual solutions, stability test, Cross nanofluid, stagnation-point flow, Buongiorno model This work aims at examining the thermophoresis and Brownian motion characteristics on the stagnation point flow of Cross nanofluid over a permeable stretching /contracting surface. Flow equations are modelled by means of the Buongiorno nanofluid model. The transformed non-linear fluid transport equations are solved numerically through Runge-Kutta Fehlberg (RKF) approach. The temporal stability test is executed to reveal the behaviour of dual solution that arises for various initial guesses. To validate the present model, first and second solutions are compared with earlier published works which found good agreement. The fluctuations of velocity, heat and mass transfer distributions are scrutinized through the graphs with active parameters such as Wessienburg number, Brownian motion, Eckert number, and thermophoresis. The results exposed that the Brownian motion declines the rate of heat transfer for the first solution. Cross nanofluid velocity amplifies by rising Weissenberg number. By the impact of Eckert number, the second solution has a higher magnitude than the first solution. For the first solution, the cross nanofluid velocity rises when increasing the suction/injection parameter. Journal of Thermal Engineering Journal of Thermal Engineering 2021-12-24T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5516 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5516 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5516

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5405 2021-08-01T21:00:00Z 1

Energetic and Exergetic Performance Comparison of An Experimental Automotive Air Conditioning System Using Refrigerants R1234yf And R134a Alpaslan Alkan, Ahmet Kolip, Murat Hoşöz R1234yf, R134a, Automotive, Air Conditioning, Refrigeration, Performance In this study, energetic and exergetic performance merits of an automotive air conditioning (AAC) system using R134a and R1234yf have been investigated. For this aim, a laboratory AAC system was developed and equipped with devices for mechanical and electrical measurements. The refrigeration circuit of the system mainly had an evaporator, condenser, liquid receiver, fixed capacity compressor and thermostatic expansion valve. The tests were performed by changing the compressor speed and air stream temperatures incoming the condenser and evaporator. Based on energy and exergy analyses, various performance parameters of the AAC system for both refrigerants were determined and presented in comparative graphics. It was found that R1234yf resulted in 0.4-10.9% lower refrigeration capacity, 5.5-11.6% lower COP and 4.7-16.1°C lower compressor discharge temperature, while yielding 9.3-22.3% higher refrigerant mass flow rate and 1.1-3.5 °C higher conditioned air stream temperatures in comparison to R134a. Moreover, the components of the R1234yf system usually destructed more exergy, and the total exergy destruction rate per unit refrigeration capacity of the R1234yf system was 4.1-15.3% greater than that of the R134a one. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-01T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5405 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5405 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5405

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5371 2021-04-29T21:00:00Z 1

A Numerical Study of Entropy Generation on an Oldroyd-B Nanofluid flow Past a Riga Plate Zachariah Mbugua Mburu, Sabyasachi Mondal, Precious Sibanda, Ramprakash Sharma Entropy Generation, Overlapping Grids, Relaxation and Retardation Time, Oldroyd-B Nanofluid, Hyperbolic Time-Varying Boundary Conditions, Riga Plate This study investigates entropy generation due to the unsteady boundary layer flow of an Oldroyd-B nanofluid past a Riga plate. The velocity, temperature and concentration fields are obtained and the flow equations solved numerically using the spectral collocation method with overlapping grids. The local entropy generation distribution is obtained by solving the entropy generation equation numerically. Sensitivity and convergence analysis is performed to demonstrate the accuracy and convergence of the numerical method. The effect of principal flow parameters on entropy generation is investigated and it is established that entropy generation is directly proportional to the width of the Riga plate, Brinkman number, Prantl number and the Brownian motion parameter. It is further shown that the entropy generation is inversely proportional to the Eckert number and Deborah number in relaxation time. The range of parameter values were obtained from the reported literature. The current study may have applications of physics, including in the design of both cooling and heating devices. Journal of Thermal Engineering Journal of Thermal Engineering 2021-04-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5371 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5371 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5371

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5426 2021-08-05T21:00:00Z 1

Experimental testing of Scroll Machine Driven by Compressed Air for Power Generation and Its integration in Small Scale Organic Rankine Cycle Pavan Kumar Reddy, M S Bhagyashekar Scroll compressor, Expander, Compressed air, ORC. Organic Rankine Cycle (ORC) is a proven technology in the field of waste heat recovery and present days ORC is being used in exploiting biomass, geothermal and solar energy. The overall performance of ORC depends on the expander, making it the core component of the system. Generally, these expanders are classified into velocity type and displacement type. The velocity type expanders find their applications in large scale power generation and are not preferred in small scale power application as their rotational speeds exponentially increase with a decrease in expander power output. As a result, the displacement type expanders are best suited for small scale power generation in ORC. Yet, till date expanders capable of producing power at small scale are not commercially available in the market for ORC application. Asan effect commercially available scroll compressors are modified to work as expanders in ORC systems. The present study aims to examine the feasibility of using one such scroll compressor as an expander in ORC with and without modification. A test rig was developed to test the compressor running in reverse as expander using compressed air, before and after modifications. The scroll machine was tested for operating conditions consisting of pressure varying from 0.5 bar to 4.5 bar and the load varying from 0.2kg to 2.2 kg for a constant airflow rate. The configurations tested were, scroll compressor with the suction port as inlet, modified scroll compressor with the suction port as inlet and modified scroll compressor with discharge port as an inlet. Based on the experimental test data obtained it is observed that, in all three configurations, for various loading conditions at given inlet air pressure there exists a maximum power generation point and a further increase in the load at given pressure has a negative effect on power output. Also, a significant increase in speed is observed from 300 to 4250 rpm at no load condition with increasing inlet air pressures. Maximum power of 210 W was achieved at a load of 1.1 kg with the inlet pressure of 4.5 bar for modified scroll machine when the discharge port was used as an inlet. Finally, it is recommended to use a modified scroll machine with discharge port as inlet as it gives more power when compared with other configurations for the same operating conditions. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-05T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5426 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5426 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5426

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5160 2020-09-24T21:00:00Z 1

Numerical and Experimental Investigations on Performance Evaluation of a Conical Offset Vortex Generator Inserts to Improve Convective Heat Transfer Coefficient Shivaji Mundhe, Rupa Bindu Conical offset vortex generator (COVG), Convective heat transfer coefficient, Angle of attack, Pitch to diameter ratio The passive augmentation technique is widely used by researchers from thermal engineering field and it has shown excellent results for convective heat transfer rate. This paper shows the numerical and experimental findings for convective heat transfer characteristics and friction coefficient. Tests were conducted for turbulent flow, using air as medium through a uniformly heated steel pipe containing a novel kind of insert named as Conical offset Vortex Generator (COVG). The simulation tests were performed for turbulent flow with varying Reynolds number in the range 4000 to 50000. The parameters were analyzed during tests are pitch to smooth tube diameter ratio (p/d) and angle of attack (α). Various simulation tests were carried out with the help of ANSYS Fluent software to optimize the geometry. The simulation tests were carried out for different angle of attack (α = 15°, 30°, 60°). COVG with angle of attack (α = 60°) shows more enhancement in heat transfer rate, hence it was used for the experimentation purpose. The experimentation is conducted for various pitch to diameter (p/d = 1.18, 1.97, 3.94). The numerical and experimental results show improvement in heat transfer rate as there is decrease in pitch to smooth tube diameter ratio (p/d) and it also increases the value of friction factor. The reason behind the improvement in heat transfer rate is that, the braking of thermal boundary layer near the wall surface. Experimental results show the enhancement of Nusselt number from 3.46 – 6.7. Journal of Thermal Engineering Journal of Thermal Engineering 2020-09-24T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5160 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5160 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5160

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5407 2021-08-01T21:00:00Z 1

Comparative Thermal Analysis of Applications Using Novel Solar Air Heater with U-Shaped Longitudinal Fins: Suitable for Coastal Regions Taranjeet Sachdev, Vivek Kumar Gaba, Anil Kumar Tiwari solar energy, air heater, fins, desalination, solar drying The aim of present work is to analyze a novel solar air heater configured with U- shaped longitudinal fins. The application of proposed air heater for fresh water production and agriculture drying has also been analyzed for the coastal area of India. The results are motivating for use of proposed air heater for household requirements and small scale industrial purposes to improve the earning in coastal regions. The mathematical model for time dependent behavior of proposed air heater has been prepared by considering energy balance of air heater components and solved to get outlet temperature of air from air heater. The results proved that the heater is suitable for desalination and drying of many agricultural products. The effect of operating parameters has also been analyzed to find suitable values for fresh water production. Optimum air mass flow rate of 160 kg/hr in air heater has been found whereas higher water temperature in storage tank and lower temperature of cooling water in dehumidifier found suitable for higher yield of fresh water. In drying process, significant improvement has been observed compared to direct solar drying and conventional air heater with 12 hours drying time for banana slices and 10 hours for garlic was found. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-01T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5407 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5407 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5407

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5427 2021-08-07T21:00:00Z 1

Effect of Orientation of Elliptic Tube on the Total Melting Time of Latent Thermal Energy Storage Systems Mebrouk Benbrika, Mohamed Teggar, Mohamed Benbelhout, Kamal Abdel Radi Ismail, Said Bouabdallah Elliptic Enclosure, Melting, n-Eicosane, PCM, Thermal Storage Encapsulation of Phase Change Materials (PCM) for energy storage, thermal comfort and many other energy applications is receiving much attention due to the fact that material, physical characteristics and geometry of the container can affect drastically the thermal performance of the PCM. Phase change materials have usually low thermal conductivity which impairs their thermal charging and discharging characteristics. Different geometries were investigated including rectangular, cylindrical and spherical with and without extended surfaces to investigate the heat charge processes. Cylindrical geometries of circular sections were intensively investigated while cylinders and tubes with elliptic and elongated cross section received less attention, although they may have better thermal performance for thermal storage. The present numerical investigation is aimed at contributing to better understand the effects of the elliptic geometry and how the different geometrical and operational parameters can affect the thermal performance of the enclosed PCM. The present investigation reports the results of a numerical study on elliptic cylinders containing PCM under melting conditions. The 2D inward melting problem is modeled by using a CFD code. The numerical model is based upon the enthalpy-porosity method along with the finite control volume techniques. The numerical predictions are validated against available experimental results. The inward melting process is analyzed for two orientations of the elliptic enclosures. Due to the flow field effect namely the Rayleigh-Bénard convection, the numerical results showed that the horizontal elliptic enclosure have higher melting rate and hence lower total melting time compared to those of the vertical elliptic enclosure. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-07T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5427 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5427 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5427

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5430 2021-08-08T21:00:00Z 3

Factors Influencing The Performance of Solar Air Heater (SAH) Having Artificial Coarseness: A Review Gaurav Bharadwaj, Kamal Sharma, Kuwar Mausam Solar Air Heater, Nusselt Number, Friction Factor, Thermohydraulic Performance Variable A review of studies focused on promoting the rate of heat transfer with the help of an optimum rise in friction factor, by offering a simulated irregularity to the interior surface of the absorber plate of SAH, is expressed. In this article an effort has been made to explore different coarseness configurations as used by number of researchers to boost the SAH heat transfer rate. Furthermore, different correlations developed by researchers for Nusselt number and friction factor are also presented. On the basis of these correlations, thermohydraulic performance variable was calculated and attributed for various coarseness configurations. Friction factor and Colburn factor of various coarseness configurations have also been compared and presented. This review focused on use of different coarseness configurations with different coarseness parameter and flow parameter is deeply discussed from which future researchers can easily identify that which coarseness is to be used for designing SAH duct for the better augmentation of heat transfer and friction factor. It also helps the researchers to determine the optimum value of coarseness parameter so that the SAH works efficiently and effectively. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-08T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5430 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5430 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5430

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5437 2021-08-13T21:00:00Z 1

Simulation Modeling and Experimental Validation of Solar Photovoltaic PMBLDC Motor Water Pumping System Vinayak Deokar, Rupa S. Bindu, Tejashri Deokar Renewable Energy, Photovoltaic Panel, Simulation, Solar PMBLDC Motor Water Pumping System, Error Analysis Solar energy is abundantly available on the earth and can be utilized in various applications by converting it in a suitable form. Water supply in remote places and rural areas is still critical due to the unavailability of the grid power. In a developing country like India, the grid construction cost is 6670 $/km because of which some remote areas are still waiting for electricity. There is a large scope to meet this need with the help of a standalone solar water pumping system. In this context, this work presents detailed simulation in MATLAB/Simulink and experimental validation of photovoltaic (PV) permanent magnet brushless DC (PMBLDC) motor water pumping system without energy storing. Simulation is a tool to get system behavior at the various input parameters immediately reflects a change in the output parameter. The simulation results are validated with the help of field trials on the experimental setup. A 0.5 hp photovoltaic permanent magnet brushless DC (PMBLDC) motor water pumping system was used for extensive field trials experimentation. After extensive field trials, the optimum irradiation observed for full water discharge 19.9 L/min was 330 W/m2 where voltage and current were 35.1 V and 3.1 A respectively. The Water flow - Irradiation characteristic curve and percentage variation in simulation and experimental results showed a good agreement with each other. The efficiency of the photovoltaic panel and the entire solar water pumping system observed was 12.76 ± 0.64 % and 9.07± 0.45 % respectively. The 0.5 hp PMBLDC motor water pumping system is sufficient to lift 10000 L water every day. PMBLDC motor, shown added advantage of lesser running maintenance due to the absence of carbon brushes which need frequent replacement in case of brushed DC motor. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-13T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5437 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5437 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5437

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5431 2021-08-08T21:00:00Z 1

Numerical Investigation of Heat Transfer and Pressure Drop Characteristics in an Offset Strip Fin Heat Exchanger Bahadır Doğan, M. Mete Ozturk, L. Berrin Erbay Strip fin, Fin spacing, Fin bending ratio, Heat exchanger This paper presents a numerical simulation to determine the air-side heat transfer and the pressure drop characteristics of a flat tube heat exchanger with offset strip fin. The effects of the fin bending ratio such as 29%, 36%, 44%, 50% and the fin spacing such as 2.10 mm, 2.35 mm, 2.60 mm on the performance of the heat exchanger are studied by using a commercial CFD software. The air having constant viscosity, thermal conductivity and density enters the heat exchanger at 298 K and the wall temperature of the strip fins is considered as constant at 314 K. Variations of the heat transfer coefficient and the pressure drop in the airside are presented with respect to the frontal air velocity while Colburn j-factor and the friction factor f are presented with respect to the airside Reynolds number ranging from 200 to 1200. Finally, the thermal-hydraulic performance of all investigated cases is compared by using volume goodness factor, j/f 1/3. The results show that the air-side heat transfer coefficient and the pressure drop increase when the frontal air velocity ascends. The air-side heat transfer coefficient decreases with the increase of fin spacing. The fin bending ratio does not have a significant effect on the pressure drop in the considered fin spacing. Both the Colburn j-factor and friction factor reduce with the increment of Reynolds number and fin spacing. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-08T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5431 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5431 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5431

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/4056 2020-04-01T21:00:00Z 1

Shipping Emission Dispersions on the Port of Ambarli via CFD Modelling Kaan Ünlügençoğlu, Ahmet Yurtseven, Fuat Alarçin Shipping Emissions, Ports, CFD, Green Shipping Maritime transportation is taken into account as an environmentally friendly transportation option. Approximately 90% of the world trade is done by sea transportation and growing of globalized world conditions increase shipping and port emissions. The use of heavy fuels on ships and the positioning of port areas close to the habitats affect the health of people living in coastal cities. Accordingly; NOx, SOx, PM and CO2 emissions are especially limited for international regulations by International Maritime Organization (IMO) and the European Union (EU). In this study, real-time air quality measurements of PM2.5, PM10, SO2, CO, NO and NO2 emissions are performed for three months where the measurement tool is located in the Port of Ambarli, Marport Terminal. The ships are monitoring during berth and manoeuvring around the critical dates and times at the terminal. The hourly values of real-time emission data measurements are shown for 25 May to 15 August 2017. Critical dates and times which are the highest value of the all emissions are determined between measured dates. SO2, NO, CO and CO2 emissions are investigated for different wind speeds using a single ship positioned at different angles and two ship models in different operating modes via Computational Fluid Dynamics (CFD) modelling. Journal of Thermal Engineering Journal of Thermal Engineering 2020-04-01T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4056 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4056 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=4056

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5441 2021-08-22T21:00:00Z 1

Analysis and Simulation of Thermal Performance of a PTC with Secondary Reflector Hanane Maria Regue, Belkacem Bouali , Toufik Benchatti , Ahmed Benchatti Conjugate Heat Transfer ,Receiver Tube ,Solar Thermal Energy ,Solar Parabolic Trough Collector ,Secondary Reflector, Ray Tracing ,Optical Modeling. In this paper, a numerical simulation of fluid flow and conjugate heat transfer in a solar thermal parabolic trough collector (PTC) system is presented. The simulation is being carried out on a prototype designed in the Mechanical Laboratory in order to analyze the performance of this system. The main objective is to compare the system performance with and without a secondary reflector (SR). PVSYST software is used to provide numerical temporal values of the solar heat flux in Laghouat city (ALGERIA). Solar flux density values for four days in different seasons have been taken. SolTrace code is used to determine the heat flux distribution on the absorber tube. The conjugate heat transfer and fluid flow equations in the tube absorber are solved by using ANSYS-CFX CFD software. A comparison between two cases (traditional PTC and PTC with parabolic secondary reflector) with the same working fluid (Therminol VP-1) is carried out. The obtained results show that the system performance are practically the same for the four seasons. Moreover, the performance of the system with a second collector is better than that without a second reflector with a ratio of about 1.65. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-22T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5441 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5441 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5441

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5428 2021-08-07T21:00:00Z 1

Mixed Convection Heat Transfer from a Vertical Flat Plate Subjected to Periodic Oscillations Selma Akcay, Unal Akdag Heat Transfer Enhancement, Mixed Convection, Oscillating Vertical Plate In this study, effects on mixed convection heat transfer of oscillation parameters on a vertical flat plate surface subjected to constant heat flux are experimentally and numerically investigated. The experimental setup includes a hanger–pulley system installed above a transparent enclosure contain a moving experimental model, flywheel-motor assembly generating the oscillating movement of the experimental model, power supply, and datalogger. The experimental model comprises two copper plates with attached thermocouples and Kapton heaters placed between the plates. In the study, heat flux applied to surface of the plates (q¨), the Womersley number (Wo) and dimensionless oscillation amplitude (Ao) are varied. The effects of these parameters on the heat transfer performance are analyzed. This study is numerically solved using a control-volume based Computational Fluid Dynamics solver based on experimental data. The numerical results are compared with the experimental results and open literature. Instantaneous velocity and temperature profiles on the plate are obtained to explain the heat transfer mechanism. According to the numerical and experimental results, heat transfer performance is significantly affected by oscillation parameters and heat flux applied to the plate surface. The mixed convection heat transfer increases with the increase in oscillation parameters for all tested heat fluxes. The obtained results are presented as a function of dimensionless numbers. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-07T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5428 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5428 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5428

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5442 2021-08-22T21:00:00Z 1

Influences of the Dead End on the Flow Characteristics at the Exhaust Manifold of a Marine Diesel Engine Görkem Benek, Osman Azmi Ozsoysal Exhaust Manifold, Dead End, Computational Fluid Dynamics, Pressure Distribution A 3D Computational Fluid Dynamics (CFD) model of an exhaust manifold with and without a dead end has been developed to investigate the impacts of its geometry on the flow structure and the pressure distribution within the manifold. The model differs from previously studied models principally for its ability to approach the realistic operating principle of an engine as the modelled exhaust valves of the investigated engine open and close according to the firing order. The experimental results of an exhaust manifold without a dead end has been used to validate the CFD model through the pressure distribution and the flow structure. The outcomes demonstrated that the developed CFD model concurred well with the experimental data. The effects of the dead end on the exhaust manifold were then investigated using the validated CFD model. The study has revealed that the addition of a dead end (i) provides a smoother pressure distribution inside the manifold and increase in the efficiency of the turbocharger and (ii) decreases the pressure inside of the interconnection pipes of cylinders while the exhaust gas discharges. Moreover, the results disclose a smoother discharge of exhaust gases leading to a more effective sweeping of the exhaust gas thorough the cylinder without causing any exhaust backpressure. Furthermore, the dead end reduces the turbulence kinetic energy at the blind end of the exhaust manifold resulting in a decrease of pressure loss within. The abovementioned findings regarding to the flow structure and the pressure distribution within the exhaust manifold improve the efficiency of the engine. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-22T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5442 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5442 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5442

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5425 2021-08-05T21:00:00Z 1

Impact of Outer Velocity on Flow, Heat and Mass Transfer of Casson Nanofluid over a Non-Linear Stretching Sheet Vinita Makkar, Vikas Poply Non-linear Stretching Sheet, Brownian Motion, Thermophoresis, Casson Fluid, MHD Steady boundary layer flow with Casson nanofluid in the presence of outer velocity towards a non-linear stretching sheet has been studied numerically. The main purpose of present study is to investigate the significance of various fluid parameters namely Casson fluid (non-Newtonian fluid) parameter, thermophoresis parameter, magnetic parameter, Brownian motion parameter and non-linear stretching parameter on profiles of velocity, temperature and nanoparticle concentration. Non-linear governing equations and the linked boundary conditions are computed by shooting technique with the help of Runge Kutta Fehlberg (RKF) method by applying similarity conversions on it. The influence of various fluid parameters for different values of outer velocity on the rate of mass, heat and flow transportation are determined and represented through graphs and tables. The outcomes reveals that with an increase in outer velocity, the velocity increases while temperature and concentration decreases. Present results of the study are correlated for ${-\theta_{0}}^{'}(0)$ with the extant outcomes in literature as a limiting case in absence of thermophoresis parameter and Brownian motion. The present study finds utilization in industrial, biological, manufacturing as well as technological fields as these results are helpful for better controlling of heat transportation due to the presence of magnetic flow and outer velocity flow. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-05T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5425 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5425 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5425

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5319 2021-01-30T21:00:00Z 4

A Bayesian Network-Based Approach For Failure Analysis In Weapon Industry Melih Yucesan, Muhammet Gul, Ali Fuat Guneri Bayesian Network, Fault Tree Analysis, Weapon Industry Gun and rifle manufacturing contain various failures in the process of CNC machining, material supply, research & development, infrastructure and, operator. Due to these failures, the enterprise is exposed to great economic losses and a decrease in competition in the global market. In addition, failures in production cause events that seriously threaten human health. Failure analysis can increase safety by determining the cause of potential errors and taking measures for identified errors in the life cycle of the products. Therefore, this study employs a Bayesian Network (BN)-based modeling approach for capturing dependency among the basic events and obtaining top event probability. Firstly, a fault tree analysis (FTA) diagram is constructed, since its target is to pinpoint how basic event failures result in a top event (system) failure by an AND/OR logical gate. While, AND logical gate should take place in both cases, it is sufficient to realize one of the states in the OR logical gate. Then, a BN-based on fault tree transformation is applied. A case study in a leading weapon factory that produces various types of guns and rifles in the Black Sea region of Turkey is performed. For the application viewpoint, appropriate control measures can be taken into account to decrease the number of failed products based on the performed failure analysis. Journal of Thermal Engineering Journal of Thermal Engineering 2021-01-30T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5319 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5319 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5319

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5132 2020-07-03T21:00:00Z 1

A Simulated Study on The Effect of Water Temperature on Cooling Efficiency of Water Mist Fire Extinguishers Amir Omidvar, Amirhossein Mahdavi, Reza Mehryar Cooling efficiency, Droplet Evaporation, Spray Formation, Water Mist System In this paper, the effect of initial water temperature on the cooling performance of a water mist fire suppression system has been investigated. A zero-dimensional analytical model was first developed to study the thermal and dynamic behavior of a single water droplet. The developed model was validated against available experimental data in the literature. The developed model was further extended to simulate the transient heating, evaporation, break-up and liquid penetration length of a hollow-cone water spray. Results indicated that increasing the initial temperature of the water spray before injection resulted in a decrease in the initial size distribution of the spray droplets. It was further found that the evaporation time of the injected droplets decreased by about 11% and the cooling power of the pre-heated water mist system enhanced by 12% in exchange for increasing the initial temperature of the water spray by 10°C. It was concluded that pre-heating the sprayed water droplets would likely improve the cooling efficiency of the water mist system. It could be also inferred that at equal cooling power, less water was consumed by the pre-heated spray compared to conventional water mist systems. Journal of Thermal Engineering Journal of Thermal Engineering 2020-07-03T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5132 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5132 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5132

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5443 2021-08-22T21:00:00Z 1

Numerical Investigation of Supercritical Heat Transfer of Water Flowing In Vertical and Horizontal Tube with Emphasis of Gravity Effect Anand Sundaravel, Suresh Sivan, Deenadaylan Santhosh Kumar Supercritical Heat Transfer, Horizontal Tube, Buoyancy, Heat Transfer Deterioration, Turbulence Model Over a decade, coal-based thermal power plants are upgraded to operate at supercritical pressure conditions due to its high efficiency and low emissions. Water wall panels of a typical supercritical boiler are structured spirally in the lower furnace and vertically placed in the upper furnace. The spiral tubes are inclined at 19 to 22 degrees in which fluid behaves as in horizontal tubes. The design of water wall panels plays the key role in designing a supercritical boiler. The present work aims to numerically investigate the heat transfer behavior of both vertical and horizontal tubes at the supercritical conditions. Since the temperature distribution across the cross-section of vertical tube is uniform, a 2D axis symmetry tube has been considered for analyzing the vertical tube. Unlike vertical tube, the heat transfer characteristics is different for horizontal tubes. Therefore, a 3D tube has been modelled for the computation of horizontal tubes. In order to gain confidence, the present simulations are validated with experiments results available in the literature. Ansys-Fluent has been used in the present simulation. SST k-ω turbulence model is used in this analysis. In the present work, 10 mm diameter of 4m length of vertical tube has been chosen and simulated at low heat flux to mass flux ratio 0.27 and high heat flux to mass flux ratio 0.67 with pressure 241 bar. The effect of heat flux (q) to mass flux (G) ratio which is responsible for heat transfer enhancement and heat transfer deterioration has been studied for both vertical and horizontal tubes. The wall temperature has been plotted along the length of the tube for both top and bottom portion of horizontal tube and compared with wall temperature of vertical tube. The effect of buoyancy plays a vital role in the heat transfer behavior of horizontal tube compared to vertical tube. Heat transfer deterioration occurs due to buoyancy which has a direct linkage with gravity. Three cases were studied, one with full gravity (factor 1), half gravity (factor 0.5) and zero gravity (factor 0). It has been observed that, sudden rise in wall temperature occurs for the case gravity factor 1.0, i.e, considering the gravity effect. For the case of zero gravity, no sudden peak of local wall temperature is observed due to the absence of buoyancy term in the Navier-Stokes equations. Some of the thermo-physical properties like velocity, turbulent kinetic energy, density, wall temperature and turbulent viscosity are analyzed for three cases. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-22T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5443 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5443 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5443

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5419 2021-08-02T21:00:00Z 1

A Study on Heat and Mass Transfer Analysis of Solar Distillation System Vikias Thakur, Manoj Kumar Gaur, Manish Kumar Sagar, G.N. Tiwari Heat and Mass Transfer, Solar Still, Energy balance, Single slope, Double slope The solar stills were developed to fulfill the freshwater need of the growing population. The paper presents the recent modifications made in stills to improve their productivity like the application of phase change materials (PCM), connecting flat plate collector (FPC), use of nanoparticles, stepped solar still, and attaching separate condenser in the still. Active solar stills are found more productive than passive ones and the thermal efficiency of active solar stills lie in the range of 50-70%, which is far better than passive still having 20-55% thermal efficiency. According to the literature studied in the paper, the maximum productivity of active solar still is 10 liters per day and in passive solar stills, it is 6 liters per day. The different approaches used to carry out the heat and mass transfer analysis of single and double slope active and passive solar stills are also discussed in the paper. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-02T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5419 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5419 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5419

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5308 2021-01-24T21:00:00Z 1

Numerical Investigation of Rod-Airfoil Configuration Aeroacoustic Characteristics Using Ffowcs-Williams-Hawkings Equations Ece Aylı, Hasmet Turkoglu, Eyup Kocak LES, FW-H technique, Computational Fluid Dynamics, Multi-zone mesh The rod-airfoil configuration is a fundamental study to understand sound generation processes and the acoustic phenomena in the application of turbines, fans, and airfoils. In the present research, the noise that is originated by the rod-airfoil configuration is examined using numerical methods which are Large Eddy Simulation (LES), and Reynolds Averaged Navier Stokes (RANS) models, coupled with an FFOWCS-WILLIAMS-HAWKINGS (FW-H) technique. For the RANS method, k-? SST and Spalart Allmaras (S-A) turbulence models are utilized in order to investigate the capability of different models for the analysis of the aeroacoustic flow field. Results are obtained for both in the near field and acoustic far-field. The obtained numerical results are verified with an experimental study from the literature, and the results of both approaches are compared with each other and the experiment. The results obtained show that LES is preferable for this problem as it is capable of capturing the flow separation, reattachments, vortex street, and various length scale of turbulence. Although both RANS and LES methods provide a consistent flow field with experimental methods, the RANS approach overestimates the vortex shedding frequency and Strouhal number. The RANS model predicts the flow field well; however, it overestimates the noise spectra. The LES model predicts satisfactory acoustic spectra. Journal of Thermal Engineering Journal of Thermal Engineering 2021-01-24T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5308 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5308 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5308

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5323 2021-01-31T21:00:00Z 1

Experimental Research and CFD Simulation of Cross Flow Microchannel Heat Exchanger Zeynep Küçükakça Meral, Nezaket Parlak Microchannel, Cross Flow Microchannel Heat Exchanger, CFD In this study, a cross flow microchannel heat exchanger has been manufactured out of standard sizes using aluminum material. The plate dimensions of heat exchangers have been 50x50x3 (mm3) that composed of two plates in cross flow arrangement. All evaluated geometries have been consisted of square microchannels with 490 μm width and 490 μm depth. An appropriate experimental facility has been established to perform the fluid flow and heat experiments. Moreover, heat transfer and fluid flow characteristics in microchannels have been simulated by ANSYS Fluent V15 Computer Program and experimental results have been compared with Computational Fluid Dynamics (CFD) results. Results showed that experimental heat transfer data was a very good agreement between data obtained by CFD simulation. However, the numeric pressure drop values have not been compatible with experimental ones. Journal of Thermal Engineering Journal of Thermal Engineering 2021-01-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5323 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5323 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5323

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5429 2021-08-07T21:00:00Z 1

Boiling Heat Transfer Simulation in Rectangular Mili-Channels Aliihsan Koca, Mansour Nasiri Khalaji, Soroush Sepahyar Mili-Channel, Two-Phase Flow, Heat Transfer Due to the high heat transfer coefficient and compactness of a system, mili-channel -based cooling and heating techniques are greatly expected to be distributing high heat flux from the electronic devices. In terms of cooling performance, the two-phase evaporating flow of boiling flow in mini and mili-channels is more effective than the single-phase flow due to the inclusion of latent energy in the process. In this study, a numerical model was proposed to simulate the boiling heat transfer of multiphase flow in a channel using different boundary conditions in the channel surfaces. The fluid volume approach regulating the hydrodynamics of the two-phase flow was used. Source terms of the energy and mass transfer that were taken into account at the interface of liquid and vapor were included in the management equations for the conservation of energy and vapor quality. A 3D Ansys-Fluent© simulation model was developed and numerical simulations were conducted for four different boundary conditions. A mili-channel with a length of 140 mm was used. The liquid and gas phases that were used in the model were liquid water and vapor; the total mass flux at the inlet was varied at 118-126 kg/m2s. In order to realize thin film annular flow over the boiler surface, employed specific boundary conditions in the 3D simulation model were obtained by means of one dimensional Matlab© simulation code. By means of utilizing the evaluated numerical results, distribution of heat transfer coefficient, vapor quality and dimensionless temperature over the heat transfer surfaces were reported and compared to experimental results. Numerically evaluated results are in agreement with experimentally measured results. For the studies cases an average value of 23600 W/m2.K was obtained for the heat transfer coefficient. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-07T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5429 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5429 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5429

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5439 2021-08-14T21:00:00Z 1

Thermodynamıc Analysıs of The Allam Cycle and Its Pressure Sensıtıvıty Duygu Uysal Zıraman, Bekir Zühtü Uysal Allam Cycle, Efficiency, Entropy, Pressure Sensitivity The Allam cycle is a novel system which operates the oxy-combustor at a high pressure under supercritical conditions, uses a single gas turbine, circulates carbon dioxide as the working fluid in a semiclosed-loop and utilizes low-pressure-ratio recuperated Brayton cycle. These properties of the Allam Cycle enable to reach high efficiencies. This system was simulated using Chemcad software for a methane feed flow rate of 1 kmol/s. The pressure at the inlet of turbine was taken as 285 bar. The net power generation rate was estimated considering the generation in the turbine and the usage in the compressors for circulating carbon dioxide and for oxygen and natural gas feeds. The calculations using energy balance for the process gave 388 MW net power output, whilst Chemcad software gave 392 MW. The thermal energy recovered by lowering the temperature of the flue gas before condensing its water content was also considered in the overall efficiency of the system. The net power cycle efficiency was determined as 48.89%. The second law analysis of the cycle was also made. Entropy generation rate, Sgen, was determined as 965.79 kW/K and exergy destroyed, \psi_{destroyed}, was found as 287.81 MW from entropy balance for the process. The exergy balance for the process was also made and the results were compared with the findings from the entropy balance. The second law efficiency of the process was found as 62.54%. Working at high pressure, naturally, affects the material of construction and consequently the fixed capital investment as well as operating and maintenance costs. Therefore, in this work, a sensitivity analysis is also made to see the effect of pressure on power generation and efficiency. The sensitivity analysis was made using Chemcad software simulation. It was found that the optimum pressure range for operation of the system was between 250 and 350 bar. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-14T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5439 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5439 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5439

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5444 2021-08-28T21:00:00Z 1

Energy and Exergy Analysis of an Enhanced Solar CCHP System with a Collector Embedded by Porous Media and Nano Fluid Navid Tonekaboni, Hesamoddin Salarian , Majid Eshagh Nimvari , Jahanfar Khaleghinia Exergy Analysis, Solar Cogeneration system, Porous Media, Nano Fluid Low efficiency of Collectors that absorb energy can be mentioned as one of the drawbacks in solar cogeneration cycles. In the present study, solar systems have been improved by adding porous media and Nano fluid to collectors. One advantage of using porous media and nano materials is to absorb more energy while surface area is reduced. In this study, first, solar collectors are enhanced using 90% porosity copper in solar combined cooling, heating and power systems (SCCHP). Second, different percentages of CuO and Al2O3 nano-fluids are added to flat plate and parabolic collectors to enhance thermal properties. Simulations are performed in different modes (simple parabolic collectors, simple flat plate collectors, improved flat plate collectors, parabolic collectors with porous media, and flat plate and parabolic collectors with different density of CuO and AL2O3 nano fluids). A case study is investigated for warm and dry regions with mean solar radiation Ib = 820 w / m2 in Iran. The maximum energy and exergy efficiencies are 60.12% and 18.84%, respectively, that is related to enhanced parabolic solar collector with porous media and nano-fludis. Adding porous media and nano-fluids increases an average 14.4% collector energy efficiency and 8.08% collector exergy efficiency. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5444 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5444 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5444

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5153 2020-09-23T21:00:00Z 1

An Experimental Investigation on Radiant Floor Heating Systems at Various Operating Conditions Yakup Karakoyun, Özgen Açıkgöz, Ahmet Selim Dalkılıç, Zehra Yumurtacı Natural Convection, Enclosure, Radiant Heating, Floor Heating, Energy Saving In this study, heat transfer characteristics pertaining to a heated radiant floor are investigated experimentally. In order to achieve this aim, experiments have been conducted within extended supply water temperature ranging from 30 oC to 55 oC, and mass flow rate ranging from 0.056 kg/s to 0.125 kg/s according to experimental condition ranges in the relevant literature. Correlation comparison has been accomplished using a large number of experimental data including pioneer studies and international standards regarding with the determination of heat flux and heat transfer coefficients. Moreover, novel correlations providing convective, radiative and total heat fluxes have been derived, and it has been observed that most of the outcomes of correlations remain within deviation bands of ±15%, ±5% and ±20%, respectively. Apart from the literature, heat flux correlations corresponding to each heat transfer mechanisms are given and evaluated separately. Throughout experimental studies, the proportion of the radiative heat transfer to total one is found 60% approximately. Measured experimental data are given in the paper for other researchers validation problems on their theoretical and numerical works. Journal of Thermal Engineering Journal of Thermal Engineering 2020-09-23T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5153 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5153 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5153

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6611 2022-08-16T21:00:00Z 1

Energy and Exergy Analyses of a Two Stage Organic Rankine Cycle with Low Pressure Stage Regeneration for IC Engine Waste Heat Recovery Pereddy Nageswara Reddy IC engine, two stage organic Rankine cycle, regeneration, waste heat recovery A two-stage Organic Rankine Cycle (ORC) with Low Pressure Stage Regeneration (LPSR) proposed in this article is intended to utilize the engine coolant energy completely for vaporization of organic fluid in a Low Pressure stage Heat Exchanger (LPHE) and the engine exhaust energy for sensible heating, vaporization and super heating of organic fluid in a High Pressure stage Heat Exchanger (HPHE) besides utilizing the superheated vapor energy of exhaust from Low Pressure stage Turbine (LPT) in a regenerator. Since regeneration is used only at low pressure stage, the energy associated with the engine exhaust gases can be utilized to the maximum extent by lowering its temperature nearer to the temperature of liquid phase working fluid after High Pressure stage Pump (HPP), thereby maximizing the Waste Heat Recovery (WHR) potential of the bottoming two stage ORC. The WHR efficiency of two-stage ORC with and without LPSR is analyzed at a typical operating condition of the engine using a nearly dry fluid R123 and a nearly isentropic fluid R134a as the working substances. It is observed that the thermal efficiency of the two-stage ORC with R123 is higher than that with R134a. The LP stage regeneration has been found to be effective in increasing the thermal efficiency and, in turn, the WHR efficiency of the two-stage ORC with both R123 and R134a. The increase in the fuel efficiency of the IC engine due to the bottoming two-stage ORC is found to be 7.22% with R123 and 6.21% with R134a with LPSR and 6.58% with R123 and 5.51% with R134a without LPSR. The optimum pressure in HPHE is found to be about 2.5 MPa and 3.5 MPa with R123 and R134a respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2022-08-16T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6611 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6611 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6611

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5420 2021-08-02T21:00:00Z 1

Experimental Study of a Stand-alone Earth to Air Heat Exchanger for Heating and Cooling in Arid Regions Nasreddine Sakhri, Younes Menni, Houari Ameur, Ali J. Chamkha Earth to Air Heat Exchanger, Sub-Soil Temperature, Arid Region, Heating, Cooling Earth to air heat exchanger EAHE is a renewable technique based on a geothermal source. Arid regions are characterized by hard winter and summer weather conditions, which lead to a large thermal discomfort for the big part of the year. In this paper, we study by experiments the performance of a stand-alone earth to air heat exchanger without external devices (fans, etc.), but only with the local climatic conditions of the region of Bechar (located in the Southwest of Algeria). The EAHE contains a PVC pipe with 66 meters of length and 110 mm of diameter, and it is buried at a depth of 1.5 m in an agriculture zone, where the annual undisturbed sub soil at 1.5 m is 28 °C. The stand-alone EAHE has the capacity to rise the air temperature by 10 °C in the heating regime, and reduce it by 11.9 °C in the cooling regime. Furthermore, the relative humidity is raised by 19% in the humidification regime and reduced by 27% in the dehumidification regime. The daily working regime was: 62.5% of heating (from 00h to 08h and from 18h to 23h) and 37.5% of cooling (from 09h to 17h) for the thermal regime, 62.5% of dehumidification (from 00h to 09h and from 18h to 23h) and 37.5% of humidification (from 10h to 17h) for the hygrometric regime. The stand-alone EAHE technique presents a great potential for the pre-heating, pre-cooling, and natural ventilation of dwelling and buildings in arid regions. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-02T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5420 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5420 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5420

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5509 2021-12-06T21:00:00Z 1

Mixed Convective Flow of Heat and Mass Transfer of Nanofluids Over a Static Wedge with Convective Boundary Conditions M. Sreedhar Babu, V. Venkata Ramana , G. Ravi Shankar , C.S.K. Raju Nanofluid; Wedge Surface; Mixed Convection; Convective Heat and Mass Conditions With the fast improvement of the industry and the utilization of inventive strategies, scientists want to think over the steady blending convection of water-based nanofluids past static wedges. The Buongiorno model with convection is applied. Also, incorporated the Brownian motion and thermophoresis. The attention is on the nature of mixed wedge-formed convective heat and mass transfer of the nanofluid flow. Utilizing comparable change, the governing partial differential equations (PDEs) are reduced to ordinary differential equations (ODEs) solved by the R-K Gill method. The physical quantities of velocity, temperature and concentration fields, as well as diffusion and thermal transfer rates with friction factor coefficients, is discussed. The investigation demonstrated that the temperature convergence of the liquid was higher within the sight of the thermophoresis parameter and Biot numbers. It has been seen that divider pressure increments with expanding wedge and mixed convection parameters. Journal of Thermal Engineering Journal of Thermal Engineering 2021-12-06T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5509 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5509 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:8 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5509

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5150 2020-09-17T21:00:00Z 4

Optimization of Biodiesel Production from Waste Cooking Sunflower Oil by Taguchi and ANN Techniques Aditya Kolakoti, Prakasa Rao Mosa, Tulasi Ganesh Kotaru, Manohar Mahapatro Waste cooking sunflower oil; Taguchi, ANN and Properties Sunflower oil is commonly used for cooking purposes. After their repetitive usage, these oils are treated as waste and being dumped. Due to the huge population, the utilization of oil for daily requirements is also high. Every day tonnes of waste cooking oil (WCO) are being discarded which eventually increases environmental pollution. Therefore, WCO is proposed to use for biodiesel production. To achieve maximum biodiesel yield with limited experiments, optimization techniques are popular. In this endeavor, nine experiments were conducted based on Taguchi orthogonal array and Artificial Neural Network (ANN) based feedforward backpropagation is used for validation of the transesterification process. A maximum yield of 92.17% is achieved at a molar ratio (MR) of 12:1, catalyst concentration (CC) of 15, reaction temperature at 550C and reaction time for one hour. CC is observed as the highest influence factor on biodiesel yield. The accuracy of the chosen optimization models is determined by the coefficient of determination which is almost the same for Taguchi (0.9959) and ANN (0.9955). This shows that these models are highly accurate in prediction. As a conclusion, by utilizing WCO for biodiesel production can decrease the overall production cost and the obtained biodiesel properties meet the international standards. Journal of Thermal Engineering Journal of Thermal Engineering 2020-09-17T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5150 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5150 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5150

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5313 2021-01-29T21:00:00Z 1

Mixed Convection Heat Transfer of SiO2-water and Alumina-PAO Nano-lubricants Used in a Mechanical Ball Bearing Mohammad Hatami, Farooq Hassan Ali, Ammar I. Alsabery, Songwei Hu, Dengwei Jing, Hameed K. Hamzah Nanofluids, Nano-lubricant, Alumina-PAO, SiO2-water, Ball bearing, Mixed-convection In this study, the mixed convection heat transfer in a mechanical ball bearing filled with nano-lubricants were investigated theoretically. In our case, the bearing including eight balls revolving in counter clockwise while the inner shaft rotates in clockwise direction and the inner and outer walls of bearing were kept at constant hot and cold temperatures, respectively. Two kinds of nano-lubricants SiO2-water and Alumina- Polyalphaolefin (PAO) with different shapes of nanoparticles were considered. The governing equations including velocity, pressure, and temperature formulation were solved based on the Galerkin finite element method. The governing parameters such as nanoparticle volume fraction, Reynolds and Rayleigh numbers, etc., were discussed. It turns out that the average Nusselt number increases by increasing the nanoparticle volume fraction (averagely 15% for each 0.02 increase) and the oil-based nano-lubricant has greater Nusselt number than the water based one. More importantly, the Nono-rod Alumina was found to show much greater heat transfer performance (averagely 5%) than the spherical alumina nanoparticles and nano-rod Alumina-PAO has the best performance and maximum Nusselt numbers for the heat transfer. Journal of Thermal Engineering Journal of Thermal Engineering 2021-01-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5313 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5313 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5313

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5445 2021-08-28T21:00:00Z 1

Comparison of Thermal Response Times of Historical and Modern Building Wall Materials Ahmet Yüksel, Müslüm Arıcı, Hasan Karabay Historical Buildings; Thermal Mass; U-Value; Indoor Air Temperature; Insulation; Lumped Capacitance Method The study aims to identify the main reason of the thermal response time difference between historical and modern buildings. Therefore, in this study, the thermal response time of historical and modern wall structures and its effect on the interior air temperature change was investigated parametrically. Considering the environmental conditions of Kocaeli province, Turkey, the thermal response time of a historical building wall made of a cut stone was compared with those of brick and gas concrete wall structures having the same overall heat transfer coefficient using the second-order lumped capacitance approach. The insulation thicknesses of the three different construction materials for U-values of 0.6, 0.4 and 0.2 W/m2K were calculated and temperature variations of indoor environment, wall and insulation material were analyzed. In addition, the required thicknesses of insulation material to obtain the same heat transfer coefficients were determined in case of using the 0.1 m thickness of cut stone, brick and gas concrete structure materials. The maximum and minimum amplitudes of the inside air temperature were recorded as 0.59 and 0.18oC for the aerated concrete in Case 3 and for the cut stone in Case 2, respectively. As a result, the walls with high thermal inertia are less affected by the changes in the environmental temperature although their U-value is relatively high. For this reason, it can be stated that one of the reasons why historical buildings have thick walls is to increase thermal inertia and thereby improve thermal comfort by reducing energy loss. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5445 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5445 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5445

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5131 2020-07-03T21:00:00Z 1

Analysis and Optimization of Vapor Absorption Generator-Heat Exchanger using Kern Method and CFD Salem Alabd Mohamed, Munawar Nawab Karimi Vapor absorption system (VAS), Generator, Lithium bromide- water solution, kern method, Computational fluid dynamics (CFD) The growing demand for new and eco-friendly energy resources has raised the need of sustainable sources or renewable energy for use in present era. A vapor absorption refrigeration system (VARS or VAS) is a closed loop refrigeration system which requires low heat for its functioning and, it is therefore, considered an eco-friendly solution. Since, generator is the main component of VAS which can significantly influence the efficacy of overall system, the current paper involves modeling and thermal analysis of generator using Computational Fluid Dynamics (CFD). The objective of this study is to optimize the heat transfer by changing baffle spacing of generator heat exchanger, running on a single effect LiBr/water absorption cycle. For this purpose, hot water driven generator of 1ton capacity is taken. The simulation results of CFD were validated by comparing them with theoretical results. The overall design estimation and design technique that follows Birmingham Wire Gauge (BWG) and Tubular Exchangers Manufacturers Association (TEMA) standard are considered in this study. It was found from the analysis that the design model with smallest baffle spacing has the highest heat transfer coefficient. On reducing the baffle spacing from 137mm to 101mm, an increment of 48% in overall heat transfer coefficient was observed. Likewise, an increase in velocity by 36% and drop in static pressure by 27% were seen. Similar trend was observed in the theoretical results. Journal of Thermal Engineering Journal of Thermal Engineering 2020-07-03T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5131 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5131 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5131

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5477 2021-10-27T21:00:00Z 1

Numerical Comparison Study on Heat Transfer Enhancement of Different Cross-section Wire Coils Insert with Varying Pitches in a Duct Taha Göksu, Fuat Yılmaz Fluent,Thermo-hydraulic, Friction, PEC, Wire Coil Heat transfer enhancement (HTE) efforts spent during the last half-century have become one of the most important working areas of researchers from both academia and industry. One of the most popular passive methods, with regard to the price-performance ratio, is to place wire coils in a pipe or duct. In this study, the heat and pressure drop characteristics of diamond, triangular, and circular cross-sectional wire coils (DWC, TWC, and CWC) in a square duct were investigated by using the FLUENT program. In addition to the cross-section examination, the thermo-hydraulic behavior of three different pitches (p = 54, 72, and 90 mm) for the specified geometries were also investigated. The Reynolds number was between 4387 and 18,415. The square duct was 1.25 m in length, and was 18 mm in diameter. The results showed that the Nusselt number of CWC, TWC, and DWC were higher than that of a smooth pipe within 38-88%, 37-93%, and 38-98% range, respectively. The friction of CWC, TWC, and DWC was observed to be higher than that of a plain tube within a range of 87-278%, 82-266%, and 107-366%, respectively. The TWC with 90 mm pitch showed the highest heat transfer performance evaluation criteria (PEC) with a performance coefficient of 1.3 at Reynolds number of 4504, whereas the DWC with 54 mm pitch was observed to show the lowest PEC. Thus, the as-obtained PEC, which is 30% higher than that of a plain tube, indicates the prominence and effectiveness of the numerical study in increasing the heat transfer. Journal of Thermal Engineering Journal of Thermal Engineering 2021-10-27T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5477 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5477 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:7 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5477

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5479 2021-10-28T21:00:00Z 1

Experimental Investigation on Thermal Conductivity and Thermal Degredation of Honge Oil Methyl Ester with B-20 Blend Vinay Atgur, G. Manavendra , G.P. Desai, B Nageswara Rao Emperical Relation, Mass Degradation, Biodiese, TG-DTG Analysis, Mass Loss Honge oil methyl ester (HOME) with B-20 blend is considered to examine thermal conductivity and thermal degredation of the biodiesel. Transient hot wire method is adopted to determine thermal conductivity of the samples.Heat source is clubbed with C-DAQ and LAB-VIEW software is utilized to record temperature and time. Following Sastry’s power law model, an improved emperical relation is developed for thermal conductivity of HOME with B-20 blend.Thermogravitometry (TG-DTG) analysis is performed under atmospheric conditions with 100C/min heating rate of pure air flow.Diesel is exhibited one mass loss event from 55-3340C,whereas two mass loss event in case of biodiesel. Maximum decoposition temperature noticed for diesel,HOME andB-20 blend are 1950C, 2270C and 1750C respectively. Complete mass degradation takes place for diesel and HOME at 4980C, in case of HOME with B-20 blend complete mass degradation occurred at 3770C. Journal of Thermal Engineering Journal of Thermal Engineering 2021-10-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5479 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5479 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:7 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5479

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5312 2021-01-27T21:00:00Z 1

Dynamic Simulation of an Air-Gap Membrane Distillation (AGMD) Process Using Photovaltaic Panels System and Flat Plate Collectors Abdelfatah Marni Sandid, Driss Nehari, Abderrahmane Elmeriah, Ahmed Remlaoui Membrane Distillation, Solar Water Heater, Flat Plate Collector, Photovoltaic System, Trnsys In the desalination field, the membrane distillation (MD) is a new process of producing distilled water that has been developed and tested in recent years. In this paper, the integrated single cassette air-gap membrane distillation (AGMD) module in the solar thermal desalination system is validated and numerically simulated with the TRNSYS program. This model is studied to be ideal for obtaining a distilled water flow rate of 5.5 kg/h at different times under changing climatic conditions throughout the year in Ain-Temouchent weather, Algeria. The auxiliary heater is added to ensure the thermal energy continuity in the cold climatic conditions, where the photovoltaic system is used to power electrically the auxiliary heater. Therefore, the energy needed is calculated for the auxiliary heater and is replaced by 10 photovoltaic panels, each one has an area of 1.6 m² using seven of the energy storage batteries (12V, 200Ah) with 1.5 KW via TRNSYS and PVGIS help programs. Simulated results showed excellent compatibility with experimental results in previous studies. Additionally, it was found that when the inlet temperature of AGMD reaches 85 °C, the distilled water flow from the distillation membrane reaches 5.5 kg /h and that remains stable on different days throughout the year by relying solely on solar energy. Journal of Thermal Engineering Journal of Thermal Engineering 2021-01-27T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5312 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5312 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5312

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5501 2021-11-25T21:00:00Z 1

Topographical Thermal Imaging for Solid Square Shaft Cooling Sadoon Daham, Nebras Ghaeb, Faiz Mustafa Nondestructive Test, IR Camera Inspection, Topographical Heat Maps, Thermal Imaging ABSTRACT Thermal imaging has its own rapid change and development, both in theory and application. Starting from their military research extended to different real-life applications. This work represents the thermal topographical maps of the thermal image based on the direct projection for material thermal inspection. The test set here uses a square cross-sectional shaft that has been heated to around 200 o C and then measures 9 projections angle of 45o thermal images with an infrared (IR) thermal camera. The final thermal images were analyzed and rearranged to understand the thermal behavior of the shaft with the aid of cooling. The results show that a local slice C_22 indicates twice times in two different projections (2 and 9) with significant differences in temperature with respect to the real measured values. Also, layer C_28 shows the highest temperature difference before about 2.51 o C in projection 4 more than all the other layers. These represent an abnormal behavior for the slices or the local positions mentioned above, which may need more mechanical inspection to confirm the results. The mechanical topographical specifying the projection and slice position will increase the percentage of correctness of local and global assessments for test samples. Journal of Thermal Engineering Journal of Thermal Engineering 2021-11-25T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5501 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5501 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:8 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5501

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5279 2020-12-27T21:00:00Z 1

Large Eddy Simulation of Flow Over Elliptic Cylinder Array in Square Configuration at Subcritical Reynolds Numbers Rajesh Kumar, Nirmal Kant Singh Array of Elliptic Cylinders, Square Configuration, Vortex Shedding, Large-Eddy Simulation Flow over arrays of cylinders of different cross-sections has been an essential area of research interest for a long time. For the estimation of flow characteristics around arrays of cylinders, numerical simulation of the flow past four elliptic cylinders in a square arrangement for a range of spacing ratios is analysed in this paper. Three spacing ratios considered in the present study are 3.45, 4.14 and 5.17. The results from the numerical simulation are compared with the experimental findings obtained previously using square cylinder arrays. The fluid flow modelling is performed by applying three-dimensional LES (Large-eddy simulation) with commercial software ANSYS Fluent 19R1. The results from the simulation for elliptic cylinder arrays involve both quantitative and qualitative analyses in the form of various patterns of flow, drag and lift coefficients, St (Strouhal number) and PSD (Power Spectral Density) plots. The Strouhal number values found for cylinder 1 and cylinder 2 in case of elliptic cylinder arrays are 0.642 and 0.703. It is observed that the force coefficients encountered by the cylinders are moderately varying for different spacing ratios. Journal of Thermal Engineering Journal of Thermal Engineering 2020-12-27T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5279 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5279 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5279

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5369 2021-04-28T21:00:00Z 1

Design, Implementation and Analysis of the Overall Performance of a Micro Hydro Turgo Turbine Shpetim Lajqi, Qëndresa Bresa, Arlinda Bresa, Ilir Doçi, Bojan Ðurin Design, Analysis, Micro Hydro Turgo Turbine, Performance, Turbine Efficiency The increasing demand for energy and the concerns regarding environmental protection have been driving forces toward the exploitation of renewable energy sources as a better alternative compared to conventional energy sources. Furthermore, renewable energy sources enable an independent energy supply for isolated locations or communities that lack access to the main electricity grid, and additionally, they offer the possibility to use available energy sources for beneficial individual purposes. Considering these statements, the use of micro hydropower plants represents a convenient and advantageous option to implement. A micro hydro Turgo turbine is used for analysis in this paper, due to its simple design, structure, easy production and low installation cost. In this manner, this paper deals with the use of Euler equations in detailed analysis in designing and implementation of a micro hydro Turgo turbine. The presented methodology will be based on numerical calculations of micro hydro Turgo turbine characteristic parameters in various operating regimes. The obtained results from numerical calculation will be compared to the current performance of the real existing Turgo turbine. Accordingly, based on obtained results, recommendations for improving the performance of micro hydro Turgo turbines will be presented. Journal of Thermal Engineering Journal of Thermal Engineering 2021-04-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5369 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5369 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5369

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5531 2022-01-27T21:00:00Z 1

Parametric Study of Natural Convection Showing Effects of Geometry, Number and Orientation of Fins on A Finned Tube System: A Numerical Approach Gaurav Krishnayatra, Sulekh Tokas, Rajesh Kumar, Mohammad Zunaid Natural Convection, Fin Effectiveness, Fin Geometry, Heat Transfer Enhancement The present study provides a thorough numerical analysis of natural convection heat transfer from a horizontal cylinder with external longitudinal fins. The Three-dimensional(3D) forms of Continuity, Navier-stokes, and the energy equations have been solved to understand the flow field and temperature distribution using the Ansys Fluent software. The purpose of the study is to investigate the effects of fin length L_f, fin thickness (t), number of fins (N) and material of fin (Aluminum & Steel) on the parameters namely, the heat transfer rate from the inner isothermal wall and effectiveness (Q^*)of the system for a constant Rayleigh number in the laminar range (Ra≤10^6). Additionally, the effect of two different orientations (A&B) of fins has been discussed. Orientation-A consists of fins starting from horizontal plane placed at equal angular spacing subsequently, whereas the fins in orientation-B originate from the vertical plane followed with equal angular spacing. Non-dimensional fin length (L^*) is being varied from 0.222 to 2, non-dimensional fin thickness (t^*) as 0.022 ~0.044 and the number of fins (N) between 6~24. It is observed that for a fixed number of fins there exists an optimum fin length and for a fixed fin length there exists an optimum fin thickness & an optimum number of fins. For a fixed number of fins there exist an optimum fin length and maximum effectiveness, the maximum possible effectiveness for the taken fin-tube system is 4.34 for 12 fins. The maximum effectiveness reported in the current study was 1.86 for L^*=0.444, t^*=0.022 and N=12. Furthermore, the optimum length for N=12 came out to be L^* =1.8. Journal of Thermal Engineering Journal of Thermal Engineering 2022-01-27T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5531 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5531 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5531

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5366 2021-04-25T21:00:00Z 4

Turbulent Heat Transfer for Internal Flow of Ethylene Glycol-Al2o3 Nanofluid in A Spiral Grooved Tube with Twisted Tape Inserts Ahmed Fakhrey Khudheyer, Audai Hussein Al-Abbas, Mihail-Bogdan Carutasiu, Horia Necula Ethylene glycol, water-Al2O3, Numerical analysis, Corrugated spirally tube, Heat transfer, Internal flow. Numerical investigation for turbulent flow of nanofluid (Ethylene glycol/water-Al2O3) is carried out with a volume fraction of 0.5%, 1%, and 1.5%. The diameter of solid nanoparticles is equal to 20 nm. The range of Reynolds number in this simulation is from 6300 to 27500 through a three-dimensional steel corrugated spirally tube. For enhancement of the heat transfer performance in internal flow through the horizontal tube, the tube is combined with aluminum twist tape of a thickness of 0.8 mm and a width of 10 mm along the spirally corrugated tube. In the present work, the same twisted ratios TR=(y/w) are implemented for corrugated tube and tape. The predicted results showed that there is a clear increase in the values of heat transfer and the pressure drop in the direction of flow. Furthermore, the friction factor is increased because of the grooved and twisted tape which rise the resistance of the fluid flow. The values of Nusselt number are increased with the VOF of nanofluid. These numerical results are compared with the experiment found in the literature and showed a good agreement. Journal of Thermal Engineering Journal of Thermal Engineering 2021-04-25T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5366 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5366 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5366

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5307 2021-01-22T21:00:00Z 1

Mixing Enhancement in Electroosmotic Micromixers Narges Jafari Ghahfarokhi, Morteza Bayareh, Afshin Ahmadi Nadooshan, Sara Azadi Electroosmotic Micromixer, Numerical Simulation, Mixing Efficiency, Obstacle Micromixers have important applications in various pharmaceutical and medical fields. In the present study, the enhancement of mixing index in electroosmotic micromixer with different geometries is investigated. The commercial software COMSOL Multiphysics 5.4 is employed to solve the mathematical models. The SIMPLEC algorithm is employed for coupling the velocity and pressure fields. A second-order upwind scheme is used to reduce the artificial diffusivity. The results show a remarkable effect of the electric field on the mixing efficiency. The optimum geometry is the one with no obstacle in the mixing chamber. For the optimum geometry, it is demonstrated that the mixing efficiency increases with the voltage, however there are optimum values for frequency and inlet velocity in which the micromixer exhibits its best performance. The optimum values of frequency and inlet velocity are 8 Hz and 0.1 mm/s, respectively. It is revealed that the micromixer with no obstacle can reach the mixing efficiency of about 97%. Journal of Thermal Engineering Journal of Thermal Engineering 2021-01-22T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5307 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5307 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5307

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5471 2021-10-22T21:00:00Z 1

Experimental Investigation of Heat Transfer Characteristics of an Inverse Diffusion Flame in a Coaxial Tube Burner for with and without Swirl Shankar Badiger, Vadiraj Katti, Anil T.R. Coaxial Tube Burner, Radial Heat Flux, Inverse Diffusion Flame, Twisted Tape, Thermal Imager Heat transfer by flame jet impingement is widely used in many of the industrial and domestic applications like heating metal bars, scrap melting, shaping the glass, metal slab cutting, domestic cooking and others. Aim of the present experimental work is to study an effect of swirl on a local heat flux distribution of an inverse diffusion flame (IDF) jet impinging on a flat target surface in a coaxial tube burner. The twisted tape of twist ratio 3 (corresponding to the swirl number, S = 0.52) is used to create a swirl in the central air jet of the burner. The flame shapes and heat flux distributions are compared for the with and without swirling IDF under the different air jet Reynolds number (Rea) of 1000 to 2500, equivalence ratio (?) of 0.4 to 1.3 and a burner-to-impingement plate distance (H) of 10 to 100mm. The distributions of heat fluxes are studied within a radius of 75mm from the point of stagnation on an impingement plate. Results show that the swirling IDF helps in clean combustion of the fuel with much shorter flame height. Swirling in the flame jet enhances the peak heat flux for the higher air jet Reynolds number for slightly fuel rich conditions of ? = 1.1 at the optimal burner-to-target plate distance of 40mm. Journal of Thermal Engineering Journal of Thermal Engineering 2021-10-22T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5471 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5471 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5471

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5476 2021-10-27T21:00:00Z 3

Drop-in Retrofit Refrigerants As Replacement Possibilities of R134a in Domestic/Commercial Refrigeration and Automobile Air Conditioner Applications Kamel Hmood, Valentin Apostol, Horatiu Pop, Viorel Badescu, Elena Pop R134a, HFOs, HCs, Drop-in, Retrofit Refrigerants According to the EU F-gas Regulation, the phase-out of the high global warming potential (GWP) refrigerants (with higher than 150 GWP value) had been established. The most currently existing household and commercial refrigerators and automobile air conditioners applications based on single-stage vapour compression systems operate with R134a as working fluid. The present paper aims, to review and evaluate the performance of a set of eco-friendly alternatives refrigerants to replace R134a, without change or with minor modifications in refrigeration equipment. The theoretical and experimental studies performed in this field of research were reviewed for this objective. These alternative refrigerants are some of HFCs, HFOs and HCs and their mixtures, which are expected to be an excellent candidates in many refrigeration applications. There are Many replacement possibilities had been proposed viz. drop-in replacement, retrofit refrigerant, and new systems. The results exhibited that the most suitable refrigerants as R134a drop-in substitutes are R1234yf, R152a, R450A, and R513A. The pure R1234ze and its mixtures are not suitable drop-in replacements of R134a but can be a good alternative to R134a only in new refrigeration systems. In terms of hydrocarbon refrigerants R290, R600, and R600a could replace R134a with some modifications to existing refrigeration systems to overcome the flammability issue. We should be using certain HFC and HC mixtures with the lowest TEWI index. Journal of Thermal Engineering Journal of Thermal Engineering 2021-10-27T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5476 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5476 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:7 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5476

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5484 2021-11-03T21:00:00Z 1

The Temperature Distribution of the Wet Cylinder Liner of V-12 Engine According to Calculation and Experiment Kien Nguyen Trung Thermal circuit method, cylinder liner, ANSYS, APDL, FEM, temperature distribution, IC Engine Thermal Load In order to serve the design, improvement and manufacture of engine cylinder liners, it is necessary to accurately determine its temperature distribution. This paper presents the calculation of the temperature distribution of the V-12 engine cylinder liner by the finite element method (FEM) written in ANSYS Parametric Design Language (APDL) and verified with experimental results. In this model, the process of heat transfer (heat conduction) from the rings and the piston skirt region to the cylinder wall is considered by using the thermal circuit method. The calculation of the thermal distribution is carried out corresponding to with loads of 50%, 60%, 75% and 100% of full load, at speeds of 2000 [rev/min] and 1200 [rev/min]. Test results show that the theoretical model has high reliability with the largest relative error of 5.49%. Journal of Thermal Engineering Journal of Thermal Engineering 2021-11-03T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5484 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5484 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:8 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5484

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5467 2021-10-18T21:00:00Z 1

Enhancement technique of heat transfer using inserted twisted tape Prashant Rohidas Nawale, Atharva A. Mule, Sudesh B. Powar, Pramod P. Kothmire Augmented Pipe, CFD analysis, Heat Transfer Enhancement Technique, Twisted Tape Enhancements in heat transfer systems are being applied for the recovery of heat in domestic as well as industrial applications in many areas. These are done by generating turbulence and swirl motion in the flow by inserting inserts to reduce the thermal resistance of heat transfer. This paper presents the experimental and numerical results of heat transfer enhancement of cooling of a confined space by inserting twisted tape in a pipe buried in concrete under the floor. The Reynolds number is fixed to 15000. Thirteen cases are considered varying the configurations and designs of twisted tapes and the effects of different types of perforations and slots on twisted tapes are studied. Water as the test fluid flowed in pipe inserted with twisted tapes. Heat is transferred from a heating plate to water along the pipe length through concrete to simulate the heat transfer from a room and the water temperature rise is studied. To validate the experimental results, ANSYS-FLUENT is used as the CFD tool with a Standard k-? turbulence flow model and the SIMPLE algorithm is implemented. Flow physics behaviour is displayed using velocity and temperature profiles inside the pipe. Insertion of twisted tapes shows that the heat transfer is enhanced due to swirling action, friction and turbulence. The experimental differences in inlet and outlet water temperature validated the CFD simulation results. The temperature distribution on a single twisted tape with increasing twist ratio is found to be the most efficient for heat transfer enhancement of the cooling floor surface with a water temperature rise of 1.62 ºC along a pipe length of 1.8 m. Journal of Thermal Engineering Journal of Thermal Engineering 2021-10-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5467 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5467 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:7 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5467

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5468 2021-10-18T21:00:00Z 3

Heat transfer enhancement using different types of turbulators on the heat exchangers Hamdi Selçuk Çelik, L. Berrin Erbay Heat Exchangers, Vortex Generators, Baffles, Ribs, Perforation, Winglets Energy-saving and heat transfer enhancement considerations are more crucial due to nearly running out energy resources and ensuring the sustainability of nature. The heat exchangers are one of the main components and directly affect the thermal efficiency of the systems. To enhance the heat transfer rate, the fin and plate structure is widely used. Various vortex generators may be involved generally on the surface of fins, like ribs, baffles, delta winglets, and perforations. Turbulators make the heat transfer performance better significantly but increase the friction of the fluid on the contacting surfaces and cause the pressure drop-down which depends on thermal properties of the fluid characteristics. This paper presents general protrusion vortex generators overview to heat transfer augmentation with pressure loss as an extensive literature review. The correlations are derived in terms of some parameters of turbulators like; angle, pitch, shape and combinations of an array. The target of this study is consolidating the verified outputs of the literature and support the increasing thermal performance of the heat exchangers. In conclusion, two tables are made for the first time and summarizing the crucial features of solid, perforated baffles/blockages and winglet turbulators, mentioned in the literature are presented. Obstacles such as winglets and vortex generators are used commonly to increase the heat transfer rate per unit volume for finned to tube exchangers with various types. In order to augment the heat transfer, the design parameters of important consideration are attack of angles, height and array structure in both laminar and turbulated fluid characteristics. Involving perforation forms on the surface may be used for winglets with variable angles both decrease the pressure loss and increase the heat transfer performance. Journal of Thermal Engineering Journal of Thermal Engineering 2021-10-18T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5468 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5468 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:7 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5468

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5215 2020-11-22T21:00:00Z 1

Biogas Production from Waste in a Sanitary Landfill Reactor Assem Ali Aldrawsha, Ahmed Ismail, Rajamohan Natarajan, Osama Ibrahim Methane, Emissions, Yield, Landfill In this research study, the feasibility of waste to biogas conversion in a sanitary landfill unit was investigated. The academic work was about quantifying the methane emission values during the wet season, by applying the FOD method on a static flux chamber and a pilot-scale sanitary landfill, and the methane emission potential table was established. The study was conducted for a period of 16 weeks from November 2018 to February 2019. The waste used in the pilot-scale sanitary landfill included food and cattle waste. It was observed that the methane emission rate peaked at 0.25 g/m2.d during week 10 and decreased to 0.12 g/m2.d during week 16. In addition, the carbon dioxide concentration obtained was 45% during the anaerobic phases and around 50% during the aerobic phases. The academic work studied the contribution of leachate pH, waste moisture content, and gas temperature to change methane emission values. The waste moisture content proved to have a direct relationship with the methane emission values, unlike the gas temperature. The leachate pH value during week 10/5th test day was found to be 7.92, and increased steadily throughout the remaining study period, even though the methane emission values decreased during that period (after week 10/5th test day).It was observed that the leachate recirculation process decreased the leachate content even though it affected the methane emission values. Journal of Thermal Engineering Journal of Thermal Engineering 2020-11-22T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5215 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5215 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5215

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5464 2021-10-18T21:00:00Z 1

Experimental Effect of Inclination on the Process of Melting Paraffin in a Square Cavity Hocine Guellil, Abdel Illah Nabil Korti Thermal Storage, Latent Heat, PCM, Paraffin, Melting Front Phase change material (PCM) is a promising strategy for reducing energy consumption in various applications. Among the large number of PCMs studied in the literature, paraffin is considered to be promising for latent heat thermal energy storage LHTES due to its appropriate thermal properties and their chemical stability. The interest of this work is to carry out an experimental procedure to visualize the phase change process of paraffin in a square cavity at different inclination angles. This article reveals how the melting rate could be affected by changing three orientations 90° (vertical heating), 0° (bottom horizontal heating), and 45° (inclined heating). The enclosure is heated on one side while the other walls are thermally insulated. The numerical photos, infrared thermal image, and thermocouples-temperatures recorded during the melting processing are used to calculate the melting fractions and to estimate the intensity of heat transfer in different angles. The results show that the inclination angle has a great influence on the behavior of natural convection, affecting the front melting propagation and heat transfer rate. When the inclination angle decreases from 90° to 0° the convection currents in the cavity progressively evolve from a dominant single-cell movement to an unstable Rayleigh-Benard movement. The total melting time for the bottom and inclined heating cavities were, on average, 56% and 45% less than that of the vertical heating, respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2021-10-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5464 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5464 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:7 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5464

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5510 2021-12-06T21:00:00Z 1

Thermoeconomic Analysis and Multi-Objective Optimization of a Novel Trigeneration System Consisting of Kalina and Humidification-Dehumidification Desalination Cycles Pooria Behnam, Meysam Faegh, Iman Fakhari, Pouria Ahmadi, Ehsan Faegh, Marc A. Rosen Trigeneration, Kalina cycle, Humidification-dehumidification, Desalination, Optimization A comprehensive thermoeconomic analysis and multi-objective optimization of a new trigeneration system are performed. The proposed system, which is an integration of Kalina and humidification-dehumidification (HDH) cycles, is dri ven by low-temperature geothermal water to produce electricity, heating and freshwater. For the Kalina cycle, an evaporative condenser is used. It also acts as humidifier and heater of the humidification-dehumidification desalination cycle, resulting in a reduction in complexity of the trigeneration system. A detailed parametric analysis is carried out in order to investigate the effects of key design parameters, including turbine inlet pressure, condenser temperature, basic solution ammonia concentration, air mass flow rate and heat source temperature, on the thermoeconomic criteria. Then, a multi-objective optimization is conducted to determine the best design parameters, considering exergy and total cost rate as the objective functions. The optimal solution Pareto frontier indicates that the exergy efficiency and total cost rate vary in the range of 14.9-41.6% and 1.13-2.19 $/h, respectively. Analyses of the scattered distributions of design parameters reveal that lower heat source temperatures tend to optimize the objective functions. However, altering other design parameters has a significant effect on the trade-off between exergy efficiency and total cost rate. Journal of Thermal Engineering Journal of Thermal Engineering 2021-12-06T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5510 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5510 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5510

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5480 2021-10-28T21:00:00Z 1

Influence of Convective Boundary Condition on Heat and Mass Transfer in a Walters’ B Fluid over a Vertical Stretching Surface with Thermal-Diffusion Effect Akinbo Johnson, Olajuwon B.I Thermal Radiation, Similarity Variables, Local Weissenberg Number, Thermal-Diffusion, Homotopy Technique This paper presents heat and mass transport in the flow of Walters' B fluid via a vertical stretching sheet with the thermal-diffusion impact as a function of Convective Boundary Condition. The coupled nonlinear partial differential equations governing the system are presented in the form of coupled ordinary differential equations via similarity transformation variables which then solved by the Homotopy Analysis Method. The effect of various parameters on velocity, temperature and concentration profiles as well as Local Skin-friction, Nusselt and Sherwood numbers are plotted and discussed. The findings outcome revealed among others that distinct values of thermal buoyancy parameter speed-up the movement of the fluid and cools the thermal layer while the surface heat transfer is boosted when the strength of Radiation improves. Also, large values of Biot number constitute strong convective heating which consequently maximizes the thickness of the associated boundary layer and enables the heat influence to break through into the quiescent fluid. Biot number is of great importance in the engineering field for drying of the materials. Journal of Thermal Engineering Journal of Thermal Engineering 2021-10-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5480 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5480 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:7 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5480

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5304 2021-01-11T21:00:00Z 1

Numerical investigation of MHD Casson Nanofluid Flow towards a Non linear Stretching Sheet in presence of Double-Diffusive effects along with Viscous and Ohmic Dissipation Vinita Makkar, Vikas Poply, Rangoli Goyal, Naresh Sharma Non-linear stretching sheet; Brownian motion; Thermophoresis; Casson fluid; MHD, Viscous dissipation; Ohmic dissipation The intention behind carrying out this research work is to analyze the steady Magnetohydrodynamic (MHD) boundary layer flow with Casson nanofluid in presence of Viscous and Ohmic dissipation effects towards a non-linear stretching sheet. Two phase representation of nanofluid studied the consequence of Brownian motion along with thermophoresis. The major purpose of study is to investigates the significant role of prominent fluid parameters especially yield stress, slip velocity, thermophoresis, Brownian motion, Eckert number, Schmidt number, magnetic parameter and non-linear stretching parameter on profile of velocity, temperature distribution and concentration while keeping the other parameters under study constant. Runge Kutta Fehlberg (RKF) approach was adopted to numerically solve the non-linear governing equations and the linked boundary conditions by use of shooting technique. In present study, we use bvp4c in MATLAB for finding the final outcomes and relating the concluding results for local Nusselt number ${-\theta_{\delta}}^{'}(0)$ with extant outcomes in literature as a limiting case in the absence of thermophoresis and Brownian motion and an excellent agreement is noted. Over all the consequence of prominent fluid parameters are explained via graphs, whereas distinction of several valuable engineering quantities like skin friction coefficient, local Nusselt number and local Sherwood number are also tabulated. The finding of present study helps to control the rate of heat transportation as well as fluid velocity in any manufacturing processes and industrial applications to make desired quality of product. Journal of Thermal Engineering Journal of Thermal Engineering 2021-01-11T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5304 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5304 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5304

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6649 2022-11-23T21:00:00Z 3

Advancements and Challenges in the Fluidized Bed Gasification System: A Comprehensive Review Surender Antil, Gulshan Sachdeva, Avdhesh Sharma Gasification; Bubbling Fluidized Bed Gasifier; Design Parameters; Process Parameters; Efficiency The gasifier employs partial ignition of biomass and conversion to gaseous fuels of high calorific value. The bubbling fluidized bed gasifier, which is based on one of the most important gasification technology, has several important features like large and small scale applications, efficient heat and mass transfer rates due its fuel flexibility, low capital and operating costs, etc. However, low mixing rate of biomass feedstock and gasifying agent, high tar content in the product gas and low calorific value of producer gas are some of its limitations which need proper attention to improve the performance of the bubbling fluidized bed gasifier. The present study analyzes the effect of design parameters of the proposed biomass gasifier reactor in addition to the feedstock characteristics and process parameters on the quality of producer gas. This review paper examines the present global status of biofuels, different types of gasification technologies, approaches adopted for a gasification, different types of parameters affecting gasification performance, enhancement of product gas conditioning, technical, cost-effective viability and future prospects of gasification. Journal of Thermal Engineering Journal of Thermal Engineering 2022-11-23T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6649 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6649 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6649

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5461 2021-10-09T21:00:00Z 1

3d Investigation of Semi-Underground Room Comfort in A Desert Climate Mohammed Tahar Messaoudi, Boubekeur Dokkar, Naoui Khenfer, Mohamed Cherif Benzid Semi-Buried Room, Desert Climate, Passive Cooling, Experimental Investigation, 3d Simulation In Algeria, the residential sector registries a high rate of energy consumption which requires an important action for rationalizing this charge and integrating renewable energies. Particularly, the geothermal energy with its less intermittence presents an attractive candidate to reinforce energy-saving and building thermal comfort. In this paper, geothermal energy is used to create a favorable environment for creating a better life inside a semi-buried building during the very hot period in the desert climate of southern Algeria. The cooled room is buried in rocky soil until 3 m depth, and only 0.5 m of the room high is above the ground level. The upper parts of southern and northern room walls are provided by small windows for aeration and lighting purposes. Inside room the air flow is modeled by Navier-Stocks and energy equations. The computational domain is taken as 3D design, and the prediction of temperature is calculated by ANSYS-Fluent code. For the base case, at 2 m height, the indoor temperature fluctuates between 30 and 33°C which is in good concordance with experimental data. For reducing the indoor temperature, some simple design modifications are introduced and a small ventilation system is installed. The new results show that the indoor temperature does not exceed 25 °C at the height of 2 m, therefore the temperature for height between 2 and 3 m it fluctuates between 25 and 26 °C. This indoor thermal behavior ensures acceptable cooling with negligible electricity consumption. Journal of Thermal Engineering Journal of Thermal Engineering 2021-10-09T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5461 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5461 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:7 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5461

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5481 2021-10-28T21:00:00Z 1

Numerical Simulation of Heat Transfer Characteristics of Taper Helical and Spiral Tube Heat Exchanger Amit Sharma, C. S. Rajoria, Dharmendra Singh, J. P. Bhamu, Ravi Kumar Heat Transfer Coefficient, Taper Helical and Spiral Tube, Nusselt Number, Reynolds Number The paper investigates the heat transfer characteristics of the heat exchanger under two different configurations namely taper helical tube and spiral tube type heat exchanger. The working fluid is water which flows in tubes kept horizontally and the mass flow rate ranges from 0.04 kg/s to 0.16 kg/s. The effect of tube configuration parameters and Reynolds number on heat transfer coefficient and Nusselt number were studied. Regression equations have been developed for both the configurations under horizontal orientation using various process parameters and regression tools available in Minitab Software. A comparison has been made between the theoretical results and the results obtained from simulation gives an error of 15% which is well within the permissible limit. The result indicates that the highest value of Nusselt number is greater by 21% than taper helical tube heat exchanger which is attributed to better heat transfer characteristics of spiral tube heat exchanger and hence the former is thermally superior over the latter. In this study, temperature and velocity contour have been developed for both the configurations which clearly indicates that, when heat transfer is considered, spiral configuration should be preferred over taper helical configuration. Journal of Thermal Engineering Journal of Thermal Engineering 2021-10-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5481 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5481 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:7 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5481

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5534 2022-02-05T21:00:00Z 1

Heat Transfer Investigation of Non-Newtonian Fluid Flow in an Annular Pipe Embedded with Porous Discs: A Turbulent study Zohreh Poursharif, Hesamoddin Salarian, Kourosh Javaherdeh, Majid Eshagh Nimvari Non-Newtonian Fluid, Turbulent Flow, Nusselt Number, Annular Pipe, Porous Medium Porous materials are used in thermal devices such as heat exchangers to improvement the heat transfer. The heat transfer of a non-Newtonian fluid flow in an annular pipe with porous discs is numerically investigated in this paper. The flow regime in both porous medium and clear region are considered to be turbulent. The effects of power-law index of the non-Newtonian fluid and porous discs pitch variationson the heat transfer rate, friction coefficient are studied and compared to each other for two porous layer thicknesses. Finally, the thermal performance is defined which determines the optimum porous media and non-Newtonian fluid characteristics in the annular pipe. Journal of Thermal Engineering Journal of Thermal Engineering 2022-02-05T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5534 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5534 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5534

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5324 2021-02-09T21:00:00Z 1

Experimental and Numerical Investigation of Convection Heat Transfer in an Enclosure with a Vertical Heated Block and Baffles Salah Abid Aun, Safaa Ghadhban, Kadhum Jehhef heat transfer enhancement, Nusselt number, enclosure, heating block, baffles. In this study, the natural and forced convection heat transfer in an enclosure with vertical heated block and baffles are experimentally and numerically investigated. The enclosure walls are kept as adiabatic, and the heating block contains extended baffles and receives heat flux. The effect of heat flux, Reynolds number and baffle configuration on the heat transfer characteristics and flow behaviour inside the enclosure is examined. The configuration parameter for natural and forced convection involves three heating block models, namely, block without baffle (plain), block with baffles and block with partially cut baffles. The widths of baffles are 2.5, 5 and 10 cm for the block with baffle case, and the width of partially cut baffle is 5 cm. The heat flux (q) ranges from 240 w/m2 to 1425 w/m2 for all the models. The Reynolds number (Re) ranges from 5650 to 15950 for forced convection heat transfer. In the numerical part, a finite volume method (via Ansys Fluent) is used to solve the governing equations. Result shows that the increase in baffle width has no remarkable effect on the heat transfer, and the partially cut baffles provide an enhancement of approximately 30% compared with the plain heating block. The baffle cases have an evident effect in reducing the block surface temperature by approximately 11% compared with the plain case at Re = 0 and q = 240 w/m2. Empirical correlations for the block with baffles are obtained for each heat flux to predict the average Nusselt number Journal of Thermal Engineering Journal of Thermal Engineering 2021-02-09T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5324 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5324 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5324

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5472 2021-10-22T21:00:00Z 1

Experimental Investigation on Thermal Conductivity and Stability of Water-Graphite Nanofluid Kyathanahalli Yashawantha, A. Venu Vinod Ultrasonication, Nanofluid, Thermal conductivity, Graphite Nanopowder, Stability Enhanced thermal conductivity of nanofluids has proven importance in enhancing heat transfer for many application. In this study, thermal conductivity of graphite nanopowder dispersed in water at different temperatures was studied experimentally. Stable nanofluids of different concentrations (0.2 vol%, 0.5 vol%, 0.8 vol%, 1 vol% and 1.5 vol%) are prepared using ultrasonic cleaner by sonicating for 3 hour. Thermal conductivity was measured from temperature 25 to 55 ºC with an interval of 5 ºC using KD2 Pro thermal properties analyser. Experimental results showed that thermal conductivity increases with increase in temperature and volume concentration. Thermal conductivity of Water - Graphite nanofluid showed enhancement of 5.6% to 20.42% for 0.2 vol% to 1.5 vol% of concentration at 25 ºC respectively. However, the maximum improvement of 39.72% was found at 1.5% of concentration at 55 ºC compared to water. A correlation was developed considering the effect of temperature and concentration using the regression method. The proposed correlation effectively predicts the thermal conductivity of Water - Graphite nanofluids with an accuracy of ±2.8%. Journal of Thermal Engineering Journal of Thermal Engineering 2021-10-22T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5472 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5472 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:7 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5472

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5483 2021-10-31T21:00:00Z 1

Analysis of Heat Transfer Performance of the Absorber Tube with Convergent-Divergent Structure for Parabolic Trough Collector Zhao Xuyi, Wang Fuqiang, Shi Xuhang, Cheng Ziming, Gong Xiangtao Solar energy; Parabolic trough collector; Monte Carlo ray tracing; Finite Volume method; convergent-divergent structure; Heat transfer enhancement In order to effectually improve the performance of parabolic trough solar collector system and homogenize the temperature distribution on the absorber tube, an innovative convergent-divergent tube was designed as the absorber tube of PTR. The finite volume method (FVM) and the Monte Carlo ray tracing method (MCRT) are combined to simulate the heat transfer process in parabolic trough collector. The average relative error between the numerical results and the experimental results conducted in the Spanish DISS test facility is 1.103%, which confirms the reliability of the simulation results in this paper. The heat transfer characteristics and flow characteristics of PTR and convergent-divergent PTR are compared in the inlet velocity range of 0.05-0.75m/s, and the effect of the number of zoom sections(N) for CD-PTR performance is also studied. The simulation results show that the parabolic trough collector with convergent-divergent tube has significantly enhanced heat transfer capability. The average Nu of CD-PTR increases as the number of zoom sections increases, and is always higher than that of PTR. When Re=86400 and N=25, the average Nu increased by 66%. Journal of Thermal Engineering Journal of Thermal Engineering 2021-10-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5483 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5483 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:8 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5483

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5230 2020-12-23T21:00:00Z 1

Numerical Investigation of Non-Uniform Heat Transfer Enhancement in Parabolic Trough Solar Collectors Using Dual Modified Twisted-Tape Inserts Farhad Afsharpanah, Amirhossein Zabihi SheShpoli, Khashayar Pakzad, Seyed Soheil Mousavi Ajarostaghi Heat Transfer Enhancement, Parabolic Trough Collector, Twisted Tape, Numerical Simulation, Solar Collector In this paper, a numerical investigation is presented on heat transfer augmenting by using various kinds of modified multiple twisted tape inserted in solar parabolic trough collectors. The pressurized water is considered as working fluid and Reynolds number varying from 10000 to 20000. The received heat flux on the solar absorber was assumed non-uniform due to hemispheric insolation of sun. The obtained numerical results for the Nusselt number, friction factor and thermal performance are presented for each cases. Various types of twisted tape including single twisted tape, normal, perforated, center-cleared, square, and V-cut dual twisted tape are considered and analyzed. The numerical simulations are performed by a commercial CFD code, ANSYS FLUENT 18.2. The obtained results revealed that at Re=10000 and 20000, the average Nusselt numbers of case with dual v-cut twisted tapes are more than plaine tube by 19.58 and 17.44%, respectively. Moreover, thermal performance of all cases with various twisted tapes is larger than 1 which means that utilizing twisted tape with various configurations leads to more thermal performance than plain tube. The thermal performances of case with dual square-cut twisted tapes (as the best case) for Re=10000 and 20000 are more than plain tube by about 16 and 12% improvement, respectively. Furthermore, for the case with perforated dual twisted tape (as the case with lowest thermal performance), the thermal performances for Re=10000 and 20000 are more than plain tube by about 9.2 and 7% improvement, respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2020-12-23T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5230 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5230 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5230

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5329 2021-02-17T21:00:00Z 1

Thermal Analysis of Nickel Alloy/Al2O3/TiO2 Hybrid Metal Matrix Composite in Automotive Engine Exhaust Valve Using FEA Method Jayappa Kumaraswamy, Vijay Kumar, Gange Gowda Purushotham, Rohit Suresh Nickel alloy, Hybrid metal matrix composites, Thermal conductivity, Heat flux, Finite element analysis The current research aims to develop a hybrid metal matrix composition that focuses on the nickel alloy and its thermal properties. The different temperature ranges are used to analyze the function of MMCs such as thermal conductivity and coefficient of thermal expansion. This paper addresses the thermal properties obtained from a series of Al2O3 and TiO2 reinforced nickel alloy (ASTM A494 M), with dispersed particle sizes ranging from 40-45 microns of Al2O3 and 1-5 microns of TiO2. The quantity of the Al2O3 addition varies from 3-12 weight % and 9 weight % of TiO2 unvarying in the stages of three weight percentages. The microstructural investigation states that, because of the stir casting on the vortex, the distribution of reinforcements is uniform with a strong bond. With the increase in Al2O3 and TiO2 content in HMMCs, a thermal property is found to diminish significantly. The results indicate that the reinforcements have a major effect on the thermal expansion coefficient as well as on the thermal conductivity of the hybrid composites being produced. Various types of microstructural have been performed using electron microscopy scanning and EDAX. The limited examination of the exhaust valve of the I C engine shows that the nickel combination composites can be utilized as a substitute for the present valve material (Ni-Cr alloy steel). All tests acted in this investigation meet ASTM specifications Journal of Thermal Engineering Journal of Thermal Engineering 2021-02-17T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5329 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5329 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5329

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5305 2021-01-19T21:00:00Z 1

Thermal Behaviour Kinetic Modeling of Capsicum Annuum Waste Biomass Using an Iso-Conversion Method Vijetha ponnam, Ramesh Naidu Mandapati, Praveen Ghodke, Subbaiah Tondepu Capsicum Annuum; Thermogravimetric Analysis; Kissinger-Akahira-Sunose (KAS); Ozawa Flynn Wall (OFW); Coats Redfern Method In the present study, the pyrolysis behaviour of Capsicum Annuum stem Waste (CAW) was studied applying thermogravimetric analysis to evaluate the intrinsic kinetic parameters to develop a pyrolysis reactor for utilizing CAW. The thermal decomposition of CAW was achieved between 373 – 1173 K under inert conditions at different heating rates of 10, 20, and 30 K min-1. Model-free kinetic methods like Kissinger-Akahira-Sunose (KAS), Ozawa Flynn Wall (OFW) and Coats Redfern methods were applied to work out the kinetic parameters. To identify the utility of CAW and its biochar, physio-chemical characteristics such as proximate and ultimate analysis, scanning electron microscopy, and Fourier Transform Infrared analysis are reported. Journal of Thermal Engineering Journal of Thermal Engineering 2021-01-19T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5305 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5305 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5305

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5511 2021-12-06T21:00:00Z 1

A Numerical Investigation of the Species Transport Approach for Modeling of Gaseous Combustion Upendra Rajak, Prem Kumar Chaurasiya , Prerana Nashine , Tikendra Nath Verma, Rohit Kumar Species Transport Model, Computational Fluid Dynamic (CFD), k- ε Model, NO Emission, Emission This present work shows a study of the effect of thermal radiation in the simulation of a turbulent, non-premixed diesel-air, hydrogen-air, kerosene-air, n-butanol, pentane-air, propane-air and methane–air used in a 2D geometry cylindrical combustion chamber. The numerical simulation based on the solution of the mass, momentum, energy and the chemical species conservation equations was performed for steady state condition using computation Fluid Dynamic (CFD), while the turbulence modeling was considered via standard k–? model. The results indicate that highest mass fraction of NO emissions with hydrogen-air fuel compared to diesel fuel. The results showed a better performance of kerosene-air alternative based on the emissions characteristics in the present work. The CO2 emission reduced with hydrogen-air compared to diesel fuel due to better combustion. A significant decrease of emissions characteristics (O2, H2O and NO) was observed. The present numerical investigated results of methane-air are compared to experimental results compared to Silva et al. (2007) and Garreton and Simonin (1994) for tool validation. Journal of Thermal Engineering Journal of Thermal Engineering 2021-12-06T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5511 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5511 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:8 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5511

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5081 2020-06-09T21:00:00Z 9

Professor Somchai Wongwises on His 60th Birthday Mohamed M. Awad, Pranab Kumar Mondal, Omid Mahian, Ho Seon Ahn, Ahmet Selim Dalkiliç, Ioan Pop, Dieter Mewes, Adrian Bejan, Bahri Şahin Birthday Professor Somchai Wongwises is one of the well-known names in the fields of two-phase flow, and heat transfer enhancement. Professor Somchai Wongwises was born on the 3rd October 1959 in Bangkok, Thailand. He received his B.Sc. in Bachelor of Engineering (with honors) in Mechanical Engineering, Faculty of Engineering, King Mongkut’s University of Technology Thonburi (KMUTT), Bangmod, Bangkok, Thailand in 1982. Then, he transferred to the Asian Institute of Technology (AIT), Khlong Luang, Pathum Thani, Thailand to prepare for a Master’s Degree in Energy Technology that was awarded in August 1984. Subsequently, he obtained a Ph.D. in Mechanical Engineering from Chulalongkorn University, Bangkok, Thailand in 1989. He received his Doktor Ingenieur (Dr.-Ing.) in Mechanical Engineering from Institute of Process Engineering, University of Hannover, Hannover, Germany in August 1994 under the supervision of Professor Dr.-Ing. Dieter Mewes. With greatly appreciated scholarships from DAAD (German Academic Exchange Service) and from the University of Hannover, his research work in Germany was crowned with complete success. Journal of Thermal Engineering Journal of Thermal Engineering 2020-06-09T21:00:00Z Editorial application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5081 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5081 Journal of Thermal Engineering, Year:2020, Vol:6, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5081

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5503 2021-11-26T21:00:00Z 1

Investigation of Laminar Forced Convection Heat Transfer of Nanofluids Through Flat Plate Solar Collector Farzad Hossain, Md Ashrafuzzaman Miah, Afshana Morshed, Md Insiat Islam Rabby , Eric Hu Heat Transfer, Nanofluid, Nanoparticle, Forced Convection, Solar Collector, Flat Plate. The paper analyzes laminar forced convection heat transfer for both single and mixture phase models utilizing Al2O3-water and CuO-water nanofluids as the working fluid and examines the effect of internal fins in the collector tubes in order to improve collector efficiency. A physical model with governing equations has been defined. Finite volume method has been utilized for discretizing governing equations and finite element method has been utilized for three dimensional analysis of solar plate model with finned tubes. Convective heat transfer coefficient, Nusselt number and shear stress have been analyzed for Reynolds numbers from 200 to 700 with 0-5% volume fractions of nanofluid. Moreover, the efficiency of the collector has been investigated for constant flow rates from 0.02 to 0.04 mL/s and variable overall heat loss coefficient for the same range of volume fractions of nanofluid. It has been found that increment of shear stress and heat transfer coefficient occurred with the increment of concentration of nanoparticles and the Reynolds number. Investigation of particle size has not shown any notable variation with the mixture phase model. Mixture-phase model gives comparatively lower values due to the reduction of viscosity near the wall. Noticeable increment of efficiency has been observed by changing working fluid from Al2O3-water to CuO-water which has been further improved by utilizing variable overall heat loss coefficient. Efficiency increases up to 6.5% and 8.7% than the base fluid for utilizing Al2O3-water and CuO-water nanofluid respectively. Additionally, utilizing internal fins to the riser tubes, the efficiency increases up to 11%. Journal of Thermal Engineering Journal of Thermal Engineering 2021-11-26T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5503 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5503 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:8 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5503

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5506 2021-11-28T21:00:00Z 1

Three Dimensional Flow Over Elliptic Cylinders Arrays in Octagonal Arrangement Rajesh Kumar, Nirmal Kant Singh Array Attack Angle, Vortex Shedding, Drag and Lift Forces, Gap Spacings A numerical study of flow characteristics around eight elliptic cross-section cylinders in an octagonal configuration is presented. The axis ratio of elliptic cylinder is taken as 1:2. Three spacings between the cylinders (0.07 m, 0.14 m and 0.2 m), two angles of attack (α=0° and α=15°) and two Reynolds numbers (Re=4060 and Re=45800) are considered to investigate the parametric influences. The flow is modelled using three-dimensional large eddy simulation. Simulations are performed by utilizing ANSYS Fluent software. The results comprise of flow patterns and force coefficients (drag and lift). It is seen that both the drag and lift forces acting on the cylinders vary with the spacings values, angle of attack and Reynolds numbers. The lift force peaks at α=15° and Reynolds number 45800. The drag force on the upstream cylinder reaches its peak at α=0° and Reynolds number 4060. It is observed that the drag on the upstream cylinders decreases as the value of the Reynolds number increases. Contours of velocity and subgrid turbulent viscosity are also presented. Moreover, it is concluded from the present study that the effect of change in the Reynolds number on flow characteristics is more significant as compared to the change in the spacing between the cylinders. Journal of Thermal Engineering Journal of Thermal Engineering 2021-11-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5506 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5506 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:8 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5506

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5460 2021-10-08T21:00:00Z 1

Estimation of Hourly Global Solar Radiation Using Artificial Neural Network in Adana Province, Turkey Onur Goncu, Tahsin Koroglu, Naime Filiz Ozdil Global solar radiation, Artificial neural network, Levenberg-Marquardt algorithm, Mean square error, Linear correlation coefficient Since global solar radiation (GSR) is an important parameter for the design, installation, and operation of solar energy-based systems, it is important to have precise information about it. As the indicating devices are expensive and their requirements such as operation and maintenance should be carried out, the measurement of solar radiation cannot be frequently taken. On the other hand, the measurements of different meteorological parameters such as relative humidity and ground surface temperature are more prevalent in meteorology stations. Therefore, the estimation of solar radiation is a significant parameter for the areas where the measurements could not be performed and to complete the missing information in databases. Many different models, software, and simulation programs are utilized to calculate solar radiation data, provide an economic advantage, and obtain high accuracy. The main purpose of this study is to perform an estimation of solar radiation in Adana, where is on the east of the Mediterranean in Turkey, by using an artificial neural network (ANN) model. The best estimation performance is obtained by optimizing the neuron numbers used in the network’s hidden layer with the trial and error method. With this aim, hourly data including wind speed, wind direction, humidity, actual pressure, and average temperature are taken as inputs while solar radiation is taken as a target. All these data, which is for 2018, has taken from the Turkish State Meteorological Service. A linear correlation coefficient value has been obtained to be about 0.87313 with the mean square error (MSE) of 5.8262x107 W/m2 for the testing data set. The ANN’s testing/validation results show that it has a low MSE, indicating the accuracy and adequacy of the network model. Besides, the predicted ANN output is evaluated to be remarkably close to the measured target data by considering the linear correlation coefficient. Journal of Thermal Engineering Journal of Thermal Engineering 2021-10-08T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5460 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5460 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:8 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5460

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5462 2021-10-11T21:00:00Z 1

Numerical Investigation of Laminar Forced Convection and Entropy Generation of Fe3O4/Water Nanofluids in Different Cross-Sectioned Channel Geometries Edip Taşkesen, Mutlu Tekir, Engin Gedik, Kamil Arslan Nanofluid; Forced Convection; Laminar Flow; Cross-sectioned Channels In this study, forced convection of nanofluid flow in various channel geometries with a hydraulic diameter of 16 mm and length of 1.5 m under laminar flow condition has been investigated numerically. Constant heat flux of 6 kW/m2 has been applied on to the surfaces of the channels. Fe3O4/water nanofluid has been used in the analyses to enhance the convective heat transfer of the base fluid. Analyses have been performed for Reynolds numbers between 500?Re?2000, and for volume concentrations of nanoparticles between 1% and 5% in cylindrical, square, rectangle, and triangle cross-sectioned channel geometries. The finite volume discretization method has been used to solve the governing equations. The effects of some parameters; Reynolds number, nanoparticle volume fractions, channel geometries on the average Nusselt number, Darcy friction factor and entropy generation have been investigated in detail. The results indicate that nanofluid offers further convective heat transfer enhancement according to base fluid and cylindrical cross-sectioned channel gives the best heat transfer performance among other cross-sectioned channel geometries. Using water as a working fluid, cylindrical cross-sectioned channel geometry gives the highest heat transfer rate among other channel geometries, whereas triangle one gives the lowest. Cylindrical cross-sectioned channel geometry offers up to 77.6% enhancement compared to triangle cross-sectioned channel geometry for the same hydraulic diameter and same heat flux. However, triangle cross-sectioned channel geometry has highest convective heat transfer increment ratio (4.12%) for changing working fluid as water to nanofluid. Also, some new Nu correlations based on the channel geometries and nanoparticle volume fractions were proposed in the present study. Journal of Thermal Engineering Journal of Thermal Engineering 2021-10-11T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5462 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5462 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:7 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5462

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5465 2021-10-18T21:00:00Z 1

Combined Effect of Variable Parameters on the Performance of Gas Turbine Cycles M. N. Khan Pressure Ratio, Net Output, Thermal Efficiency, Exergy Destruction, Gas Turbine Cycles The gas turbine cycle is the key solution for the power generation system from the last decade. several types of research are going to enhance the overall system efficiency of the gas turbine cycle. In the present study, six sets have been investigated parametrically for energy and exergy. Thermodynamic assessments have been effectively achieved for the compressor pressure ratio from 4 to 14, turbine inlet temperature (TIT) from 1000K to 1500K, and ambient temperature 250C to 450C. Results show that for every 100 rises in ambient temperature the maximum decrease in peak output and peak thermal efficiency is 6.2% and 5% respectively at 1000K and 3.6% and 1.9% respectively at 1500K. The exergy loss by exhaust gases of set 4 and set 5 increased by 107% whereas set 6 is decreased by 85.5% as compared to set 1 under the conditions when the exergy loss by exhaust gases of set 1 is minimum at TIT 1000K. The total exergy destruction of set 3, set 4, set 5, and set 6 is increased by 102%, 32.6%, 133.3%, and 102% respectively as compared to set 1 under the conditions when the total exergy destruction of set1 is minimum at TIT 1000K. Regenerative Gas Turbine cycle is the best in terms of the ratio of net output to exergy destruction of the plant as well as initial, operational, and maintenance costs. Journal of Thermal Engineering Journal of Thermal Engineering 2021-10-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5465 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5465 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:7 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5465

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5514 2021-12-21T21:00:00Z 3

A Review on Thermal Analysis of Hybrid Greenhouse Solar Dryer (HGSD) Pushpendra Singh, M.K. Gaur Hybrid, Greenhouse, Heat Transfer, Mass Transfer, Solar Dryer The objective of the paper is to present the modifications done in hybrid greenhouse solar dryers to make them more efficient. As hybrid dryers were developed to overcome the various limitations of other types of solar dryers. Due to modifications in dryers, the effect on various heat transfer parameters like heat transfer coefficient, drying time, drying efficiency, etc. is studied and also encapsulated in the paper. It is found that in most of the hybrid dryers, the maximum temperature of the drying chamber is around 65-80°C. This shows the suitability of a hybrid dryer for drying high moisture crops. Also, the drying time for most of the crops is around 2-3 days, which shows the faster moisture removal rate inside the hybrid dryers. According to the literature studied, the maximum drying efficiency of a hybrid dryer is reported by about 35%. The paper also encapsulates the various relations/equations used by different researchers to carry out the thermal modeling and heat transfer analysis of greenhouse dryers. Journal of Thermal Engineering Journal of Thermal Engineering 2021-12-21T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5514 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5514 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5514

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5478 2021-10-27T21:00:00Z 1

Performance of Phase Changing Material in an Artificially Created Cold Region to Promote Latent Heat Thermal Energy Storage Rupali Patil, Avinash Desai Phase Changing Material,Latent Heat Thermal Energy Storage,Charging,Discharging In the present contribution, the authors investigate the peculiarity of Phase Changing Material for accumulating heat in the region equivalent to the hilly area by creating its atmosphere, having 20°C DBT and 18°C WBT. A water cooler is used in 5*7 feet bathroom to conceive the above-intimated temperature, which is then measured by a sling psychrometer. In particular, in this study, trials are carried out in the LHTES tank where water is charged from ambient temperature to 55°C with the aid of an Immersion water heater rod of 1000W,230V thereby liquifying PCM and then discharging to ambient temperature. Two Orientations namely, Circular and Cross are appropriated into the study, where Circular Orientation poses better results articulating the charging in an hour and discharging in 25 long hours, whereas Crossed Orientation represents charging in an hour and discharging in 23 hours. The volume of PCM and the net heat transfer surface have been kept constant in both cases, to compare them in the same operative conditions. The reason for the detour is manifested. Journal of Thermal Engineering Journal of Thermal Engineering 2021-10-27T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5478 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5478 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:7 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5478

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5500 2021-11-22T21:00:00Z 1

Performance Assessment of an Electrolyte-Supported and Anode -Supported Planar Solid Oxide Fuel Cells Hybrid System Abdulrazzak Akroot, Lutfu Namli Electrolyte-Supported Model (ESM),Planar Solid Oxide Fuel Cell (SOFC), Anode-Supported Model (ASM), Energy Analysis, Exergy Analysis. In this study, a system-level zero-dimensional model for planar solid oxide fuel cell- gas turbine (SOFC/GT) hybrid system has been studied to investigate the effect of diverse operating conditions such as operating pressure, air utilization factor (Ua), and fuel utilization factor (Uf) on the performance of a selected hybrid system. Moreover, the system's power production and performance were discussed in two different configurations: anode-supported model (ASM) and electrolyte-supported model (ESM). This study's models were implemented in Matlab® to calculate the optimum operating parameters and determine the hybrid system's performance characteristics. According to the finding, a maximum of 717.8 kW power is produced at 7.7 bar pressure for the ASM. In contrast, a maximum of 630.3 kW power is produced at 12 bar pressure for the electrolyte-supported model. The highest electrical system efficiencies for the ASM and the ESM are 62.32% and 56.23%, respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2021-11-22T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5500 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5500 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:8 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5500

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5473 2021-10-26T21:00:00Z 1

The Effect of Nusselt Number on a Bi-viscosity Fluid Subjected to Discrete Heating Effect M. Adnan Anwar, Mudassar Razzaq Bi-viscosity, Thermal Effects, Finite Element Method, Nusselt Number, Discrete Heaters Discrete heating action has been established as an energy-efficient method. Nusselt number plays a significant role in the heat transfer rate. Local Nusselt number is useful in analyzing the heat transfer rate along the sections of the side walls with different or the same temperature in a heated enclosed cavity. Whereas, the average Nusselt number quantifies the total heat change in the closed cavity. While the path of the trajectory of the heat flow is being analyzed by heat function. In the current work, multiple heaters of length l1, l2, and l3 are assembled at each side of the isosceles triangle. The numerical simulations of the modeled system along with boundary conditions are carried out by using the standard Galerkin Finite Element Method. The discretized nonlinear algebraic system is solved by using the Newton's method, and the resulting linear system of equations is solved by the direct solver (UMPACK). The behavior of fluid inside the closed triangle with (Pr=0.7,10) is observed. The results are reported in terms of the graphs of the temperature contours, streamlines, average, and local Nusselt numbers. The maximum heat transfer rate is observed in convection dominant cases. By increasing the magnitude of a bi-viscosity parameter, secondary circulation is observed for Pr = 10. The rate of heat transfer has a direct relation with the bi-viscosity parameter. The maximum values of average and local Nusselt numbers are achieved by using the heat generation parameter against the Grashof number. Journal of Thermal Engineering Journal of Thermal Engineering 2021-10-26T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5473 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5473 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:7 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5473

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5474 2021-10-27T21:00:00Z 1

Examining Performance and Optimization of a Cogeneration System Comprised with Allam Cycle and MED-TVC for Generating Power and Drinking Water: Case Study: Kish Island Azadeh Ahmadi, Ali reza Noorpoor, Alireza Kani, Alireza Saraei Multi-effect distillation, Allam Cycle, Exergy, Energy, Optimization In this paper, a new thermodynamic cycle for power and fresh water production is presented, which includes MED-TVC desalinations and Allam cycles due to the important influence they have on the electric power industry in controlling and limiting greenhouse emissions. First, the Allam cycle analyzed and the appropriate location for heat-extraction identified to produce the required water vapor for the desalination system. It was determined that the heat site suitable for use in the desalination cycle is the heat from the outlet of the Compressor, which is estimated as 100 MW. The MED-TVC Desalination, one of the most suitable and most economical desalination, is used to combine the Allam cycle and desalination in the Kish district, located in the south of Iran. The proposed cycle is analyzed from the perspective of energy and exergy. The results show, the highest amount of exergy used to generate power in turbine and the amount of produced freshwater increase with increasing the capacity of Turbine. For this purpose genetic algorithm is used in two different scenarios to minimize and maximize the exergy destruction and produced fresh water respectively. The optimization of the system with genetic algorithm led to 18% decrease in total exergy destruction of the cycle in the first scenario and 7% decrease in the second optimization scenario. Furthermore, the efficiency of the cycle in first scenario and second scenario increased by 30% and 13% respectively. In the scenario optimization scheme, the amount of fresh water increased by 22%. Journal of Thermal Engineering Journal of Thermal Engineering 2021-10-27T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5474 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5474 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:7 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5474

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5546 2022-03-08T21:00:00Z 3

Hybrid Nanofluids Development and Benefits: A Comprehensive Review S. Suneetha, K. Subbarayudu, P. Bala Anki Reddy Nanofluid, Heat Transfer, Thermal Conductivity, Viscosity, pH control Hybrid nanofluids (HNFs) have received the prominent attention of researchers due to their improved thermophysical properties than conventional liquids and single-phase nanofluids. Such high potential heat transfer fluids are obtained from the suspension of two or more dissimilar nanoparticles in a regular heat transfer liquid. Owing to the high heat transfer properties of hybrid nanofluid, these are widely used in industrial processes, manufacturing processes, and biomedical engineering. This framework presents a detailed review of hybrid nanofluids preparation, stability, thermophysical properties, and importance in various engineering fields. Furthermore, present analysis addresses the pH control and ultrasound intensity of hybrid nanofluid. This analysis also manifests a hybrid nanofluid preparation method and suitable nanoparticles mixers for various industrial uses. This study reveals some future trends and possibilities related to HNF and a few suggestions regarding the scope in the future research in this area. A big impact with small particles for coming years. Journal of Thermal Engineering Journal of Thermal Engineering 2022-03-08T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5546 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5546 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5546

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5475 2021-10-27T21:00:00Z 1

Thermoeconomical Optimization of a Regenerative Air Turbine Cogeneration System Andrii Kostikov, Victoriia Tarasova, Mikhail Kuznetsov, Marat Satayev, Dionis Kharlampidi Air Turbine, Cogeneration System, Exergy, Thermo-economic Optimization The concept of optimization of operating and design parameters of the regenerative air turbine cogeneration (RATC) system is proposed. To determine the energy efficiency indicators of this system, its thermodynamic analysis was performed. At the same time, it is shown that it is not correct to search for the optimal parameters of such a system only by energy indicators, and modern thermoeconomic methods should be more actively involved in pre-design practice, which allow a comprehensive evaluation of the efficiency and economy of the energy-technological system as a whole and its individual elements. Therefore, on the basis of the data obtained during the thermodynamic analysis, exergy destruction and losses in the main system elements were calculated. Then, using the structural-variant method in combination with the graphical apparatus of C-curves, the pre-project thermoeconomic optimization of the RATC system was performed. This made it possible to choose the optimal operating and design parameters of the system and determine the minimum cost for its creation and operation throughout the entire life cycle, taking into account the thermodynamic perfection of the main system elements. Each variable operating mode parameter of the system serves as a kind of navigator when searching for the option of system parameters that is optimal in terms of energy and economic indicators, which is accompanied by graphic visualization. Therefore, the proposed approach makes the optimization of the system being designed convenient and clear. It can be used in the optimal design of various types of thermal transformers and other energy-technological systems. Journal of Thermal Engineering Journal of Thermal Engineering 2021-10-27T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5475 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5475 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:7 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5475

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5513 2021-12-20T21:00:00Z 1

Numerical Investigation of the Heat Transfer Enhancement Inside a Square Duct with Rectangular Vortex Generators Mustafa Al-Dulaimi, Fadhil A Abdulrazzaq Kareem, Faik Hamad Heat Transfer, Pressure Drop, Rectangular Vortex Generators, Heat Exchanger, Square Duct. This paper presents a numerical investigation of heat transfer and Pressure drop characteristics in a heated square duct in the presence of rectangular vortex generators (VGs) fixed at the center line of the duct. The Reynolds number is fixed at 5000 for all cases. The geometrical properties in this investigation are: i) The blocking ratios are 0.1, 0.15 and 0.2), ii) Vortex generator numbers are 1, 2, and 3), iii) Attack angles are 0, 30, and 45, iv) The aspect ratios are 1, 1.5 and 2. The numerical simulation is carried out using ANSYS FLUENT 15 . The results show that the rectangular vortex generators have a positive influence on heat transfer as a result of the augmentation in turbulence level. The maximum enhancement in average heat transfer could reach 40%. The heat transfer is found to increase with the blocking ratio. The heat transfer enhanced by 17% for one VG and 28% for 3 VGs for blocking ratio = 0.2. The VGs at angle ? value of 45?^° produce the highest heat transfer enhancement. The aspect ratio is found to have an adverse effect on heat transfer rate. Journal of Thermal Engineering Journal of Thermal Engineering 2021-12-20T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5513 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5513 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5513

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5528 2022-01-26T21:00:00Z 1

Three Dimensional MHD Nanofluid Stagnation Point Flow with Higher Order Chemical Reaction S. Jagadha, D. Gopal, P. Vijay Kumar, N. Kishan, P. Durgaprasad Chemical Reaction Parameter, Brownian Motion Parameter, Magnetic Parameter, Darcy Number, Variable Viscosity Parameter and Thermophoresis Parameter This work is focused on mathematical modeling on three dimensional nanofluid on heated vertical surfaces. We investigated MHD stagnation point flow with variable viscosity in the governing fluid flow where nanoparticles are suspended in it. The impact of higher-order chemical reaction of nanofluid flow at a stagnation point in three dimensional is the novelty of the problem. The Brownian motion parameter and thermophoresis parameter are incorporated in the present MHD Nano fluid model. This model helps the industry especially in cooling the devices by analyzing the energy level, is the main investigation of this paper. The physical interpretations of nanofluid flow is extracted in terms of mathematical equations containing partial derivatives along with boundary conditions. The numerical results are obtained by reducing governing equations into coupled nonlinear mathematical ordinary differential equations with transformations using similarity variables. The numerical method Runge-Kutta is employed and computed using MATLAB bvp4c and graphical presentations are obtained for numerical solutions. The effect of dimensionless flow parameters such as order of chemical reaction ‘n’, magnetic strength , Darcy number , buoyancy parameter , thermophoretic force parameter , variable viscosity parameter , Brownian motion parameter in Nano fluid flow, homogeneous chemical reaction process are discussed. This investigation revealed that temperature and concentration profile enhance at a large value of the thermophoresis parameter in the nanofluid flow and random Brownian motion parameter develops energy level and decline concentration profile at more values. Comparison of the present results with known numerical results is shown and a good agreement is observed. The heat and mass transfer characteristics were obtained and tabulated. The Nusselt and Sherwood numbers enhance for the dimensionless Nano parameters. Journal of Thermal Engineering Journal of Thermal Engineering 2022-01-26T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5528 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5528 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5528

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5532 2022-01-31T21:00:00Z 1

Effect of HVAC System Size on the Optimum Insulation Thickness of the Buildings in Different Climate Zones Maryam Karami, Ehsan Anbarzadeh, Shahram Delfani Climate zone, Energy saving, Genetic algorithm, Heating and cooling system, Optimum insulation thickness Thermal insulation is one of the most effective methods of reducing energy consumption in buildings. Therefore, the parameters influencing the optimum insulation thickness are widely investigated. In this study, the optimum insulation thickness is obtained using the life cycle analysis method and the genetic algorithm by considering the size of the heating and cooling systems as an optimization variable, which has not been addressed in the earlier researches. Furthermore, the effect of the climate conditions on the optimum insulation thickness is comprehensively studied using five different climate zones, including Hot-Dry, Cold-Dry, Moderate-Humid, Hot-semi Humid, and Hot-Humid. It is found that the optimum thickness of expanded polystyrene insulation increases between 5%-19% considering the size variation of the heating systems including the central heating system and wall-hung gas boilers. By size variation of the cooling systems including the evaporative cooler and split air conditioner, this increase is between 8-19%. This is because the cost reduction due to the reduction of the required size of the heating and cooling systems can be expended for insulating the building with larger thickness which results in lower energy consumption. Based on the obtained results, the energy cost saving increases between 3.5%-14.5% and also, the payback period decreases about 1 to 3 months, depending on the considered heating and cooling systems and climate zone. The results confirm that the optimum insulation thickness can be determined with significant inaccuracy, ignoring the size variation of the heating and cooling systems as a result of thermal insulation. Journal of Thermal Engineering Journal of Thermal Engineering 2022-01-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5532 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5532 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5532

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5527 2022-01-23T21:00:00Z 1

Numerical Analysis of A Two-Phase Injection Refrigeration Cycle Using R32 Praveen Alok, Debjyoti Sahu R32, Two-phase Injection, Discharge temperature, EER, Scroll Compressor The present paper reports the performance of a popular refrigerant R32 (Difluoromethane, CF2H2) experiencing the two phase injection process. Two phase injection process may lower the discharge temperature of a multistage compressor. In order to investigate the role and impact of two-phase injection on a compressor, a Scroll compressor is selected because scroll compressor has high tolerance for liquid refrigerant. A reputed compressor is chosen where all the operating conditions and specifications are available in public domain. The modelling and analysis of refrigeration system is carried out using a simple MATLAB code. Around 200 iterations were performed for four different condensing and evaporating temperatures. The maximum reduction in discharge temperature is found to be 44? when compared to R410A used in the same system. Journal of Thermal Engineering Journal of Thermal Engineering 2022-01-23T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5527 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5527 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5527

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5529 2022-01-26T21:00:00Z 1

Performance Estimation of a Solar Chimney Power ‎Plant (SCPP) ‎in Several Regions of Turkey Khaoula Ikhlef, İbrahim Üçgül, Salah Larbi, Samir Ouchene Solar Chimney Power Plant (SCPP), Storage system, Turkey meteorological‎ data, ‎Numerical study As the demand for energy increases, it will be more and more necessary for Turkey to diversify its energy sources by investing in renewable energy technologies. In this study, we have presented an updated ‎review of solar chimney power plants, including most analytical, experimental, and numerical ‎simulation studies. We have also analyzed the effect of environmental factors on the performance of a large/small scale prototype of a solar chimney with a thermal storage system for different meteorological data. We have considered five regions of Turkey corresponding to different weather conditions (Adana, Antalya, ‎Burdur, Isparta, and Izmir). The small-scale prototype's theoretical results were ‎compared with ‎the solar chimney prototype's experimental data acquired at the Suleyman ‎Demirel University. Good ‎agreement is observed between theoretical and experimental results. The obtained results ‎showed ‎that the global horizontal irradiance, the ‎temperature, the relative humidity, and the wind velocity ‎influence the power output. Antalya region has the best power production according to it is the warmest and most irradiating site. Notice that the total annual power produced is 46.34E+6 kWh and 439.1E+3 kWh for large and small prototypes, respectively. The high wind velocity of the region generates a ‎decrease in power production. Journal of Thermal Engineering Journal of Thermal Engineering 2022-01-26T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5529 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5529 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5529

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5572 2022-04-19T21:00:00Z 1

CFD Analysis and Heat Transfer Characteristics of Printed Circuit Heat Exchanger Nizar El Hakim, Jeffry Assaf, Bechara Nehme, Barbar Zeghondy, Walid Said, Jad Jelwan PCHE, SCO2, Cubical fins, Enhance Heat Transfer, Fanning Friction Coefficient This paper aims to investigate the cubical fins and the thermal-hydraulic characteristics in a Printed Circuit Heat Exchanger (PCHE). The working fluid is considered as a supercritical LNG. Results show that the thermal-hydraulic performance is improved using the cubical fins comparing it to the straight channel. The maximum and minimum difference of N_u/E_u between the cubical fins channel and the straight channel was 71.7 % and 64.8 % respectively. It is observed that the pressure drop and the heat transfer coefficient increased with increasing the mass flux. Using Ansys Fluent 15.0, numerical optimization is conducted to study the effect of the sparser staggered arrangement. The computed results show that this type of arrangement improves the thermal-hydraulic performance of the cubical fins in a PCHE. A comparison between the straight fins arrangement and the staggered fins arrangement is reported. It has been noticed that the velocity of the LNG flow in the cubical fins channel is increased along the length of the PCHE, and decreased by increasing the vertical separation? L?_V. The effect of the vertical separation L_V on the PCHE’s performance was more evident than that of the staggered arrangement L_S. Finally, a feasibility study is performed in order to inspect the power consumption in relation to the new design. Journal of Thermal Engineering Journal of Thermal Engineering 2022-04-19T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5572 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5572 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5572

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6971 2024-03-22T21:00:00Z 3

Growth in Turbine Size and Technological Development of Modern Commercial Large Scale Wind Turbines in Türkiye Mehmet BİLGİLİ, Hakan ALPHAN, Arif AKTAŞ hub height; potential visibility; rotor diameter; wind turbine size; wind turbine technology; specific power capacity In this study, along with the recent progress and trends of wind turbine technology around the world, the progress of commercial wind turbine technology installed in Turkey has been studied thoroughly. In this respect, several metrics for installed wind turbines such as installed power capacity (MW), number of turbines, mean rated capacity (MW), mean rotor diameter (m), mean specific power capacity (W/m2), and mean hub height (m) have been obtained between the years of 2011 and 2019. According to the obtained results, the mean rated capacity of yearly installed wind turbines in Turkey increased from 1.86 MW in 2011 to 3.52 MW in 2019. However, the mean specific power of yearly installed wind turbines decreased from 423.7 W/m2 to 314.1 W/m2. Results show that the growth in the size and the decrease in the specific power have contributed to the tendency of higher power outputs, and wind power generation capacity and turbine capacity factors have been on the rise in Turkey. Eventually, wind turbines with higher hubs and rotor diameters have become more visible in landscapes. To this end, a potential visibility model (PVM) has been proposed as an auxiliary variable to control turbine visibility during site-selection. Journal of Thermal Engineering Journal of Thermal Engineering 2024-03-22T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6971 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6971 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6971

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5331 2021-02-25T21:00:00Z 1

Exergetic and Energetic Evaluation of an Innovative Solar Air Heating System Coated with Graphene and Copper Oxide Nano-Particles Rahul Kumar, Sujit Kumar Verma Triangular Solar Air Heater, Entropy Generation, Solar Intensity, Nano-particles, Absorber Plate Coating, Heat and Mass Transfer. In the 21th century, renewable energy has to play very important role in socio-economic and industrial development. This paper evaluates the exergy- energy analysis, which is based on the second law of thermodynamics. The triangular solar heater is developed to determine the heat transfer rate, thermal efficiency, exergy efficiency and Bejan number. In addition, we have examined the effects of entropy generation with respect to solar radiation and ambient temperature of air. Absorber plates coated with graphene and copper oxide nano-particles by the different percentages (0.1%, 0.2%, 0.3% & 0.4%) doped into black paint which increases the absorption of heat. The Reynolds number (4500≤R_e≤22700) varies for the fixed selective coating on absorber plate and mass flow rate. The experimental observations were performed for constant mass flow rate of air ranging from 0.0035kg/s to 0.018 kg/s. The experimental result gives the average thermal efficiency enhancement of 3.58% for 0.3% graphene/CuO-black paint. Entropy generation is more for 0.1% and minimum for 0.3% graphene/CuO-black paint coating. The entropy generation analysis concludes that the entropy generation increases with increasing the mass flow rate. Exergy efficiency enhancement can be found 0.169%for 0.3% with respect to 0.1% graphene/CuO-black paint. Journal of Thermal Engineering Journal of Thermal Engineering 2021-02-25T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5331 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5331 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5331

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5573 2022-04-24T21:00:00Z 1

Performance Analysis of Microchannel Heat Sink with Flow Disrupting Pins Vinayak Gaikwad, Suhas Mohite Pin-enhanced Microchannel, Enhancement Factor, Pressure Drop, Thermo-hydraulic Performance, Electronics Cooling Study of thermo-hydraulic characteristics of a novel microchannel heat sink having flow disrupting pins is numerically and experimentally carried out in this paper. Cylindrical pins are inserted from top cover into the rectangular microchannel instead of the conventional technique of pin-fins originating from the base of microchannel. Initially, the effect of pin diameter on the thermo-hydraulic performance is studied and the optimum pin diameter is established, later on thermo-hydraulic performance of pin enhanced microchannel heat sink (PEMCHS) is compared with conventional microchannel heat sink (MCHS). Of the five pin diameters studied, pin having 0.2mm diameter (relative pin diameter γ=0.4) gives the best performance. Both conventional MCHS and PEMCHS are subjected to heat flux ranging from 65W/cm2 to 200 W/cm2 and cooled by water flowing at Reynolds number ranging from 745 to 1500. The presence of pins disturbs the velocity distribution completely and increases the heat transfer capacity of the MCHS accompanied by higher pressure drop penalty. The average enhancement factor obtained by this technique is 1.24. Correlations showing the effect of channel width to pin diameter ratio (Wc/Dp) on Nusselt number (Nu)and friction factor (f) are proposed. Journal of Thermal Engineering Journal of Thermal Engineering 2022-04-24T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5573 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5573 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5573

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5502 2021-11-25T21:00:00Z 1

No Formation and Its Reduction Through Co-flow Methane Reburn in a Pulverised Coal Combustion Process Under Various Overall Equivalence Ratio Ajay Kumar Sahu, Prakash Ghose Pulverized Coal, Combustion, Equivalence Ratio, Co-flow Methane, Reburn Computational simulation has been carried out to investigate the NO formation/depletion in pulverized coal combustion process. Newlands Bituminous coal is injected along with career air through a central hole of an axi-symmetric burner. A certain amount of co-flow methane is injected coaxially as reburn fuel. The effect of overall equivalence ratio on NO formation and NO reburn are mainly focused in this study. Species concentration for various species are also investigated, because both NO formation and depletion are related closely to various species concentration. From the study it is observed that, at overall equivalence ratio ?=0.8 and 1.0, although the rate of Thermal-NO, Prompt-NO and Fuel-NO formation is high but due to narrow reaction zone and higher air velocity, a weak NO concentration field is observed. On the other hand, a higher NO concentration has been observed with higher equivalence ratio (ratio ?=3.0,6.0 and 9.0). It also has been observed, the maximum NO reduction efficiency at ?=0.8, 1.0 and 3.0 is in between 1% to 7%, whereas for ?=6.0 and 9.0, the maximum NO reduction efficiency is 27% and 34% respectively. Therefore co-flow methane injection NO reduction method is more suitable for highly rich mixture conditions. Moreover the percentage of coal burnout is also relatively higher for higher equivalence ratio condition. Journal of Thermal Engineering Journal of Thermal Engineering 2021-11-25T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5502 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5502 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:8 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5502

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5603 2022-06-24T21:00:00Z 1

Heat Transfer Analysis using a Duct Filled with Metal Foams Abhisek Banerjee, Diplina Paul Conjugate Heat Transfer, Heat Pipes, Heat Exchangers, Porous Media, Reynolds Number, Nusselt Number Thick-walled pipe experiencing internal flow is widely used in a variety of applications in the industry. Some of the most prominent ones are heat exchangers, heat pipes, furnaces, etc. In this study, conjugate heat transfer has been examined in a pipe filled with a porous medium experiencing a constant external heat flux. The analysis is based on a two-dimensional domain using a quasi-thermal equilibrium model. Effects of porosity, pore density, Reynold’s number and thermal conductivity of solid and fluid on the Nusselt number have been studied. Three types of porous foams based on the pore density have been chosen for the analysis: 10 PPI, 40 PPI and 60 PPI. The results have been generalized for use in a wide range of Newtonian fluids. Additionally, the pressure drops across the pipes filled with porous media have been studied as a function of pore density and Reynold’s number. Numerical results indicate augmented performance with porous foams of high pore densities. However, using a porous medium with higher pore density leads to higher pressure drop, thus needing pumping power. The computational model used in this manuscript predicts that Nusselt number is increased by 38.7 % with Reynold’s number < 10000, when the porous medium is changed from 10 PPI to 60 PPI. The numerical data presented in the manuscript supports the application of low porosity foam with low pore density to achieve better thermal transport at the cost of pressure drop. Journal of Thermal Engineering Journal of Thermal Engineering 2022-06-24T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5603 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5603 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5603

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5574 2022-04-25T21:00:00Z 1

Design studies on horizontal and vertical configuration of Ground Earth Heat Exchanger Ankur Sukhija, Amit Sharma Ground Earth Heat Exchanger; Design Software; Horizontal and vertical exchanger Configuration. In this work, user friendly software is described for the easy design of the GEHE. There are different procedures for designing the geothermal heat exchanger. Based on the different ways to extract the energy and the configurations of the GEHE system several methods are used for the design of the system. The software developed is based on two of such methods which are explained along with their applications in this paper. Results of the software along with some images of the software is also presented in this work which is compared by the help of a system which is installed in the library building of Deenbandhu Chhotu Ram University of Science and technology, Murthal along with the results of the software are compared with various scholarly articles published by different researchers based on different experimental setups or the simulation results for both the horizontal and vertical systems. A proposed system for the vertical type GEHE which can be installed in DCRUST Murthal is also presented in this paper. The results show that the methods used in the designing of the GEHE in the software gives very close values, i.e., the percentage average deviations are in the range of 0.5 to 6% to the actual system for the cases considered in this work. Journal of Thermal Engineering Journal of Thermal Engineering 2022-04-25T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5574 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5574 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5574

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5337 2021-02-27T21:00:00Z 1

Experimental Assessment of Comparative R290vs. R449a Refrigerants by Using 3E (Energy, Exergy and Environment) Analysis: A Supermarket Application Erhan Arslan, Meltem Kosan, Mustafa Aktas, Suleyman Erten Comparative R290vs. R449A, Refrigerant, Environmental Analysis, Energy and Exergy Analysis Efficiency is becoming an increasingly important issue in cooling systems. It is important to use micro channel heat exchangers in order to increase the cooling system efficiency. In this study, performance analysis of refrigerants used in supermarkets was tested experimentally. Thermodynamic analyses of the refrigerants were examined. The compatibility of R290 and R449A refrigerants with the environment has been experimentally observed. Energy, exergy, and environmental analyses were performed using R290 and R449a refrigerants based on the test results for 24 hours using double inlet and double outlet evaporator. Accordingly, in the experiments using R290, the exergy efficiency and COP value are 43.52 % and 2.09, respectively. In experiments using R449A, these values were found to be 22.28 % and 1.59. Exergy efficiency was increased by 48.81 % in experiments using propane. In addition, an increase of 24.12% was observed in the Coefficient of Performance (COP) value. Considering the environmental analysis results, the amount of CO2 emitted by the R290 refrigerant to the atmosphere during the test period was 3.14 kg/h and R449A was calculated as 3.97 kg/h. It was seen in this study that the R290 refrigerant emits 26.22 % less CO2 to the atmosphere. Journal of Thermal Engineering Journal of Thermal Engineering 2021-02-27T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5337 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5337 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5337

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5498 2021-11-17T21:00:00Z 1

Performance Evaluation of a Rotary Dryer in Both Co-Current and Counter-Current Configurations Asmae Echeeri, Mostafa Maalmi Co-current, Counter-current, Energy and exergy analysis, Mathematical model, Rotary dryer, Superphosphate fertilizer A mathematical model was developed to simulate the process of superphosphates fertilizers drying in a rotary dryer in both co-current and counter-current configurations. Besides, the performance of the rotary dryer, installed in a local industrial unit, was assessed using the concept of energy and exergy analysis. Matlab software was used to develop the mathematical model, which is based mainly on mass and energy conservation equations. Good agreement between the simulated results and the experimental results from literature was obtained. The simulation results showed that the product’s moisture content was reduced from an initial value of 0,14 kgH2O / kg dry solid to 0.0912 and 0.0862 kgH2O / kg dry solid at the dryer's outlet for the co-current and the counter-current configurations, respectively. A parametric study was carried out to evaluate the effect of the length of the dryer and the inlet drying air temperature on the moisture content to compare both configurations. Energetic and exergetic indicators were formulated and then computed based on the inlet operating conditions. The energy efficiency and the specific energy consumption for the co-current and the counter-current configurations were, respectively, found to be 13% and 24% and 5762 and 3502 kJ per kg of water evaporated. The exergy indicators, namely the exergy loss, the exergy destruction rate, and the exergetic efficiency, were 11.37 and 17.82 kW, 1.026 and 1.098 kW, 25.86 and 41.38% for the co-current and the counter-current configuration, respectively. A sensitivity analysis was used to investigate the effect of varying the inlet drying air temperature on energetic and exergetic performance parameters. Journal of Thermal Engineering Journal of Thermal Engineering 2021-11-17T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5498 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5498 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:8 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5498

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5507 2021-11-29T21:00:00Z 1

Development and Performance Analysis of Hybrid Photovoltaic/Thermal (PV/T) System Hamza Pervez, Muhammad Ali Kamran, Sallah udin, Abdul Ahad, Muhammad Alam Zaib Khan, Muhammad Faiq PV Module, Photovoltaic/Thermal, Critical Temperature, Thermal Efficiency Increase in the surface temperature of Photovoltaic (PV) module affects its efficiency and life adversely. This relationship between efficiency and surface temperature of a PV module is defined as the temperature coefficient. Since solar parks are long-life projects, a small drop in efficiency of modules might result in a significant reduction in overall power output for large projects making this option unfeasible, for both economical and energy yield perspectives. This loss in power can be reduced by cooling of PV modules. A hybrid Photovoltaic and Thermal system (PV/T) system was developed in this study to investigate the impact of this system on overall efficiency. In addition to producing electrical energy, the heat gained by the circulating fluid was utilized for domestic usage. A critical temperature of the PV module was identified in this study beyond which the drop in efficiency was higher than the temperature coefficient. This critical temperature was noted to be a function of radiation intensity and decreased with decreasing intensity. Incorporation of the cooling system resulted in a decrease in surface temperature of the module by 20% with an increase in electrical efficiency of up to 2.3%. The overall efficiency of the PV/T system of at least 70%, with a maximum overall efficiency of 85% was observed at different radiation intensities, making this system a viable alternative to the conventional PV or thermal systems being used currently. Journal of Thermal Engineering Journal of Thermal Engineering 2021-11-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5507 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5507 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:8 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5507

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5601 2022-06-14T21:00:00Z 1

Combined Heat Pump Heating and Ventilation System Using Heat of Soil, Sewage Water and Ventilation Emissions Mykhailo Bezrodny, Serhii Oslovskyi Heat pump, Thermodynamic analysis, Vertical ground heat exchanger, Recovery, Low-temperature energy sources, Conditionally clean wastewater, Energy efficiency Currently, one of the main energy consumers in many countries is the communal sector. In this case, the bulk of the energy is supplied by fossil sources. In this regard, studies in the field of alternative energy sources that can help solve not only the problem of energy saving, but also the problem of environmental pollution and prevent the approaching environmental collapse deserve special attention. One of the most promising sources of alternative energy in the field of communal utilities is heat pump that use the low-temperature heat of renewable sources and the heat of the upper layers of the soil. Soil, as an energy source, has an almost constant and sufficiently high temperature level, which determines the sufficient efficiency of using its heat. However, the widespread occurrence of this type of heat pump is hindered by the high cost of the ground heat exchanger and its installation. In this regard, the development of new heat supply schemes having higher energy efficiency is relevant. To solve this problem, a combined heating and ventilation scheme based on ground heat pump was developed. The feature of this scheme is the use of additional low-temperature energy sources, such as the heat of ventilation emissions and wastewater of a heat supply facility. On the basis of the scheme the thermodynamic model in which the equation of the basic balance of separate elements and the scheme as a whole found the defining parameters characterizing work of system is developed. An algorithm for determining parameters at the nodal points of the chain is proposed, on the basis of which a numerical analysis of the circuit is performed. The results of the analysis are presented in the form of graphical dependencies. Features of operation of the scheme depending on the set initial parameters and ambient temperature are shown. Conclusions are made on the possible reduction of capital and operating costs for heating and ventilation due to the proposed solution. Journal of Thermal Engineering Journal of Thermal Engineering 2022-06-14T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5601 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5601 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5601

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5333 2021-02-26T21:00:00Z 3

Comprehensive Review on the Flow Characteristics of Two-Phase Flows in Inclined Tubes Hakan Karademir, Güven Özçelik, Özgen Açıkgöz, Ahmet Selim Dalkılıç, İbrahim Timuçin İnce, Josua Meyer, Somchai Wongwises Flow Boiling, Flow Condensation, Two-Phase Flow Heat Transfer, Inclined Tubes, Heat Transfer Coefficient, Pressure Drop, Comprehensive Review This paper presents a comprehensive review of research works on condensation and boiling heat transfer characteristics in horizontal, vertical and inclined tubes both smooth and enhanced. Although there are many studies examining two-phase flows inside tubes, it is almost impossible to find such a comprehensive study for two-phase flow in tubes. Moreover, while number of the studies concerning condensation or boiling inside tubes are limited, the present study covers almost all studies of condensation and boiling inside inclined tubes. Previous studies are classified into many subtitles according to configuration (horizontal, vertical or inclined) and roughness (smooth or enhanced) as well as aim of the study (researching the effect of parameters on the heat transfer coefficient, pressure drop or evaluation of prediction correlation). Such a wide range of classification and scope have no done before. Condensation and boiling phenomena are of great importance in heat exchangers, cooling systems, etc. due to their wide utilization in those devices. Additionally, two-phase flow and the associated heat transfer are becoming increasingly important in industrial applications because the heat transfer coefficient in two-phase flows is much higher than in single-phase flows. In this research, major topics such as heat transfer, pressure drop, friction factor and void fraction were studied using active and passive techniques in the literature. The fluids used in the reviewed studies diverse in a very wide range. For pure refrigerants (single component-fluorocarbon refrigerant), R11, R12, R22, R32, R-113, R123, R-124, R125, R134, R134a, R142b, R152a, R236fa, R245fa, R-600a, R1234ze, R1234yf and for zeotropic blend refrigerants, a mixture of two or more components having different boiling points, R410A, R404A, R407C, R447A are used. As zeotropic blend refrigerants, a mixture of two or more components that boil at the same temperature, R502. Besides, water (steam for condensation), FC72, CFC 113, Propane, HFE 7000 (1-methoxyheptafluoropropane), R744 (CO2), and liquid nitrogen are involved in researchers’ studies. In the present review, effects of parameters on two-phase flow heat characteristics are evaluated. Based on the evaluation, it can be drawn that inclination angle have significant effect on both condensation and boiling heat transfer coefficient and pressure drop. On the other hand, it was found that vapour quality and roughness were the main parameters affecting two-phase flow heat transfer characteristics. Effects of all parameters are discussed in the corresponding section. When existing correlations in the literature on prediction flow boiling heat transfer coefficient are evaluated, correlations proposed by Müller-Steinhagen and Heck [103] and Friedel [113] were to be best for prediction well according to majority of researchers and for performance of prediction on pressure drop correlation by Müller-Steinhagen and Heck [103] stood out. Journal of Thermal Engineering Journal of Thermal Engineering 2021-02-26T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5333 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5333 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5333

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5607 2022-08-05T21:00:00Z 1

Transient Analysis of Convective-Radiative Heat Transfer through Porous Fins with Temperature-Dependent Thermal Conductivity and Internal Heat Generation Armin Emamifar, Hesam Moghadasi, Mohammad Javad Noroozi, Hamid Saffari Porous Fin, Galerkin Weighted Residuals Method, Convective-Radiative Heat Transfer, Thermal Conductivity. In this research study, the transient study of heat transfer through a convective-radiative porous fin is carried out considering temperature-dependent thermal conductivity and internal heat generation. The unsteady Galerkin weighted residuals technique is employed to obtain the transient temperatures of the porous fin. The results indicate that increasing of the fin base temperature, internal heat generation and, thermal conductivity lead to increase heat transfer along the fin and consequently the higher temperature of the entire of the fin achieved. However, increasing of the porous and radiative parameters result in more heat dissipation from the fin and cause to lowering the fin temperature which leads to increase heat flux entering the fin through the base. Furthermore, the transient thermal analysis of the porous fin illustrates that by increasing the porous and the radiation parameters, the fin cools down faster, so in the applications that the time of cooling is more important, these parameters can be more noticeable. Journal of Thermal Engineering Journal of Thermal Engineering 2022-08-05T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5607 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5607 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5607

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5424 2021-08-02T21:00:00Z 1

A Review on Effect of Various Artificial Roughness on Heat Transfer Enhancement in a Channel Flow Sudharani Panda, Rakesh Kumar Dimple, Friction factor, Heat transfer, Protrusion surface, Artificial surface roughness Theheat transfer rate of gas turbine blade of power plant, combustion lineras well as solar air-heater can be enhancedby implementingroughness element like rib turbulators, pin fins and dimple by creating disturbance in the flow. Solar energy transported from the sun to the earth surface is one of theworld’s most interminable renewableenergy sources. This energy is in the form of electromagnetic waves in space and then converted into heatwhen it interactswith the earth surface. The solar air heater absorber absorbsthe solar radiation over which the air heated to be passed. The heated air then utilized in various application such as drying agricultural crops, space heating and used in industrial application by the help of solar air heater. As the air has lower heat transfer coefficient hence in order to increase the convection heat transfer rate the surface area ofthe absorber plate is enhanced by implementing roughness element. Toimprovethe rate of heat transfer, comprehensive reviews of literatures have been carried out on various types of dimples and rib turbulators. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-02T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5424 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5424 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5424

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5604 2022-06-26T21:00:00Z 3

A Critical Assessment of the Implementation of Phase Change Materials in the VCC of Refrigerator Manish S. Deshmukh, Dheeraj S. Deshmukh, Sandip P. Chavhan VCC, Refrigerator, PCM, LHSX, Condenser, Evaporator. The ultimate heat storage system is an alternative way of improving the heat exchange in the home refrigerator. This research is a systematic analysis of the studies that are being performed with its advantages and limitations. Comments of the researcher on potential improvements in the current work to enhance efficiency are also checked. Key parameters influencing system performance and key issues related to effective system integration are discussed here. PCM integration with the standard setup is restricted by the use of low-temperature PCMs, which is why PCM analysis with Nano-particle additives can be performed. Most experiments are limited to a hot wall form only, the investigation of a PCM application for another form of the condenser is subject to further work. Besides, a combination of two thermal enhancement methods, such as LSHX and PCM, can be used to test the performance. Journal of Thermal Engineering Journal of Thermal Engineering 2022-06-26T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5604 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5604 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5604

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5432 2021-08-08T21:00:00Z 1

Heat Transfer Performance of a Radiator with and without Louvered Strip by using Graphene-based Nanofluids Sandhya Madderla, Devarajan Ramasamy, Sudhakar Kumarasamy, Kumaran Kadirgama, W.S.W. Harun Radiator, Louvered strip, Graphene (G) and Graphene Oxide (GO), Heat transfer The present work is focused on the Graphene-based nanofluids with high thermal conductivity which helps to improve the performance and enhance heat transfer. The thermal systems emphasis on the fluid coolant selection and statistical model. Graphene is a super-material, lighter than air, high thermal conductivity, and chemical stability. The purpose of the research is to work up with Graphene-based Nanofluids i.e., Graphene (G) and Graphene oxide (GO). Nanoparticles are dispersed in a base fluid with a 60:40 ratio Water & Ethylene Glycol and at different volume concentrations ranging from 0.01%-0.09%. Radiator model is designed in modelling software and louvered strip is inserted. The simulation (Finite Element Analysis) is performed to evaluate variation in temperature drop, enthalpy, entropy, heat transfer coefficient and total heat transfer rate of the considered nanofluids, results were compared by with and without louvered strip in the radiator for the temperature absorption. 58-60% enhancement of enthalpy observed when Graphene and Graphene oxide nanofluid was utilized. 1.8% enhancement of entropy is observed in 0.09% volume concentration of the Graphene and Graphene oxide nanofluid when louvered strips are inserted in the radiator tube at a flow rate of 3 LPM. With louvered strip inserted in the radiator, heat transfer coefficient enhanced by 236% for Graphene and 320% enhancement is identified for Graphene oxide nanofluid when compared to without louvered strip insert. The results stated that high performance is observed with the utilization of louvered strip in the radiator tube. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-08T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5432 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5432 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5432

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5602 2022-06-24T21:00:00Z 1

A Critical Re-Examination of Reynolds Analogy for Micro-Convective Flow Rajan Kumar Micro-convection, Thermophysical fluid properties, Heat transfer, Friction factor, Non-dimensionalization The present research numerically investigates the validity of Reynolds analogy for micro-convective water flow between Stanton number (St) and Fanning friction factor (ff), taking into account combined fluid properties variations such as temperature-dependent density, viscosity, and thermal conductivity. The Reynolds analogy is suggested to be valid when St increases for thermophysical fluid properties (TFP) with a decrease in ff. This analogy therefore helps to find the flow regime that increases heat transfer while shear stress decreases for TFP. Hence, Reynolds analogy for TFP helps to design and improve the performance of the different devices, including micro-scale heat exchangers for electronics cooling, internal cooling passages of turbine airfoils, and a number of bio-medical devices. Three modified non-dimensional parameters (?S?T, ?SµT, and ?SkT) appear from the non-dimensionalization of the governing conservation equations. Using dimensional analysis, the dependence of the friction factor on these parameters is examined. Journal of Thermal Engineering Journal of Thermal Engineering 2022-06-24T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5602 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5602 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5602

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5526 2022-01-15T21:00:00Z 1

An Application of Conventional and Advanced Exergy Approaches on a R41/R1233zd(E) Cascade Refrigeration System Under Optimum Conditions Cenker Aktemur, Servet Giray Hacıpaşaoğlu Cascade Refrigeration System, Advanced Exergy Analysis, Conventional Exergy Analysis; R41, R1233zd(E) Painstaking adjustment of an optimum low-temperature cycle (LTC) condenser temperature allows cascade refrigeration system (CRS) to operate at maximum performance. This study exhibits an original approach because, for the first time, advanced exergy analysis is implemented under an optimum LTC condenser temperature of CRS operating with R41/R1233zd(E) as an environmentally-friendly refrigerant pair. Under the auspices of advanced exergy analysis, there is endogenous exergy destruction of 50.43% and exogenous exergy destruction of 49.57% within total exergy destruction. It is pointed out that the interactions between the CRS components (external irreversibilities) are partly less than exergy destruction that occurs within components (internal irreversibilities). The avoidable part within total exergy destruction, which is greater than the unavoidable part, indicates that components have a high improvement potential with a value of 56.31%. Furthermore, LTC compressor is dependent to a great extent on other components, as it has the largest exogenous part of exergy destruction with 75.82%. The results indicate that the CRS’s exergy efficiency, which can be determined based on conventional exergy analysis, is only 36%. However, this increases to 68% with the improvements needed for the components. Journal of Thermal Engineering Journal of Thermal Engineering 2022-01-15T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5526 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5526 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5526

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5545 2022-02-16T21:00:00Z 1

Application of ANN and Prediction of Drying Behavior of Mushroom Drying in side Hybrid Greenhouse Solar Dryer: An Experimental Validation Anand Kushwah, M.K. Gaur, Anil Kumar, Pushpendra Singh Mushroom: Drying, HGSD, Drying Kinetics, heat transfer ANN. The hybrid greenhouse solar dryer attached with evacuated tube solar collector is developed in roof of the campus of MITS, Gwalior, India. The heat transfer analysis of the developed dryer is carried out by drying mushroom inside it. The heat transfer coefficient plays an important role in the drying process. The study emphasizes on determining the convective and evaporative heat transfer coefficients and the determination of best drying rate model fit for the mushroom drying inside the dryer. The artificial neural network is developed for predicting the convective and evaporative heat transfer coefficients. The value of convective and evaporative heat transfer coefficients varies from 2.10 to 3.43 and 25.68 to 49.85 W/m2°C respectively. The developed ANN model helps in predicting the heat transfer coefficient once trained using input parameters like solar radiation, relative humidity, ambient temperature and time. The value of R2 for the developed ANN model is 0.99, which shows that model predicts the value very close to the calculated value of heat transfer coefficients. The drying kinetics of the mushroom is tried to fit in nine drying rate models. The Midili-Kucuk model shows the better fit among the other models. Journal of Thermal Engineering Journal of Thermal Engineering 2022-02-16T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5545 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5545 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5545

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6614 2022-08-21T21:00:00Z 1

Natural Convection Between Hot and Cold Cylinders in Enclosed Space Filled with Wopper-Water Nanofluid Houssem Laidoudi, Houari Ameur Nanofluid, Natural convection, Adiabatic cavity, Cold cylinder, Hot cylinder The present contribution is a numerical investigation of the natural convection between two circular objects, where the first one is hot and the second is cold. Both cylinders are placed in an enclosed adiabatic cavity filled with copper-water nanofluid. The cylinders are arranged horizontally in the middle of cavity height. The main target of this paper it to examine the effects of geometrical configurations and the thermo-physical characteristics of nanofluid on the fluid motion and heat transfer rates. Thestudy is conducted for various parameters: Rayleigh number(Ra = 103 to 105), nanoparticle volume fraction (? = 0 to 10%), the diameter of cylinders (d/H = 0.2 to 0.4), and the gap spacing between cylinder (S/H = 0.25 to 0.7). Also, two cavity shapes are studied (square and circular). The average Nusselt number of the cylinders is computed and plotted as function of the studied parameters. It was concluded that the cavity shape and the particle volume fraction have a negligible effect on the heat transfer rate, whereas the distance between cylinders and the cylinder diameter have a remarkable effect on the flow patterns and convective heat transfer. Journal of Thermal Engineering Journal of Thermal Engineering 2022-08-21T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6614 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6614 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6614

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5381 2021-05-01T21:00:00Z 1

Numerical Simulation of Prandtl Number Effect on Entropy Generation in A Square Cavity Nawal Ferroudj, Hasan Köten, Sacia Kachi, Saadoun Boudebous Generation Entropy Generation, Prandtl Number, Square Cavity, Finite Difference Method In this study, entropy generation in laminar mixed convection in a square fluid-filled cavity is numerically studied. The middle of the lower wall of the cavity is heated to a constant temperature Th while the side-walls are maintained at a constant temperature Tc, and moving upper ward at a constant velocity to understand the effects of irreversibility distribution on the entropy generation for different engineering applications. For the studied control surface, remaining parts of lower and upper walls are adiabatic. The finite difference method is used to solve the governing equation. The entropy analysis is carried out to determine the irreversibility which is generated in the cavity for different Prandtl number (Pr=0.0212, 0.71 and 6.35), the effect of the irreversibility distribution ratio on entropy generation was investigated. It seen that effect of irreversibility distribution ratio (γ=10-2 and 10-4) have play important role on the total entropy for different Prandtl number. Also it is clear that, for all Prandtl number, the total entropy generation increase by increasing the irreversibility distribution ratio and the increase of Prandtl number regardless the values of Ri=1 and Re=100 because of the increase of the velocity gradients. Journal of Thermal Engineering Journal of Thermal Engineering 2021-05-01T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5381 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5381 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5381

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6834 2023-10-16T21:00:00Z 1

Experimental Investigation for the Decisive Role of Vehicles in the Air Pollution of Arak City in Iran and Presenting the Related Solutions to Reduce the Air Pollution Seyyed Alireza Mostafavi, Hamed Safikhani, Hasan Köten, Yasin Karagoz Ecosystem; air pollution; Arak; air quality measuring stations; vehicles. In the World, in many of the large and industrial cities air quality is in a dire situation, and air pollution is considered a major problem. The first step in reducing the level of pollutants is to acquire enough detailed information about these pollutants, including the type, amount, and the rate of annual occurrence. In this study, the data obtained from the existing air quality measuring stations throughout the city of Arak in Iran have been used to conduct an accurate investigation and to perform hourly, daily, monthly, and annual analyses of various pollutants. The hourly analysis of the data collected from the Shariati square station at the downstream of the prevailing wind, which include the collective pollutions of the refinery, petrochemical plant, thermal power plant and the pollution generated by the vehicles in a high-traffic area, with regards to the annual calendar and the variation of pollutants during official holidays, indicates the determining share of vehicles in the air pollution of the city of Arak. Considering the effective role of vehicles in the extensive air pollution of this city, some policies have been suggested for reducing the level of air pollution. As a result of this study, using the stated transportation model the level of pollution in this city is considered to reduce, correcting the city streets and routes from engineering perspective. Also, results showed that the role of industry and vehicles on the air pollution and the pollution points in Arak city in ratio. The levels of all the pollutants like CO, NOx, PM2.5, O3 and SO2 measured by a station at the downstream and resulted about 3ppm, 20ppb, 10, 40ppb and 4 as a ratio respectively. Lastly, result of model was reported at the end of this paper in term of the optimization of the Arak city residential area.In the World, in many of the large and industrial cities air quality is in a dire situation, and air pollution is considered a major problem. The first step in reducing the level of pollutants is to acquire enough detailed information about these pollutants, including the type, amount, and the rate of annual occurrence. In this study, the data obtained from the existing air quality measuring stations throughout the city of Arak in Iran have been used to conduct an accurate investigation and to perform hourly, daily, monthly, and annual analyses of various pollutants. The hourly analysis of the data collected from the Shariati square station at the downstream of the prevailing wind, which include the collective pollutions of the refinery, petrochemical plant, thermal power plant and the pollution generated by the vehicles in a high-traffic area, with regards to the annual calendar and the variation of pollutants during official holidays, indicates the determining share of vehicles in the air pollution of the city of Arak. Considering the effective role of vehicles in the extensive air pollution of this city, some policies have been suggested for reducing the level of air pollution. As a result of this study, using the stated transportation model the level of pollution in this city is considered to reduce, correcting the city streets and routes from engineering perspective. Also, results showed that the role of industry and vehicles on the air pollution and the pollution points in Arak city in ratio. The levels of all the pollutants like CO, NOx, PM2.5, O3 and SO2 measured by a station at the downstream and resulted about 3ppm, 20ppb, 10, 40ppb and 4 as a ratio respectively. Lastly, result of model was reported at the end of this paper in term of the optimization of the Arak city residential area. Journal of Thermal Engineering Journal of Thermal Engineering 2023-10-16T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6834 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6834 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6834

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6752 2023-05-18T21:00:00Z 1

Designing of System for High Grade Heat Recovery in Thermal Cooling System for Process Heat Applications Alka Solanki, Yash Pal Single effect absorption system; water-lithium bromide; process heat; dairy industry An experimental investigation on design of a vapour absorption system using LiBr-H2Ofor high grade heat recovery in thermal cooling system for process heat applications has been conducted. A 1.5 kW cooling capacity of the LiBr-H2O vapour absorption system has been designed and tested under various operating conditions. Generator temperature, absorber temperature, condenser temperature and evaporator temperature have been varied and performance of LiBr-H2O vapour absorption system has been analysed. Experimental results are presented in terms of COP and circulation ratio. Further, to validate the results thermodynamic model is developed using first law of thermodynamics and simulate in Engineering Equation Solver. The COP and the circulation ratio estimated through simulations and experiments have been in good agreement with ±5% standard deviation. Further, this this research work is beneficial for dairy industries in process heat applications and realizing the importance of the need for energy conservation in dairy industries. Journal of Thermal Engineering Journal of Thermal Engineering 2023-05-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6752 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6752 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6752

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6608 2022-08-12T21:00:00Z 1

The Effects of Different Typical Meteorological Year Data on the Heating and Cooling Demand of Buildings: Case Study of Turkey Uğur Acar, Önder Kaşka, Nehir Tokgöz Typical meteorological year, Weight coefficients, Building energy analysis, Türkiye The most important parameter which affects the results of building energy analysis is the weather data and it can be obtained by different methods for the same location. Although lots of studies have been conducted for Türkiye, it was seen that the impact of different weather data for the same location has never been investigated. The aims of this study were to compare the heating and cooling demands of the buildings with respect to different weather files. Building loads were calculated using five different meteorological source data. Calculations are made for eight cities which represent heating and cooling dominated climates of Türkiye. Calculation procedure of internal heat gain was explained in detail. All simulations were performed using Energyplus v9.2. The findings of the comparison showed that although some results are similar to each other for some weather files, they could have great variances in the energy analysis also. A common missing meteorological data-filling algorithm may be developed in order to reduce the deviations in energy analysis results. Journal of Thermal Engineering Journal of Thermal Engineering 2022-08-12T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6608 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6608 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6608

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6609 2022-08-14T21:00:00Z 1

Natural Ventilation in A Lege Space with Heat Source: Cfd Visıalization and Taguchi Optimization Anthati Sai Chandra, P. Nithish Reddy, Harish R Natural Ventilation, Louvers, CFD, Heat Source Louvre-equipped generic enclosed (LEGE) space with heat source and guiding vents is commonly seen in many buildings, heat transfer equipment and has plenty of practical applications. In the current work, natural winddriven convection in a LEGE space system with a mono-centric heat source under five louvre configurations and different wind speeds are analyzed. The system walls are assumed adiabatic, and a heat source is introduced at the centre with five different levels of heating in the range of 100 and 400 W/m2. The system is placed in an ample rectangular space to generate natural wind flow conditions. The efforts of conducting several experiments are reduced by applying Taguchi method and Anova is used to rank the experiments based on the responses from CFD simulations. Firstly 3D steady RANS equations are solved using the Finite volume approach where RNG k-E the model was chosen for turbulence modelling. The Nusselt number and temperature of the heat source were noted down as responses for each case. Secondly, the percentage contribution of different factors on the temperature of heat source and optimum experiment were explored using ANOVA technique. The results are reported in contours and velocity vectors inside the enclosure, disclosing the heat flow and air circulation under different design configurations. Results show that louvres position had a maximum of 5 percent effect on the responses than other factors. From the ANOVA method, results show that the contribution of air velocity is around 80%. Journal of Thermal Engineering Journal of Thermal Engineering 2022-08-14T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6609 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6609 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6609

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6667 2022-12-04T21:00:00Z 1

Bouyancy Force and Magnetic Field Effects on Laminar Vortex Breakdown and Fluid Layers Brahim Mahfoud, Mohammed Moussaoui Buoyancy Force, Fluid Layers, Integral Transforms, Magnetic Field, Vortex Breakdown In this study, the Generalized Integral Transformation Technique (GITT) is used to describe the effect of buoyancy force and magnetic field on the vortex breakdown process generated by the rotation of an electrically conductive fluid. A magnetic field is positioned vertically to stabilize the swirling flow caused by the rotation of the bottom disc of a cylindrical recipient. Three fluids were compared in this study where the range of Richardson number is 0 ≤Ri ≤2.0. When the temperature difference is greater than Ri = 0.1, many layers become visible. These stratified fluid layers act as thermal insulators. In the case of stratification, the increased magnetic field reduces the total number of layers formed in the fluid. The influence of gradient temperature on the distribution of the layers generated is discussed. The limitations between the multilayer structure and the monolayer structure for three fluids are calculated as a function of the flow parameters. Journal of Thermal Engineering Journal of Thermal Engineering 2022-12-04T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6667 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6667 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6667

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5482 2021-10-31T21:00:00Z 1

Modeling of the Effect of Nano-Enhanced Phase Change Material on the Performance of a Large-Scale Wallboard Leyli Bahrami, Alibakhsh Kasaeian, Fathollah Pourfayaz, Sahar Ghafarian Phase Change Material; Computational Fluid Dynamics; Building; Nano-enhanced PCM The main goal of this present study is to investigate the effects of the application of PCM and Nano-enhanced PCM as wallboard on the thermal behavior of a room. For this purpose, a room was modeled in two dimensions under Tehran's summer weather conditions through computational fluid dynamics (CFD). The effect of using the PCM as a wallboard in the southern wall in both pure and enhanced with nanoparticles was investigated. The indoor temperature, the wall surface temperature, and the interior wall heat flux, in both cases, were reported and compared. At the end of this study, the acquired results were compared with the pre-modified room, and thermal improvement was reported. The results indicate that the use of solid nanoparticles in PCM reduces the energy consumption of air-conditioning system by 7.4% compared to the conventional room. In the case of the Nano-enhanced PCM wallboard, the room has better thermal performance than the pure PCM, with 4.37% more energy storage, about 0.273 reductions in temperature decrement factor, and a 21.6 min increase in the time delay to peak temperature. Compared to the conventional room and room with pure PCM, the room’s temperature fluctuation, modified by Nano-enhanced PCM, reduces by 52% and 31%, respectively. This study's obtained results could help the researchers and designers have a more appropriate PCM selection for building ventilation system applications. Journal of Thermal Engineering Journal of Thermal Engineering 2021-10-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5482 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5482 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:8 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5482

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6612 2022-08-16T21:00:00Z 1

Evaluation and Optimization of Single-Effect Vapour Absorption System for the Dairy Industry using Design of Experiment Approach Alka Solanki, Yash Pal Vapour absorption system, RSM, ANOVA, COP, optimization Several investigations have emphasized on process parameters of single effect vapour absorption system; yet, the influence of process parameters on thermodynamic performance of the absorption system has not been focussed for the best performance conditions. Several process parameters such as absorber, generator, evaporator and condenser temperatures influence the exergetic and energetic performance of an absorption refrigeration system. In the present study,design of experiments have been used for the optimization of process parameters. A 1.5 kW cooling capacity of the LiBr-H2O absorption system has been developed and tested under various operating conditions. Performance characteristics such as in COP and heat dissipated by the condenser (Qc) of the ARS system have been studied at different ranges of operating parameters. For the process parameter optimization, a central composite design under Response Surface Methodology has been used. The maximum COP and Qc have been obtained as 0.827 and 2488.79, respectively at optimum values of generator temperature (Tg) = 95.1oC, condenser temperature (Tc) = 45.3oC, absorber temperature (Ta) = 28.4oC and evaporator temperature (Te) =15.0oC. The optimum conditions obtained by the design of experiments have been validated through experiments on the ARS system and experiments have been conducted at closer conditions of the optimized values of the operating parameters and found the maximum COP and Qc as 0.926 and 2518.01, respectively.The results of this paper has been very useful in designing a better vapour absorption system. Journal of Thermal Engineering Journal of Thermal Engineering 2022-08-16T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6612 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6612 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6612

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6615 2022-08-21T21:00:00Z 1

Experimental Studies on Drying Characteristics of Green Chilies in a Solar Dryer Sanjay Ssalve, Ajay Fulambarkar Selective Coating, Critical Radius of Insulation, Solar collector, Solar Drying, Maximum heat transfer. Green and clean technology is the demand of today’s world. Solar dryer, for drying agricultural produce is one of the major applications of solar energy. The flat plate air collector plays a crucial role in drying the agricultural produce in solar dryer application. This research work focuses on the design and development a solar collector for drying agriculture produces using waste aluminum cans of beverages. A solar air collector is designed and developed in the laboratory as per IS 1933, 2003 standard. A solar collector developed has been tested and the overall performance of the system is evaluated for three different mass flow rates (0.01 kg/s, 0.008 kg/s and 0.006 kg/s) for drying 15 kg of green chilies. The selective coating material made by mixing activated charcoal and blackboard paint is applied on the cylindrical curved surface of the tubes considering the critical radius of insulation. The inlet and outlet temperature of the air has been recorded for different mass flow rate and the overall collector efficiency is calculated. Further, the moisture removal rate from green chilies is evaluated for every 30 minutes of time interval in a day. It is found that the efficiency is decreased with an increase in mass flow rate. A maximum moisture removal rate of 88% is observed for a mass flow rate of 0.01 kg/s and the maximum efficiency of a solar collector of 50.27%. is attained for a mass flow rate of 0.006 kg/s. Journal of Thermal Engineering Journal of Thermal Engineering 2022-08-21T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6615 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6615 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6615

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6644 2022-10-24T21:00:00Z 1

Experimental Investigation and Validation of Solar PV Cooling for Enhanced Energy Conversion Efficiency for Indian Climatic Conditions Pritam Bhat, Ananth S. Iyengar, Abhilash N., Pavan Kumar Reddy Solar PV Cooling, Performance Enhancement, PV Efficiency, Thermal Collector, Front Water Cooling Solar Photovoltaic (PV) cells convert an average of 10 to 15% of the incident solar radiation into electricity and remaining energy is wasted as unused heat energy. The performance of solar PV is largely dependent on its operating temperature, which is again dependent on solar irradiation. The efficiency of solar PV reduces the higher PV temperature due to charge carrier recombination. The solar PV efficiency drops considerably with increasing temperature. Dust deposition on the surface of solar PV cells reduce incident energy and no technology is commercially available to mitigate the problem. The objective of the present work is to enhance the energy conversion efficiency of solar PV by adopting Front Water (FW) cooling technique. The FW cooling technique maintains the cell temperature at Standard Test Conditions (STC) irrespective of ambient air conditions and also washes away dust deposits, thereby providing maximum energy conversion efficiency specified by the cell manufacturer during the operation with increased lifecycle of solar cells. The experiment was carried out on a 100 W solar panel for a period of 2 weeks and data acquisition system with Arduino controller was used to analyze and maintain STC of the panel to obtain maximum power. The mathematical model of the system was analyzed and obtained results were in good agreement with the experimental measurements. The solar PV panel with FW cooling yielded an efficiency improvement of 9% with 17 W of increased power output at Maximum Power Point (MPP). MATLAB Simulink software is used to model the FW cooling technique. The model is able to predict the power generated by the solar PV cells for the given irradiance with and without cooling. The developed model can now be utilized to design cooling systems for larger installation of solar PV systems. Journal of Thermal Engineering Journal of Thermal Engineering 2022-10-24T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6644 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6644 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6644

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6640 2022-10-16T21:00:00Z 1

Numerical Investigation of 3D Unsteady Flow Around a Rotor of Vertical Axis Wind Turbine Darrieus Type H Amar Berkache, Abdellah Boumehani, Belkhir Noura, Rabah Kerfah Wind Turbine Darrieus, Aerodynamic, CFD, DDES This article presents an analysis of the complex and unsteady flow associated with the functioning of the rotor of a vertical axis wind turbine Darrieus - H. In this study, the influence of different numerical aspects on the accuracy of the simulation of the flow around a rotor of three straight blades in rotation is performed, which are the effect of the turbulence modeling, and the effects of the mesh and the time step. The Delayed Detached Eddy Simulation (DDES) approach is used. The aim of this article is to describe and analyze the unsteady flow in 3D predicted numerically considering the effects of arms like blade-arms interference, blade-wake interactions around the Darrieus rotor and the effect of tip vortices. Two-dimensional simulations are used in a preliminary numerical configuration. Then, three-dimensional simulations are performed to precisely determine the characteristics of the complex aerodynamic flow associated with the operation of the wind turbine rotor. The flow field around the rotor is studied for several values of the tip speed ratio, dynamic quantities, such as the torque and the power of the rotor that are presented and analyzed. From the results obtained, it is clear that the approach of the Detached Eddy Simulation with the SST K-ω model can be considered as a reliable prediction. A comparison of the performance of the results showed that the predicted coefficients of performance are very close to the experimental data from the bibliography. Journal of Thermal Engineering Journal of Thermal Engineering 2022-10-16T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6640 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6640 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6640

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5414 2021-08-02T21:00:00Z 1

Optimisation on the Thermal Insulation Layer Thickness in Buildings with Environmental Analysis: An Updated Comprehensive Study for Turkey's All Provinces Cenker Aktemur, Feyza Bilgin, Sezer Tunçkol CO2 reduction; Degree-day; Energy saving; Optimum insulation thickness; Payback period This study determines the optimum insulation layer thickness to be applied to external building walls considering the heating degree-day (HDD) method, then energy saving costs, payback periods, and carbon dioxide (CO2) emissions are calculated accordingly. The optimisation analysis is performed for four different thermal insulation materials (glass wool, rock wool, extruded polystyrene, and expanded polystyrene). Natural gas is chosen as fuel for heating purposes, and horizontal perforated brick is preferred in the wall. One of the original features in this study is environmental analysis to determine the CO2 emission for the insulated wall in Turkey provinces. Another feature is that it has the most up-to-date data about HDD values and fuel and insulation material costs. The worst and best insulation materials are obtained as rock wool and glass wool, respectively. The optimum insulation layer thickness for the best case is varied between 0.07 m and 0.23 m, depending on the HDD values of provinces. The annual total energy saving cost is in the range of 4.4-53.5 $/(m2year), and the payback period is 0.11-0.38 years. Besides, the reduction in annual CO2 emission is changed between 53.2% and 94% for the best case, compared to the uninsulated wall. Journal of Thermal Engineering Journal of Thermal Engineering 2021-08-02T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5414 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5414 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5414

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6641 2022-10-16T21:00:00Z 1

Heat Transfer Enhancement for Corrugated Facing Step Channels Using Aluminium Nitride Nanofluid - Numerical Investigation Kafel Azeez, Abd Rahim Abu Talib, Riyadh Ibraheem Ahmed CFD, Heat transfer, Heat exchanger, Nanofluid, Numerical analysis The present work carries out a three-dimensional numerical analysis study of Aluminium Nitride (AlN)-water hybrid nanofluid enhanced heat transfer in laminar forced convection flow heat exchanger with four different channels, flat, backward facing step, triangle and trapezoidal facing step channels. The influence of different Reynolds number (100≤ Re ≤1500) and different solid nanoparticles volume fraction (1% and 4%) on the heat transfer and fluid flow were numerically investigated. The numerical analysis was carried out by using a laminar model of ANSYS-Fluent CFD code and the governing equations were resolved using the finite volume method. The results indicate that the thermal conductivity of the nanofluids increases with the increase values of both the nanoparticles volume fractions and Reynolds number, compared with base fluids. Likewise, the pressure drop showed slightly increased due to the increased of both parameters. The use of high nanoparticles volume fractions (4% volume) nanofluid corresponded with the use of four different channel designs resulted in heat transfer augmentation about 30% when compared to that pure water for the trapezoidal channel. Journal of Thermal Engineering Journal of Thermal Engineering 2022-10-16T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6641 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6641 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6641

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5469 2021-10-21T21:00:00Z 1

Positive Impact of Vibration on Heat Transfer in Twisted Tape Inserted Heat Exchanger Shanmukh Arasavelli, Ramakrishna Konijeti, Govinda Rao Budda Heat exchanger, Counter flow, Heat transfer enhancement, Nusselt number, Vibration, Twisted tape insert This paper describes experimental investigations on convective heat transfer in counter flow double pipe heat exchanger under transverse vibration for single-phase flow with twisted tape insert in the inner tube. Experiments were conducted on twisted tape inserted counter flow double pipe heat exchanger under vibration for twist ratio from 7 to 17, amplitude from 23 to 69 mm, frequency from 20 to 100 Hz and Reynolds number (Re) changing from 10710 to 21420. A maximum gain of 91% in Nusselt number (Nu) was obtained at 40 Hz frequency and 69 mm amplitude for twist ratio of 7 and Re of 10710. The maximum value of performance evaluation criteria with compound enhancement technique on double pipe heat exchanger reached 1.38 in turbulent flow conditions. Empirical correlations for Nu were developed and predicted values were found to be within ± 9% of experimental values for both frequency ranges. Journal of Thermal Engineering Journal of Thermal Engineering 2021-10-21T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5469 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5469 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:7 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5469

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6645 2022-10-26T21:00:00Z 1

Experimental Study of Heat Transfer in a Helical Coiled Tube Biomass Fired Rotary Device Prashant Deshmukh, Satyajit Kasar, Niteen Sapkal biomass; bagasse; helical coiled tube flow; rotary combustion chamber The present investigations put forth the development of a novel double wall vented rotary fluid heating device. In this device water used as a process fluid and is heated by the combustion of sugarcane bagasse. The proposed combustion method is found to provide use of more systematic fuel transport system and ensure the efficient heat transfer process to the fluid. It is observed to offer many advantages over the conventional furnaces and obviates the use of any mechanized system such as traveling grate, fluidized bed system, dumping grate etc. in conventional systems. Also, the heat liberated in combustion is used effectively for heating fluid through a helical coiled tube mounted over the surface of drum. The present study aims to assess the thermal performance of proposed rotary combustion chamber at different experimental parameters. It was concluded to have maximum temperature rise, and the thermal efficiency of this system at 45.3?C and 45.2% when drum speed is 6 RPM at Reynolds number equal to 1176. Journal of Thermal Engineering Journal of Thermal Engineering 2022-10-26T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6645 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6645 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6645

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6639 2022-10-15T21:00:00Z 1

Numerical Investigation of Heat Transfer & Hall Effects on Mhd Nanofluid Flow Past over An Oscillating Plate with Radiation S. Sarala, E. Geetha, M. Nirmala Nanofluid, Oscillating plate, Magnetohydrodynamic, Radiation, Hall Parameter The effects of convective heat generation and the oscillatory motion of a plate in the presence of MHD, Alumina nanofluid flow, thermal radiation, and Hall current are considered. The plate oscillates harmonically in its axes with uniform temperature. The dimensional equations have to be changed into non-dimensional equations with a set of dimensionless parameters. The Laplace transformation technique is utilized to get an exact solution. The possessions of velocity and temperature are analyzed with several parameters like Prandtl number (Pr), Grashof number (Gr), Hall parameter (m), magnetic parameter (M), radiation (R), solid volume fraction(ᵠ), phase angle(ω).The influence of primary and secondary velocity is discussed by the graph. It is observed that the increment of Hall parameter (m) diminishes the primary velocity, an increment of Grashof number leads to an increase in both velocities, and increasing solid volume fraction raises the temperature. The Nusselt number and skin friction coefficient values have expressed in the table. It is apparent that an increment of radiation increased the value of the Nusselt number and also an increment of phase angle value diminished the skin friction coefficient value. Journal of Thermal Engineering Journal of Thermal Engineering 2022-10-15T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6639 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6639 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6639

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5485 2021-11-14T21:00:00Z 3

Occupational Heat Stress under High-heat Furnace Work Environments - A Comprehensive Review on Developing Countries Milap Sharma, Md Sarfaraz Alam, Narendra Mohan Suri, Suman Kant Furnace Work, High-Heat Environment, Workers, Heat-Strain, Assessment, Harmful Impacts In developing countries, workers’ employed under high-heat furnace work environments are exposed to severe heat stress; an ignored occupational health hazard especially under the unorganized work-sectors. During hot summer season, lot of underprivileged workers are strained by harsh thermal work-conditions with subsequent health challenges, declining their productivity and attributes to financial burden. As compared to developed countries, absence of adequate regulatory guidelines and control policies increases the risk-severity under the rampant conditions. The aim of the present study is to gain insights on the prevalence of occupational heat-stress under high-heat furnace work environments with special reference to developing countries. Present review study recognizes the prevalent issues by summarizing the dominant heat-stress factors (environmental, individual, and physiological), suitable assessment strategies, and consequent negative impacts on health and productivity followed by encapsulation of related heat-stress assessment studies particularly from the developing countries. From the assessment studies, it’s evident that the predominant chronic heat-stress adversely impacts the workers’ health and accompanying performance loss. Apart from heat related morbidities, severe health impacts such as immunological suppression, renal/urologic anomalies, and sub-cellular DNA damage are also attributable to this occupational health hazard. The prevalent thermal work-conditions necessitates implementation of adequate preventive measures and control policies to ameliorate the workers’ productive capacity and social well-being. Remedial control interventions like proper ventilation design, installing reflective thermal protective shields, providing cooling spots, optimized cooling vest design, and sensor based intelligence may be considered as an effective control measures with emphasis on ameliorating the heat stress exposure under high-heat furnace work environments. Journal of Thermal Engineering Journal of Thermal Engineering 2021-11-14T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5485 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5485 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:8 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5485

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5486 2021-11-15T21:00:00Z 1

Five Different Distributions and Metaheuristics to Model Wind Speed Distribution Mohammed Wadi Wind Energy, Statistical Distributions, Probability Distribution Function (PDF), Cumulative Distribution Function (CDF), Inverse CDF (ICDF), Grey Wolf Optimization (GWO), Whale Optimization Algorithm (WOA) This paper presents a comprehensive empirical study of five different distribution functions to analysis the wind energy potential, namely, Rayleigh, Weibull, Gamma, Burr Type XII, and Generalized Extreme Value. In addition, two metaheuristics optimization methods, Grey Wolf optimization and Whale optimization algorithm are utilized to determine the optimal parameter values of each distribution. To test the accuracy of the introduced distributions and optimization methods, five error measures are investigated and compared such as mean absolute error, root mean square error, regression coefficient, correlation coefficient, and net fitness. To conduct this analysis, the Catalca site in the Marmara region in Istanbul, Republic of Turkey is selected to be the case study. The experimental results confirm that all introduced distributions based on optimization methods are efficient to model wind speed distribution in the selected site. Although Gamma distribution based on GWO and WOA outperformed other distributions for all datasets at all heights, it was the worst in terms of computation complexity. Rayleigh distribution occupied the latest rank, but it was the best in terms of computation complexity. MATLAB 2020b and Excel 365 were used to perform this study. Journal of Thermal Engineering Journal of Thermal Engineering 2021-11-15T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5486 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5486 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:8 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5486

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5505 2021-11-28T21:00:00Z 1

Numerical Investigation of Effect of Different Parameter on Heat Transfer for a Crossflow Heat Exchanger by Using Nanofluids Mustafa Kılıç, Atta Ullah Computational Fluid Dynamics, Heat Exchanger, Nanofluid, Unmanned Air Vehicles. The heat loads on electronic systems of an unmanned air vehicle are a significant problem. So enhancing heat transfer is a critical key to solve these thermal problems. This study is focused on increasing heat transfer rate in a crossflow heat exchanger by using nanofluids numerically. Effects of different Reynolds number of hot fluid (Re= 6000, 8000, 10000, 12000), different inlet velocity (Vair,inlet=30, 45, 60, 90 m/s) of cooling fluid, temperature of cooling air at different altitude (Tair,inlet=15, 10, 4, -17℃) and different types of nanofluids (Cu-H2O, CuO-H2O, TiO2-H2O, H2O) on heat transfer were studied numerically. Realizable k-ε turbulence model of ANSYS FLUENT computational fluid dynamics code was used for numerical analysis. It was obtained that increasing Reynolds number from Re=6000 to 12000 causes an increase of 44.65% on average Nusselt Number. Increasing inlet velocity of cooling air from 30 m/s to 90 m/s causes an increase of 6.96% on average Nusselt number. Increasing or decreasing air inlet temperature at different attitude does not cause any significant change on average Nusselt number. Using Cu-H2O nanofluid, which shows the best performance, causes an increase of 6.63% on average Nusselt number according H2O. Numerical results were also compared with experimental results at literature. It was obtained that numerical model can represent experimental results in a good level. Journal of Thermal Engineering Journal of Thermal Engineering 2021-11-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5505 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5505 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:8 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5505

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6633 2022-10-03T21:00:00Z 4

Feasibility Study of Synthesized Carbon as Catalyst in Biodiesel Production Tourangbam Rahul Singh, Thokchom Subhaschandra Singh, Tikendra Nath Verma, Prerana Nashine, Upendra Rajak Carbon; Wood Biomass; Heterogeneous Catalyst; Biodiesel; Transesterification The thrust in biofuel production has pushed researchers in finding more of environmentally friendly materials for use as catalyst in the biofuel production process. Commercially available catalyst materials are not sustainable, and they generally incur higher cost of operation. In the present study, locally available native woods species of Manipur, India namely, Yenthou (Arundo donax.L) and Uningthou (Phoebe hainesiana) were exposed at elevated temperature of 400 °C and variable exposure time of 90 and 120 minutes for possible use as catalyst during biofuel production. Muffle furnace has been employed for production of catalyst and characterization techniques such as XRD, FT-IR and SEM with EDX are used. XRD analysis shows diffraction peak corresponding to (0 0 2), (1 0 0) and (1 0 1) of the face centered cubic phase at 28.61°, 28.54° and 30.02° respectively while Scherrer equation shows 29.737 nm as average grain size. FT-IR analysis also shows C=C formation from the samples. The SEM & EDX analysis shows good formation of carbon in the catalyst and the weight % of the components are obtained to be 89.18% and 10.82% for C and O respectively. Transesterification of waste cooking oil at 5% (wt%), 10:1, 75 °C and 60 minutes for catalyst loading rate, alcohol-to-oil ratio, reaction temperature and reaction time respectively shows conversion rate of 87.4±1.3% with reusability of 3 times. Journal of Thermal Engineering Journal of Thermal Engineering 2022-10-03T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6633 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6633 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6633

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5518 2021-12-28T21:00:00Z 1

Parametric Optimization of Blowdown Operated Double-Effect Vapour Absorption Refrigeration System Deshdeep Gambhir, Ahmad Faizan Sherwani, Akhilesh Arora, Ashwni Goyal Double-effect vapor absorption system; Exergy; Cogeneration; RSM; ANOVA The present work investigates the thermodynamic optimality of a double-effect vapor absorption refrigeration system (VARS) driven by blowdown heat of 210 MW thermal power plant at Badarpur using response surface methodology (RSM). RSM helps to develop a relation amongst the decision variables and the second law efficiency via second-order nonlinear polynomial regression equation. In addition, the analysis of variance technique (ANOVA) is applied to identify the decision variables having a significant effect on the system’s thermal performance. Moreover, coefficient of structural bond (CSB) analysis of the evaporator is carried out. The decision variables are temperatures of the high-pressure generator, low-pressure generator, condenser, absorber, and evaporator. Results conclude that the second law efficiency is affected significantly by absorber temperature (F value = 2049.4), followed by condenser temperature (F value = 1596.4), and is least affected high-pressure generator temperature (F value = 495). CSB value of the Evaporator is 0.5851. Journal of Thermal Engineering Journal of Thermal Engineering 2021-12-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5518 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5518 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5518

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5504 2021-11-28T21:00:00Z 3

Factors Affecting on Human Thermal Comfort Inside the Kitchen Area of Railway Pantry Car - A Review Md Sarfaraz Alam, Urmi Ravindra Salve Indoor thermal environment, Environmental ergonomics, Thermal sensation, Pantry car, Railway Railway transportation plays a significant contribution to carrying passengers in India. In which during the journey, pantry cars are involved to serves the food to all onboard passengers. The kitchen atmosphere of the pantry car gets very hot and humid during cooking which could affect occupants' thermal comfort. Therefore, the current research article describes a review of the factors affecting human thermal comfort inside the kitchen of the railway pantry car. The factors influencing of human thermal comfort inside pantry car kitchens are classified into two categories viz; environmental factors that include "air temperature, mean radiant temperature, relative humidity, air velocity" and personal or individual factors including "metabolic rate and clothing insulation". All these factors need to be considered in order to achieve the optimum level of thermal comfort inside the kitchen environment of the pantry car. With the assistance of all these factors, we can estimate the thermal comfort indices such as; SET "standard effective temperature," PMV "predicted mean vote," PPD "predicted the percentage of dissatisfied," thereby recognizing the acceptable thermal sensation range for occupants' (chefs) in the pantry car kitchens during the work period. These kinds of parametric studies can cover a wide group of all pantry car chefs in evaluating thermal comfort. Furthermore, there is a need to apply all the consequences of this research to increase the chef's thermal comfort inside the pantry car kitchen while working. Journal of Thermal Engineering Journal of Thermal Engineering 2021-11-28T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5504 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5504 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:8 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5504

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5515 2021-12-22T21:00:00Z 1

Design and Development of a Novel Multichannel Data Acquisition System Using Labview for an Automobile Air Conditioning Application Sandeep Shalgar, Rupa Bindu Multi Channel Data Acquisition System, Error Analysis, LabVIEW, Automobile Air-Conditioning System, Triggering Circuit To sustain in the ever-changing environment and to combat the atmospheric effect, development of a highly efficient and an environment friendly air conditioning system which can run in parallel or as an alternative to an existing vapor compression system is the need of the hour and such novel hybrid air conditioning system are under development today. For the parameters attribution mapping of such novel hybrid air conditioning system, todays commercially available data acquisition systems (DAS) need to be customized to the requirements of addition of sensor nodes and their integration with triggering mechanism for actuation of devices for its programmed operation. Therefore, this paper describes the design and development of novel multichannel data acquisition system (NMDAS) for automobile air conditioning application. The details of the hardware design, software design, error analysis and testing of the NMDAS are presented. The proposed NMDAS uses PLC module DVP16SP configured with analog reader DVP 04TC for temperature measurement at 32 nodes and DVP04AD for pressure or humidity measurements at 8 nodes. The triggering circuit for activation of the relay is enabled using NI LabVIEW user interface and PLC data. The output of the NMDAS is integrated with processor by RS 232 port for data storage and processing. The error analysis of temperature, pressure and humidity measurements are done by comparing with reference calibration standards. The average thermal stability of the temperature sensors over the operating range of -5˚C to 150˚C is 0.0015°C. The average accuracy of pressure transmitters for operating range of pressure 0 to 40bar is estimated 98.219%. The minimum error in the output current is 0.375% and maximum error is 7.125% over relative humidity span of 0%RH to 100% RH respectively. The proposed NMDAS is used for testing of the novel hybrid air conditioning system of automobile during development stage and is found expedient. Journal of Thermal Engineering Journal of Thermal Engineering 2021-12-22T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5515 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5515 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5515

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6643 2022-10-19T21:00:00Z 1

Thermo-economic Feasibility Analysis of Trilateral-cycle Power Generators for Waste Heat Recovery-to-power Applications Habeeb A. Ajimotokan, Isiaka Ayuba,Hassan K. Ibrahim Trilateral Cycle Configurations; Waste Heat Recovery; Power Generation; Specific Investment Cost; Net Present Value. The trilateral cycle (TLC), a promising alternative waste heat recovery-to-power cycle, is receiving increasing attention due to feats such as the high thermal match between the exergy of the heat source temperature profiles and its working fluid. Although the TLC has neither been broadly applied nor commercialised because of its thermo-economic feasibility considerations. This study examined the thermo-economic analysis of different TLC power generator configurations; i.e., the saturated subcritical simple (non-recuperative) and recuperative cycles using n-pentane as the working fluid for low-grade waste heat recovery-to-power generation. Based on the thermodynamic and economic analyses, the feasibility analysis models of the cycles were established using Aspen Plus, considering efficiency, cost, and expected operating and capacity factors. Furthermore, the capacity factor, specific investment cost (SIC), and payback period (PBP), among other, were used to evaluate the cycle design configurations and sizes. The SICs of the simple and recuperative TLCs were 3,683.88 $/kW and 4,220.41 $/kW, and their PBPs were 8.43 years and 8.55 years, respectively. The simple TLC had a lower investment ratio of 0.24 compared to an investment ratio of 0.28 for the recuperative TLC. These economic values suggest that the simple TLC is more cost-effective when compared with the recuperative TLC because the recuperation process does not recompense the associated cost, making it unattractive. Journal of Thermal Engineering Journal of Thermal Engineering 2022-10-19T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6643 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6643 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6643

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6638 2022-10-14T21:00:00Z 1

Modeling of Parabolic Collector (A New Approach of Concentration Ratio Calculation) Tahseen Ali Jabbar, Raed S. Batbooti, Bassam A. Mohammed Parabolic Collector, Concentration Ratio, Solar Energy Solar energy light and heat are utilized using different solar collecting techniques. The parabolic solar collector is one of the most popular collector types that used to absorb solar energy. In this work, a new approach is used to calculate the radiation concentration ratio in a parabolic collector. The concentration ratio is calculated from the ratio of the reflection beam to the incident beam radiation, where two variables influenced the concentration ratio: the collector width (W) and the focal length (P). The model is tested and compared to results from previously published work. The comparison showed that the model results are correlated with that from previously published results. Another point to note is that, increasing the width of the collector (W) leads to an increase in the concentration ratio (RC), while the contrary is true when the focal length (P) increased. The collector efficiency minimum values were 19.3%, 21.07 %, 22.35% and 23.33% at concentration ratios of 69, 80, 103 and 148 in line with the focus length values of 0.6m, 0.7m, 0.8m and 0.9m, respectively. Also, the results show that the efficiency of the collector decreases with increasing the focus length. The developed model is applied according to the conditions of Basra, Iraq (47.78o longitude and 30.5o latitude) Journal of Thermal Engineering Journal of Thermal Engineering 2022-10-14T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6638 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6638 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6638

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6647 2022-11-21T21:00:00Z 3

Review on Latent Thermal Energy Storage Using Phase Change Material Sattar Aljabair, Israa Alesbe, Sahira Hasan Ibrahim PCM, phase change material, solidification, melting, thermal storage. Latent heat thermal energy storage is one of the attractive technologies that help to increase the energy storage density. The heat of fusion is isothermally stored at a temperature representing the phase converting temperature of the phase change material (PCM). The present paper is review on applications of phase change materials for melting and solidification. Generally, the range of working temperature extends from -20? to 200? for solidification and melting applications. The first range (-20 to 5?) is employed for commercial and domestic refrigeration. The second range (5-40 ?) is used for to reduce energy consumption in the applications of heating and cooling in buildings. The applications of third range (40-82 ?) are solar collector and heating of water. Applications of absorption cooling, waste electricity generations, and heat recovery are operated at high temperature range (82-180?). There are various types of PCMs for all the above temperature ranges. The present review paper will discuss the application field, Geometry, PCM type, heat transfer augmentation technique and their effects on the performance. The conclusions are mentioned to give more insight about the behavior of PCM in different applications. Journal of Thermal Engineering Journal of Thermal Engineering 2022-11-21T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6647 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6647 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6647

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6690 2022-12-13T21:00:00Z 1

Energy, Exergy Analysis and Optimization Of Insulation Thickness on Buildings in a Low-Temperature District Heating System Meryem Terhan, Sena Saliha Abak Buildings, Low-temperature District Heating System, Energy and Exergy Analysis, Life Cycle Assessment, Heating Degree Day (HDD) In the study, energy and exergy analysis of the buildings on a campus in Turkey are conducted by using actual operating data and taking measurements in the district heating system as a case study. The energy and exergy demands, losses that stem from all buildings are calculated according to average daily outdoor temperature data. Due to the high heat losses in the buildings, determining the optimal insulation thickness for the exterior wall should be investigated. Therefore, optimal insulation thicknesses, energy savings, fuel consumptions and payback periods of the insulation material on the exterior wall of the building are examined by using Life Cycle Assessment and P1-P2 method for natural gas. Optimal insulation thicknesses are calculated for different insulation materials such as XPS, glass wool, rock wool and EPS for the climatic regions (HDD=800-4250°C days). According to average exergy losses from the building components per unit area, the average total exergy loss is calculated as 2.39x10-2 kW/m2.year and 1.42x10-3 kW/m2 (5.92%) of this loss stems from the exterior walls, 1.93x10-3 kW/m2 (8.07%) from the floors, 7.37x10-4 kW/m2 (3.08%) from the roofs, 1.58x10-2 kW/m2 (65.99%) from the windows and doors, 4.04x10-3 kW/m2 (16.92%) from the ventilation with infiltration. Energy requirement values of the building are found between 2.68-25.70 kWh/m3 towards from the warmest to the coldest climatic region for the uninsulated wall. In the un-insulated state, fuel consumption varies between 1.93-18.48 m3/m2 from the warmest to the coldest region. The optimal insulation thickness values of the building’s exterior wall are calculated as between 2.3-10.0 cm according to different climatic regions. In-state of exterior wall insulation of 3 cm, fuel consumption decreases by 46.63% -53.46% compared to different insulation materials and climatic regions compared to the un-insulated state. Journal of Thermal Engineering Journal of Thermal Engineering 2022-12-13T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6690 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6690 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6690

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5508 2021-11-29T21:00:00Z 1

Empirical Modelling for Work Piece Temperature During End Milling of Inconel625 Using a Green’s Function Approach Based on Dirac Delta Function Satish Kumar, Pankaj Chandna, Gian Bhushan Work Piece Temperature, Inconel625, Empirical Model, End Milling and Green’s Function Approach. Milling is a very versatile process for the manufacturing of dies and aerospace components. Especially in the manufacturing of thin walled components, the dimensional accuracy is greatly affected due to heat generation and deflection in the wall. Therefore, minimization of heat generation during milling by optimizing controllable input process parameters, leads to improved accuracy in thin walls. In the present study, an empirical model for work piece temperature by solving the non-homogeneous partial differential equation using Green’s function has been simplified with Dirac delta approach during the end milling of Inconel625 work-piece with the assumption of single-pass cutting and one-point observation. This technique is normally used for solving the complex higher-order partial differential equation, but it is rarely applied in the heat dissipation problem during manufacturing in the recent past. The empirical approach is more effective and accurate as compared to experimental approaches used earlier in the recent past. To verify the adequacy of the empirical model of work piece temperature, 9 conformational experiments have been performed at 3 different cutting speeds with a constant depth of cut 5 mm and feed per tooth 0.05 mm. A good compromise has been observed among the responses obtained among the results obtained from an empirical approach and experimental observations at different cutting speeds. However, by little modification and adding a small algorithm, this single pass problem can be implemented on the multi-pass problems and even can also be applied to complex shapes. Journal of Thermal Engineering Journal of Thermal Engineering 2021-11-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5508 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5508 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:8 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5508

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5372 2021-04-29T21:00:00Z 1

Conceptualization, Thermal Analysis, and Manufacturing of Nano-Textured Micro-Structured Surfaces for Enhanced Condensation Heat Transfer Mete Budakli Micro-structured Surfaces, Dropwise Condensation, Heat Transfer, Thermal Modelling In the present study, nano-micro-structured surfaces have been systematically designed and manufactured in order to generate controlled dropwise condensation mode for enhanced heat transfer during phase-change from vapor to liquid. The conceptualization of micro-structures was conducted by using thermal modelling of an individ-ual droplet pinned at a single micro-hexagonal cavity. By varying droplet radius, resulting contact angles and geo-metric dimensions of micro-structure, threshold values have been determined for the later manufacturing process. According to the calculations for instance at contact angles of 150°, a subcooling of 1 K and a maximum droplet radius of 100 µm, the edge length and the depth of the micro-structures should be kept below 50 µm and 25 µm, respectively. Ensuring these parameters, a roughly 100 % larger heat transfer coefficient would result compared to that predicted by the classical Nusselt theory for filmwise condensation. Taking into account the mathematical analysis, laser ablation technique was adopted on 7075 aluminum samples to emboss hexagonal structures with respect to the predicted dimensions. After this step, the samples were electrochemically etched in order to achieve contact angles of more than 150° to ensure superhydrophobic solid-liquid interaction at the surface. Measurements with a high-precision microscope show that most of the structure dimensions and geometric shape were precisely manufactured. The Tensiometer results disclosed that the surface topography at all samples exhibit contact angles larger than 150° for a sessile droplet with a radius of 100 µm pinned on an individual micro-hexagon. Journal of Thermal Engineering Journal of Thermal Engineering 2021-04-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5372 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5372 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5372

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5608 2022-08-09T21:00:00Z 1

Optimization of Energy Transmittance through Building Envelope for Hot Dry Climate Mohd Shahid, Munawar Nawab Karimi Energy Efficiency, Heat Load, Residential Envelope Transmittance Value (RETV), Taguchi, WWR Fenestrations of the buildings are playing an important role in the building's energy efficiency for the tropical climate. The energy that comes from the glass window into the building can be restricted by providing shading on the windows. So to provide the shading on the window, the most common way is fixed shade like overhang and fin. Shading devices are very helpful to control the SHGC and light transmittance through the fenestrations of the building. Most of the studies analyze the impact of WWR, shadings and SHGC on a building's energy demand but did not consider the combined effect of these parameters. By considering all the parameters of the building envelope in the analysis like WWR, orientation, shading devices, projection factor, and type of glass, the energy demand in the building can be significantly reduced. The goal of this paper is to analyze the variation of residential envelope transmittance value with the window-wall ratio, projection factor, and fixed shading devices and also to optimize the energy from building envelope elements in residential buildings using a statistical method, namely the Taguchi method. The transmittance of energy through the building envelope is calculated in 8 cardinal directions by providing shading with the fin and overhang. Based on the result, the optimum energy saving achieved by selecting the optimum combination of the process parameters for minimizing the energy from the building envelope is A1B1C3D2 i.e. window to wall ratio 7%, triple glazing type of glass used, shading with the overhang fin and orientation in the west direction. The result shows the most significant factor among the selected parameter is the window to wall ratio. Also by focussing on the building envelope parameters, an architectural designer may reduce the building energy demand significantly, and offer more alternatives to achieve energy-efficient buildings. Journal of Thermal Engineering Journal of Thermal Engineering 2022-08-09T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5608 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5608 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5608

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6646 2022-11-19T21:00:00Z 1

Thermodynamic Sensitivity Analysis of SOFC Integrated with Blade Cooled Gas Turbine Hybrid Cycle Tushar Choudhary, Tikendra Nath Verma, Mithilesh Kumar Sahu, Upendra Rajak, Sanjay SOFC; Hybrid Cycle; Gas Turbine; Efficiency In the area of clean energy production along with higher efficiency, integrated combine power system, specifically gas turbine (GT) cycle with solid oxide fuel (SOFC) system, is gaining the attention of researchers. Thermodynamic modeling for the SOFC-GT hybrid cycle has been presented in this paper. For the proposed hybrid cycle, a high-temperature SOFC has successfully integrated with the recuperated-blade cooled gas turbine cycle. The gas turbine outlet waste heat has perfectly utilized the recuperator to power the fuel cell system. However, to maintain the temperature of the gas turbine blade within the permissible limit, air–film blade cooling scheme has been used. The SOFC-GT hybrid cycle has been operated under steady-state conditions, and a developed MATLAB program has been used to solve the governing equations for the components of the hybrid cycle. The impact of main operating parameters such as the temperature intake turbine (TIT), compression ratio (rpc), fuel utilization ratio (UF), and recirculation ratio are examined. From the obtained result, it can be revealed that the integration of the SOFC has seen significant improves overall hybrid cycle efficiency. The performance of fuel cell (SOFC) increases notably as the level of recuperation increases. To check the influence of main operating parameters, a sensitivity analysis has been performed for the hybrid cycle, and the maximum efficiency of 73% has been achieved. Moreover, to extend this research, an exclusive performance map has been plotted for power plant designers. Journal of Thermal Engineering Journal of Thermal Engineering 2022-11-19T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6646 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6646 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6646

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6747 2023-05-16T21:00:00Z 1

Performance Comparison of Basic and Parallel Double Evaporator Organic Rankine Cycle Integrated with Solar Based Supercritical CO2 Cycle Yunis Khan, Radhey Shyam Mishra Comparison analysis, intercooled cascade sCO2 cycle, organic Rankine cycle, solar power tower, parallel double evaporator organic Rankine cycle Performance comparison of basic organic Rankine cycle (ORC) and parallel double evaporator ORC (PDORC) integrated with solar power tower (SPT) driven intercooled cascade sCO2 (supercritical carbon dioxide) cycle was carried out in present study. The intercooled cascade sCO2 cycle/ORC (configuration-1) and the intercooled cascade sCO2 cycle/PDORC (configuration-2) were considered for comparison on basis of parametric analysis. The effects of SPT design parameters such as solar irradiation, solar receiver emittance, and concentration ratio on system performance were investigated. It was concluded that the addition of basic ORC and PDORC to the intercooled cascade sCO2 cycle improved the thermal efficiency by 2.26% and 6.66% respectively at solar irradiation of 950 W/m2. In the case of basic ORC and PDORC, the waste heat recovery ratios were 0.1197 and 0.1775, respectively. It was also discovered that configuration-2 performed better than configuration-1 in terms of waste heat recovery. The combined cycle's performance can be improved even more by lowering solar emittance and increasing the concentration ratio. Journal of Thermal Engineering Journal of Thermal Engineering 2023-05-16T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6747 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6747 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6747

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6652 2022-11-27T21:00:00Z 1

Experimental Investigation for Heat Transfer Augmentation Method of Jet Impingement Using a Fluid of Different Concentrations of Water and Ethylene Glycol (EG) Subhash Lahane, P.W. Deshmukh, Manoj Nargade Jet Impingement; Heat Transfer Augmentation; Water and Ethylene Glycol, Average Heat Transfer Coefficients; Laminar and Turbulent Flows In the modern world, with rapid inventions in microscale electronics, devices suffers undesirable internal heat generation and, due to their tiny shapes, undergo large heat flux conditions. This emphasizes the development of effective and efficient heat dissipation methods to boost their performance and keep them in safe working conditions. The jet impingement cooling method is used for cooling purposes in many engineering applications, and is popular for quick removal of heat from the solid surfaces. The present experimental study is an investigation of effect impingement of jet of water and ethylene glycol mixture over a heated surface. The blending of ethylene glycol (C2H6O2) with water (H2O) as a base fluid enhances the average (convective) heat transfer coefficient (HTC). The cooling fluid with different concentrations of C2H6O2 varying from 10%, 25%, 50%, and 100% shows higher values of average convective coefficient at similar flow conditions than pure water. The fluid having mixture proportions 50 % C2H6O2 and H2O shows an optimum value for heat transfer enhancement in the range of 30% to 75% than pure water at the same flow rates. It can be noted that based on mechanical stability and the cost associated, the experimental results reveal that the optimum value of the concentration of C2H6O2 in water is 50% for maximum heat transfer and at higher values of C2H6O2 hamper the mechanical stability and causes higher pumping power due to increase in viscosity of the fluid. Journal of Thermal Engineering Journal of Thermal Engineering 2022-11-27T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6652 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6652 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6652

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6655 2022-11-27T21:00:00Z 1

Performance Analysis and Exergy Assessment of an Inertance Pulse Tube Cryocooler Prateek Malwe, Bajirao Gawali, Mahmadarfik Choudhari, Rustem Dhalait, Nandkishor Deshmukh Energy Conservation, Exergy Analysis, Pulse Tube Cryocooler, Helium, Exergy Efficiency The world is facing the problems of the energy crisis. Thermal analysis and energy conservation of the engineering devices help to improve their performance. This paper conducted an experimental investigation for the performance analysis and exergy assessment of an Inertance Pulse Tube Cryocooler (IPTC) that uses working fluid - helium operated between 80 K cold end side temperature and room temperature. The variation of the different performance parameters like the effect of charge pressure, pulse tube volume, pulse tube length, etc., and its effect on the refrigerating effect is described graphically. Exergy analysis involves the use and concepts of energy and exergy balances, enthalpy, entropy, and exergy calculations at various stages in the system. Exergy analysis identifies the zones of key exergy destruction that occurs inside the system, which afterward can be subjected to its minimization to amend the system performance. The actual exergy efficiency value calculated for the overall system is 21.30 %. The decreasing order of exergy efficiency among the different components is a compressor (38.79 %), a hot end heat exchanger (6.19 %), regenerator, pulse tube and inertance tube (6 %), and cold end heat exchanger (2.70 %). Journal of Thermal Engineering Journal of Thermal Engineering 2022-11-27T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6655 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6655 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6655

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5497 2021-11-17T21:00:00Z 4

Hydrodynamics of Single Bubble Rising Through Water Column Using Volume of Fluid (VOF) Method Emad Qasem Hussein, Farhan Lafta Rashid, Ahmed Kadhim Hussein, Obai Younis Hydrodynamics, Rising velocity, Single bubble, Dynamic mesh, VOF The importance of air bubble dynamics in liquid is in some phenomena like chemical and biochemical processes in refinery units. The 2D Volume of Fluid (VOF) method together with the CFD technique were employed for simulating. The dynamic meshing technique is used to simulate the hydrodynamics of rising air bubble in liquid water column via the User Defined Function (UDF) code in the C++ environment was developed to evaluate bubble rising through the water column. The rising of air bubble through a stagnant water column has been considered and the influence of column dimension, bubble size, and aspect ratio on the rising velocity characterized is investigated. The obtained results showed that the bubble rising velocity increase with the bubble size and its shapes was transformed from ellipsoidal-to-ellipsoidal cap shape. The rising velocity of air bubbles was affected by the column diameter. It was observed that the air bubble moving toward the top of the water column with oscillation for all cases. A good agreement was obtained between the rising velocity predicted in the simulation with that obtained from the literature. Journal of Thermal Engineering Journal of Thermal Engineering 2021-11-17T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5497 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5497 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:8 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5497

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5533 2022-01-31T21:00:00Z 1

Mathematical Modeling of Semitransparent Photovoltaic Thermal (SPVT) System with Different Packing Factors: An Experimental Validation Vivek K. Chopra, Rajeev Kumar Mishra, Vijay Kumar Dwivedi, Baibaswata Mohapatra DC fan, PV, Efficiency (Electrical) Solar energy is guided by mix mode photovoltaic cell (PV)having thermal effect not only take a part of electricity generation, besides other fundamental approach is to control the rise in temperature of the cell. Our main priority of this type of configuration of cell is for electricity generation. Other aspect of controlling temperature of the cell, fluid is used which carries away excessive gain in temperature. In this paper air as fluid is used that pull out undue amount of heat from the cell module. As the temperature regulated there is very favourable chance of efficiency (electrical) shoots up. In this article, four different experimental set up of mix mode has taken in which a duct made of wood having dimensions 0.86m ×0.63m×0.05m fixed along with the module in which 10 W capacity DC fan is also incorporated for the circulation of air. Various observations deduce from this paper that case-III has the highest efficiency among other cases. On comparing efficiencies with different cases. Case-III gain of 0.7% more as compared to Case-II where as it is 1.7% more gain than case-I. Journal of Thermal Engineering Journal of Thermal Engineering 2022-01-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5533 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5533 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5533

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6680 2022-12-05T21:00:00Z 1

Control of Noise and Temperature using Radial Air Injection inside Engine Silencer Nilaj Deshmukh, Abhijeet Waghmode Silencer, Air injection, Noise, Sound pressure level, Exhaust gases Silencer is a device mainly used for attenuation of the engine exhaust noise. Several modifications were attempted to improve the performance of a silencer. In this paper experimental and simulation study was carried out to determine the effect of radial air injection on the temperature and sound pressure level. The radial air injection is introduced in the form of jets inside the silencer. The design of available silencer was studied, and the 3D model was prepared using CATIA software. Simulation study was carried out using ANSYS Fluent, to determine the temperature distribution inside the silencer with and without modification. The radial jets at different pressure were introduced inside the silencer at three different locations. To acquire sound pressure level and temperatures at different locations, Lab View software and FFT analyser were used. The performance of silencer is analysed by comparing temperature of exhaust gases and sound pressure level at constant speed of 3000 rpm. With radial air jets of 2 bar reservoir pressure at three different location Overall Sound Pressure Level reduces by 6 dB and 42 K reduction in temperature of exhaust gases. Journal of Thermal Engineering Journal of Thermal Engineering 2022-12-05T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6680 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6680 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6680

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6650 2022-11-24T21:00:00Z 1

Experimental and Numerical Analysis of the Forced Draft Wet Cooling Tower Noor Samir Lafta, Fadhil Abdulrazzaq Kareem, Maha H. Ghafur Cooling Tower; Number of transfer unit; Lewis factor; Merkle number; efficiency; inlet water temperature; water to air mass flow rate ratio Cooling towers are essentially large boxes designed to maximize the evaporation of water. The inlet water temperature and water to air mass flow rate ratio (L/G) significantly affect the performance of the cooling tower. The number of a transfer unit (NTU), Merkel number (Me), Lewis number (Le), and efficiency of the cooling tower define the performance of the forced cooling tower. In this research paper, different inlet water temperatures ranging from 28 °C to 42 °C and (L/G) ranging from 0.5, 1, and 1.5 were used to investigate the performance of the forced cooling tower. Mathematical modeling equations were used to calculate NTU, Me, Le, and efficiency at different inlet water temperatures and (L/G). Engineering equation solver (EES) software was used to solve these mathematical modeling equations. Further, an experimental investigation was carried to find forced cooling tower performance at different inlet water temperatures and (L/G), and results were compared with the theoretical results. The results revealed that increasing the inlet water temperature, NTU, Me, Le, and efficiency increased and were directly related to each other. Further, NTU and efficiency were increased by increasing (L/G). At the same time, the Me and Le reduced with (L/G). Finally, an acceptable and better agreement has been obtained between experimental and theoretical results. Based on obtained results, it has been concluded that higher values of inlet water temperature and (L/G) provided the higher performance of the forced cooling tower. Journal of Thermal Engineering Journal of Thermal Engineering 2022-11-24T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6650 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6650 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6650

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5597 2022-06-06T21:00:00Z 1

Refrigerant Progression - An Investigation into Eco-Sustainability with Evolution and Viability of Fourth Generation Refrigerants Salma Khatoon, Munawar Nawab Karimi Cascade Refrigeration System, TEWI, Environmental Impact Assessment, Refrigerant, Environmental Sustainability Global warming is one of the most pressing issues the world is facing today. The refrigeration sector, one of the major contributors to global warming, needs to follow a methodological approach to address this issue. This paper evaluates the overall warming impact along with the thermodynamic performance of the different generations of refrigerants in the cascade refrigeration system. The main aim of this comparative study is to present a comprehensive outlook on the environmental impact of refrigerants. A different perspective on refrigerant selection to reduce global warming is also discussed. R600a, R290, R12, R22, R134a, R152a, R245fa, R1234yf, and R1234ze are used in the high-temperature circuit, while R32 is used in the low-temperature circuit. Exergy and energy analyses are done for thermodynamic performance, and total equivalent warming impact (TEWI) assessment is carried out to show global warming produced. While the refrigerant couple R152a/R32 shows the best thermodynamic performance with maximum COP, minimum exergy destruction, and maximum second law efficiency, R1234yf/R32 displays the worst thermodynamic performance. R12/R32 shows maximum TEWI while R290/R32 shows minimum TEWI. The first-generation refrigerants are found to be most environmentally friendly followed by the third and fourth. Fourth-generation refrigerants have the highest indirect emissions, which make their TEWI comparable to R134a. It is concluded that thermodynamic performance plays a significant role in reducing TEWI as indirect emissions account for the major part of the TEWI, and therefore, the global warming potential cannot be the only basis for refrigerant selection. This study suggests that first-generation refrigerants and R152a can be better alternatives. Journal of Thermal Engineering Journal of Thermal Engineering 2022-06-06T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5597 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5597 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5597

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6666 2022-12-01T21:00:00Z 1

A SENSITIVITY STUDY FOR N SIMILAR PARTLY ENCLOSED WITH PHOTOVOLTAIC THERMAL FLAT PLATE COLLECTORS HAVING SERIES CONNECTION Raj Vardhan Patel, Anuj Raturi, Desh Bandhu Singh Sensitivity Analysis, Solar Collector, PVT, FPC, Inclination Effect A sensitivity study for N similar partly enclosed with photovoltaic thermal flat plate collectors with a series connection (N-PVT-FPCs) has been carried out in this research study. The analysis has been done for a typical day of May, wherein data for the ambient conditions of New Delhi (India) has been received from the metrological department (IMD Pune, India. In addition, further computational work has been carried out on the MATLAB programme for the daily heat gain of N-PVT-FPCs. One-at-a-time (OAT) methodology has been used for the sensitivity analysis. From the sensitivity analysis, it has been found that the heat gain from the proposed system is more sensitive with respect to the number of collectors (N) followed by inclination angle, mass flow rate (MFR) and packing factor (PF). The sensitivity figure has been found to be 0.08, 0.17, 0.25 and 0.94 for daily heat gain of N-PVT-FPCs with respect to PF, MFR, inclination angle and N, respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2022-12-01T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6666 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6666 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6666

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6689 2022-12-13T21:00:00Z 1

Impact of The V Cap on Induced Turbulent Air Flow in a Solar Chimney: A Computational Study Nguyen Minh Phu, Nguyen Hoang Kha, Nguyen Van Hap Solar Chimney, Natural Ventilation, CFD, Top Cap. In this paper, a 2D numerical simulation of a solar chimney with a top V cap was performed to evaluate the induced air flow degradation. Dimensions including the width of the cap and the cap offset from the top of chimney are specified as key parameters. Meanwhile, height and width of the chimney are fixed. The numerical model was confirmed to be accurate compared to the published data. The results showed that reducing the offset and increasing the width reduces airflow through the chimney. The effect of offset on chimney intake air is significant. When considering the addition of the top V cap, the airflow is reduced by about 20% compared to the chimney without a cap. This is because the cap forms three primary vortices including one vortex below the cap and two ones above the cap. The vortex under the cap in the direction from the absorber plate to the glass cover increases the air flow out of chimney at the side of the glass cover. The region with great turbulent kinetic energy forms at upper side of the cap. The air flow correlation as a function of the heat flux to the absorber plate, cap offset and cap width have been developed with errors of less than 2.5%. Journal of Thermal Engineering Journal of Thermal Engineering 2022-12-13T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6689 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6689 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6689

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5517 2021-12-24T21:00:00Z 1

Thermal Analysis on The Impact of Spray Charactristics on Evaporative Cooling Process Behzad Siavash Amoli, Seyed Soheil Mousavi Ajarostaghi, Kurosh Sedighi, Mojtaba Aghajani Delavar Evaporative cooling Process, Spray, Nozzle, Two-Phase Flow, Droplet, Eulerian–Lagrangian Approach. In hot and dry climates, evaporative cooling of the air by water spray can be applied in several requirements, such as evaporative condensers which the airflow is precooled by the water spray before it reaches the condenser. The interaction between water droplets and the air is a complicated two-phase flow that is affected by the several parameters. Here, an Eulerian-Lagrangian 3D model was developed to investigate the influence of important parameters on spray cooling performance in a rectangular duct. The evaluated parameters include the number of nozzles, inlet air flow rate, and spray water flow rate. The results represented that growth in the number of nozzles causes a reduction in the spray cooling efficiency. This is due to decrease of droplets retention time within the duct by increasing the number of nozzles at a constant total spray flow rate in the cases. The maximum and minimum spray cooling efficiency belong to the cases with one nozzle at water flow rate of 20 l/h and four nozzle at water flow rate of 5 l/h, respectively. The difference between spray cooling efficiency at 3 and 4 number of nozzles is less than 1.8%. Moreover, increasing the air flow rate from 0.5 l/h to 2 l/h (by 300%) makes a decrease in the spray cooling efficiency up to 58.6%. Journal of Thermal Engineering Journal of Thermal Engineering 2021-12-24T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5517 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5517 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5517

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5530 2022-01-26T21:00:00Z 1

Profile Drying: A Novel Multistage Convection Drying Method for Indian Dark Red Onion Slices Mahesh G. Bhong, Vinayak M. Kale Drying, Profile, Onion, Slices, Velocity, Rehydration, Nutrition Drying increase shelf life and preserve nutritional value. Convection drying experiments are conducted at different novel multistage drying profiles and at constant 60 °C temperature. Velocity varied in the range of 2, 3.6, 5.7, and 7.7 m/s for the dark Indian dark red onion. The objective is to analyse the multistage novel convection profile drying method for onion slices at high velocity. The constant 60 °C air-drying process consumes 18.88% to 34.98% more energy than multistage drying profiles for the 360 minutes of convection drying. The arithmetic mean of effective moisture diffusivity lies between 1.002396 ×10-12 to 7.898936 ×10-11. A better drying rate is found for constant 60 oC constant temperature, but higher activation energy (1.23710647 to 1.8186585 kJ/ mol) is required than drying profiles. The rehydration ratio of the profile is observed to be higher and rises uniformly with time compared to a constant 60 °C. In the proximate analysis, it was observed that crude FAT, Carbohydrate, total energy, Potassium, and Calcium contents are increased on the onion's drying. Total ash content and total mineral content were detected to be decreased with drying. Journal of Thermal Engineering Journal of Thermal Engineering 2022-01-26T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5530 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5530 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5530

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6757 2023-05-18T21:00:00Z 1

A Numerical Investigation on Thermal Analysis of RPC Based Solar Thermochemical Reactor for Two-step H2O Splitting Cycle for Hydrogen Production Jeet Prakash Sharma, Ravindra Jilte, Ravinder Kumar solar thermochemical; hydrogen production; RPC thickness; gas flow gap; two-step water splitting process Ceria based solar thermochemical cycle is a high-temperature based redox chemical reactions to split H2O or CO2to produce hydrogen and/or syngas. The redox reactions are carried out in a reactor cavity thus the analysis and optimization of design as well as thermal analysis is a crucial factor to improve the solar-to-fuel conversion efficiency. This paper proposes the hybrid design of cylindrical and hemispherical cavity and its effects of geometrical parameters such as reticulated porous ceria (RPC) thickness (15 mm, 20 mm, and 25 mm) and gas flow gap (5 mm&10 mm) on temperature and flux distribution and solar-to-fuel efficiency for both steady-state and transient condition. A numerical computational fluid dynamics (CFD) analysis is carried out to study heat and mass transfer as well as geometrical design consideration of the STCR cavity under SolTrace generated Gaussian distributed concentrated solar flux. Two-step water-splitting reaction in the Solar Thermochemical cavity reactor (STCR) using ceria (CeO2) has been modeled to explore the oxygen evolution/reaction rate and to estimate solar-to-fuel efficiency and its relationship with geometrical factors. The RPC of 25 mm thickness yields the highest oxygen evolution rate of 0.34 mL/min/gCeO2 and solar-to-fuel efficiencies are 7.82%, 12.07% and 16.18% for 15 mm, 20 mm and 25 mm of RPC thickness, respectively without heat recovery. The operating conditions and optimized geometric factors, based on result analysis and comparison, are discussed in detail. Journal of Thermal Engineering Journal of Thermal Engineering 2023-05-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6757 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6757 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6757

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6648 2022-11-23T21:00:00Z 1

Evaluation of Summer Thermal Comfort using in Situ Measurement and Dynamic Simulation, Hot and Arid Climate in Algerian Saharan Region Amri Khaoula, Alkama Djamel Contemporary architecture, In situ measurement, Local materials, Simulation, Traditional architecture, Thermal comfort. The interest to ensure thermal comfort becomes one of the major challenges in the building sector, not only for the quality of interior ambiences, but also to reduce the quantity of energy consumed for heating and cooling. This paper presents the advantage of using the adaptive approach and numerical simulation to assess the level of thermal comfort of dwellings of different architectural typology in hot climate. For this purpose, the method includes in situ measurements effected on two samples of traditional and contemporary typology; using an anemometer measuring the following climatic parameters: ambient temperature, outdoor temperature, relative humidity, air velocity. The simulation work is performed by Energy-plus software; consequently experimental tests are realized on the local material in order to know their physical and thermal characteristics. The results obtained demonstrate the efficiency of the traditional passive devices, which are able to provide a comfortable thermal ambience without referring to the air conditioning system, with an operating temperature of 30.5ºC and a satisfaction rate of 80%. Journal of Thermal Engineering Journal of Thermal Engineering 2022-11-23T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6648 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6648 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6648

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6686 2022-12-12T21:00:00Z 1

Design and Analysis of an Alkaline Fuel Cell Mohammed Azzam, Zabayyan Qaq, Mehmet Fatih Orhan Fuel Cell; Alkaline fuel cell; Thermoelectricity; Electrochemistry; Electrolyte; CFD This study provides a step-by-step, up-to-date fuel cell fundamentals, thermodynamic and electrochemical principles, and system evaluation factors via a case study of a 10-kW alkaline fuel cell designed to operate in space applications. The system also produces 100 kg of pure water and 5.5 kW of heat. The system is modelled using MATLAB and ANSYS Fluent. Then, the model is verified with theoretical and experimental results from the literature. A parametric study of various design and operating parameters, and material selection is carried out to optimize the overall performance. A net output voltage of 0.8 V is obtained at 150 mAcm-2 current density, which yields an overall efficiency of 75%. The results indicate that increasing the electrolyte thickness or operating temperature results in a lower net voltage output. Additionally, improving the performance of a fuel cell through the bipolar plate can be achieved by understanding the contribution of different parameters towards minimizing the pressure drop across the bipolar plate. It is found that implementing an optimized selection of fluid flow rate, channel width, channel depth, number of channels and current density minimize the pressure drop throughout the bipolar plate. Relative humidity has a significant effect on the pressure drop. Results indicate that increasing the relative humidity consequentially rises the pressure drop. Finally, the CFD simulation illustrates that the end-zones in the bipolar plate accumulates fluid due to the nature of stagnation at those locations. Thus, total pressure at those locations is the highest. One of the major contributions here is studying the effect of KOH concentration on the performance of the AFC at different operating temperatures. In addition, a wide range of design and operating parameters were analysed to understand their effect on the overall performance of the fuel cell Journal of Thermal Engineering Journal of Thermal Engineering 2022-12-12T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6686 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6686 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6686

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6683 2022-12-08T21:00:00Z 1

Comparative Analysis and Optimization of Thermodynamic Behavior of Combined Gas-steam Power Plant Using Grey-Taguchi and Artificial Neutral Network Komal Madan, Omender Kumar Singh Performance enhancement; Grey-Taguchi analysis; Artificial neural network; optimal conditions; Gas-steam power cycle; Response table; In the published studies, to the best of the authors’ understanding, the grey Taguchi-based statistical technique has not been applied for the optimization of combined gas-steam power plants. In view of this, seven essential input parameters namely compressor inlet air temperature, pressure ratio, fuel temperature, volumetric flow rate of fuel, gas turbine maximum temperature, compressor efficiency, and turbine efficiency are chosen with the aim of determining the optimal combination of design variables that maximize the net power generation, thermal efficiency, exergetic efficiency, and minimize the specific fuel consumption. Also, the impact weight of each parameter on output indicators has been evaluated. While the Taguchi approach helps to create an orthogonal array of L27 (3^7), the ANOVA method determines the contribution of each input argument on the objective function. Unlike the Taguchi and ANOVA optimization methodology, the grey relational analysis is performed to transform the multi-objective function into a single objective by way of estimating its grey relational grade. The most favorable combination of input parameters is determined as A1B1C1D1E3F3G3 and under this state, the optimum values of power generation, thermal efficiency, exergetic efficiency, and specific fuel consumption are found to be 259911 kW, 64.9 %, 66.27 %, and 0.1839 kg/kWh respectively. Moreover, the contribution ratio on the output characteristic of the combined cycle is found to be maximum for turbine efficiency (42.41 %) and minimum for fuel temperature (0.59 %). The effectiveness of the grey-Taguchi method is acknowledged and validated using an artificial neural network technique in MATLAB. Journal of Thermal Engineering Journal of Thermal Engineering 2022-12-08T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6683 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6683 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6683

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6691 2023-02-05T21:00:00Z 1

Effect of Different Aluminium Oxide Based Nanofluid Concentrations on the Efficiency of Solar Water Desalination System Naveen Kumar Gupta, Ajit Katiyar Mass flow rate; Nanoparticles; Efficiency; Nanofluid; Water; Solar energy In this study, the effect of different concentration of the Aluminium oxide-based nanoparticles on the performance of Solar Desalination system was discussed. The Aluminium Oxide was used added in different concentrations 1%, 2% and 6% on weight basis. The flow rate was also varied and its effect on the system efficiency was discussed. The nanofluid was compared with the water and there was improvement occurred in the efficiency during variation of incident radiation. With an increase in the concentration of Aluminium oxide nanoparticles, improvement in the efficiency was attained. More efficiency was attained at 6% nanoparticles addition with compared to 1% and 2%. With an increase in mass flow rate of the fluid, the nanofluid also showed better performance in terms of improvement in the efficiency. Journal of Thermal Engineering Journal of Thermal Engineering 2023-02-05T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6691 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6691 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6691

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6613 2022-08-16T21:00:00Z 1

Evolution of Steam Turbines: A Bibliometric Approach Asım Sinan Karakurt, İbrahim Özsari, Veysi Başhan, Ümit Guneş Steam Turbine, Bibliometric, Power Generation, Research Trends, Thermal Power Plant This study investigates the contribution from researchers around the world in the field of steam turbines during the period 2000-2020. A comprehensive bibliometric approach has been applied to illustrate the scientific publications on steam turbines and related topics using the Scopus database, which has 11,751 publications published by 652 authors from more than 500 organizations scattered over 101 countries. Various aspects of the studies have been analyzed such as publication type, fundamental research areas, journals, citations, authorship patterns, affiliations, and most used keywords. In addition, the impact factor, h-index, and Paper İmpact Parameter (PIP) for the number of total citations have been used to reveal the power of countries, institutes, authors, and journals in the field of steam turbines. The results show that the most productive journal or proceedings, author, and country according to PIP are Energy, Ibrahim Dincer, and Singapore, respectively. The results also indicate turbomachinery to cover more papers than other core research areas and engineering subjects to also have the highest ratio. Journal of Thermal Engineering Journal of Thermal Engineering 2022-08-16T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6613 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6613 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6613

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6681 2022-12-06T21:00:00Z 1

CFD Modeling of Influenza Virus Diffusion During Coughing and Breathing in A Ventilated Room Sattar Aljabair, Israaa Alesbe, Ali Alkhalaf CFD, Coughing and Breathing Flow, Lagrangian Model, Influenza Virus The virus diffusion in a ventilated room with the droplets produced by coughing and breathing are presented by the Lagrangian model. When the human body is located in the middle of the room with two locations of AC, in front of and behind the human body, three angles of Air Conditioning (AC) gate are applied 0o, 30o, and 60o to show droplet particle diffusion in the room in these cases. Three types of coughing velocity profiles were selected, real human coughing, sinusoidal cough, and cough jet with one velocity profile of breathing as a step function to cover the inhaling and exhaling cycle. The simulation results show that the uncovered standing in the middle of the room, are more susceptible to infection for the bouncy and forced flow around the human body. Droplet particle moves in the room as a random diffusion and it is very sensitive to the thermal load inside the room, generally depends on the bouncy force and pressure force due to convection heat transfer. when the AC location at the opposite direction of coughing flow, the droplet travels a distance of about 3 m, 2.85 m, and 2.75 m for real cough, sinusoidal cough, and cough jet respectively. While the droplet travel distance is about 3.1 m, 3.2 m, and 2.9m when the AC location is at the same direction of coughing flow. Finally, the adopted CFD modeling was also used to show the effects of different AC locations on coughing, breathing particle droplets distribution in different indoor spaces, such as buildings, hospitals, and public transports, Also, showed good visual demonstration and representation of the real physical processes. Journal of Thermal Engineering Journal of Thermal Engineering 2022-12-06T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6681 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6681 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6681

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6792 2023-07-28T21:00:00Z 1

Theoretical Exploration of Low GWP Refrigerant Mixtures as Replacement to HFC-134A in a Vapour Compression Refrigeration System Mohammad Hasheer Sk, Srinivas Kolla, Desari Kondala Rao, Yellapragada Naga Venkata R430A, GWP, LSHX, household Refrigerator Hydro-fluorocarbons (HFCs) are not harmful to the ozone layer and are used in many applications, including refrigerants, aerosols, solvents, and blowing agents for insulating foams replace chlorofluorocarbons and hydrochlorofluorocarbons (HCFCs). However, some HFCs have relatively high GWP (Global Warming Potential) and are subject to further examination due to growing concerns about global climate change. The main objective of this work is the theoretical analysis of eco-friendly refrigerant mixtures AC5, R430A, and R440A as a direct substitute to HFC-134a in a refrigerator. At the same time, the performance of the household refrigerator was improved with the help of an LSHX. The performance of the domestic refrigerator was compared in terms of compressor discharge temperature, COP, VCC, and power consumption of a compressor. It was found that the average COP of R440A and R430A was higher than HFC-134 by approximately 2.5% and 1.47%, while the COP of AC5 was 6.1% lower than that of HFC-134a. The VCC (volumetric cooling capacity) of R430A is almost equal to HFC-134a. The results also show that AC5, R440A, and R430A consume less power than HFC-134a. Compressor outlet temperatures R440A, AC5 provide higher values than HFC-134a, which affects the compressor life. The best overall performance is achieved when using R430A in the Household refrigerator. Journal of Thermal Engineering Journal of Thermal Engineering 2023-07-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6792 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6792 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6792

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6653 2022-11-27T21:00:00Z 2

Comment on “Numerical Analysis of Heat Transfer in Multilayered Skin Tissue Exposed to 5g Mobile Communication Frequencies” by Jagbir Kaur and S.A. Khan Paul Ben ishai 5G, Skin, Temperatures, Pennes Bioheat Equation. Kaur and Khan have published a simulation study demonstrating that a 5G device should cause only minimal temperature variations in the skin layer. For this they use a 4 - layer skin model and the Pennes’ bioheat equation. The comment points out some differences between the 4 layered model they used and those of the groups of Abdulhalim and Feldman, who also incorporated the presence of the human sweat duct in the model. Furthermore, the comment notes that theoretical work by Neufeld and Kuster that takes into account the disparity between the time constants for electromagnetic absorption and thermal perfusion will lead to significantly higher temperature spikes that those found by the authors. Finally new research by Gultekin and Siegel is noted that does indeed confirm temperature spikes in biological tissues for 5G frequencies. Journal of Thermal Engineering Journal of Thermal Engineering 2022-11-27T21:00:00Z Short Communication application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6653 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6653 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6653

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6657 2022-11-27T21:00:00Z 1

Optimization of Energy and Exergy Parameters for a Conceptual Afterburning Turbojet Engine Hakan Aygün Turbojet, Afterburner, Optimization, Exergy, Engine Performance In this study, parametric cycle analysis of a conceptual turbojet engine with an afterburner (TJEAB) was conducted at sea level conditions-zero Mach. Based on this analysis, exergetic sustainability parameters of TJEAB were scrutinized for military mode (MM) and afterburner mode (ABM). Constitutively, several design parameters of TJEAB were chosen so as to optimize performance and exergetic parameters which consist of specific fuel consumption (SFC), overall efficiency, exergy efficiency, environmental effect factor (EEF) and exergetic sustainability index (ESI). In this context, compressor pressure ratio (CPR), turbine inlet temperature (TIT) were preferred due to high effect of these variables on engine performance. CPR ranges from 4 to 11 whereas TIT varies from 1150 K to 1550 K. According to optimization of performance parameters, minimum SFC was achieved as 28.59 g/kN.s at MM and 43.95 g/kN.s at ABM. On the other hand, maximum overall efficiency is determined as to be 13.07 % at MM and to be 8.5 % at ABM. As for exergetic parameters, exergy efficiency was calculated as maximum with 30.85 % at MM and 23.2 % at ABM. Finally, maximum exergetic sustainability index of TJEAB was computed as 0.446 at MM and 0.269 at ABM. It is thought that energetic and exergetic parameters analyzed in this analysis could guide in designing turbojet engines in terms of lower fuel consumption thereby environmental-benign. Journal of Thermal Engineering Journal of Thermal Engineering 2022-11-27T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6657 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6657 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6657

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6679 2022-12-05T21:00:00Z 1

Performance Improvement of Shell and Tube Heat Exchanger by Using Fe3O4/Water Nanofluid Adnan Hussein, Saad Najim, Suad Danook CFD, Reynolds number, Thermal efficiency, Nusselt number, Nanofluid, Heat exchanger The objective of this paper is to study the effect of nanofluid on the performance of the heat exchanger, as well as the heat transfer rate, coefficient of total heat transfer, friction influence and average Nusselt number, and thermal efficiency factor and has been investigated and discussed. In this work, the output heat transfer of Fe3O4/water nanofluid through shell and tube heat exchanger has been numerically investigated under laminar flow. CFD simulations with ANSYS FLUENT 2020R1 were used adopting finite volume approach to solve the governing equations. Numerical calculations were carried out for Reynolds numbers ranging from 200 to 1400, with nanoparticles as the volume fraction (0.2% and 0.35%). The results show that the augmentation in increase Nusselt number and amount of heat transfer rate and the efficiency of nanofluid at the concentration of 0.35% are approximately 19%, 25% and 12% respectively. It was observed through the results that the friction decreases as the Reynolds number increase. Journal of Thermal Engineering Journal of Thermal Engineering 2022-12-05T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6679 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6679 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6679

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6651 2022-11-26T21:00:00Z 1

Field-Synergy and Nanoparticle’s Diameter Analysis on Circular Jet Impingement Using Three Oxide–Water-Based Nanofluids Abanti Datta, Pabitra Halder Field Synergy; Nanoparticle Diameter; Nanoparticle Concentration; Al2O3, TiO2 and CuO; Circular Jet Impingement, Heat Transfer The field synergy study is carried out using three oxide nanofluids impinging circular jet on the horizontal circular disc to analyse the synergetic interaction of cooling processes between temperature and flows fields. The heat transfer effect of the nanofluid is examined by rising the Reynolds number and the nanoparticle concentration depending on field synergy number. For jet impinged cooling process, the scale of synergy between the nanofluid flow speed and temperature is decayed with the increase of Reynolds number. Hence, it is contributed to a lower heat transfer efficiency of the nanofluid. Whereas, the scale of synergy between the nanofluid flow speed and temperature can be enhanced by rising the particle concentration. Thus, the heat transfer efficiency of the nanofluid is increased. Analysis showed that Al2O3 nanofluid has the maximum relative field synergy among selected three oxide nanofluids. It is evident that the nanoparticle concentration, nanoparticle material and Reynolds number have significant effect on the heat transfer augmentation. In addition, the study is explored by varying jet-disk spacing. Moreover, the investigation has shown that the reducing heat transfer effect for the materials is Al2O3, CuO and TiO2 subsequently. It is revealed that the heat enhancement is higher for smaller nanoparticle’s diameter (i.e., 20 nm) than bigger nanoparticle’s diameter (i.e., 80 nm) of the same material. Journal of Thermal Engineering Journal of Thermal Engineering 2022-11-26T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6651 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6651 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6651

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6748 2023-05-16T21:00:00Z 1

Second Order Cyclic Analysis of Counter Flow Pulse Tube Refrigerator Mahmadrafik Choudhari, Bajirao Gawali, Prateek Malwe, Nandkishor Deshmukh, Rustum Dhalait Counter flow pulse tube refrigerator, Second order cyclic analysis, CFD modeling Stirling machines are ecologically propitious refrigeration devices that utilize natural gases like helium, nitrogen, or air. Stirling machines are active refrigerators that should be designed with minimal vibrations and durability in order to fulfil current and future commercial demands and requirements. The present paper deals with the modification of the inertance pulse tube refrigerator in which the reservoir is eliminated and replaced with another pulse tube refrigerator. These two pulse tube refrigerators are operated at 180 degrees out of phase, called counter-flow pulse tube refrigerators (CFPTR). The second-order cyclic analysis approach is used to develop a mathematical model for evaluating the performance of CFPTR. This paper describes a modified second-order cyclic approach in detail. The performance of CFPTR is evaluated by estimating the ideal refrigerating effect, ideal power input, and losses individually, yielding net power input and net refrigerating effect. The net refrigerating effect of 30.88W at 70K is obtained with the percentage of Carnot COP of 13.71. The CFD modeling of CFPTR is used to corroborate the second order cyclic model. Journal of Thermal Engineering Journal of Thermal Engineering 2023-05-16T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6748 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6748 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6748

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5463 2021-10-16T21:00:00Z 1

Experimental Investigation on The Effect of Thermophysical Properties of a Heat Transfer Fluid on Pumping Performance for a Convective Heat Transfer System Reza Rahman, Agri Suwandi, Muhammad Nurtanto : Convective Heat Transfer, Heat Transfer Fluid, High-Temperature Pump, Slip Factor, Volumetric Efficiency Pumping performance is crucial for a convective heat transfer system. However, there is a limited study that specifically discusses the relation between thermophysical properties of a Heat Transfer Fluid (HTF) and pumping performance. This study aims to find the effect of the change in thermophysical properties of HTF on the pumping performance, particularly for the delivery rate, slip factor coefficient, and volumetric efficiency. In this study, five different HTFs are used to assess the effect of working temperature and pumping speed on the pumping performance. Delivery rate is evaluated by setting the pumping speed from 0 to 1300 RPM where the working fluid temperature is set at 40, 140, and 200 °C. It shows that the HTF with a lower viscosity has a better delivery rate. The slip coefficient for all working fluid is ranging between 0.11–0.31 at temperature 200 °C. It is found that a higher working temperature for the fluid increases the slip coefficient and delivery rate. The volumetric efficiency is directly affected by the slip ranging from 69 – 89% at 200 °C. The heat transfer rate ranges from 40 – 98 °C for all fluids, which is mainly affected by the volumetric efficiency of the pump and also pumping speed where a higher pumping speed decreases the heat transfer rate. It can be concluded that the change in thermophysical properties of the working fluid will change the pumping performance. Therefore it is important to adjust the pumping operation according to the temperature and properties of the working fluid to achieve the highest heat transfer rate for a convective heat transfer system. Journal of Thermal Engineering Journal of Thermal Engineering 2021-10-16T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5463 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5463 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:7 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5463

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6705 2023-02-18T21:00:00Z 1

Prediction of Recital Characteristics of a CI Diesel Engine Operated by Bio-fuel Extracts from Cotton Seed Oil, Linseed Oil and Mahua Seed Oil using ANN Method Srinivasa Reddy Kunduru, Hanumantha Rao Yarrapathruni Venkata, Dhanaraju Vallapudi, Narmatha Deenadayalan, Arul Raj Kumaravel Bio-Diesel, ANN method, Brake Power, Brake Thermal Efficiency, Transesterification, Specific Fuel Consumption In the wide survey, it is explored that the potential of artificial neural network is used to foretell the recital (performance) characteristics of a four stroke single cylinder diesel engine using the biofuel obtained from cottonseed, linseed and Mahua seed. The test engine was powered with diesel and biofuel with its blends from cotton seed, linseed and Mahua seed separately. Experimental results of the cotton seed oil, linseed oil and mahua oil as a substitute for diesel revealed that linseed oil provides the better engine performance nearly equal to diesel. The ANN is used to compute the performance characteristics such as Indicated power, Brake power, Friction power, Thermal efficiency, brake mean effective pressure, brake thermal efficiency, Brake specific fuel consumption, Indicated thermal efficiency, indicated mean effective pressure, Mechanical efficiency, Indicated specific fuel consumption, volumetric efficiency and combustion characteristics as compression ratio at different conditions of torque, speed, water flow , air rate and fuel rate. An ANN sculpt was developed with 80% of training data and 20% of testing data from experimental values. In this model, back propagation feed forward neural network with five inputs and eleven outputs has been used. The ANN model result accuracy was found to agree nearly with the experimental results with the regression coefficient value approximately equal to one and low mean square error value. Thus, the proposed ANN model was legitimate tool for predicting the combustion and performance of diesel engine. Journal of Thermal Engineering Journal of Thermal Engineering 2023-02-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6705 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6705 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6705

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6915 2024-02-06T21:00:00Z 1

Brownian Motion Models Effect on the Nanofluid Fluid Flow and Heat Transfer in the Natural, Mixed, and Forced Convection Behrooz Mozafary, Ali Akbar, Ghanbar Ali Sheikhzadeh Nooshabadi, Mohammad Salimi Nanofluid; Brownian motion; Numerical solution; Variable properties; Natural convection; Mixed convection; Forced convection. In this research, the effect of different models of thermal conductivity and dynamic viscosity has been investigated by considering the effect of Brownian motion of nanoparticles on the flow field and heat transfer of nanofluids. This study was performed numerically in a square cavity with water/aluminum-oxide nanofluid in three modes of natural, mixed and forced convection by changing the independent variable such as nanoparticle volume fraction, Rayleigh number, Richardson number, and Reynolds number. The governing equations with certain boundary conditions are solved using the finite volume method. Also, according to the obtained numerical results, Nusselt number has been investigated for different conditions with and without considering Brownian motion. The results showed that for all the studied models, in all three modes of natural, mixed and forced convection, the average Nusselt number when the effect of Brownian motion is considered, is more than the case that the effect of this motion is not considered. In all cases, the Koo & Kleinstreuer and Li & Kleinstreuer models show approximately the same values for the maximum mean Nusselt number. The similar results are obtained employing the Wajjha & Das and Xiao et al. models. For mixed convection, the highest and lowest increases of Nusselt number, considering Brownian motion are 17.68% and 14.84%, respectively. While referred values for forced convection are 30.46% and 17.94 %, respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2024-02-06T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6915 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6915 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6915

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5525 2022-01-10T21:00:00Z 1

Mini-Channel Heat Exchanger Optimization Using Genetic Algorithm And Multiple-Criteria Decision Making Abdussamet Subası Mini-channel, Heat exchanger, Heat transfer, Optimization, Genetic algorithm, VIKOR This study aims to apply an integrated optimization approach that combines Multi-objective Optimization (MOO) and Multiple-criteria Decision-making (MCDM) to optimize a multiport mini-channel having 2D sawtooth micro fins under laminar, transitional, and turbulent flow conditions. Water was considered as working fluid. The Reynolds number (Re), fin height (Hf), fin width (Wf), the number of micro-fins in each mini-channel (N), and the distance between the successive fins (S1) were selected as design and flow parameters and the Nusselt number (Nu) and the Poiseuille number (Po) were selected as objective functions. A Genetic Algorithm based MOO study was conducted using the correlations available in the literature aiming to find the optimum values of design and flow parameters that maximize Nu and minimize Po. Then, the VIsekriterijumska Optimizacija I Kompromisno Resenje (VIKOR) method was employed to help designers to select an optimum design among the Pareto optimal solution set which is the output of MOO. Finally, the optimization results obtained were compared with those obtained by the 1st Law of Thermodynamics based Performance Evaluation Criteria (PEC). The advantages and disadvantages of these methods were discussed in detail. It is revealed that the integrated approach is a more comprehensive and flexible approach that also covers the results of PEC. Journal of Thermal Engineering Journal of Thermal Engineering 2022-01-10T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5525 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5525 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5525

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5568 2022-04-13T21:00:00Z 1

Impact of Baffle on Forced Convection Heat Transfer of CuO/water Nanofluid in a Micro-scale Backward Facing Step Channel Shailendra Rana, Hari Bahadur Dura, Sudip Bhattrai, Rajendra Shrestha Nanofluids, Thermal Performance, Forced Convection, Finite Volume Method, Baffle Numerical simulations have been carried out to investigate the thermal-hydraulic characteristics using water-based CuO nanofluid with volume fraction (ϕ) = 0 - 5% and fixed nanoparticle size (dp) = 20 nm at Reynolds numbers (Re) = 100 - 389 in a micro-scale backward facing step channel with and without a baffle using finite volume method. The flow is steady, laminar, and incompressible. The channel has an expansion ratio (ER) = 1.9423with a fixed step height (S) of 490 μm. To study the effect of the baffle, different geometrical configurations have been developed by varying its height and location. The height of the baffle is varied as Hb = 160 - 640 μm. The baffle is stationed on the upper wall of the channel at a dimensionless distance (D)= 1, 2, 3 and 4. The upstream, step and upper walls are thermally insulated while the lower wall downstream of the step is under a constant heat flux (qs") = 20000 W/m2. The parameters of interest for analysis are Nusselt number, skin friction coefficient and velocity distribution under different flow conditions. Results indicate that the rise in volume fraction and Reynolds number enhances the Nusselt number, indicating improved heat transfer. However, the skin friction coefficient decreases with the increment in Reynolds number. The increase in baffle height causes the Nusselt number and skin friction coefficient to rise. As the baffle is moved away from the step, the Nusselt number tends to decrease. In comparison to water, the heat transfer improved by about 164% using CuO nanofluid at Re = 389 with ϕ = 5% in the presence of the baffle with Hb = 640 μm and D = 1. However, the heat transfer enhancement has been achieved at the cost of higher pumping power requirements. Journal of Thermal Engineering Journal of Thermal Engineering 2022-04-13T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5568 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5568 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5568

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6682 2022-12-07T21:00:00Z 1

Effect of Module Operating Temperature on Module Efficiency in Photovoltaic Modules and Recovery of Photovoltaic Module Heat by Thermoelectric Effect Ramazan Kayabaşı, Metin Kaya Photovoltaic Module, Photovoltaic/Thermal, Renewable Energy, Phase Changing Material One of the parameters affecting the efficiency of photovoltaic (PV) modules and PV systems is the temperature. The factors that increase the temperature in PV modules cause loss of efficiency. In this study, experiments have been conducted with the aim of reducing the module temperature. For this purpose, four polycrystalline and four monocrystalline PV modules, all with the same features, were used. A pair of polycrystalline and monocrystalline modules were used as reference modules. The aim of this study is to reduce the operating temperature of the modules, while also decreasing the transient temperature fluctuations in the system, in order to prevent the loss of efficiency. For this reason, current, voltage and power values of PV modules have been examined and the relationship between these values and module temperature has been explained. As a result, temperature values were measured at 30-80°C in reference modules, 30-50°C in heat pipe modules, 30-37°C in modules using heat pipes and phase-changing material, and 30-66°C in modules using phase-changing material with flexible surfaces. If the PV module operating temperature is increased by 35°C, the module efficiency decreases by 10%. Heat pipe and PCM balance the temperature in PV/T/PCM monocrystalline and polycrystalline modules. In PV/T/PCM modules, efficiency loss caused by temperature increase is 1%. In addition, electrical energy is produced from the heat accumulated on the surface of the PV module by means of Thermoelectric Generator (TEG). When the temperature difference between the surfaces is 15°C, the naturally cooled TE provides 0.45V energy output, while the forced-cooled TEG provides 0.97V energy output. As the temperature gap between the surfaces increases, the voltage and current values of the TEG also increase. Briefly, TEG's power values increase up to 5W depending on the temperature gap between surfaces. Journal of Thermal Engineering Journal of Thermal Engineering 2022-12-07T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6682 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6682 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6682

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6610 2022-08-14T21:00:00Z 1

Numerical Analysis of an Isolation Room to Prevent the Spread of COVID-19 Erhan Arslan CFD, isolation room, numerical analysis, COVID-19 COVID-19 virus, which is a member of the coronavirus family, is a virulent virus that is transmitted by physical contact or air and results in death in infected people. People infected by the COVID-19 virus must be kept in quarantine in a closed area. Therefore, it is very important for the health of the individuals (patient, doctor, nurse, etc.) in the isolation room that, where the area kept closed is completely free of virus. This study was conducted to examine the flow dynamics of the air in the isolation chamber. With the simultaneous operation of the sanitized air machine and the ventilation in the room, it is aimed to investigate the virus killing effect of the air mixed with each other. The flow dynamics, velocity, temperature and turbulence kinetic energy of the air in the isolation chamber were examined. Investigations were carried out to ensure that the mixture of the two air in the room was better and distributed throughout the room. Journal of Thermal Engineering Journal of Thermal Engineering 2022-08-14T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6610 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6610 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6610

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5571 2022-04-18T21:00:00Z 1

Thermo-hydraulic Characteristics of Mixed Convection of Transition Flow in a Conduit at Different Tilts Taiwo O. Oni Flow tilt, Forced convection, Mixed convection, Nusselt number, Velocity In this study, numerical investigation was carried out on combined free and forced convection for transition flow of water in a conduit that has a mechanical component, which is a three-sided-polygon-perforations-tranverse-axes tape, inserted in its interior. The purpose of the investigation is to find out the thermo-hydraulic characteristics of mixed convection of transition flow in the tube, and compare them with those of forced convection. Fluent software was used to perform the numerical investigation for the transition flow at Reynolds number (Re) in the range 2,150\leRe\le3,700\ for the tube bent at sundry tilts (λ) in the range{\ 15}^o\le\lambda\le{\ 90}^o. The results indicated that the inside temperature and surface temperature of the tube whose fluid flow is forced convection are lower than the case of the tube whose fluid flow is mixed convection, and that the temperatures (tube’s inside temperature, dimensionless outlet temperature, and surface temperature) increase as the tube tilt increases. Not only that, as the tube tilt increases, the dimensionless outlet temperature increases, but the outlet velocity decreases. The Nusselt number in the tube whose fluid flow is forced convection is lower than the case of mixed convection. For the tube with flow tilts of {15}^o,\ {30}^o,\ {\ 60}^o, and \ {90}^o, the Nusselt number are 4.01 to 6.10%, 4.60 to 7.41%, 5.32 to 8.71%, and 6.31 to 10.12%, respectively, greater than the case of the tube whose fluid flow is forced convection, for the Reynolds number considered. The validation of the numerical work with an experimental work confirms the correctness of the numerical work. Journal of Thermal Engineering Journal of Thermal Engineering 2022-04-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5571 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5571 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5571

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6758 2023-05-18T21:00:00Z 1

Simulation of Heat Transfer and Effectiveness in a Helical Heat Exchanger Made from Thermally Enhanced Polymer Material for Use in Absorption Cooling Talib Ahmadu, Hamisu Adamu Dandajeh Modelling, helical heat exchanger, thermally enhanced polymer, absorption chiller Heat exchangers in absorption chillers are usually made of copper material. However, problems of corrosion are usually encountered, especially in the solution heat exchanger. In this study a numerical investigation of the heat transfer effectiveness in a double pipe helical heat exchanger made from a thermally enhanced polymer material was conducted. The material consists of a Liquid crystal polymer (LCP), (Vectra A950) as the matrix material, while carbon fibre is the filler material. The resulting composite has a carbon fibre weight fraction of 74%. The heat exchanger was modelled as a counter flow solution heat exchanger to be used in a lithium bromide – water absorption chiller of 3 kW capacity. The numerical software ANSYS fluent (version 14.5) was used for the modelling and simulation. Thermal and mechanical properties of the thermally enhanced polymer were used in the modelling and simulation. The viscous laminar model was used, while employing a second order upwind solution method. Results indicate that the heat exchanger was able to perform the required duty by reducing the strong solution temperature from 90oC at inlet to 57oC at outlet, while increasing the weak solution temperature from 40oC at inlet to 67oC at outlet. The effectiveness of the heat exchanger was 77.4%. Results were numerically compared to a corresponding heat exchanger of same geometry and flow conditions, made of copper. It was observed that the polymer heat exchanger attained 89.2% effectiveness of the copper heat exchanger. Journal of Thermal Engineering Journal of Thermal Engineering 2023-05-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6758 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6758 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6758

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6710 2023-02-23T21:00:00Z 4

Influence of Nano Additives on Performance and Emissions Characteristics of a Diesel Engine Fueled with Watermelon Methyl Ester Arunprasad J, Rajkumar S, Aklilu Teklemariam, Dawit Tafesse, Mebratu Tufa, A. Bovas Herbert Bejaxhin Watermelon seed Oil, Transesterification, Lanthanum Oxide, Performance, Emission. Significant population and automobile expansion have resulted in a rapid rise in energy demand. Because of the high demand for energy and the rapid depletion of fossil fuels, experts are concentrating their efforts on developing a suitable alternative fuel for diesel. The performance and emission characteristics of biodiesel made from watermelon methyl ester were investigated using a lanthanum oxide (La2O3) nanoparticle addition. Through the transesterification method, biodiesel was produced from non-edible watermelon seed oil. Compared to B20, addition of 100 parts per million (ppm) of La2O3 nanoparticles to biodiesel emulsion fuel reduces CO and HC emissions by 4.75% and 6.67%, respectively. Compared to B20 at full load circumstances, the inclusion of La2O3 nanoparticles at 100 ppm enhances the brake thermal efficiency (BTE) and brake specific fuel consumption (BSFC) by 2% and 8.8 %, respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2023-02-23T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6710 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6710 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6710

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6685 2022-12-08T21:00:00Z 1

A Theoretical Analysis on the Operating and Design Parameters Affecting the Performance of a Sewage Wastewater Sourced Heat Pump System Ercan Doğan, İsmail Solmaz, Özgür Bayer Heat Pump, Sewage Wastewater, Indirect Type Heat Exchanger, COP Sewage wastewater heat exchanger (SWHE) has a significant role in the performance of sewage wastewater sourced heat pump (SWSHP) system as it provides to transfer the energy of wastewater to intermediary fluid or working fluid. Thus, a theoretical analysis of the SWSHP system was carried out to investigate the effects of SWHE design parameters on the system’s performance. For this purpose, a simulation program based on the proposed mathematical model of the SWSHP system was developed in MATLAB. Afterward, the indirect type SWSHP system that can meet 50 kW heating load was theoretically designed. The influences of SW temperature, its mass flow rate, the inner diameter of the heat exchanger tube, and intermediary fluid mass flow rate on the performance of the designed SWSHP system were analyzed. The results indicate that variation of SW temperature affects the COPsys more than the variation of SW mass flow rate. Considering the ranges of parameters investigated, the COPsys raises from 2.56 to 4.51 and 2.89 to 4.27 with the variations of SW temperature and SW flow rate, respectively. Moreover, an increase in the intermediary fluid mass flow rate provides an improvement on the COPsys and COPunit. However, SWSHP performance is adversely affected by the increasing value of the inner diameter of the tubes. As a result, small changes in the design parameters of the SWHE directly affect the system performance and system operating conditions. Journal of Thermal Engineering Journal of Thermal Engineering 2022-12-08T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6685 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6685 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6685

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5470 2021-10-21T21:00:00Z 1

Exergoeconomic, Environmental, Economic, and Energy-Matrices (4E) Analysis of Three Solar Distillation Systems Equipped with Condenser and Different Heaters Davoud Javadi Yanbolagh, Alireza Saraei, Hossein Mazaheri, Saeed Jafari Mehrabadi Thermoelectric heating, Exergoeconomic, Enviroeconomic, Active solar still, Energy-matrices The water scarcity in the world in the near future become to a global challenge. The main aim of present study was to elucidate the performance of the three identical solar distillation units with different configurations under climatic conditions of the city of Tehran. All systems were equipped with different heating source that are thermoelectric heating modules (TEH), copper heater (CH), and solar water heater (SWH) while all system assisted with an active external condenser. Performance of all systems is scrutinized from different thermodynamic, thermoeconomic, environmental, and energy-matrices viewpoints. Findings revealed that the highest daily and annual productivity obtained by the system with CH. Economic analysis on the basis of uniform annual cost (UAC) revealed that the system with SWH has the lowest cost per liter (CPL) rather than other system while the highest CPL was for the case of TEH. Furthermore, it was concluded that the system with TEH obtain the most promising results in terms of exergoeconomic, enviroeconomic, and energy payback time (EPBT) because of the highest daily and annual energy and exergy output. Eventually, the environmental analysis indicated that the solar still with CH with 6342, 48.169, 18.46 kg emission of CO2, SO2. And NO have the best results rather than other systems. Journal of Thermal Engineering Journal of Thermal Engineering 2021-10-21T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5470 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5470 Journal of Thermal Engineering, Year:2021, Vol:7, Issue:7 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5470

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6688 2022-12-13T21:00:00Z 1

Numerical Assessment of Stability Behaviour in Supercritical CO2 Based NCLs Configured with Heater, Heat exchanger and Isothermal Wall as Heat Sources Srivatsa Thimmaiah, Tabish Wahidi, Ajay Kumar Yadav, Arun Mahalingam Supercritical CO2; Instability; Rectangular natural circulation Loop; Flow transition; Computational fluid dynamics. Three-dimensional numerical analysis is presented in this study to assess the transient and stability behaviour of supercritical CO2 (sCO2) based NCLs configured with three different types of heat sources, i.e., heater, a hot heat exchanger (HHX) and isothermal wall (ISO) at the source, and a cold heat exchanger (CHX) at the sink in all three NCLs. Unsteady three-dimensional conservation equations (mass, momentum and energy equations) are solved to assess the transient and stability behaviour of sCO2 mass flow rate, temperature and velocity as a function of time. Further, the effect of pressure on sCO2 mass flow rate is also assessed to compare the loops performance. Performance of the loop has been studied for various heat inputs at the source by keeping constant mass flow rate and temperature at the sink. It is observed that for any boundary condition at the source, the loop experiences some initial disturbances or instabilities before reaching the steady-state. However, the time needed to attain a steady-state varies with the nature of heat input employed at the source. Results show a higher magnitude of instabilities in the Heater-CHX loop than HHX-CHX and ISO-CHX loops, and these instabilities mitigate at a faster rate in the ISO-CHX loop at all levels of heat input and operating pressure of the loop. It is also observed that as loop fluid operating pressure increases, the instability of the system decreases and the loop fluid mass flow rate increases. Further, the Nusselt number in the Heater-CHX loop is more than other loops because of its high turbulent kinetic energy. The findings of this study are validated with the published experimental and numerical data and found a good agreement. Journal of Thermal Engineering Journal of Thermal Engineering 2022-12-13T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6688 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6688 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6688

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6687 2022-12-12T21:00:00Z 1

Thermal Performance Analysis of Heat Pipe Using Response Surface Methdology Udayvir Singh, Naveen Kumar Gupta Heat Pipe, Nanofluids, Thermal Performance, Response Surface Methodology Heat pipes are the specific class of heat exchangers. They are used in thermal management of electronic components. Research community is continuously working to obtain the optimum heat transfer performance. In present work, parametric study of heat pipe using nano- fluid has been carried out. The operating parameters of heat pipe like power supply, orientation (gravity assisted angle), filling- ratio, and nano-fluids concentration are being investigated to find the optimum thermal performance of heat pipe. Response surface method (RSM) is used to analyze the effect of operating parameters on thermal performance. The optimum value of thermal resistance and thermal efficiency are 0.3994 oC/Watt and 68.44% respectively. Most suitable power supply, inclination angle, filling ratio and nanofluid concentration are 185.85 W, 60.09o, 50.7% and 1.05 % respectively. The experimental results confirm and validate the RSM predicted results. Journal of Thermal Engineering Journal of Thermal Engineering 2022-12-12T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6687 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6687 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6687

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6755 2023-05-18T21:00:00Z 1

Optimization of Exergetic Performance and Payback Period of Organic Rankine Cycle Integrated Vapor Compression Refrigeration System Based on Exergy, Economic, and Environmental Criteria Ashwni Ashwni, Ahmad Faizan Sherwani Payback period, exergy analysis, ORC, VCR, Pinch point, sensitivity analysis In this paper, a multi-objective optimization study is carried out to determine the optimal exergetic performance (?_ex) and the payback period (PB) of the organic Rankine cycle (ORC) integrated vapor compression refrigeration (VCR) system based on exergy, economic, and environmental criteria using non-dominated sort genetic algorithm-II (NSGA-II). Moreover, a sensitivity analysis is carried out to improve the exergetic performance of the system. The working fluid, the pinch-point temperature difference of the ORC evaporator (??T?_oe^p), condenser (??T?_cond^p), and the VCR evaporator (??T?_ve^p), cooling water inlet temperature (Tcw1), chilled fluid temperature (Tcf2), and heat-source inlet temperature (Th1) are taken as the decision variables. The results of this study indicate that butane is the most suitable working fluid for optimal exergetic efficiency, ?_ex (33.7%) and payback period, PB (4.9 years) of the system. The optimal values of other decision variables such as Th1, Tcw1, Tcf2, ??T?_oe^p , ??T?_ve^p , and ??T?_cond^pare 378 K, 313 K, 276 K, 10 K, 5 K, and 5 K respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2023-05-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6755 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6755 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6755

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5606 2022-06-30T21:00:00Z 1

Effect of the Position of the Hot Source on Mixed Convection in a Rectangular Cavity Sereir Tewfik, Missoum Abdelkrim, Elmir Mohamed, MebarkiI Brahim, Douha Mohamed Numerical heat transfer; Rectangular enclosure; Mixed convection; Position of the hot source; Cooling; Sinusoidal temperature; Finite element methods. This paper presents a numerical study of heat transfer by mixed convection in a two-dimensional rectangular cavity with a sinusoidal temperature imposed on the right vertical wall while the other wall on the left is kept at a cold temperature. The upper and lower walls are thermally insulated, the inlet and outlet ports are respectively located on the hot wall to the bottom and on the top to the left. The enclosure represents a practical system such as an air-cooled electronic device, the heat source represents a radiator or an electronic component located in three different positions towards the left side at the bottom, the center and towards the right side at the top in such an enclosure. All calculations are made for a range of Richardson number from 0 to 10 and Reynolds numbers from 50 to 200. The influence of Richardson number, the position of the heat source and the influence of amplitude and Phase shift of the temperature imposed on the Nusselt number on the hot surface is studied. The results are presented in the form of streamlines and isotherms graphs as well as the variation in maximum temperature and mean Nusselt number under different conditions. The numerical resolution of the governing equations is obtained using the software of Multiphysics Comsol based on the finite element method. The results thus found show that the fluid flow, the average temperature and the heat transfer rate depend on the position of the source for the different values of Ri and Re. Journal of Thermal Engineering Journal of Thermal Engineering 2022-06-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5606 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5606 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5606

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6868 2023-12-08T21:00:00Z 1

Numerical Simulation to Study Mixing Vane Spacer Effects on Heat Transfer Performance of Supercritical Pressure Fluid in an Annular Channel Satish Kumar Dhurandhar, Shobha Lata Sinha, Shashi Kant Verma Mixing vane spacer, Heat transfer, Supercritical pressure, CFD, Vertical annular flow The spacer represents an essential part in the nuclear fuel rod. Spacer grid with mixing vanes in fuel rod bundle of nuclear reactor core has a significant impact on heat transfer performance in downstream to grid spacer. Grid Spacers are located on the nuclear fuel rod assembly to hold suitable clearance among the rods in a bundle. The objective of this paper is to study the enhanced heat transfer performance of R134a at supercritical pressure 4.5 MPa near downstream to mixing vane spacer in a vertical channel of annular flow. A spacer of 0.38 blockage ratio with mixing vanes, situated at mid-span of an annular channel is used in the present work. Numerical simulations have been accomplished for a spacer with mixing vane and spacer without mixing vane in an annular channel by using commercial CFD (Computational fluid dynamics) code ANSYS Fluent. The present investigation represents the comparative study for a spacer with mixing vane and spacer without mixing vane effects on heat transfer and flow field characteristics in a downstream direction with the flow condition of mass flow rate as 0.41469 kg/s and heat flux as 160 kW/m2. The results indicate that the spacer with mixing vane has a notable influence on heat transfer performance and flow characteristics downstream to mixing vane spacer as compared to spacer without mixing vane. Wall temperature reduction and augmentation in coefficient of heat transfer are significantly greater near downstream to the spacer. The spacer effect in the improvement of the ratio of the coefficient of heat transfer is observed up to distance X/D = 40 downstream to the spacer and then flow is found as fully developed. The CFD results of the ratio of Nusselt number are compared with the data of correlations proposed by researchers and found to be in good agreement qualitatively. Journal of Thermal Engineering Journal of Thermal Engineering 2023-12-08T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6868 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6868 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6868

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6793 2023-07-28T21:00:00Z 1

An Allusive Realization on the Performance Analysis of Glass to Glass, Glass to Tedlar and Aluminum Base Flexible Photovoltaic (PV) Module Vivek Chopra, Rajeev Kumar Mishra, Vijay Kumar Dwivedi, Baibaswata Mohapatra Solar energy, PV module, G-T, G-G, F-Al, ANN The photovoltaic effect plays a significant role in power generation by using solar PV modules. The two most popular types of PV panels majorly available in the market: Glass-to-Tedlar (G-T) and Glass-to-Glass (G-G) type. Both G-T and G-G type of modules are rigid in structure due to the involvement of transparent glass cover on the top of the module. In order to have non rigid or flexible type of module, a module structure with aluminum as base and transparent plastic sheet at the top has been taken which is known as flexible type of PV module (F-Al). The use of plastic and aluminum makes these modules more flexible and lighter in weight as compared with G-T and G-G type of PV modules. The advantage of using F-Al PV module is that it can easily be modified into desired shapes. Initially, the mathematical modeling of F-Al PV module has been developed on Simulink. The different set of data for these three types of modules has been taken for analyzing the performance of these modules. The performance analysis of G-T type, G-G type and F-Al type of PV modules have been compared in terms of efficiency, cell temperature, daily energy production. The maximum electrical efficiency has been observed with G-G PV module. It is also observed that being with flexible nature, efficiencies of F-Al PV modules are almost comparable with G-T modules. The cell temperature of F-Al PV module and G-T PV module is found to be larger than G-G module. The daily electrical energy production was found to be more with G-G module in comparison to G-T and F-Al PV modules for a typical day in the month of April, 2019. It is also observed that due to flexible nature of F-Al module, efficiency is also converging faster towards regression line in comparison to G-G and G-T module. Further, efficiency and daily energy consumption of all three modules of PV panel are realized through artificial neural network(ANN).It is observed that least mean square error (MSE) is obtained with F-Al in comparison to G-G and G-T under the implication of ANN. Therefore, additional feature of least MSE for F-Al makes its preferable over others. Journal of Thermal Engineering Journal of Thermal Engineering 2023-07-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6793 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6793 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6793

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6695 2023-02-15T21:00:00Z 1

Temperature Analysis for the Horizontal Target Cooling with Non-Confined and Inclined Air Jet Sunil B. Ingole Jet Impingement, Inclined Jet, Comprehensive Cooling, Cold Spot In jet impingement cooling applications, the inclined jet in non-confined condition; also called as submerged jet is experimentally investigated. The objective is to analyze for hot surface cooling applications. Air is used as the working fluid, by using placement of jet on the leading edge of a horizontal rectangular target plate at height H, and examined for downhill side comprehensive cooling performance approach. The jet Reynolds number in the range of 2000≤Re≤20000 is investigated with circular jet for inclination of 15^0≤θa≤75^0. The effect of jet to target distance (H) is also investigated in the range 0.5≤H⁄(D≤6.8). The temperature variation at the center line of target is studied with analysis of temperature profile. Its variation with respective to horizontal distance of jet from leading edge (X) and counters are plotted for jet diameter (D) of 16mm. The location of minimum temperature during cooling by jet impingement, goes to downhill side for jet impingement with an angle of 75, 60, 45, 30 and 15 °. Cooling is observed to be increase up to X⁄D = 5, and then it declines. The cold spot is seen at (X⁄D) of around 5 to 7 except at high Reynolds number. The impact of jet inclination is more on temperature variation of flat target, compared to other parameters. Journal of Thermal Engineering Journal of Thermal Engineering 2023-02-15T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6695 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6695 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6695

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6708 2023-02-19T21:00:00Z 1

A New Trochoidal Toolpath In Milling Operations Murat Kıyak, Uğur Emiroglu, Orhun Bastekeli Trochoidal milling, toolpath, temperature, surface quality, cutting force, tool wear TThe milling is a widely used method in the manufacturing industry, especially in the production of complex engravings such as die&molds. Rough milling often requires a large material removal rate in a short time. This purpose also requires the selection and use of the best milling tool path. Today, trochoidal milling is receiving more attention than conventional milling, especially as it significantly increases tool life. In this study, a new toolpath model for trochoidal milling is suggested and this proposed toolpath model is examined in terms of cutting temperature, cutting force, surface quality, tool wear. In this new trochoidal toolpath model proposed for the milling method, the cutting force did not change much compared to the standard trochoidal tool path, but better surface quality and less tool wear were observed. Journal of Thermal Engineering Journal of Thermal Engineering 2023-02-19T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6708 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6708 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6708

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7021 2024-05-26T21:00:00Z 1

Impact of Nano-Silica (SiO2) on Thermal Properties of Concrete Alaa Saleh, Omer Khalil Ahmed, Alyaa A. Attar, Abdullah A. Abdullah Nano-silica, Concrete, Thermal properties Nanotechnology is currently receiving wide attention in various fields of science and engineering applications, and the application of this technology in the field of construction and concrete structures is one of the main objectives of this study because of this technology's role in enhancing the properties of concrete and increasing the efficiency of building materials, in addition to preserving natural resources raw materials and reduce environmental pollutants. The current study aims to study the effect of silica nanoparticles (SiO2) on the thermal properties of concrete, such as thermal conductivity, specific heat capacity, and thermal diffusivity, by partial replacement of cement with silica nanoparticles to obtain lightweight concrete with good thermal insulation ability. Nano-silica was added at percentages (1%, 2%, and 3%) as a replacement percentage of the weight of the cement. It was noted through the results that there is a decrease in the thermal conductivity coefficient values, which ranged between (0.5-0.92) W/m.?C in the mixtures containing Nano-silica, which means an increase in the thermal insulation ability of Nano-concrete by (41.8%, 53.15%, 65.57%) respectively. Moreover, through the results, we note that the lowest value of the thermal conductivity coefficient was at a ratio of (3%). Therefore, replacing more than this percentage will reduce the various properties of concrete. Also, a decrease in the specific heat capacity values was observed compared to conventional concrete. Journal of Thermal Engineering Journal of Thermal Engineering 2024-05-26T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7021 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7021 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7021

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6787 2023-07-28T21:00:00Z 1

Geometrical Optimization of City Gate Station’s Water Bath Indirect Heater to Minimization of Fuel Consumption Davood Shafiei, Seyed Alireza Mostafavi, Saeid Jafari Mehrabadi Natural gas, Geometrical parameters, Thermal modeling, Water bath indirect heater, Optimized geometry, Fuel consumption Gas industry as one of the greatest sectors of energy, has a major role in environmental issues. A category of energy intensive parts in gas industry is heaters in City Gate Stations which consume colossal volumes of the purified gases. Different optimization strategies to improve the efficiency of these heaters entailing preheating, waste heat recovery of exhausts, insulating pipelines and mounting economizers or recuperators or even using renewable energy sources have been already introduced. Besides, finding the optimized geometry is very essential in improving the efficiency. In this study, a far efficient model for heaters was introduced using the thermal modeling of the process. Based on the properties of the inlet gas, the volume of the gas passing from the CGS and ambient conditions, the consumption of the fuel as well as heater efficiency have been computed as a function of inlet gas properties, CGS’s gas flow rate and ambient condition. Then, results were verified by real data taken from Arak CGS station in Iran. The comparison proves the great correlation between the theoretical and experimental results. Findings show that with an increase in the heater length, a reduction in thermal resistance coincides with a higher thermal hysteresis. This causes higher fuel consumption and lower efficiency. Moreover, the higher the length of the fire tube, the more heat is transferred to the pure water and the higher is the efficiency. Considering the optimized heater configuration the efficiency improves two folds; changing from 32% to 71%. Journal of Thermal Engineering Journal of Thermal Engineering 2023-07-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6787 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6787 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6787

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6835 2023-10-16T21:00:00Z 1

Experimental Evaluation of the Effect of Leakage in Scroll Compressor Niyaj Shikalgar, Shivalingappa Nagappa Sapali, Ajit Shinde scroll compressor, leakage model, axial clearance, mass flow rate, capacity loss The impact of losses and leakages on compressor performance needs to be understood. As a part of this research paper, a detailed study and analysis of the internal seal leakages, suction superheat losses was carried out. This research gives an experimental investigation of the scroll compressor, with an emphasis on the effect of leakage on performance enhancement. In the present work, the scroll compressor is modified to bypass the refrigerant gas through an orifice to create an effect of external leakage and experimentally investigate the effect of valve opening area of orifice, and opening angle to observe the effect of leakage losses on compressor performance parameters such as compressor capacity loss, discharge line temperature rise, and discharge gas temperature. Experimental results indicated that the maximum percentage rise in suction superheat is observed to be 7.13% at a maximum effective valve opening area of 0.33 m2, whereas the rise in discharge line temperature lies in the range of 0.8% to 2.75% over the entire range of effective leak area. In addition, based on experimentation the 8.9 % maximum compressor capacity loss is observed. Correlations of the above losses with capacity/performance drop are studied experimentally which support the design optimization and efficiency improvement of the scroll compressor Journal of Thermal Engineering Journal of Thermal Engineering 2023-10-16T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6835 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6835 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6835

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5569 2022-04-18T21:00:00Z 1

Second Law Analysis on An Elliptical Twisted Tube for A Heat Exchanger Toygun Dagdevir Second Law Analysis, Entropy Generation, Irreversibility, Heat Transfer Enhancement, Elliptical Twisted Tube This works presents a second law analysis on a heat exchanger tube configurated as circular smoot tube (CST), elliptical smooth tube (EST) and elliptical twisted tube (ETT) with different aspect ratios and pitch lengths. The ETTs were configurated with different aspect ratio (AR) of 1.5 and 2.0 and twist pitch length (PL) of 50, 100 and 200 mm. The hydraulic diameter was kept as constant for all cases, since the results are influenced by the change in hydraulic diameter. CFD analyzes were run to perform the second law analysis of the considered cases. The analyzes were carried out by considering that the thermo-physical properties of the water fluid change depending on the temperature. Besides, the analyzes were carried out under steady state condition and turbulent flow condition which corresponds to Reynolds number ranging from approximately 4000 to 27,000. The results are evaluated and discussed in terms of the thermal, the frictional and the total entropy generation, the Bejan number, the entropy generation number, the exergy destruction and the second law efficiency. It is resulted that the increase in AR and the decrease in PL for the ETTs show better the second law efficiency. As a result, in the case of ETT_AR=2.0_PL=50 at the minimum mass flow rate considered in the study, the highest second law efficiency is obtained as 0.45, which corresponds to a value greater than 80% in the case of CST. Journal of Thermal Engineering Journal of Thermal Engineering 2022-04-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5569 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5569 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5569

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6788 2023-07-28T21:00:00Z 1

Thermo-economic Assessment of Air Bottoming Cycle Technology for Waste Heat Recovery Purposes from the Preheater Tower of an Algerian Cement Plant Youcef Redjeb, Khatima Kaabeche-Djerafi, Hamza Semmari Air bottoming cycle, Waste Heat Recovery, Thermo-economic Optimization, Cement plant, Heat transfer coefficient. The present work deals with the deployment of an air bottoming cycle as a waste heat recovery solution. This solution is integrated within the preheater tower on an Algerian cement plant. A combined MATLAB- Coolprop optimization code has been developed to carry out a thermo-economic calculation allowing to design and optimize the air bottoming cycle and also check its economic returns. The developed code employs the genetic algorithm through a multi-objective function aiming to maximize the net power output of the cycle as a priority objective, then minimize the area of exchange of the heat exchanger, and also maximize the net present value of the cycle. through the implemented models on it, the code gives the ability to confirm the applicability of this technology through the Algerian market which is characterized by one of the cheapest prices of electricity in the world that doesn't exceed 0.040 $ kW-1. The obtained results highlight that the integration of the air bottoming cycle for energy valorization purposes at the level of preheater tower of this cement industry can be a profitable and attractive solution, especially in case of water deficiency. Since the implementation of this technology presented a power capacity of 1.2 MW covering then around 7.8% of the electricity demand of the investigated cement plant. The economic analysis of the proposed ABC cycle pointed out a net present value of 6.59 M$, and a payback time less than 3.6 years, besides a Levelized cost of energy less than 0.017 $ kW-1 which is a comparable value to the subsidized prices of electricity in the Algerian market. Journal of Thermal Engineering Journal of Thermal Engineering 2023-07-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6788 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6788 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6788

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6886 2023-12-08T21:00:00Z 1

Flow Field and Heat Transfer of Ferromagnetic Nanofluid in Presence of Magnetic Field inside a Corrugated Tube Aram Soleimani Varkaneh, Ghanbar Ali Sheikhzadeh Nooshabadi, Ali Akbar Abbasian Arani Heat exchanger; Helical ribs; Nanofluid; Two-phase mixture model; Magnetic field; Corrugation. The present study investigates the effects of using a magnetic field on the flow field and heat transfer of ferromagnetic Fe3O4/H2O nanofluid considering two-phase model for nanofluid in heat exchanger equipped with helical ribs. Three methods are employed to enhance the thermal efficiency of heat exchanger, as employing of corrugations, utilizing nanofluid as heat transfer fluid, and employing the magnetic field. The performance evaluation criteria index (PEC) is employed to analyze the thermal-hydraulic characteristics of the heat exchanger. The main aim is to achieve an optimum model with the highest performance evaluation criteria value. Usaging of corrugated heat exchanger or nanofluid can increase the average Nusselt number and friction factor in the tube sharply. Also, it is understood that the presence of a magnetic field has a significant effect on the heat transfer enhancement inside the heat exchanger. The model with magnetic field of 600 G has the highest Nusselt number ratio among all studied models, which is followed with 400 G, 200 G, and 0 magnetic fields, respectively. Furthermore the effects of different corrugation heights, widths, and pitches have been studied. Finally, usage of the novel corrugated heat exchanger with 14 mm corrugation heights, 9 mm rib width, and 12.5 mm blade pitches filled with nanofluid, and under a magnetic field of 600 G it suggested as the most efficient configuration. Also, at the Reynolds number of 4,000, the highest performance evaluation criteria values are achieved. Journal of Thermal Engineering Journal of Thermal Engineering 2023-12-08T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6886 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6886 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6886

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6830 2023-10-16T21:00:00Z 1

Temperature Effect in the Energy Degradation of Photovoltaic Power System Yasseen Almahdawi, Mohammed K.H. Abbas, Ahmed Al-Samari, Nazar Aldabash, Saadoon Abdul Hafedh Solar energy, Photovoltaic temperature, Photovoltaic efficiency The modelling of output power for the photovoltaic system is essential for system design and local resource prediction. Accurate photovoltaic power modelling the foremost vital issue is systems efficiency analysis. The temperature plays the main role in the energy degradation of the photovoltaic systems, especially in the host sites. In this paper, experimental and theoretical investigation into the photovoltaic module energy degradation due to temperature effects. This work objectives to investigate the photovoltaic power generated due to the ambient temperature effect. The presented results show that the ambient temperature has positive effects on the photovoltaic module energy production during the winter period and negative effects during the summer period. For the proposed photovoltaic system with a capacity of 2.97 kWp the expected theoretical annual energy production by about 554.01 kWh while the annual experiment production was l493.73 kWh. The novelty of the work is to estimate the energy losses due to the ambient temperature effect on the photovoltaic energy production. Journal of Thermal Engineering Journal of Thermal Engineering 2023-10-16T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6830 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6830 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6830

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6692 2023-02-07T21:00:00Z 1

The Optimal Geometric Design of a V-Corrugated Absorber Solar Air Heater Integrated with Twisted Tape Inserts Issam M. Ali Aljubury, Mohammed Khalil Hussain, Ammar A. Farhan Solar air heater; Multi-objective function; effective efficiency; Optimization algorithm. The proper design of a solar air heater depends on the highest thermal performance of the solar collector. In the present paper, proposed a method to find an optimal dimension of V-corrugated absorber solar air heater (VSAH) combined with a twisted tape insert (TTI). The design variables of the VSAH-TTI are length, width, number of channels, and twisted tape ratio. The effect of each design variable is examined and studied under various ranges of Reynolds number (Re). Given the complexity in changing design variables of solar collector having a V-corrugated absorbing plate with twisted tape insert (VSAH -TTI) to find the highest thermal performances, the multi-objective function genetic algorithm is used to find the optimal dimensions of VSAH-TTI based on maximizing the heat gain, thermal and effective efficiency as well as minimizing the pressure drop on solar collector. The range of each design variable of the VSAH-TTI by means of length (1 – 2.5 m), width (0.5 – 1.5 m), number of channels (4 – 14), and twisted tape ratio (1 – 8) are specified in paper based on the most common practical values of the solar collector. The results showed for the case under study that each design variable of VSAH-TTI affects the thermal performance and the optimized geometry by using a genetic algorithm (Ga) can find the optimal geometric dimensions of VSAH-TTI. The optimal dimension by using Ga can increase the heat gain by more than 8% and increase the effective and thermal efficiency of more than 7% for the original geometry. Furthermore, the optimized geometry can reduce more than 29% for the original geometry. These improvements in optimized geometry for VSAH- TTI without introducing any additional items. Journal of Thermal Engineering Journal of Thermal Engineering 2023-02-07T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6692 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6692 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6692

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6693 2023-02-13T21:00:00Z 1

Application of Exergy Analysis in Understanding The Performance of a Coal-Fired Steam Power Plant (120 Mw) with Single Reheat and Regenerative Configuration SANKALP ARPIT, Prabhat Kumar, Prasanta Kumar Das, Sukanta Kumar Dash coal; captive; energy; exergy; steam power plant; feed water heater In the present paper, a rigorous analysis of a sub-critical steam power plant (120 MW) with reheating and regenerative configuration is presented, using energy and exergy analysis. The total work output from the power plant is 121.80 MW, which is close to the real value of 120 MW. The calculated energy efficiency of the steam power plant is 34.7%, while its exergy efficiency is 32%. In addition to it, energy analysis introduces the condenser as a major source of heat loss, on other hand, exergy analysis introduces the boiler as a major source of exergy destruction. Further to understand the effect of main steam temperature, reheating temperature and condenser pressure on the power plant, a parametric study is being conducted. Journal of Thermal Engineering Journal of Thermal Engineering 2023-02-13T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6693 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6693 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6693

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5598 2022-06-08T21:00:00Z 1

Comparative Study of Biodiesel Production from Different Waste Oil Sources for Optimum Operation Conditions and Better Engine Performance Wadhah H. Al Doori, Obed M. Ali, Ahmed Hasan Ahmed, Hasan Köten Biodiesel, Fuel Source, Catalyst, Diesel Engine, Brake Power Biodiesel from waste sources can be considered as the cheapest and most viable fuel alternative to depleting mineral diesel. In this work, biodiesel has been produced from different sources of waste oil; grilled chicken waste oil (GCWO) which is animal based source and waste cooking oil (WCO) which is vegetable based using transesterification method. The impact of different variables such as temperature, transesterification time, and amount of catalyst on the conversion and yield of biodiesel were investigated. Produced biodiesel was characterizes using ASTM standard methods for biodiesel property testing to determine the fuel properties including; kinematic viscosity, specific gravity, flash point, pour point, cloud point and acid number. Engine test has been conducted at increasing speed and constant load to evaluate the engine performance using the produced fuel. The results obtained indicate that the yield and conversion of bio-diesel from grilled chicken waste oil are greater than waste cooking oil. Both produced biodiesel fuel properties are within the standard biodiesel fuel specifications ASTM D6751. The maximum conversion and yield of biodiesel obtained by 97.76% and 94.4% suing GWCO and WCO respectively at optimum operating variables of 600C temperature, 3 h reaction time, and 0.4 wt% potassium hydroxide. Engine test results show similar trends for both biodiesels compared to diesel in term of engine brake power (BP) and brake specific fuel consumption (BSFC) with increasing engine speed. The maximum reduction in BP is found to be about 19% at 2400 rpm and a maximum increase in BSFC of 17% is obtained at 1800 rpm engine speed with both biodiesels compared to diesel fuel. Accordingly, though both biodiesels show comparable engine performance, GWCO presents higher biodiesel yield. Journal of Thermal Engineering Journal of Thermal Engineering 2022-06-08T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5598 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5598 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5598

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6642 2022-10-18T21:00:00Z 1

An Experimental Study on Resuspension, Thermostability and Migration Phenomenon of Nanoparticles in Pool Boiling Praveen Bharathwaj, Varun Pradeep, Panneerselvam Padmanathan, Anbalagan Satheesh, Ramila Devi Nanoparticles, Migration Ratio, Resuspension, Thermostability, Pool Boiling, Latent Heat Exchangers Nanoparticles have proven to be effective in sensible and latent heat exchanges alike. Applications of nanoparticles in phase change processes are associated with migration and resuspension of nanoparticles upon which our existing knowledge is very limited. This work experimentally investigates the migration ratio, stability and resuspension of nanoparticles during phase change. Knowledge on migration ratio is essential to gauge the thermal and lubricative enhancements in the subsequent processes. Al2O3/Water & CuO/Water nanofluids were prepared in four mass fractions (0.05, 0.1, 0.2, 0.4) using ultrasonic agitation technique. Nanofluids with mass fraction higher than 0.5% displayed poor stability over time also, agglomeration and sedimentation were pronounced and inevitable. Nanofluid destabilises and agglomerates rapidly at temperatures closer to saturation temperature. Resuspension of agglomerated chunks were observed during nucleate boiling where the test fluid became extremely nonhomogeneous. Migration ratio was found to commensurate with volume fraction where CuO/water nanofluid exhibited 23% lesser migration ratio than Al2O3/water nanofluid. Maximum migration ratio of 17.8% was observed for Al2O3/water with 0.05 wt%. Maximum migration was found when the molecular dimensions of nanoparticles and the base fluid are of similar magnitudes. It is inadvisable to involve nanoparticles in phase change systems. Journal of Thermal Engineering Journal of Thermal Engineering 2022-10-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6642 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6642 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6642

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6869 2023-12-08T21:00:00Z 1

Single-Phase and Two-Phase Models of a Hybrid Nanofluid Traveling Through a Non-Uniformly Heated (PTC) Receiver: A Comparative Study Amina Benabderrahmane, Ahmed Kadhim Hussein, Obai Younis Elamin, Abdelylah Benazza CFD, Forced convection, Parabolic trough solar collector, Hybrid nanofluid, Two-phase modeling, Turbulent flow. The current study used single and two-phase modeling to numerically explore three-dimensional the turbulent forced convection of a hybrid nanofluid passing through a non-uniformly heated parabolic trough solar collector (PTC) for increasing heat transfer. The typical heat flux profile on the receiver’s absorber outer wall was developed by using a finite volume method (FVM) together with the MCRT method. The results demonstrated that the single and two-phase models produced almost similar hydrodynamic results but dissimilar thermal ones. It was found that the mixture model was very close to the experimental results. The results also illustrated that the hybrid nanofluid gives the highest thermal performance for a mixture composed of 1.5 % copper + 0.5 % alumina dispersed in the water. Journal of Thermal Engineering Journal of Thermal Engineering 2023-12-08T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6869 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6869 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6869

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6838 2023-10-16T21:00:00Z 1

The Effects of Different Wing Configurations on Missile Aerodynamics Ahmet Şumnu, İbrahim Halil Güzelbey Missile Aerodynamics; Turbulence Model; Missile Wing Configuration; CFD In the present study, missile aerodynamic analysis is performed using different wing configurations at subsonic and transonic speeds. The wing is critical component in point of aerodynamic efficiency for a missile that speed is especially closer to transonic level because of flow separation. Flow on the wings may adversely effect tailfins of missile at high speed since it may cause vortex generation and flow disturbances. There are few studies that investigate the missile wing using different configurations at critical speeds when examined the previous studies. Therefore, in this study, three different wing configurations are investigated and aerodynamic performance is compared with each other at 0.7 and 0.9 Mach numbers and 5° angle of attack (AoA). In beginning of this study, missile model with only tailfins is selected from previous study that contains experimental data. Because the experimental data for the selected missile model are available at supersonic speeds, the aerodynamic analysis to verify the solutions is carried out at supersonic speeds. After wing is mounted to the selected missile, aerodynamic analysis is carried out using three different wing configurations that are Tapered Leading Edge, Tapered Trailing Edge, and Double Tapered wings. Lift to drag ratio (CL/CD) is calculated to compare wing configurations and it is concluded that Tapered Leading Edge wing configuration shows higher performance then other wing configurations. CL/CD values are 2.327, 2.306, 2.303 at 0.7 Mach number and 2.45, 2.429, 2.423 at 0.9 Mach number for Tapered Leading Edge, Tapered Trailing Edge, and Double Tapered, respectively. When the results are compared each other, CL/CD values at 0.9 Mach number is higher about % 5.28, %5.33 and %5.21 than the CL/CD values at 0.7 Mach number for missile with Tapered Leading Edge, Tapered Trailing Edge, and Double Tapered, respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2023-10-16T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6838 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6838 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6838

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5570 2022-04-18T21:00:00Z 3

A Scoping Review on Recent Advancements in Domestic Applications of Solar Thermal Systems Alajingi Ram Kumar, Marimuthu Ramakrishnan Solar Thermal Systems, Solar Energy Conversion, Solar Energy Domestic Applications, Solar Heating, Solar Cooling The rapid growth in smart technology and green energy contributing crucial role in taking our homes into next level. Meanwhile the solar powered thermal systems (STS) are much desired for energy conservation and management of houses. Domestic application of STS will not only reduce electricity consumption but also reduce carbon emission. This paper gives a scoping review on role of various types of STS namely, solar water heating, solar active and passive space heating and cooling, solar thermal water pumping, solar cooking, solar drying, solar distillation, solar green house, solar photovoltaic thermal systems (PVT) and solar thermal energy storage systems in domestic applications. The recent advancements with respect to each type of STS is outlined. Starting from various collectors and materials for STS, each system’s working principle and technological advancements in the view of adopting it to domestic applications are discussed in detail. Also, performance evaluation and role of each different STS in home application is elucidated. The research gaps and potential barriers for adopting STS for domestic homes are explored. Journal of Thermal Engineering Journal of Thermal Engineering 2022-04-18T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5570 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5570 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5570

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6794 2023-07-28T21:00:00Z 1

Experimental Performance Evaluation of Water Source Heat Pumps in Different Circumstances and Comparison to Air Source Heat Pumps Ahmad Saleh Water source heat pump (WSHP), Air source heat pump (ASHP), Ground source heat pump (GSHP) This study aims to present a novel experimental method for studying the performance of water source heat pumps which have not received sufficient attention, although this is particularly important for hot regions with great potential of hot water sources. The experimental model has special characteristics as it allows to investigate the performance of heat pumps under different operating conditions and allows a comparison between different types of heat pumps without the need to install a ground heat exchanger. The ground heat exchanger is known to be the most expensive part of any experimental model. In addition to that, it only allows to study the performance under specific conditions. The ground heat exchanger was replaced by a secondary heat pump that allows to provide an environment that simulates the different operating conditions of different types of heat pumps. It was found that water source heat pumps are more efficient than air source heat pumps with efficiency that increases with increasing water source temperature. It was found that increasing the water source temperature from 5 to 20 oC, improved the rate of heat extracted from the water source by 11.3% and the coefficient of performance by 2.8% for each degree. Another important feature of water source heat pumps is the stability of the energy flow rates, which is a guarantee of higher seasonal performance coefficients. It can be concluded that hot regions with high potential of hot water sources has valuable opportunities to invest in the field of water source heat pumps with the consequent significant energy savings. Journal of Thermal Engineering Journal of Thermal Engineering 2023-07-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6794 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6794 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6794

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6694 2023-02-13T21:00:00Z 1

A CFD İnvestigation of Flow Separation in an Elliptical and Circular Ranque-Hilsch Vortex Tube Nitin Bagre, Ashok D. Parekh, Vimal K. Patel Elliptical Vortex tube, 3D Numerical investigation, energy separation, constant area The present work investigates the flow physics inside an elliptical vortex tube. Two different 3D (three-dimensional) domains of circular and elliptical vortex tubes with four nozzles are studied. The cross-sectional area and length of the vortex tube are constant for both of its shape. The pressure at the inlet is 320 kPa for both the shapes and air as a working fluid. Standard k- ε turbulence model is used to predict the flow physics and temperature separation effect inside the tubes. The experimental and numerical findings of earlier researchers provide as validation for the present results. The deviation of the results is found within the permissible limit. The temperature separation phenomenon in an elliptical tube at various cold mass fractions is discussed. The range of cold mass fraction is 0.1 to 0.9. This work also examines the fluid characteristics and flow parameters by tracing the fluid particles within the tube. Fluid characteristics such as static pressure, density, total temperature, static temperature are evaluated. Also, the flow parameters like velocity magnitude, turbulent kinetic energy, axial velocity, and swirl velocity are discussed at the various radial locations inside the tube to get the flow pattern information. It’s an attempt to determine the feasible flow mechanism inside an elliptical vortex tube. The comparison between the circular vortex tube and the elliptical vortex tube has been done based on various fluid characteristics and temperature separation. It is found that energy separation is elevated in an elliptical tube by 49.89% at the hot end tube at 0.2 cold mass fraction whereas it is low for cold temperature separation as compared to the circular vortex. Journal of Thermal Engineering Journal of Thermal Engineering 2023-02-13T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6694 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6694 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6694

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7111 2024-09-10T21:00:00Z 1

Optimum Insulation Thickness for External Building Walls for Different Climate Zone in India Mohd SHAHID, Munawar Nawab KARIMI, Atul Kumar MISHRA Annual cooling cost, Base Temperature, Cooling Degree Days, Energy-Saving, Optimum Insulation Thickness The current study used degree-day method to determine the optimum insulation thickness for different insulation materials. Some of the commonly used insulation materials available in the market are considered in the study. Materials used in the study are, fiberglass rigid, urethane rigid, fiberglass urethane, perlite, and extruded polystyrene. The cooling degree days were calculated using the base temperature varies from 18ºC to 26ºC for the four major cities like Mumbai, New Delhi, Kolkata, and Chennai of India. The study aims to analyze the effect of the number of cooling degree days and base temperature on insulation thickness and also determine the variation of annual cooling cost with the insulation thickness. The result shows that the optimum insulation thickness varies with the cooling degree days and is also influenced by the electricity rate and the cost of insulation material. Based on the result, it is found that optimum insulation thickness is affected by the thermal conductivity of the material, base temperature, CDD, material cost, and fuel cost. The result shows best suitable insulation materials for Delhi, Mumbai, Kolkata, and Chennai are urethane rigid, fiberglass urethane, urethane rigid, and fiberglass rigid respectively. The optimum insulation thicknesses vary between 1 and 12 cm for the different base temperatures and cities. Annual cooling cost per m2 is calculated for the base temperature 21 ºC and 24 ºC, and the result shows that fiberglass urethane has the lowest annual cooling cost for different cities. Energy-saving varies with the thickness of the insulating materials apply on the wall. In addition with the help of insulation, energy can be saved up to 80% and achieve energy-efficient buildings. Journal of Thermal Engineering Journal of Thermal Engineering 2024-09-10T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7111 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7111 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7111

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6791 2023-07-28T21:00:00Z 1

Measurements of Heat Transfer Coefficients from Supercritical Fluid Flowing in Vertical Mini Channels with Constant Wall Temperature Ameer jaddoa Heat transfer, supercritical fluid CO2, mini heat sink Currently, efficient heat transmission for compact electronic elements is an essential matter. It needs a heat sink with a liquid cooling scheme that meets these demands as much as feasible. The dimensions of 50.8 × 40.6× 5.5 mm were adopted for features of heat transfer as well as the fluid flow of supercritical CO2 in the heat sink in this study. The adopted pressures, temperatures, and mass velocity ranges were 7.5 to 12 MPa, 35 to 50 oC, and 100 to 500 Kg/ m2 s, respectively, wherein the CO2 cooled under these conditions. The factors of heat transfer, the pressure at levels of local as well as medium degree were determined under these conditions. The medium temperature of CO2 in the adjacent significant point area increased, the pressure decreased and the medium temperature movement factor augmented dramatically. It was also noted that the medium temperature movement factor peaked at the pseudo-critical temperature. However, the maximum temperature movement factor declined increased pressure. Furthermore, in contrast to the pressure factor, it was revealed that mass velocity and temperature movement factor had a direct relationship. Using the obtained data, a novel correlation mechanism for limited convection of super-critical CO2 in regular multi-port micro tubes based on chilling conditions was constructed using the obtained coefficients in this study. Journal of Thermal Engineering Journal of Thermal Engineering 2023-07-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6791 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6791 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6791

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5567 2022-04-12T21:00:00Z 1

Assessment of Microwave Susceptors for Optimum Temperature Rise Using Parametric Numerical Simulation Praveen Kumar Loharkar, Asha Ingle Energy Conversion, Microwave, Multiphysics, Susceptors, Regression, Simulation, Volumetric Heating Microwave hybrid heating or indirect microwave heating has been an important development in the processing of metals using microwave energy. In this method of heating, a “susceptor” is used to absorb and convert microwave energy into thermal energy which is utilized for materials processing. Few of these processing applications are sintering, joining, cladding, casting, and composite development. However, the precise selection of a susceptor for a given process is challenging and requires a thorough understanding of the microwave heating phenomenon. In addition, predicting temperature rise in a microwave cavity is a complex task. Numerical simulation can serve to solve these two significant problems. In this work, parametric simulation of microwave heating of three major susceptor materials; silicon carbide, alumina, and coal has been carried out using a multiphysics approach. Initially, a model was developed to validate the simulation procedure. The results were in good agreement with the available data in published literature. Thereafter, the effect of microwave power, position of susceptor block, and time of irradiation on temperature rise in these materials were investigated. On comparing these susceptor blocks after altering the parametric combinations, coal exhibited the formation of hot spots and uneven temperature field with a maximum temperature of 901OC. On the contrary, the temperature attained in silicon carbide (529OC) and alumina (616OC) were lower but distributed in a relatively uniform field across the block. Regression models have also been built to correlate maximum temperature achieved with the parametric variation of parameters. It has been found that microwave power and the time of microwave irradiation have a significant coactive effect on the maximum temperature reached by the material. While the rise in the position of the susceptor block from the base leads to an adverse effect on the temperature rise. The study demonstrates that indirect microwave heating can be harnessed using the proper selection of susceptors as per the temperature requirement of the process. The regression models can be used for the accurate prediction of temperature attainment for given power input, position, and time. Journal of Thermal Engineering Journal of Thermal Engineering 2022-04-12T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5567 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5567 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5567

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6806 2023-07-31T21:00:00Z 1

Analysis of Heat Transfer and Flow Over a Rotating Cylinder at Subcritical Reynolds Numbers Based on Taguchi Method Ebrahim Barati, Mehdi Rafati Zarkak, Shohreh Jalali Thermal buoyancy, Rotational cylinder, Vortex shedding, Aerodynamic force, Heat transfer, Taguchi method The flow past the rotating circular cylinder and the effect of buoyancy on heat transfer characteristics are studied numerically for the Reynolds number of 20 and 40 and the Prandtl number of 0.7. The lift and drag coefficients, Strouhal number, and local Nusselt number on the cylinder are studied under the sway of combined buoyancy (at the Richardson number varies from 0 to 2) and different rotational directions. Although the interaction between buoyancy and rotation is a puzzling heat transfer problem, the direction of rotation is found to have significant effects on the flow patterns and heat transfer rate. The main innovation of the present work is to determine the extreme points of Nusselt numbers when different conditions are applied. For a positive rotation, the maximum local Nusselt number is at ?=225o, and the minimum local Nusselt number is at ?=100o. In contrast, for a negative rotation, the maximum and minimum local Nusselt numbers are at ?=140o and ?=270o, respectively. Applying Taguchi method, it is found that average Nusselt number is more dependent on Reynolds number than other factors. Additionally, it can be concluded that the direction of rotation can be used as a powerful tool to adjust the heat transfer rate and the required value of drag and lift. Consequently, without applying different rotation speeds, it would be difficult to stabilize the flow, and with the aid of Taguchi method, it is determined that rotation is deciding factor in stabilizing flow patterns. The results are in good agreement with the experimental results. Journal of Thermal Engineering Journal of Thermal Engineering 2023-07-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6806 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6806 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6806

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6829 2023-10-16T21:00:00Z 1

Parametric Evaluation of Solar Integrated Combined Partial Cooling Supercritical CO2 Cycle and Organic Rankine Cycle using Low Global Warming Potential Fluids Yunis Khan, Radhey Shyam Mishra, Roshan Raman, Abdul Wahab Hashmi Performance Analysis, Solar Power Tower, Organic Rankine Cycle, Low GWP Fluids, Partial Cooling Supercritical CO2 Cycle In this paper, performance evaluation of the partial cooling supercritical CO2 cycle combining with organic Rankine cycle as bottoming cycle for waste heat recovery operated by solar power tower was done. The low global warming potential and zero ozone depletion potential fluids were considered. A computer program was made in engineering equation solver software to simulate the considered model. The effects of solar irradiation, concentration ratio, solar incidence angle, CO2 turbine inlet temperature, main compressor inlet temperature and effectiveness of heat exchanger were examined. It was concluded that highest thermal efficiency, exergy efficiency and power output of the combined cycle were increased from 35.16% to 55.43%, 37.73% to 59.42% and 188 kW to 298.5 kW respectively as solar irradiation increased from 0.4 kW/m2 to 0.95 kW/m2 respectively based on working fluid R1224yd(Z). Performance of the combined system can be improved by reducing the solar incidence angle while increasing the concentration ratio. R1224yd(Z) was recommended as better performing working fluid among other considered working fluids. Journal of Thermal Engineering Journal of Thermal Engineering 2023-10-16T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6829 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6829 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6829

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6704 2023-02-17T21:00:00Z 1

Combined Effect of Upstream Ramp and Effusion Cooling in Combustion Chamber Liners of Gas Turbine Yellu Kumar, Adnan Qayoum, Shahid Saleem, Fasil Qayoum Mir Effusion cooling, Adiabatic effectiveness, Blowing ratio, Upstream ramp, Combustion chamber liners Effusion cooling technique is a highly efficient cooling method used to reduce the thermal stresses of combustion chamber liners in a gas turbine engine. The present study focuses on enhancing the adiabatic effectiveness of effusion cooling. The computational investigations are carried out using COMSOL Multiphysics 5.4 with the standard k- ε turbulence model. Detailed computations for 20 rows of effusion holes on the flat plate are examined for blowing ratios 0.25, 0.5, 1.0, 3.2, and 5.0 for each set of injection angles 30o and 60o. To enhance the effusion cooling performance, an upstream ramp (ramp angles 14o, 24o, and 34o) is introduced before the upstream of effusion holes. The results show that the adiabatic effectiveness increases with an increase of blowing ratio and ramp angles. By placing an upstream ramp, the low blowing ratios can greatly increase the adiabatic effectiveness by 29%, 31%, and 35% for ramp angles of 14o, 24o, and 34o, respectively. For high blowing ratios, an increase in the angles of the ramp shows less impact on adiabatic effectiveness throughout the effusion surface. However, adiabatic effectiveness has increased by 26% compared to the baseline model. It is also observed that injection angle of 30o provides more effectiveness than 60o. This study concludes that placing an upstream ramp increases the effusion cooling performance in the combustion chamber liners of a gas turbine engine. Journal of Thermal Engineering Journal of Thermal Engineering 2023-02-17T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6704 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6704 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6704

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6799 2023-07-31T21:00:00Z 3

Performance Enhancement of Absorption Refrigeration Systems: An Overview Abhishek Verma, S. C. Kaushik, Sudhir Kumar Tyagi Absorption refrigeration; waste heat; solar energy, renewable energy, single effect, double effect, triple effect. The introduction of absorption refrigeration technology addressed several significant concerns in the domain of energy crisis, rising cost of fossil fuel, and ecological challenges arising due to the excess use of traditional compression refrigeration systems. ARS (absorption refrigeration system) is gaining popularity as a result of benefits such as the use of low-grade heat sources and environmentally acceptable low-cost working fluid pairs. However, two significant hurdles to commercial success for this technology are the often too big size of the refrigeration system and the poor performance of the system. Numerous studies have been conducted in an attempt to discover methods for improving the COP (coefficient of performance) of ARS in order to get these systems more competitive in comparison to the conventional compression refrigeration systems. The goal of this article is to perform a review of the literature on different methods used to enhance the COP of ARSs based on cycle layout modification and working pair selection as they are the promising solutions for the enhancement of the performance of ARSs. The futuristic aspect of this technology includes the introduction of new working pairs with no corrosion to the system components, including nanoparticles to increase heat transfer rate while reducing the cost of the system. Heat recovery methods should be introduced and the efficient design of various components especially the generator and absorber are to be addressed. This technology could be combined with other refrigeration technologies while utilizing the waste heat to further improve the efficiency of ARSs. Journal of Thermal Engineering Journal of Thermal Engineering 2023-07-31T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6799 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6799 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6799

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6711 2023-03-01T21:00:00Z 1

Experimental Investigation of Nanofluids for Heat Pipes Used in Solar Photovoltaic Panels Bisma Ali, Adnan Qayoum, Shahid Saleem, Fasil Qayoom Mir Nanoparticle, Nanofluid, Thermal Conductivity, Density, Therminol-55 The current study is aimed to measure and analyze the impact of temperature (10°C < T < 90°C) and particle concentration (0.05% < ϕ < 1.5%) on thermo-physical properties of TiO2, ZnO and CuO nanoparticles suspended in Therminol-55. The nanoparticles were characterized by using various techniques, including TEM, XRD, FTIR, TGA/DSC. TEM images reveal that the morphology of TiO2 and ZnO as spherical nanoparticles whereas that of CuO is in the form of flakes. XRD pattern for TiO2, ZnO and CuO nanoparticles possess anatase, heaxagonal and monoclinic phase respectively. TGA results show that that TiO2 losses less mass than the ZnO and CuO nanoparticles at each stage of decomposition. Thereby making it more stable thermally as compared to the other samples. Two-step method has been employed to formulate stable Therminol-55 based nanofluids containing TiO2, ZnO and CuO nanoparticles for varying particle concentrations. Results show that the thermal conductivity of suspensions containing solid conducting particles increase with increasing nanoparticle content and temperature of dispersions in the fluid. The thermal conductivity of TiO2/Therminol-55, ZnO/Therminol-55 and CuO/Therminol-55 nanofluids increases up to 17.62%, 21.55% and 24.32% at particle concentration of 1.5 wt%. Further, the experimental results demonstrate that the density of nanofluids increased significantly with increase in concentration and decreased with temperature. Surface tension of nanofluids shows decrease with increase in particle concentration. This indicates that adding nanoparticles improve thermo-physical properties of nanofluid, making it suitable for use in heat pipe. The measured data for thermal conductivity and density are compared with existing theoretical models of nanofluids to check the effectivity of conventional models. A multi-variable new generalized correlations for thermal conductivity and density of Therminol- 55 based nanofluids containing TiO2, ZnO and CuO nanoparticles are proposed. Journal of Thermal Engineering Journal of Thermal Engineering 2023-03-01T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6711 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6711 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6711

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7020 2024-05-26T21:00:00Z 1

New Similarity Method Analysis of the Transient Thermal Boundary Layer on a Horizontal Flat Plate: Strouhal and Prandtl Numbers Effect. Aidaoui Lakhdar, Mohamed Bachiri, Ahcene Bouabdallah, Yahia Lasbet Thermal boundary layer; Strouhal number; Similarity solution; Flat plate; Nusselt. The present project highlights the behavior of the unsteady thermal boundary layer developing along a flat plate in terms of both Strouhal and Prandtl numbers. Basing on the boundary-layer flow evolution, an ad hoc analytic formula of the velocity profile is proposed to solve momentum equation. This result presented a good agreement with those found by Rayleigh, Blasius, and Williams–Rhyne for all Strouhal number values adopted in this study. The obtained velocity expression is included in the unsteady energy equation in order to establish the temperature profile for all considered Strouhal and Prandtl numbers. Taking into account the existence of the velocity-temperature coupling in the heat boundary layer equation, the proposed formula is used to solve unsteady energy equation for all Strouhal and Prandtl numbers. As the main results, a new analytic expression of the local heat transfer coefficient for all Strouhal and Prandtl numbers is established and interesting curves are plotted to explain the heat transfer evolutions from the initial flow “diffusion” to the steady flow “convective”. Journal of Thermal Engineering Journal of Thermal Engineering 2024-05-26T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7020 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7020 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7020

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6754 2023-05-18T21:00:00Z 1

Drying Investigation of Coriander Seeds in a Photovoltaic Thermal Collector with Solar Dryer B. Srimanickam, Sunil Kumar coriander seeds, electrical and thermal efficiency, photovoltaic thermal collector, solar dryer. This Present work deals with experimental investigation of photovoltaic thermal collector design and development with solar dryer (PVTCSD). An Solar experimental investigation is done on coriander seeds by natural, forced and open sun drying to estimate different parametric investigations such as solar radiation intensity, removal of moisture, and the air outlet in the collector. Solar radiation is utilized as a source of energy to propel the photovoltaic thermal collector dryer which was analysed in a drying testing chamber temperature in the range of 32 C to 59 C to dry 4 kg of coriander seeds. From the experimental study it is understood that coriander seeds posses much more starting moisture 68% by weight and also the results proved that final moisture content has been decreased by 9 % by weight during six bright days in the month of May 2021. The PVTCSD was used during the 9 a.m. to 4 p.m. In terms of understanding PVTCSD, solar sun drying with the forced convection achieved superior results than other two modes of operation. Journal of Thermal Engineering Journal of Thermal Engineering 2023-05-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6754 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6754 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6754

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6796 2023-07-28T21:00:00Z 1

Performance Parameters, Design Considerations, Social Adoption, and Computational Techniques for Solar Box Cooker Development: Current Status and Future Possibilities Satish Kumar Dewangan Solar box cooker (SBC), Computational fluid dynamics (CFD), Internet of things (IoT), Artificial intelligence (AI), Renewable energy Practical utility of solar cookers is on rise nowadays. However, due to certain technological challenges this is not catching very fast. Present review paper encompasses studies and future possibilities for solar box cooker research. Various aspects like thermal performance parameters, various phases of designs improvements, social acceptability issues and computational methods of analysis have been discussed in relation to Solar box cookers so that technical difficulties may be minimized. This paper discusses about introduction to solar box cookers, advantages, disadvantages, various practical considerations that are key factors for any SBC. Further, there is a handsome discussion on the various computational techniques like Computational fluid dynamics, Artificial intelligence techniques, IoT etc. Introduction, review of applications till date, and future possibilities related to research using application of these computational techniques have been presented. Emphasis has been given to future possibilities for solar box cookers development so that it could be a well-accepted future technology. Journal of Thermal Engineering Journal of Thermal Engineering 2023-07-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6796 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6796 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6796

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6802 2023-07-31T21:00:00Z 1

Thermal insulation performance curves for exterior walls in heating and cooling seasons Mohammad Batiha, Saleh Rawadieh, Marwan Batiha, Leema Al-Makhadmeh, Muhammet Kayfeci, Abdullah Marachlı Degree-day; Energy saving; Insulation characteristic curves; LCCA method; Optimum insulation thickness; Payback period Determination of thermal insulation performance (i.e. optimum insulation thickness, energy saving and payback period) is a tedious and time-consuming task that requires a thorough knowledge in thermal insulation engineering and economics. The main goal of this paper is to make the determination of insulation performance simple and timesaving by introducing thermal insulation performance curves (TIPCs) from which the insulation performance can easily be found for any climate condition and all economic factors related to energy and insulation. These curves were generated based on a life-cycle cost analysis (LCCA) method. The curves can be easily read based on a single factor, called the f-factor, which comprises the number of degree-day, coefficient of performance, present worth factor, energy cost, and insulation cost. With the gain of heating and cooling degree days (i.e. HDD and CDD), TIPCs can be used for both heating and cooling loads. TIPCs cover commonly used insulation materials for building walls with thermal conductivities range from 0.020 to 0.055 W/m K. TIPCs were validated against published data. Journal of Thermal Engineering Journal of Thermal Engineering 2023-07-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6802 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6802 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6802

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6867 2023-12-08T21:00:00Z 1

Insight of Boundary Layer Structure with Heat Transfer Through a Diverging Porous Channel in Darcy-Forchheimer Porous Material with Suction/İnjection: A Study of Separation Control Astick Banerjee, Sanat Kumar Mahato, Krishnendu Bhattacharyya, Sohita Rajput, Ajeet Kumar Verma, Ali J. Chamkha Divergent channel, boundary layer flow, separation control, non-Darcy porous material, suction/injection. Separation control and formation of boundary layer Newtonian flow in a diverging permeable channel in Darcy-Forchheimer porous material having suction/injection are discussed. Self-similar equations from governing equations are acquired and existence conditions for boundary layer structure are derived using nature of velocity gradient inside boundary layer. It reveals that if sum of Darcy permeability parameter and twice of Forchheimer parameter exceeds 2, then the boundary layer flow always exists with all type of mass suction/injection and even without suction/injection. Also, if mass suction parameter goes beyond , then there is no matter what are the values of Darcy permeability parameter and Forchheimer parameter, a boundary layer exists inside the divergent channel. In addition, obtained numerical solutions are exhibited graphically. It reveals that thicknesses of velocity and thermal boundary layers reduce with Darcy and non-Darcy resistances of porous medium and fluid temperature also diminishes. The velocity and temperature reduce with increment of mass suction and contrary results are found for mass injection. Journal of Thermal Engineering Journal of Thermal Engineering 2023-12-08T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6867 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6867 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6867

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7116 2024-09-10T21:00:00Z 1

Estimation and Analysis of Exergy Loss and Performance Evaluation of Marine Freshwater Generating System Jitendra Singh PAL, S. N. SAPALI, P. W. DESHMUKH Waste heat, Exergy loss, Plate type heat exchanger, Evaporator, Exergy efficiency This paper provides the groundwork for the most efficient design of freshwater generating systems that take advantage of waste heat from the main engines. Shell and tube-type freshwater generators or plate-type freshwater generators are used in the desalination process. The submerged shell and tube type evaporator is mostly used on merchant vessels to produce fresh water. The separation process, energetics, and economics are based on a quantitative interpretation of the second law of thermodynamics in terms of exergy and its destruction. An exergy analysis for utilizing waste heat as a source for a single effect desalination process to meet the freshwater needs is proposed with due consideration to practical aspects. A Shell and tube type freshwater generator installed at the Tolani Maritime Institute, Pune, India is analyzed. Thermal properties are calculated with the C++ program and represented with a flow diagram. Exergy analysis shows the quantity and location of unavailable work of a shell and tube type freshwater generator, mainly in its component’s evaporator, condenser, and brine section. The results are compared with the freshwater generator of Plate Type Heat Exchanger (PTHE). The rate of exergy destruction in freshwater generators with Plate Type Heat Exchanger freshwater generators is 29.33 % whereas, shell and tube type freshwater generators are 44.88 %. Journal of Thermal Engineering Journal of Thermal Engineering 2024-09-10T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7116 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7116 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7116

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6712 2023-03-03T21:00:00Z 1

Simulation and Redesigning the Methanol Production Cycle Using Coil-Wound Liquefied Natural Gas Heat Exchangers Soroush Farahbakhsh, Mohammad Mehdi Keshtkar Methanol, Pinch technology, Aspen Energy, Coil-Wound, LNG Heat Exchangers. The current research uses Aspen Software to find the best way to run the petrochemical methanol complex. This was done by using pinch technology and arranging the heat exchanger network. First, a process flow diagram of the Kaveh industrial plant was used to simulate different plant parts. Then retrofit the plant’s heat exchanger network to minimize capital costs and improve energy efficiency. Plotting the composite curve of the streams, the type, and the quantity of hot and cold utilities came next., and the most economical minimum temperature difference, etc. The best capital cost decreased by around 70%, while the utilities increased by about 50%, and the payback money lasted for 6 months. The methanol cycle was redesigned using coil-wound heat exchangers to improve operational flexibility because of high-temperature streams.The capital costs decreased by around 10%, and utility costs were saved with the liquefied natural gas heat exchangers Journal of Thermal Engineering Journal of Thermal Engineering 2023-03-03T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6712 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6712 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6712

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6870 2023-12-08T21:00:00Z 1

The Evaluation of the Performance of the Heat Exchanger of a Triple Concentric Tube Configuration with ionic Liquid (Imidazolium) and MWCNT Ionanofluid Huda Majid Hasan, Basma Abbas Abdulmajeed triple concentric heat exchanger, ionic fluids, ionanofluid, MWCNTs, [EMIM][BF4]. A triple, concentric tube heat exchanger (TCTHE) made of high conductivity copper tube was designed in this study. The designed TCTHE consisted of three tubes of diameter 34.925 mm, 22.25 mm, and 9.525 mm, and the tubes' thicknesses were 1.27 mm, 1.143 mm, and 0.762 mm, respectively. The length of the outer, middle, and inner tubes was about 670 mm. The TCTHE performance was experimented with using the hydrophilic ionic liquid (IL) and its ionanofluid (INF) of 0.5%MWCNT/[EMIM][BF4] as cooling medium and oil forty stock as hot fluid. The cooling medium flows at a flow rate range of 20-55 l/hr and a temperature of about 25-27 oC. Oil of forty stock flows at a constant flow rate of 20 l/hr and three temperatures of 50, 60, and 70 oC in countercurrent flow. The heat transfer was studied by measuring the Nusselt number, friction factor, pressure drop, and overall heat transfer coefficient of the cold fluid. The results showed that Nusselt number and the overall heat transfer coefficient of both the cooling fluid [EMIM][BF4] IL and INF increased with flow rate and Reynolds number for the inner tube and the outer annular TCTHE. On the other hand, the friction factor of both the cooling fluid [EMIM][BF4] IL and INF decreased with flow rate and Reynolds number for the inner and outer annular of TCTHE. The pressure drop of IL and INF increased linearly with the flow rate. In addition, the pressure drop in the inner tube for the INF increased by 95% or doubled compared with that of the IL. The overall heat transfer coefficient of both the cooling fluid [EMIM][BF4] IL and INF increased with the inlet temperature of the hot fluid (the oil). Journal of Thermal Engineering Journal of Thermal Engineering 2023-12-08T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6870 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6870 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6870

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6801 2023-07-31T21:00:00Z 1

Comparative Analysis of Carbon Particle Emissions from Exhaust of an IC Engine using HSD and Blends of HSD and Honge/Jatropha Biodiesel Puttabore Bore Gowda, R. Chandrashekar, Mohana Kumar S, Akanksh VN Biodiesel, Carbon Particulate emission, IC Engine Exhaust, Hongs, Jatropha, Biodiesel In spite of the surge in solar and wind energy in the recent years, the IC engines, particularly the diesel engines may be expected to stay on for the next 30 years at least. In this context, it is imperative to find alternative fuel sources for petro diesel, at least in part. Inedible oil based biodiesels are one good option for India. There is a slight decrease in performance of a diesel engine when run with biodiesel blends. It is also feared by some that pollution from exhaust gas by using biodiesel blends may be higher. This paper summarizes the results of experiments carried out on biodiesel blends with diesel to determine the amounts and particle sizes of carbon particulate matter emissions in engine exhaust. Blends of two esterified oils, viz., Honge (Pongamia Pinnata) and Jatropha, with petro diesel were used to operate a single-cylinder, four-stroke diesel engine. Blend ratios used were 5%, 10%, 15%, and 20%. The carbon particles in exhaust were collected on an INDICA filter paper for 5 minutes. The carbon content was ascertained by the standard procedure, and the size of particles was found by microscopic examination. Further ANOVA of the data was carried out separately for the Honge and Jatropha blends. The results from the experiments are clear and interesting. Both Honge and Jatropha blends increase the amount of carbon particulates in engine exhaust when compared with diesel. Carbon particulates increase with increase in load on the engine. Increase of blend ratio generally increases the carbon in exhaust in case of Jatropha blends. The behaviour with Honge blends is different. While blend H5 has highest carbon in exhaust at low loads, at high loads, H10 has the maximum carbon in exhaust. Blending with Honge or Jatropha biodiesel increases the carbon particle size in exhaust. While the size of carbon particles with diesel is < 20 µm, it is > 20 µm with all blends, increasing with load or blend ratio. In all cases, lower loads result in finer carbon particles in exhaust. The study helps in concluding that both Honge and Jatropha blends could be used in diesel engines, Honge being superior. Though the PM level in the exhaust will be higher with blending, the particle sizes will be much larger and hence causing less health hazard. Further, idling (no load), or low loads should be avoided since these result in smaller carbon particles. Journal of Thermal Engineering Journal of Thermal Engineering 2023-07-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6801 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6801 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6801

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6800 2023-07-31T21:00:00Z 3

A Review on Battery Thermal Management Strategies in Lithium-ion and Post-Lithium Batteries for Electric Vehicles Şahin Güngör, Sinan Göçmen, Erdal Çetkin Electric Vehicle; Battery Thermal Management; Lithium-ion batteries; Post-lithium Batteries. Electrification on transportation and electricity generation via renewable sources play a vital role to diminish the effects of energy usage on the environment. Transition from the conventional fuels to renewables for transportation and electricity generation demands the storage of electricity in great capacities with desired power densities and relatively high C-rate values. Yet, thermal and electrical characteristics vary greatly depending on the chemistry and structure of battery cells. At this point, lithium-ion (Li-ion) batteries are more suitable in most applications due to their superiorities such as long lifetime, high recyclability, and capacities. However, exothermic electrochemical reactions yield temperature to increase suddenly which affects the degradation in cells, ageing, and electrochemical reaction kinetics. Therefore, strict temperature control increases battery lifetime and eliminates undesired situations such as layer degradation and thermal runaway. In the literature, there are many distinct battery thermal management strategies to effectively control battery cell temperatures. These strategies vary based on the geometrical form, size, capacity, and chemistry of the battery cells. Here, we focus on proposed battery thermal management strategies and current applications in the electric vehicle (EV) industry. In this review, various battery thermal management strategies are documented and compared in detail with respect to geometry, thermal uniformity, coolant type and heat transfer methodology for Li-ion and post-lithium batteries. Journal of Thermal Engineering Journal of Thermal Engineering 2023-07-31T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6800 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6800 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6800

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6795 2023-07-28T21:00:00Z 1

Investigation of Issues Affecting Thermal Comfort in Water System Underfloor Heating Applications of Buildings with Bayesian Networks Samet Erkol, Melih Yücesan, Muhammet Gül, Ali Fuat Güneri Thermal Comfort, Water System Underfloor Heating, Bayesian Network Thermal comfort is related to the stability of the ambient temperature. Constant changes in ambient temperature appear as a situation that negatively affects comfort. The selected building systems must be arranged to maintain this stability for the continuity of thermal comfort. In this study, issues affecting thermal comfort in water system underfloor heating applications of buildings are handled and analyzed using the Bayesian Network modeling methodology. Visual examples of the problems encountered in field applications are also given. Three different scenarios are tested with the constructed Bayesian Network model. In the first scenario, assumed that mechanical project failures were prevented. In this case, it was observed that the failure rate decreased by about 5%. In the second scenario, assumed that mechanical application failures are prevented along with mechanical project failures. The failure rate decreased by 11% compared to the first situation. The third scenario assumed that the mechanical project preparation phase was concluded without any problems, the mechanical project was implemented without any failures, and the mechanical system was commissioned without any problems. In the last scenario, the failure rate decreased by 14% compared to the first case, and the probability of not providing thermal comfort remained at 2%. As a result of these three scenarios, the possibility of not providing thermal comfort in the underfloor heating system is detailed and interpreted. Journal of Thermal Engineering Journal of Thermal Engineering 2023-07-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6795 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6795 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6795

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6763 2023-05-24T21:00:00Z 1

Statistical Analysis of the Solar Diffuse Fraction Radiation using Regression Analysis of Longitudinal Data in India Hicham Salhi, Abdelmounaim Hadjira, Basharat Jamil Longitudinal data; Diffuse fraction; Sunshine ratio; Clearness index; India. In this study, the validity of the estimation of a single regression equation for the diffuse fraction across 22 stations in India using the two parameters: the clearness index and the sunshine ratio is tested. The homogeneity test based on Fisher's statistics was applied to test the homogeneity of the estimated parameters across all stations. The results showed that the p-value at the level of 5% for each model is smaller than 0.05, indicating that all stations were heterogeneous. The Hierarchical Cluster Analysis (HCA) was used to classify the data into homogenous clusters. The results of HCA indicated that the longitudinal data were divided into four main clusters. For each cluster, the regression analysis was applied based on the longitudinal data then, the fixed effects model (FEM) and the random-effects model (REM) were used for the evaluation. Further, the Hausman test was applied to choose between the fixed effects model and the random-effects model. Finally, the results showed that the four best regression models were found for the selected stations in the study area. Journal of Thermal Engineering Journal of Thermal Engineering 2023-05-24T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6763 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6763 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6763

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6764 2023-05-24T21:00:00Z 1

Parametric Analysis of Solar-assisted Trigeneration System Based on Energy and Exergy Analyses Mohd Parvez, Wasim Akram, Osama Khan Rankine cycle, energy efficiency, exergy efficiency, irreversibility, molten salt, central receiver, direct normal irradiance In this study a novel trigeneration setup is explored so as to achieve simultaneous forms of energy in the form of electrical energy, heating and cooling, driving its primary energy requirements through a solar power tower. Molten salt is used in this study to transfer the heat from the solar component to the vapor absorption apparatus. Further the vapor absorption system is tested for thermodynamic performance for a couple of refrigerants (LiNO3-H2O and LiBr-H2O), so as to establish the Pareto-optimal fluid among them. In order to remove any adherent error in the measuring procedure, all equipment’s uncertainty analysis was performed which was negligibly small approximately at 5.34 % in terms of powerplant efficiencies. An exact analysis was performed so as to estimate energy and exergy inefficiencies in the equipment while varying input parameters. Zenith exergy destruction was achieved in33.6%by the central receiver, followed by 24.9% by heliostat, and 7.8%in heat recovery steam generator. The highest energy and exergy efficiencies (62.6% and 20.6%) are is obtained by LiBr-H2O, whereas (60.9% and 19.6%) were obtained from LiNO3-H2O refrigerant. Journal of Thermal Engineering Journal of Thermal Engineering 2023-05-24T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6764 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6764 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6764

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6709 2023-02-19T21:00:00Z 1

Experimental Assessment of TiO2-POE Nanolubricant Stability and Optimization Process using one Factor at a Time (OFAT) Based on Response Surface Methodology Agus Nugroho, Rizalman Mamat, Zhang Bo, Wan Hamzah Azmi, Talal Yusaf, Fitri Khoerunnisa TiO2-POE Nanolubricant Stability, OFAT, RSM, UV Visible, Zeta Potential This paper aims to elaborate on the results of the experimental assessment of the stability of TiO2-Polyester (POE) nanolubricant. There are six samples in this investigation, with each concentration of 0.02 vol%. The TiO2 nanoparticles were dispersed into synthetic lubricant POE for 30 min using a magnetic stirrer. Then, the samples were sonicated for 0, 40, 60, 80, 100, and 120 min, respectively—the visual observation for 720 hours, UV visible spectrophotometry, and absolute zeta potential employed to investigate the samples. After data acquisition, optimization with one factor at a time (OFAT) is applied to determine the most optimum sample. The results show that the sample with sonication treatment for 120 min is the most optimum. This finding was confirmed by the absorbance ratio value of 0.95 with an -80.48mV zeta potential. The output of ANOVA analysis shows the regression coefficients are 0.9989 and 0.9999, and the adjusted R2 values are 0.9998 and 0.9983 for day 15th and 30th respectively with a p-value that is much smaller than 0.05, which is <0.0001. These results demonstrate that sonication duration has a significant effect on increasing the stability of TiO2-POE nanolubricant. Journal of Thermal Engineering Journal of Thermal Engineering 2023-02-19T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6709 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6709 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6709

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6846 2023-10-16T21:00:00Z 3

An Exploratory Review on Heat Transfer Mechanisms in Nanofluid Based Heat Pipes Udayvir Singh, Harshit Pandey, Naveen Gupta Heat transfer, Phase change. Thermal resistance, Heat exchanger, Solar energy The current work presents a review of the studies reported on nanofluid-based heat pipe technologies. The reviewed studies are categorized on the basis of the type of nanofluid incorporated in the heat pipe i.e., mono and hybrid nanofluids. It is further followed by classification on the basis of the type of study carried out i.e., experimental and numerical study. The study identifies the heat transfer mechanisms associated with the different types of heat pipes and presents their dominance over each other. It was observed that the dominance of the identified heat transfer mechanisms is a strong function of the heat pipe type investigated. The heat transfer mechanisms acting during the heat pipe operation get significantly influenced by the its operating conditions. The current review paper will aid the reader to properly understand the hidden heat transfer mechanisms prevalent in the different types of heat pipes filled with nanofluids allowing them to accordingly optimize their thermal performance. perspective Journal of Thermal Engineering Journal of Thermal Engineering 2023-10-16T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6846 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6846 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6846

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6913 2024-02-07T21:00:00Z 1

Experimental and Numerical Investigation of Heat Transfer Enhancement in Double Coil Heat Exchanger Ali Najm, Itimad Azzawi, Abdul Mun'em Karim Double helical coil; Heat exchanger; Numerical analysis; Heat transfer enhancement In the current work, a simple and cost-effective strategy was conducted to improve the performance of a coil and shell heat exchanger. Initially, we conducted a practical experiment to verify the results of the numerical analysis on a double coil heat exchanger. The results of the numerical study showed a good agreement with the experimental results. Then, the numerical analysis was conducted to find the impact of using multiple pitches with varied connections on the double coil on the ability of the exchanger to improve the heat transfer process. The main objective of this simulation is to determine the appropriate configuration of the shell and helical tube heat exchanger to obtain high thermal performance. Following the encouraging simulation results, a double coiled tube with multiple pitches was manufactured, as well as a single coiled tube, to compare the results and confirm the effectiveness of the correlation between the changes in the pitch, while maintaining the basic design parameters in terms of tube diameter (d_c), shell diameter (D_sh) height of shell (H_sh), the height of coil (H_c) and curvature diameter (D_c). The results of the numerical study showed good agreement with experimental data, with an error rate of about 9%. In general, this new design led to an improvement in the heat transfer process and Nusselt number preparation of the shell side when preparing Reynolds (400<?Re?_sh<2000). The improvement rate in the Nusselt numbers on the side of the shell was 19%. Journal of Thermal Engineering Journal of Thermal Engineering 2024-02-07T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6913 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6913 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6913

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6839 2023-10-16T21:00:00Z 1

Exergoeconomic Study of Reheat Combined Cycle Configurations using Steam and Ammonia-Water Mixture for Bottoming Cycle Parameters Mayank Maheshwari, Onkar Singh Exergy, Economics, Part load operations, Combined cycle, Reheat aqua ammonia turbine The use of combined cycle power plants though had led the pathway to maximize the fuel energy utilization but the part-load operation of these plants is of concern. In this work, an exergoeconomic comparison of 11 different reheat combined cycle arrangements has been carried out under their part-load operations for varying bottoming cycle parameters namely steam bleed fraction, deaerator pressure, separator temperature, absorber pressure, and condenser pressure. The results depict that the absorber has the highest exergy destruction with second law efficiency of 23.55% at the part load of 25% for the combined cycle power plant having high pressure drum with steam as working fluid and low pressure drum with ammonia-water as working fluid. The comparison also shows the highest cost of electricity production as 0.1243USD/kWh for the combined cycle power plant having ammonia-water as working fluid in bottoming cycle and operating at part load of 25%. While the minimum price of electricity produced is 0.05USD/kWh at 25% part load for CCPP having double pressure HRVG’s at condenser pressure of 0.09 bar. Journal of Thermal Engineering Journal of Thermal Engineering 2023-10-16T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6839 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6839 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6839

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6665 2022-12-01T21:00:00Z 3

Heat Transfer Performance of Nanofluids in Heat Exchanger: A review Rohinee M. Barai, Devesh Kumar, Atul V. Wankhade Nanofluid, Thermo-Physical Properties, Performance of Heat Transfer, Heat Exchangers, Heat Transfer Coefficient, Heat Transfer Rate Energy is a key aspect of any country's economic development. Improving heat transfer performance leads to saving energy. Nanotechnology has a key role to play in optimizing heat exchangers. Fluids containing nanosized particles are called nanofluids. Nanofluids have higher thermal conductivity than typical liquids. This paper outlines current research on convective heat transfer performance, thermophysical properties, particle size, and volume concentration effects in nanofluid studies. Measurement methods for thermal conductivity and correlations used by earlier researchers to determine thermal conductivity are also encompassed. The main applications of nanofluids as lubricants and radiator systems to improve the efficiency of heat removal from vehicle engines have also been emphasized. Results suggest that by using a larger size of particle some drawbacks include particle sedimentation, clogging, erosion, stability, and increasing pressure drop. Enhancing thermal conductivity with optimum volume concentration. Improving the efficiency of heat exchange systems is one of the possible ways to reduce energy consumption. The need for optimum concentration of nanofluids is required. The Problem of stability, corrosion, and erosion arrived by increasing the volume concentration of nanoparticles in a nanofluid. Journal of Thermal Engineering Journal of Thermal Engineering 2022-12-01T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6665 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6665 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6665

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6789 2023-07-28T21:00:00Z 1

Freeze-Drying Kinetics and Diffusion Modelling of Hawthorn Khaled Ali Hagig, Bahadır Acar, Abdullah Dağdeviren, Edip Taşkesen, Mehmet Özkaymak freeze-drying; drying kinetics; drying of hawthorn; kinetic drying model; diffusion approach model This study tests freeze-drying (FD) technology (Scanvac Coolsafe model, Labogene brand) to preserve hawthorn fruit. First, 100g hawthorn slices were frozen and then freeze-dried. Kinetic models were applied, and hawthorn’s moisture ratio and weight loss were noted after every two hours during the 14-hour freeze-drying process. Matlab program is used to perform a total of eight kinetic drying models. Results show that the root mean square error was 0.011063, the least chi-square was 1.959 x 10-4, the highest determination coefficient was 0.9987, and the effective diffusivity was 2.33742×10-10 m2/s. The Diffusion approach is the best among the eight models. Journal of Thermal Engineering Journal of Thermal Engineering 2023-07-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6789 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6789 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6789

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6753 2023-05-18T21:00:00Z 1

Assessment of Ec-toxicity Potential of Fuel by Exhaust Gas Analysis Aezeden Mohamed, Paul Kuri , Sachindra Kumar Rout, Kamalakanta Muduli Biodiesel; engine; emission; sustainable; exhaust The engine combustion products were measured and analyzed based on emissions of exhaust. Due to the utilization of a variety of fuels, such as petroleum diesel and bio-diesel in diesel-generated engines, they emit pollution-insecure emissions. To explore this emission quantity, a numbers of experiments were conducted utilizing a single-cylinder engine, Land Curser six-cylinder, Mazda WL31 engine mechanical biodiesel vehicle and In-Line engine. The performance research was given for the data acquired from the Mazda WL31 four-cylinder engine. Landcom III gas analyzer was used to sense and record the exhaust gas emissions from the burning of diesel fuel, which was utilized for data analysis. Various gas discharges and their constituents were independently analyzed. The results of the test show that the harmful emissions of biodiesel fuel are much lower than the emissions of fuel made from mineral oil. Journal of Thermal Engineering Journal of Thermal Engineering 2023-05-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6753 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6753 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6753

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6726 2021-12-31T21:00:00Z 1

Organic Rankine Cycle Systems with Mixture Of Pure Fluids: On Infeasible Fluid’s Fractions Due To The Interaction Between The Mixture Glide And The Hexs Pinchs Basma Hamdi, Abdelhamid Kheiri, Mohamed Tahar Mabrouk, Lakdar Kairouan Organic Rankine Cycle, Working Fluids, Mixture, Glide, Pinch, infeasible mass fractions The Organic Rankine Cycle (ORC) is a promising technology for power generation from low-grade heat. The selection of working fluids is one of the important key points to improve the performance of an ORC system. Zeotropic mixtures show promising performances as working fluids. In fact, their temperature glide during phase change enables better match between the working fluid and the heat source/sink temperatures. In order to reveal the performance of mixture in ORC system, this paper deals with the thermodynamic model of the subcritical Organic Rankine Cycle (ORC) systems driven by low grade heat source while using zeotropic mixture working fluids with a special consideration to the interaction between phase change glides and the pinch value and their location in both the evaporator and the condenser (HEXs). Zeotropic mixtures of seven pure fluids are evaluated as working fluids for a subcritical ORC system. The mass fraction effects of mixtures on the thermal efficiency are analyzed. For given working conditions (working fluid mass flow, pressure and bubble temperature) the results show that for each considered zeotropic mixture there exist mass fraction ranges that are not consistent with the pinch values constraint in the HEXs and leads to so-called ‘infeasible zones’ with unreal HEXs dimensions. Results shows also that, out of these “infeasible fractions” zone, keeping unchanged the working conditions, the thermal performances of ORC system using zeotropic mixture are always better than the thermal performances of the same systems using the correspondent pure fluids. In addition, out of these highlighted “unfeasible zones” it was found that mixture with high temperature glide improve the thermal efficiency of ORC system. Journal of Thermal Engineering Journal of Thermal Engineering 2021-12-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6726 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6726 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6726

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5605 2022-06-28T21:00:00Z 1

Experimental Investigation of Thermal Comfort Performance of aRadiant Wall and Ceiling Panel System Ahmet Doğan, Nurullah Kayacı, Hakan Demir, Mustafa Kemal Sevindir Radiant Systems, Heat Pump, Thermal Comfort, GSHP, Wall and Ceiling Heating The number of radiant heating-cooling systems in building applications is increasing it is because of low energy consumption, low operating temperature and high values they provide in terms of working compatibility with renewable energy sources. In this study, ground source heat pump integrated radiant panels installed on the wall and suspended ceiling of the office room in Yildiz Technical University Science and Technology Application and Research Centre were experimentally examined in terms of thermal comfort according to the relevant standards. Vertical air temperature differences and mean radiant temperatures were investigated. The mean air temperature differences at 0.1 m and 1.7 m were found to be 3,9 oC 2.9 oC 3.5 oC, 3.1 oC and 3.4 oC on average for the five different stands, respectively. PMV and PPD values were found to be 0.78 and 18.9% for February 12 (Case 1), 0.36 and 8.4% for February 13 (Case 2), respectively. In the experiment carried out under the conditions of Case 2, while the comfort conditions were provided in almost all of the day, the desired comfort conditions could not be achieved in Case 1 after 11 am. Journal of Thermal Engineering Journal of Thermal Engineering 2022-06-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5605 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5605 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5605

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6875 2023-12-08T21:00:00Z 1

Experimental Analysis of Heat Transfer Characteristics using Ultrasonic Acoustic Waves Ali Bousri Hamadouche, Nebbali Richard Natural convection; Low frequency ultrasound; Heat transfer enhancement; Experimental investigation In this experimental work, heat transfer intensification using ultrasonic waves was investigated. A heat source, consisting in a parallelepiped aluminum block in which two electrical heating cartridges of 160 W each were mounted to heat four liters of distilled water contained in a tank made of Plexiglas. To demonstrate the effectiveness of heat transfer enhancement with the use of ultrasounds, three different configurations were analyzed. In the first one, considered as a reference case, the heat transfer was studied without ultrasound field. In the second configuration, ultrasonic acoustic waves were generated using one transducer vibrating at a fixed frequency of 40 kHz with a total power of 60W. In the last configuration, ultrasounds were generated with two similar transducers mounted on two opposite walls of the water tank while maintaining the same power and frequency. The effect of the distance separating the heat source to the transducers on the convective heat transfer coefficients and the average temperature of the water in the tank were analyzed in detail. The results revealed that the natural convection heat transfer in the water tank was intensified by means of low frequency acoustic waves. Indeed, it was shown, particularly, that more the distance between the transducer and the heater is low more the heat transfer improvement is better. The acoustic cavitation and streaming were identified as the main phenomena leading to these results. This study successfully demonstrated the feasibility of heat transfer intensification using low frequency ultrasonic waves. Journal of Thermal Engineering Journal of Thermal Engineering 2023-12-08T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6875 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6875 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6875

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6637 2022-10-13T21:00:00Z 1

Energy, Economic and Environmental Analysis and Comparison of the Novel Oxy-Combustion Power Systems İbrahim Ozsari, Yasin Ust Thermodynamic Analysis, Oxy-combustion Cycle, Gas Turbine; Clean Energy, Thermal Efficiency, Oxy-fuel/s-CO2 Cycles Oxy-combustion technologies are clean energy systems with zero emission; they have great potential when considering global warming and climate change. This study presents a detailed thermodynamic analysis in terms of energy, environment, and economy. Consequently, the results obtained for an oxy-combustion power system are presented in comparison with a conventional gas turbine power system. The results are presented as a function of the pressure ratio with regard to net power, input heat, system efficiency, specific fuel consumption, equivalence ratio, fuel-air ratio, capital investment cost, fuel cost, oxygen cost, total cost, electricity revenue, and net profit. In addition, the study calculates the pollutant emissions from non-oxy-combustion systems and investigates the environmental costs. The pressure ratio for maximum net power has been obtained as 20.8 in the conventional gas turbine power system. Similarly, the pressure ratios for maximum net power in oxy-combustion power cycles with 26%, 28%, and 30% oxygen ratios are 23.3, 27.4 and 29.7, respectively. Results from 24% to 30% have been displayed to observe the effect of reactant oxygen in the oxy-combustion power cycles. The optimum cycle conditions have been determined by calculating the costs of system components, total revenues, and net profits at pressure ratios of 10, 20, 30 and 40. Finally, the results reveal the pressure ratio should be reduced to minimize the total costs per cycle. For maximum net profit, the pressure ratio in a conventional gas turbine power cycle has been calculated as 15.9; similarly, the pressure ratios in oxy-combustion power cycles with 26%, 28%, and 30% oxygen ratios have been respectively calculated as 12.8, 15.2 and 16.4. Journal of Thermal Engineering Journal of Thermal Engineering 2022-10-13T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6637 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6637 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6637

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6827 2023-10-16T21:00:00Z 1

Cfd Modelling of the Microclimate of a Cultivated Greenhouse: A Validation Study Between Experimental and Numerical Results Soumaïla Tigampo, Sami Kooli, Nizar Ben Salah, Walid Foudhil, Reda Errais, Vincent Sambou, Sadok Ben Jabrallah Ansys-Fluent, CFD modelling, validation, microclimate, plant, radiation model (discrete ordinate), temperature distribution, humidity distribution. In this work, we present the validation of a numerical model of a greenhouse thermally insulated on three sides with a tomato crop. A CFD software (Ansys-Fluent) was used to solve the numerical model. The discrete ordinate model was included to solve the radiative transfer equation. The results of the numerical model were compared with the values of air temperature observations at different points in the greenhouse. Good agreement was obtained between the simulated and measured values, with coefficients of determination R2 = 0.77, R2 = 0.84, R2 = 0.99, and R2 = 0.89 for the temperatures of the points 10 cm, 80 cm, and 210 cm above the ground and the average temperature in the greenhouse, respectively. A third-order polynomial curve was drawn between the simulated and measured values of relative humidity in the greenhouse. These R2 values are 0.9786 and 0.7165, the simulated and measured relative humidity, respectively. The simulation results showed low velocity values with an average of 0.525 m/s located between 1.5 m and 2 m from the ground. Journal of Thermal Engineering Journal of Thermal Engineering 2023-10-16T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6827 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6827 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6827

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5600 2022-06-14T21:00:00Z 1

Performance Improvement Methods for Quartz Tube Solid Particle Fluidized Bed Solar Receiver Mehmet Bölük, Senem Şentürk Lüle Computational Fluid Dynamics, Concentrated Solar System, Solid Particle Receiver, Two Phase Flow The conditions to improve performance of quartz tube silicon carbide (SiC) solid particle fluidized bed solar receiver was investigated with computational fluid dynamics (CFD) simulations. The difficulty of experimenting all possible operating conditions was overcome by preparing CFD base input with appropriate models and parameters. The amount of SiC in the bed, the size of particles, and the air inlet velocity were considered as variables. After model verification, in order to evaluate the effect of particle addition, bed without solid particles were simulated first. Outlet temperature of single-phase receiver was calculated as 421 K. Outlet temperatures of 913 K, 895 K, and 881 K were obtained for 400 µm diameter particles in 0.3 m bed height for air inlet velocities of 0.25, 0.3, and 0.35 m/s. Air outlet temperature decreases as air inlet velocity increases. On the other hand, too much reduction at inlet velocity retards the system performance since it affects fluidization. For 400 µm particle diameter and bed height of 0.2 m, outlet temperatures of 994 K, 974 K, and 955 K were found for the same air inlet velocities above. As bed height decreases, air outlet temperature increases. For particle diameters of 300 and 500 µm for bed height of 0.3 m, outlet temperatures of 980 K and 878 K were calculated for appropriate minimum fluidization velocities. Outlet temperature increased with decreasing particle size. Journal of Thermal Engineering Journal of Thermal Engineering 2022-06-14T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5600 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5600 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5600

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6921 2024-02-06T21:00:00Z 1

Influence of Different Geometrical Dimple Configurations on Flow Behaviour and Thermal Performance within a 3D Circular Pipe Ahmed Al-Obaidi, Jassim Alhamid Twisted tape, Concavity, Corrugated shapes, Thermal-hydraulic flow, Heat performance enhancement Numerical analysis has been performed to evaluate the heat transfer characteristics and performance of a circular pipe with geometrical dimple patterns. Using computational fluid dynamics (CFD) codes, we examine the effects of geometrical configurations on the flow and thermal behavior of circular pipes with concavity (dimple) diameters. Fluid mixing and flow perturbation are facilitated by perforations across the pipe core and wall regions, thereby improving thermal efficiency. In addition, a concavity with a diameter of 4 mm enhances heat transfer. Based on the results of the study, the disrupted pipe wall and pipe core region produce swirls and transverse vortices in the flow that provide superior heat transfer compared to conventional (smooth) pipes. In an increasing Reynolds number (Re), mixing, secondary, and separation flows become larger. Performance evaluation factor (PEF) values increased at low Reynolds numbers when dimple diameter was 1mm. As a result of these improved pipes, heat exchanger efficiency may improve in industrial applications, a key factor for energy conservation. Journal of Thermal Engineering Journal of Thermal Engineering 2024-02-06T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6921 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6921 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6921

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6957 2024-03-14T21:00:00Z 1

Numerical Investigation of an Amalgamation of Two Phase Change Materials Thermal Energy Storage System Pankaj R. Gharde, Sanjay N. Havaldar PCMs amalgamation, Thermal energy storage, Thermal battery In the last three decades, many researchers have published their findings on the storage of thermal energy using various phase transition materials (both organic and non-organic). One of their goals was to have a higher heat storage capacity with a shorter heat charging cycle for thermal energy storage. This study looked into a floating capsule thermal energy storage system (TESS). A number of spherical capsules filled with beeswax were placed in a paraffin-filled cylindrical shell. With heat transfer fluid flowing through three hexagonal tubes arranged at 120° inside the TESS core, the two phase change materials (beeswax with a thermal conductivity of 0.25 W/mK and paraffin with a thermal conductivity of 0.23 W/mK) were charged and discharged. For the proposed TESS, a mathematical model was created and utilised to forecast thermal energy storage capacity and charging/discharge times for various configurations. In TESS, a 70–30% mixture of the two PCMs results in a 21.5 percent increase in heat storage capacity when beeswax alone is used, and an 8.4 percent decrease in storage capacity when paraffin alone is used. For a heat storage capacity of 7300 kJ, the model estimates charging and discharging times of around 2.6 and 3.2 hours, respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2024-03-14T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6957 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6957 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6957

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7113 2024-09-10T21:00:00Z 1

Experimental Study on the Combustion of Gaseous Based Fuel (LPG) in a Tangential Swirl Burner of a Steam Boiler Karrar S. HASAN, Mohammed AL-FAHHAM, Wisam A. Abd AL-WAHID, Hasan Hadi KHWAYYIR, Ahmed R. KAREEM, Saif S. HASAN, Jameel AL-NAFFAKH Fuel combustion, LPG, Diesel, steam boiler, pollutants gases emission, boiler Efficiency In this study, pollutant gas emissions and combustion efficiency of LPG fuel burning in a steam boiler were investigated experimentally and compared with the diesel fuel-based results. A new tangential swirl burner is designed, manufactured, and used for gaseous fuel combustion (LPG) in the boiler that was already designed to be operated with liquid fuel (diesel). The experiments are carried out with a wide range of equivalence ratios (?) and with three different diameter ratios (dr = 1/10, 1/15, and 1/20) (diameter ratios = variable diameter of the burner to invariant boiler diameter). The volumetric ratios of CO2, CO as well as the HC content in the exhausted gases are measured and the boiler efficiency is predicted. The obtained results revealed that the replacement of the liquid fuel burner with the tangential swirl gas (LPG) burner is simple, inexpensive, and had no negative effect on the other parts of the boiler. In addition, the lowest pollutant gas concentrations detected in the exhausted gases and the highest boiler efficiency are obtained with a diameter ratio of 1/10. In comparison with diesel fuel combustion, the LPG fuel offered the cleanest combustion at ? approaching 1 and above, required less O2 for complete combustion, and had the least HC content in the exhaust gases at the lean mixing area. Finally, the boiler efficiency operating with LPG fuel was higher than that obtained with diesel fuel for all equivalence ratios. Journal of Thermal Engineering Journal of Thermal Engineering 2024-09-10T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7113 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7113 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7113

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6797 2023-07-28T21:00:00Z 1

Measurement of Temperature Flow Analysis by Condition Monitoring System for WTG Gear Box to Evaluate the Thermal Performance Associated with Plant Load Factor Sunil Kumar Kurugundla, Sumathy Muniamuthu, Ponnurangam Raja, Kala Raja Mohan Temperature monitoring data, Scada analysis, condition monitoring, Master gearbox analysis,Forced convection. This research work is mainly focused on the performance of the wind turbine power plant. The performance of the plant will depends on the working of wind turbine gearbox. Hence the parameters taken like inlet velocity of air, inlet temperatures and inlet pressure of the air entering into the gearbox. For experimentation a three stage gearbox has been considered and the data has been recorded for the period of 5 months. These results has been recorded with the help of SCADA software and the results are imported from SCADA for analyzing the minimum and maximum oil temperatures. Since these parameters effects directly on the thermal performance of the wind turbine power plant. From the analysis it was found that the temperature sensors for monitoring the oil TM1 and TM2 within temperature limits of 250?C and also the TS1 and TS2 Promises the sensing capacity within temperature limits upto 200 ?C and response time is 30 minutes, also the coupling temperatures TC1 and TC2 gives very promising results upto 150 ?C for 30 minutes response time. Journal of Thermal Engineering Journal of Thermal Engineering 2023-07-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6797 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6797 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6797

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6972 2024-03-22T21:00:00Z 1

Experimental Investigation of Axial Finned Tube Evaporator Thermal Distillation System Using for Diesel Engine Waste Heat Recovery Process Satyendra Kumar, Prakash Chandra thermal distillation unit; axial finned tube evaporator; waste heat recovery; exhaust gas The study aims to improve the waste heat recovery from exhaust gas of an internal combustion engine (ICE). The recovered waste heat energy was used for distillation by using a thermal distillation system. The efficiency of the thermal distillation unit was investigated by varying the evaporator type and engine load (25, 50, 75 %). Four different types of evaporators were used including one smooth copper tube and other three were two, three and four axial finned copper tube evaporators. The impact of evaporator type and engine load on the net recovered energy and exergy, overall first and second law efficiency, and distillate yield rate of thermal distillation unit was also examined. The results revealed that the net extracted heat energy and exergy for axial finned tube evaporator was approximately 26.823 – 45.513 % and 7.614 – 25.203 W higher than that of smooth tubes evaporator at 25 and 75 % engine load, respectively. The distillation yield was found to be ~ 2.35 liter/ hour in the case of four axial finned tube evaporator at 75 % engine load. Journal of Thermal Engineering Journal of Thermal Engineering 2024-03-22T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6972 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6972 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6972

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5599 2022-06-10T21:00:00Z 1

A Numerical Evaluation on the Utilization of Earth to Air Heat Exchangers in Arid Regions Algeria Abdelmadjid Kaddour, Mohammed El Hadi Attia, Müslüm Arıcı, Khalfallah Benbelgacem, Zied Driss Arid climate, Earth to air heat exchanger, Heat exchanger, Mathematical model, Temperature In this paper, the numerical results of the study on geothermal-air heat exchanger in dry areas of Algeria (Ghardaia region) were presented. Computational fluid dynamics equations were solved using our specific code compilated with Fortran. The outputs of the numerical calculations were compared and validated with the experimental results and the outputs of a commercial CFD code. In these conditions, our results present good agreements with an error not exceeding 2%. By using our numerical model, we have calculated the optimum length, the internal diameter, the air velocity of the pipe in winter and summer periods and have determined the optimum depth at different depths. The comparison of two types of pipes making material (PVC and PEHD) has taken into account the characteristics of the Ghardaia-Algeria region (specific heat capacity, density, thermal conductivity and temperature) of the soil. The obtained results proved that the chosen model gives a satisfactory agreement in all the studied variables. Journal of Thermal Engineering Journal of Thermal Engineering 2022-06-10T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5599 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5599 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5599

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6798 2023-07-28T21:00:00Z 1

Effect of Operating Parameters on the Performance of Rotary Desiccant Wheel Energized by PV/T Collectors Umutcan Olmuş, Yunus Emre Güzelel, Kamil Neyfel Çerçi, Orhan Büyükalaca Desiccant Air-Conditioning, Rotary Desiccant Wheel, Silica-gel, Photovoltaic Thermal Collector, Regeneration Temperature The main energy input of a desiccant air conditioning system is the low-quality thermal energy required for regeneration, which can be obtained from waste heat, geothermal resources or solar energy. Regeneration thermal energy can be produced as well as energizing components such as fans, pumps, auxiliary air heaters, and control elements of the system by using photovoltaic-thermal solar collectors (PV/T). In this study, parametric analyzes were performed to investigate the effect of regeneration temperature and air frontal velocity on the temperature and dehumidification performance of a solid silica-gel desiccant wheel and on the water-cooled PV/T collectors used to provide the regeneration thermal energy. The regeneration temperature was varied between 50 and 70 ?, and air frontal velocity between 1.3 and 4.1 m/s. The analyzes show that the dehumidification efficiency increases from 13.94 % to 33.04 % as regeneration temperature increased from 50 ? to 70? at 1.3 m/s air frontal velocity at which dehumidification efficiency is maximum. At 4.1 m/s air frontal velocity, the required regeneration thermal energy is maximum and increases from 49.64 kW to 132.48 kW at the same regeneration temperature change. The low regeneration temperature resulted in desirable latent performance and undesirable sensible heat transfer performance in DEW. Finally, considering the whole system, it was concluded that the optimum regeneration air temperature for the performance parameters is 60 °C. Journal of Thermal Engineering Journal of Thermal Engineering 2023-07-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6798 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6798 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6798

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6750 2023-05-18T21:00:00Z 1

Exergetic Efficiency prediction of Roughened Solar Air Heater Karmveer, Naveen Gupta, Tabish .Alam, Himanshu Singh Roughness, Performance, Solar Air heater, friction factor, Nusselt Number and, augmentation. The energy losses of flowing air through the solar air heater (SAH) duct does not consider in the thermal performance. Therefore, thermohydraulic performance based on exergetic efficiencies is a tool to assess the performance by considering energy losses in propelling the air simultaneously to identify the best ribs configuration. This paper presents the thermohydraulic performance of SAHs exploiting various ribs roughness’s. The performance of SAHs is based exergetic evaluation based on IInd law of efficiency is most suitable for design of artificially roughened SAH as it includes both requirement of pumping power and effective energy output. In this paper exergetic evaluation of differently roughened SAH has been done. The exergy efficiency of roughened SAH was calculated analytically with the help of correlations developed by researchers and the results also compared with conventional SAH under same operating parameters. The thermal and exergy efficiency curve as a function of temperature rise parameter (?T/I) has been plotted. As a results, hybrid ribs configuration exhibited the highest exergetic efficiencies when temperature rise parameters greater than 0.01 ?K.m/W, however, smooth duct also showed a significant exergetic efficiency when temperature rise parameters had low values. Journal of Thermal Engineering Journal of Thermal Engineering 2023-05-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6750 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6750 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6750

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6832 2023-10-16T21:00:00Z 1

Performance Enhancement of Stepped Solar Still Coupled with Evacuated Tube Collector Bhushan Patil, Jitendra. A. Hole, Sagar V. Wankhede Stepped solar still, Evacuated tubes, Parabolic concentrator, External basin, Productivity. The provision of fresh water is the most important problem in developing countries. With the rising need for fresh water, it is vital to look for other sources. Solar energy is still one of the most essential and technically feasible applications of the sun. There are numerous varieties of solar stills; the basin type is the most basic and well-proven. The biggest disadvantage of a traditional basin solar still is that it produces very little distilled water per unit area. Solar distillation is one of the most basic methods for removing pollutants including heavy metals, dust, salts, and microorganisms from water. When compared to rainwater, it produces more clean water. Using solar distillation technology, sea water can be converted to fresh water. In this study, a solar still with a single basin is compared against a concentrator with evacuated tubes and a stepped basin solar still to see which one produces the most output with the least amount of energy. The four cases are analyzed, and it is discovered that the productivity of case 1: a solar still with a single slope with constant flow rate is 1.05kg/m2 and the maximum temperature obtained during this case is 49.0? at 3:00 PM. The productivity for case 2: single slope solar with secondary stepped basin is 1.32kg/m2 while the maximum temperature is about 61.8? at 3:00 PM. The productivity of case 3: a solar still with a single slope linked with compound parabolic concentrator is 1.47kg/m2 with maximum temperature of 62.4? at around 3:00 PM. The output of Case 4: a solar still with a single slope with secondary stepped basin and compound parabolic concentrator is 1.72kg/m2 with maximum temperature of 70.2? obtained at 3:00 PM. The efficiency of a solar still with a single slope and a secondary stepped basin with a compound parabolic concentrator is 63.8 % higher than the reference case. Journal of Thermal Engineering Journal of Thermal Engineering 2023-10-16T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6832 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6832 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6832

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6842 2023-10-16T21:00:00Z 1

Investigation of Thermo-rheological properties of Fe3O4/Ethylene Glycol Nanofluid in a Square Cavity Mohammad Kamran, Adnan Qayoum Magnetic Nanofluid, Heat Transfer Enhancement, Thermal conductivity, Rheology, Square cavity, Natural convection, Numerical Simulation Many fluids used in heat transfer and transport phenomena restrict the effectiveness of heat exchange equipment on account of their low thermal conductivity. Using nanofluids, the effectiveness of heat exchange equipment is enhanced by many folds. The use of magnetic nanofluids for heat transfer generates a prospect of regulating flow and controlling the thermal and transport properties particularly the thermal conductivity and viscosity using an externally applied magnetic field. The present study involves synthesis of oleic acid-coated magnetic nanofluids at varying concentrations of 0 to 0.643% by volume, measurement of thermal conductivity, rheological properties and corresponding numerical simulation of Nanofluid in a heated square cavity. The thermal conductivity measurement have been carried out by transient hot-wire method using KD2-pro at varying concentrations of solid phase. The results show a significant increase in thermal conductivity with increase in particle concentration. Rheological measurements show variation in viscosity with shear rate, temperature and concentration. Moreover, it has been found that at low particle loading magnetic nanofluids exhibited Newtonian behavior unlike non-Newtonian behavior at increased concentration. Numerical simulation of the magnetic nanofluid in the heated square cavity demonstrates the immense potential of augmentation of heat transfer coefficient using such fluids. Journal of Thermal Engineering Journal of Thermal Engineering 2023-10-16T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6842 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6842 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6842

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6836 2023-10-16T21:00:00Z 1

Experimental Investigation of Double-Glazed Double-Pass Solar Air-Heater with Multi-V Ribs having Trapezoidal Roughness Geometry Swati Mor, Niraj Kumar, Basant Sikarwar, Gulshan Sachdeva Double-pass solar air-heater, Absorber plate, multi-V ribs, Thermal efficiency, Thermohydraulic performance factor In this study, roughness in the form of multi-V ribs having trapezoidal slots was crafted over the surface of absorber plate for enhancing the heat transfer rate in a solar air heater. An experimental setup was designed and fabricated for demonstrating the performance of this plate with respect to smooth absorber plate. The setup has a double glazed-double pass air flow arrangement. The experiments were conducted under Indian climatic conditions (Latitude = 28.53°N and Longitude = 77.39°E) in September and October 2021 at various rate of air flow through the duct. The results of the roughened absorber plate were compared with the smooth absorber plate. It shows that the multi-V ribs with trapezoidal slots have higher efficacy as compared to smooth absorber plate in the order of 10.42% at an air flow rate of 0.078 kg/s. In addition, the present data of proposed roughness were also compared with data of various roughness available in the literature. It was found that the maximum thermo-hydraulic performance parameter of the proposed roughness texture is higher than the other shapes of roughness texture. It is found that the combination of double-glass cover and double-pass arrangement with the proposed roughness geometry increases the efficiency of the solar air heater at least one order of the present solar air heating system. Journal of Thermal Engineering Journal of Thermal Engineering 2023-10-16T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6836 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6836 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6836

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6762 2023-05-24T21:00:00Z 1

Thermodynamic Analysis of the APCI SKIKDA Liquefaction Process Derbal Chaima, Haouam Abdallah APCI, LNG, Mixed Refrigerant, COP, Exergy Efficiency, Optimization, Genetic Algorithm In this paper, the mixed refrigeration cycle of the Skikda LNG APCI (Air Products and Chemicals Inc.) process in Algeria was studied thermodynamically in order to determine the optimal operating conditions. The energy and exergy balance equations for each process component were established. The distribution of the exergy destruction of the basic cycle equipment revealed that the compressors had the highest exergy destruction rate. The effects of operating conditions on the cycle performance coefficient (COP) and exergy efficiency of the APCI process were evaluated; mainly the inlet temperature of the compressors, the natural gas (NG) temperature after cooling in the main cryogenic heat exchanger (MCHE) and the inlet temperature of the mixed refrigerant expansion valve (MR). The results of the numerical simulation, validated using Aspen HYSYS software, indicate that the exergy efficiency and COP of the basic cycle are 59.99% and 2.66 respectively. These results can be improved by reducing the temperature at the compressor inlet, as well as the NG temperature after cooling in the MCHE and the MR expander inlet. Finally, the results of the optimization performed using the genetic algorithm (GA) are in agreement with those of the literature and show signs of improvement in the efficiency and COP of the APCI process by 3.64% and 1.48% respectively compared to the basic cycle. Journal of Thermal Engineering Journal of Thermal Engineering 2023-05-24T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6762 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6762 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6762

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7170 2024-11-18T21:00:00Z 1

Effect of Porosity on Thermal Behaviour of Sintered P/M Iron Material T. K. KANDAVEL, J. VIGNESH, D. VIJAY Density; Iron; MATLAB; Powder Metallurgy; Sintering; Thermal Conductivity. Iron components processed through Powder Metallurgy (P/M) route have complex material haracteristics due to the presence of pores. The present research work attempts to investigate the influence of porosity on the thermal conductivity of the sintered iron specimens. Green iron compacts of various densities were obtained by applying various compaction pressures. An electric muffle furnace with a capacity of 3.5kW was used for sintering the green compacts. The specimens of the same density were utilized to conduct thermal conductivity experiments. The Design Expert (DE) software has been used to design and conduct the thermal conductivity experiment on specimens. The variations of heat flow through the preforms were studied using ANSYS. Using MATLAB, a similar kind of study was also carried out, and the results were compared. The test results reveal that the thermal conductivity of the P/M iron increases with a decrease in porosity or increase in density. Journal of Thermal Engineering Journal of Thermal Engineering 2024-11-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7170 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7170 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7170

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6840 2023-10-16T21:00:00Z 1

Effect of Heat flux and Mass flux on the Heat Transfer Characteristics of Supercritical Carbon Dioxide for a Vertically Downward Flow Using Computational Fluid Dynamics and Artificial Neural Networks Rajendra Prasad K.S., Vijay Krishna, Sachin Bharadwaj sCO2; Vertical Flow; Turbulence Model; CFD; ANN Drastic variation in the thermodynamic properties of supercritical fluids near the pseudo critical point hinders the use of commercial computational fluid dynamics (CFD) software. However, with the increase in computational abilities, along with the use of Artificial Neural Networks (ANN), turbulence heat transfer characteristics of supercritical fluids can be very accurately predicted. In the present work, Heat transfer characteristics for a vertically downward flow in a pipe of supercritical carbon dioxide is studied for a wide range of heat flux and mass flux values. Firstly, to validate the used turbulent model, six different turbulent models available in the commercial CFD software - Ansys Fluent is investigated against the experimental results. The k-w Standard model with enhanced wall treatment is found to be the best-suited turbulence model. When experimental results were validated in CFD, an average error of 1% in the bulk fluid temperature and 2% in the wall temperature were recorded. Further, K- ? Std Turbulence Model is used in CFD for parametric analysis to generate the data for ANN studies. Mass flux range of 238 to 1038 kg/m2s, heat flux range of 26 kW/m2 to 250 kW/m2 is used to generate 81,432 data samples. These samples were fed into the ANN program to develop an equation that can predict the heat transfer coefficient. It was found that ANN can predict the heat transfer coefficient for the considered range of values with the absolute average relative deviation of 2.183 %. Journal of Thermal Engineering Journal of Thermal Engineering 2023-10-16T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6840 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6840 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6840

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6828 2023-10-16T21:00:00Z 1

An Experimental Investigation of the Performance Characteristics of Heat Pipe using Aqueous Hybrid Nanofluids Harshit Pandey, Sanjay Agrawal, Naveen Gupta Multiphase flow; Heat transfer; Nanofluid preparation; Graphene oxide; Copper oxide; Thermal resistance An experimental investigation was carried out on the steady-state heat transfer characteristics of a mesh wick heat pipe in the horizontal position at a heat load range of 50W to 200W. The heat pipe was tested with DI water, CuO mono-nanofluids, GO mono-nanofluid, and CuO+GO hybrid nanofluids as working fluids respectively. All the nano-suspensions were prepared surfactant-free, following the two-step method of nanofluid preparation. The heat pipe performance characteristics and its operational limit were found to be influenced by the type of working fluid incorporated. Maximum decrement of about 26.71 ºC in the heat pipe adiabatic vapor temperature and maximum increment of about 26.10% in the heat pipe thermal efficiency was attained using 1.0% (CuO 25%–GO 75%) hybrid nanofluid out of all the working fluids. The current study discusses the possible mechanisms responsible for the performance augmentation achieved using hybrid nanofluids in the heat pipe and projects prospective future scope. Journal of Thermal Engineering Journal of Thermal Engineering 2023-10-16T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6828 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6828 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6828

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6873 2023-12-08T21:00:00Z 1

Experimental Study on a Novel Waterless Solar Collector Asaad Sayer, Wed Al-Graiti, Samia Mezhr Merdas, Hameed B. Maahood, Alasdair N. Campbell Solar Energy, Solar collectors, Salinity gradient solar ponds This study is an endeavour to introduce a novel approach to enhance the performance of solar collectors. The sun emits sufficient power of solar radiation to meet the demand of energy. Harvesting the renewable solar energy needs advanced technologies and requirements. Solar ponds including salinity gradient solar ponds (SGSPs) are common solar collectors. These ponds are one of the solar energy applications used for many industrial and domestic purposes. However, challenges of the conventional SGSPs such as evaporation, salt diffusion, temperature discrepancy, and layer mixing profoundly and significantly affected their expansion globally. A novel experimental solar collector configuration to overcome the challenges of the conventional solar ponds (solar collectors) is investigated, there is no water body and no salinity gradient to build; it is entirely a collector with no water body. The experimental unit was constructed in an arid area. It is basically a cylindrical tank with a total depth of 1.4 m with three zones or layers to store heat namely, paraffin wax layer (10 cm thickness). The paraffin layer was covered with a layer of coal with a thickness of 30 cm. On the top of coal layer, an air gap with a thickness of 80 cm was left. A clear plastic cover with a thickness of 0.2 cm was utilized to cover the constructed layers and making the air gap. The experimental unit was monitored, and temperature measurements were collected for the period of 17/7/2021- 30/9/2021. The results demonstrated that temperature of the paraffin wax layer reached more than 48 °C in a short period and with a small day and night discrepancy (1 °C). Temperature of the paraffin layer remained constant around 43 °C even in night-time during the period of the study. Furthermore, the results showed that temperatures of coal layer and air gap reached the maximum at the daytime of 53 °C and 71 °C respectively with a clear discrepancy between day and night. The results of the present study are encouraging for more investigations in this new direction of solar collectors. Journal of Thermal Engineering Journal of Thermal Engineering 2023-12-08T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6873 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6873 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6873

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6707 2023-02-19T21:00:00Z 1

Numerical Investigation on The Effect of Slit Thickness And Outlet Angle of The Bladeless Fan for Flow Optimization Using CFD Techniques Dineshkumar Ravi, Thundil Karuppa Raj Rajagopal Air multiplier; Coanda effect; Computational Fluid Dynamics; Bladeless fan; Aerofoil The effect of outlet thickness and outlet angle of the bladeless fan have been analysed numerically on the aerodynamic performance of the bladeless fan. Five different aerofoil profiles have been considered for the present work is Eppler479, Eppler169, Eppler473, S1046 and S1048. The bladeless fan arrangement has been achieved by converting the aerodynamic models listed above. The ANSYS ICEM CFD 16.0 have been used to discretize the enclosure and bladeless fan through finite volume approach. The mesh model is then imported into ANSYS CFX 16.0 pre-processor for applying the required boundary conditions. The governing equations namely continuity and momentum are used to solve the flow physics through and across the bladeless fan and SST k- turbulence model has been used to predict the turbulence in the bladeless fan. The effect of outlet thicknesses and outlet angles have been varied for all the five aerofoil configurations mentioned and the volumetric flow at inlet have been adjusted from 5 LPS to 80 LPS. Outlet thickness is varied from 0.8, 1.0, 1.3, 1.5 and 2 mm and the slit angle is varied from 20 degrees to 80 degrees in step of 10 degrees. The results predicted that Eppler 473 aerofoil profile showed better performance when the thickness of slit and outlet angle has been fixed constant as 1 mm and 70 degree respectively. Also, the maximum discharge flow ratio is recorded for an inlet volumetric flow rate of 80 LPS and it is found to be 34.37. The present numerical study substantiated that outlet thickness plays a dominant role on the bladeless fan’s aerodynamic performance compared to outlet angle and aerodynamic shape considered in this numerical analysis. The contours of velocity, streamline and pressure of the bladeless fan have been discussed. Journal of Thermal Engineering Journal of Thermal Engineering 2023-02-19T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6707 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6707 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6707

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6843 2023-10-16T21:00:00Z 3

Heat Transfer Enhancement and Application of Thermal Energy Storage Techniques on Solar Air Collectors: A review Kafel Azeez, Riyadh Ibraheem Ahmed, Zain Alabdeen Obaid, Itimad DJ Azzawi Concentrating collectors, Heat transfer, Phase change material, Photovoltaic thermal collector Solar air collectors have been in use with several industrial applications which lately led to the review and overview of several papers on this subject. The extraordinary outputs of solar collectors' energy conversion and storage have attracted growing interest in the field of energy science. The current review paper focuses on the advancement of solar thermal applications and includes an overview of storage devices for thermal energy and solar collectors. Solar collectors of several types, concentrating and non-concentrating, are presented and discussed in this paper. The Phase change material with melting temperatures above 300 §C, used in these plants as energy storage media, was reviewed. The objective of this paper is to deliver the essential knowledge for advance studies in the production of cost-effective thermal storage systems for high temperatures. Finally, a description of the presentation and possible solar power stations are also reviewed. Journal of Thermal Engineering Journal of Thermal Engineering 2023-10-16T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6843 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6843 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6843

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6845 2023-10-16T21:00:00Z 3

Fossil Energy Reduction for Heating and Cooling of Buildings using Shallow Geothermal Integrated Energy Systems – A Comprehensive Review Balaji Kumar Building heating, ground source heat pump, refrigerant, compressor, shallow geothermal energy Ground source heat pumps (GSHP) are a very efficient system for space heating and cooling, and it was established in 1904. GSHPs can minimize the environmental effect of buildings by using the ground as a renewable energy source. The ground will act as a heat sink or heat source. The research collection aims at finding the various possible opportunities for the effective integration of shallow geothermal energy (SGE) to decrease the fossil energy in the built environment and to reduce emission associated with it. The direct utilization of SGE using a ground source heat pump (GSHP) has been reviewed in detail for global north and global south countries, with a primary focus on heating application. The punctual information of results of various authors have been extensively summarized. This review discusses the GSHP installation status, SGE availability, GSHP system simulation, feasibilities, and performance. Worldwide more than one million GSHP systems have been installed, and the system is prevalent in Europe, the Americas, and Asia. Most of the systems are installed for heating-dominated buildings in the global north. This paper also contains the research details pertaining to the last two decades about refrigerants and compressors for the development of GSHP. Finally, the feasibility study and the performance of the GSHP unit for different climatic conditions are reviewed and it is found that the technique is more feasible for cold and dry climatic conditions. This paper highlights the recent research findings and a potential gap in the above components for further research and development. Journal of Thermal Engineering Journal of Thermal Engineering 2023-10-16T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6845 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6845 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6845

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6876 2023-12-08T21:00:00Z 1

Heat Transfer Enhancement of Electronic Devices by using Flexible Printed Circuit Boards Mustafa Emad, Sattar Aljabair, Ahmed Abdulnabi Imran flexible printed circuit board, Substrate board orientation, electronics system cooling, enhancement heat transfer In this paper, heat transfer in electronic equipment was studied numerically and experimentally, by investing in the flexible printed circuit board and changing the board's orientation, which is the substrate of the electronic equipment from a vertical to a horizontal position. ANSYS Fluent software has been used to solve the continuity, momentum, and energy equations with the three-dimensional, unsteady, laminar and incompressible flow. In this study, the oscillatory motion equation was used as a boundary condition to represent the motion of the flexible board. In the experimental aspect of this study, a simulation of an ASUS motherboard (X399-A) with dimensions (30 x 25) cm and a Core i9 CPU with a fully working power of 130W was used to study the enhancement of heat transfer in the electronic devices by test rig specially made for this study. The results show that the flexible board's enhancement in the heat transfer was (7%) vertically and (7.6%) horizontally compared with the rigid board for the same working conditions. The horizontal position is better than the vertical of the two types of rigid and flexible board, with improved heat transfer rates of (2.7%) and (3%); correlation Equations of the Nusselt number from experimental results are presented. Journal of Thermal Engineering Journal of Thermal Engineering 2023-12-08T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6876 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6876 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6876

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6706 2023-02-19T21:00:00Z 1

Improving the Energy Efficiency of a Refrigerated Warehouse Through the Use of Palm Tree Pruning Waste as Thermal Insulator Hicham Lakrafli, Soufiane Tahiri, Mohamed Sennoune, Abdelmajid El Bouardi Palm tree pruning waste, Thermal insulation, Refrigerated warehouse, Energy efficiency, Dynamic thermal simulation This work investigates the effect of palm tree pruning waste (PTPW) on thermal insulation and energy consumption of a refrigerated warehouse (RW). The thermal properties of PTPW depend strongly on its compactness, i.e. how much it weighs divided by how much space it takes up. The thermal conductivity of PTPW measured using the box method is about 0.069 W/m °C for a mass/occupied volume ratio of 0.064 g/cm3. It is comparable or lower than that of other natural materials discussed in the literature. The dynamic thermal simulation tool “TRNSYS” was applied to predict the thermal behavior of RW. The thickness of PTPW material was considered as variant to choose the better condition allowing achieving results very close to those of polyurethane. Obtained results highlight that 30 cm thick PTPW can reduce temperature by 1 to 2°C compared to 10 cm thick polyurethane. An improvement in the energy efficiency of the refrigerated warehouse was also highlighted. So, because of its performance, low cost, and eco-friendly nature, PTPW can compete with conventional insulating materials. Journal of Thermal Engineering Journal of Thermal Engineering 2023-02-19T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6706 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6706 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6706

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6751 2023-05-18T21:00:00Z 1

Simultaneous Estimation of Reference Temperature and Heat Transfer Coefficient in Transient Film Cooling Problems Vashista Ademane, Ravikiran Kadoli, Vijaykumar Hindasageri Transient film cooling, effectiveness, heat transfer coefficient, inverse heat conduction problem, Levenberg-Marquardt algorithm This paper aims to simultaneously estimate the reference temperature and heat transfer coefficient in film cooling situations from transient temperature measurements. The existing steady-state technique is a tedious process and employs distinct boundary conditions to evaluate each parameters of the film cooling. Applying different boundary conditions may lead to errors in the estimated parameters due to differences in aerodynamic conditions. On the other hand, a transient technique can estimate both parameters in a single test by utilizing short-duration transient temperature data. Hence, the present study uses a novel approach for solving transient film cooling problems based on the inverse heat conduction approach, which can simultaneously estimate heat transfer coefficient and reference temperature. The present method employs an optimization technique known as the Levenberg-Marquardt Algorithm. The objective function for the inverse algorithm is constructed using the analytical solution of a transient one-dimensional semi-infinite body. The transient surface temperature data required for the present analysis is obtained through a numerical simulation of film cooling arrangement over a flat surface. Laterally averaged effectiveness and heat transfer coefficient for blowing ratios of 0.5, 0.8, and 1.0 are analyzed using the present technique and compared against the steady-state simulation results to demonstrate the methodology. An average deviation of around 7% for the estimated effectiveness and 4% for the heat transfer coefficient values are observed between the present IHCP method and the steady state simulation results. The deviation in heat transfer coefficient predominately occurred near the film hole exit of x/d<5, which might have occurred due to the conjugate solution employed in the present work. Journal of Thermal Engineering Journal of Thermal Engineering 2023-05-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6751 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6751 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6751

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6760 2023-05-24T21:00:00Z 1

Predicting Heat Transfer Performance of Fe3O4-Cu/Water Hybrid Nanofluid Under Constant Magnetic Field Using ANN Edip Taşkesen, Mahmut Dirik, Mutlu Tekir, Hayati Kadir Pazarlıoğlu Artificial Neural Network (ANN), constant magnetic field, laminar flow, hybrid nanofluid. In this study, the experimental results using mono (Fe3O4/water and Cu/water) and hybrid (Fe3O4-Cu/water) type nanofluid with nanoparticle volume concentrations of (0???0.02) under laminar flow conditions (994?Re?2337) were compared with the results obtained by ANN. While the Reynolds number (Re), hydraulic diameter (Dh), thermal conductivity (k) of working fluid, and volume concentration of the nanoparticles (?) were selected as input layers, the Nusselt number (Nu) were considered as output layers. The %75 of the findings obtained from experiments were used to train Artificial Neural Network (ANN). The estimated data by ANN is in perfect agreement with the experimental data. The success of ANN was determined by comparing it with SVM, Dec Tree, and their variations. Mean square error (MSE), root mean square error (RMSE), R-sq (R2), and mean absolute error (MEA) were considered in evaluating the results obtained. According to findings, MAE 0.00088274, MSE 1.4106e-06, RMSE 0.0011877 and R2 1.00 were measured. These findings show that the use of ANN is a feasible way to predict the convective heat transfer performance of hybrid nanofluid under a magnetic field (MF). Journal of Thermal Engineering Journal of Thermal Engineering 2023-05-24T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6760 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6760 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6760

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6837 2023-10-16T21:00:00Z 1

Heat Transfer Model for Dropwise Condensation on Hydrophobic and Superhydrophobic Interfaces R. Yuvaraj, D. Senthilkumar dropwise condensation, biot number, heat transfer, hydrophobic surface, superhydrophobic surface, interface temperature Heat transfer models for condensation on hydrophobic and superhydrophobic interfaces are broadly available based on thermal resistance correlations. In the previous studies, very few models are presented based on the scaling factor or Nusselt number and no model is available which directly correlates Biot number. In this study, a heat transfer model is developed for dropwise condensation which correlates with the Biot number to predict the heat transfer, temperature variation at the interfaces, solid-liquid, and liquid-vapor, and the growth rate of droplet condensate on the hydrophobic, and superhydrophobic interfaces by using Archimedes' hat-box theorem. The present model is validated with analytical and experimental results of similar working parameters made excellent agreements. The analytical model for dropwise condensation produces inaccurate results due to discrepancies and discontinuities due to multiple correlations in the modeling. The present model is modified using experimental data and the modified model is used for analyzing heat transfer by varying Biot numbers from 0.0001 to 1000. Simulation of present model results, constant heat transfer at Bi = 4, negligible coating resistance when Bi>0.1, negligible curvature effect when Bi>0.04, negligible droplet resistance when Bi<0.02, the maximum liquid-vapor interface temperature at Bi?10, maximum solid-liquid interface temperature at Bi?0.5, are presented. Journal of Thermal Engineering Journal of Thermal Engineering 2023-10-16T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6837 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6837 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6837

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6882 2023-12-08T21:00:00Z 1

Geometric Modification and Placement of High Flux IC Chips on Substrates of Different Materials for Enhanced Heat Transfer Shankar Durgam, Ajinkya Bhosale, Vivek Bhosale Heat transfer enhancement, Computational heat transfer, IC chips, High heat flux, Horizontal channel flow, Electronic cooling, Forced convection This article presents the significance of using different sizes and positions of IC (Integrated Circuit) chips that are mounted on substrates of different materials. The ICs are cooled by forced convection in a horizontal wind tunnel. COMSOL Multiphysics 5.4 solve the IC chip cooling problem by selecting a conjugate heat transfer module with laminar flow. FR4, bakelite, single and multi-layer copper clad boards are used as substrate materials. Numerical simulations are performed for FR4, bakelite with a constant heat flux of 5000 W/m2, at 2.5 m/s air velocity. In contrast, single and multi-layer copper clad boards are studied for 10000 W/m2 with 1.5 m/s air velocity. The prime objective of this research is to use adequate size and placement of chips generating high heat fluxes for enhanced heat transfer. Results showed that larger chips placed at bottom rows and sequentially decreasing sizes in the subsequent rows for the same overall input for high substrate thermal conductivity give more heat dissipation. Among all configurations A0 – F considered in the study, case E provides minimum temperature using single and multi-layer copper clad boards. In addition to modification of chip sizes, geometric spacing of X1/X2 = 1.8 results in lower maximum temperature. Journal of Thermal Engineering Journal of Thermal Engineering 2023-12-08T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6882 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6882 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6882

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6844 2023-10-16T21:00:00Z 3

Surface Modification Techniques for Cooling by Impinging Jets - A Review Supern Swapnil, Ajoy Debbarma Heat transfer enhancement, jet impingement, heat transfer coefficient, surface modification, roughness, surface coating The following paper is a review of the recent published literature on these three techniques for heat transfer augmentation. With global trend of the miniaturization of today’s systems and the rapid development due to innovative equipments on a rise, the associated heat generation rates are increasing. As a result, the need to develop techniques to achieve faster and efficient cooling are also increasing., Heat transfer by impinging jets poses a good and economical solution to this problem since, among all the processes used for heat removal, heat transfer by impinging jets have the highest rates associated with them. Although, the heat generation rates have increased over period of time, jet impingement is in the industrial use for quite a long time and is still relevant for the field. This is because overtime the impingement heat transfer effectiveness has been improved by various innovations. Innovations such as surface modifications, use of flow control techniques etc. The modifications reported had seen actual use of them in industries, thus bringing more interest of the researchers towards them. The need to achieve higher heat transfer rates and efficient working of the systems is still seeing numerous interactions pertaining to surface modifications integrated with jet impingement reported on them. Primarily, the use of various types of extended surfaces such as pin fins, plate fins, ribs etc., inducing the roughness elements on the surface by employing dimples, protrusions etc., applying specific surface coatings found a plethora of research work reported on them. For any work, it is necessary to study these modifications and their interactions in details. This paper, thus presents the above stated three surface modifications in detail. Journal of Thermal Engineering Journal of Thermal Engineering 2023-10-16T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6844 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6844 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6844

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6841 2023-10-16T21:00:00Z 1

Simulation of Vapour Compression Air Conditioning System using Al2O3 Based Nanofluid Refrigerant Mohammed Dilawar, Adnan Qayoum Nanorefrigerants; air conditioning system; energy saving; net refrigeration effect (NRE); vapour compression cycle The energy crisis, Greenhouse Gas (GHG) emissions, and Chlorofluorocarbon (CFC) emissions are major environmental issues at present. It is critical to achieve and reduce emissions and energy consumption through the use of environmentally friendly refrigerants. Utilizing an environmentally friendly refrigerant such as HFC-32 may offer a viable solution to the ozone depletion potential (ODP) and global warming issues. This study examines the effects of aluminium oxide (Al2O3) nanoparticles at volume concentrations of 0.06, 0.08, 0.1, 0.12, and 0.14% in pure refrigerants such as HFC-32 and R-410a used in air-conditioning systems based on the vapour compression refrigeration cycle. The thermophysical properties of pure and nanorefrigerants have been determined using REFPROP (NIST properties of fluid Reference) and a theoretical formulation model using MATLAB software. The important outcomes of HFC-32 nanorefrigerant show the maximum performance with 0.14% alumina nano additives which results in a 46.14% increase in the coefficient of performance (COP) and massive power savings upto 31.59%. Thermal conductivity exhibited an increase with an increment in nanoparticle concentration. Maximum thermal conductivity of 0.172 W/m-K is recorded in the case of HFC-32/Al2O3 nanorefrigerant with 0.14% volume concentration. The net refrigeration effect of pure refrigerants (R410a and HFC-32) is 77% and 79% and on addition of nanorefrigerants to the pure the net refrigeration effect increases to 81.2% and 83.5% for R410a and HFC-32 respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2023-10-16T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6841 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6841 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6841

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6874 2023-12-08T21:00:00Z 1

Analysis of Solar Water Desalination using Hybrid Nanofluids: An Experimental Study Ajit, Harshit Pandey, Naveen Kumar Gupta Water purification. Hybrid nanofluid, Solar heater, Pyramid solar still, Fresh water The performance characteristics of a novel solar water desalination system has been investigated experimentally. The desalination unit consisted of a square basin-pyramid solar still coupled with a solar heater. Different DI water based mono and hybrid nanofluids were prepared using CuO and GO nanoparticles following the two-step method. DI water when employed as the heat transfer fluid in the system, improved the distillate water yield by about 28.80% relative to the conventional solar still. Out of all the considered CuO mono-nanofluids, the 1.0 wt.% concentration resulted in the maximum increment of about 78.80% in the distillate water yield followed by 1.5 wt.% (62.05%) and 0.5 wt.% (53.30%) respectively. Utilizing the CuO+GO hybrid nanofluid, resulted in maximum increment of about 127.46% at 25:75 nanoparticle proportion followed by, 50:50 (101.33%) and 75:25 (89.30%) respectively, while employing the 1.0 wt.% GO mono-nanofluid, resulted in an increment of about 54.93% in the distillate water yield. The pumping power of the prepared nanofluids was found to be the function of their concentration. Hence, the performance index was evaluated for all the tested heat transfer fluids followed by an economic analysis of all the considered cases. The purity of the produced distilled water was also assessed by comparing with the Bureau of Indian Standards. Finally, the study proposed the best suitable heat transfer fluid for the investigated system and suggested the possible futuristic research objectives. Journal of Thermal Engineering Journal of Thermal Engineering 2023-12-08T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6874 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6874 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6874

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6761 2023-05-24T21:00:00Z 1

An investigation of the MHD Cu-Al2O3/H2O Hybrid-nanofluid in a Porous Medium Across a Vertically Stretching Cylinder Incorporating Thermal Stratification Impact Ashish Paul, Jintu Mani Nath, Tusar Kanti Das Heat transfer, stretching vertical cylinder, MHD, heat source/sink, boundary layer, Bvp4c. The thermal aspects of Cu-Al_2 O_3/water hybrid nanofluid in a porous medium across a vertically stretched cylinder with the incorporation of heat sink/source impact are investigated in this numerical study. A magnetic field along the transverse direction of the stretching cylinder and the thermal buoyancy effect is considered in the flow problem. A pertinent similarity variable has been employed to simplify the boundary layer equations which govern the flow and convert the coupled nonlinear partial differential equations into a set of non-linear ordinary differential equations. The numerical results are computed using the 3-stage Lobatto IIIa technique, Bvp4c. The impacts of non-dimensional parameters, including Prandtl number, heat source/sink parameter, magnetic parameter, porosity parameter, curvature parameter, thermal stratification parameter, and thermal buoyancy parameter on the velocity curve, thermal curve, skin-friction coefficient, and Nusselt number, are illustrated graphically and numerically portrayed in tables. The important results demonstrate that hybrid nanofluids are more thermally conductive than nanofluids. Therefore, the hybrid nanofluid has a considerable impact on improving thermal developments. It has been found that the absolute skin friction of the hybrid nanofluid is up to 31% higher compared to the nanofluid. The heat transport rate of the hybrid nanofluid is 7.5% enhanced in comparison to the nanofluid. The influence of heat stratification of the hybrid nanofluid flow is appreciably significant. Journal of Thermal Engineering Journal of Thermal Engineering 2023-05-24T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6761 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6761 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6761

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6872 2023-12-08T21:00:00Z 1

Experimental Investigation of Impact of Fire Size on Heat Transfer and Flame Behavior of iIitial Stage Unsteady Pool Fires inside a Cubical Enclosure. Akanksha Mathur, Anjan Ray, S. R. Kale unsteady growing pool fire, heat flux, flame behavior, mass loss rate, enclosure, ceiling duct. The ventilation equipment for enclosed spaces or office rooms is specified according National Building Code of India published by the Bureau of Indian Standards. Natural ventilation periodically together with mechanical ventilation is recommended to remove pollutants. The need to study fire and smoke behavior inside a completely closed room with air intake and exhaust vents becomes important in case of low or no mechanical ventilation service. An experimental study on unsteady heptane pool fires of different sizes in their initial stages was conducted in a cubical fire test chamber of 27 m3 inside dimensions. The compartment was naturally ventilated with a typical configuration of a vertical intake on a side wall and an exhaust vent at the ceiling leading into a duct. Three circular pans of diameters 0.34, 0.47 and 0.61 m were employed to generate the fire with n-heptane as fuel on a bed of water. Temperatures, wall heat fluxes and mass loss rate were measured. The flame was visualized using a video camera through a tempered view glass. The total heat transfer to the ceiling and wall increased with the increase in fire size as the flames became taller in the initial stages (3-4 minutes) with significant increase in case of 500 kW fire. The smoke layer was observed at about mid height (1.5 m) above floor. The leaning behavior of flames was seen due to naturally induced air inflow. The wall heat flux of about 50 kW/m2 obtained indicate hazardous environment for further flame spread. A fourfold increase in mass loss rate was observed with just 2.5 times increase in fire size inside the ceiling vented compartment. Journal of Thermal Engineering Journal of Thermal Engineering 2023-12-08T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6872 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6872 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6872

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6766 2023-05-24T21:00:00Z 1

Analysis of the Slip flow in the Hydrodynamic Entrance Region of a 2D Microchannel Ayhan Nazmi İlikan, Ramazan Aydın Microchannel, Lattice-Boltzmann method, Slip flow, Entrance Region, Hydrodynamic development length Two-dimensional developing flow in the entrance of a microchannel has been studied numerically. Due to its nature, a microchannel can be used in tight space applications and the length of channel can get very small values. Furthermore if the hydrodynamic development length of flow in microchannel has comparably the same value with the channel length, the channel entrance parameters play critical role on the flow performance of a microscale channel. Lattice Boltzmann Method (LBM) was considered for studying and simulating the developing slip flows through a rectangular microchannel. A unique computational code for this study was developed by using LBM. The slip velocity boundary condition along with Knudsen number values in the slip flow regime was used for this model. The bounce-back boundary condition was considered at the top and bottom walls of the microchannel. The effects of the Reynolds numbers (1-100) and Knudsen numbers (0.001, 0.01, 0.1) on the hydrodynamic entrance length has been examined. The numerical results have been compared with the previous studies in the literature and the similarities have been found satisfactory. The entrance length is found to be increasing with the increase of Reynolds and Knudsen numbers. A correlation for hydrodynamic development length as a function of Knudsen and Reynolds numbers was obtained by using the data extracted from LBM simulations performed in this study Journal of Thermal Engineering Journal of Thermal Engineering 2023-05-24T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6766 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6766 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6766

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6805 2023-07-31T21:00:00Z 1

Thermal Analysis of PCM-based Hybrid Micro-channel Heat sinks: A Numerical Study NAGA RAMESH KORASIKHA, KARTHIKEYA SHARMA THOPUDURTHI Hybrid microchannel heat sink; Electronic cooling; Phase change material (PCM); Thermal management; Liquid Fraction; Thermal resistance; Thermal performance Heat sinks play a vital part in the heat dissipation in electronic devices and energy systems. Heat generation in the present-time electronic equipment is very high because of the high power density and the miniaturization of the components. An efficient and high-capacity thermal management system is needed for the efficient performance of the latest electronic equipment. Micro-channel heat sinks (MCHS) are an effective solution for the cooling of electronic devices in view of large heat dissipation and compactness. Improvement of performance of the MCHS is the prime focus of most of the researchers. In the present work, the improvement of heat transfer in MCHS with the introduction of phase change material (PCM) was investigated numerically using ANSYS-FLUENT. The finding of the computational model applied for the present numerical work was compared with existing literature and noticed a good agreement with both experimental and numerical works. The performance of three different PCM-based hybrid MCHS models were investigated and compared with the model of heat sink without PCM using the parameters, thermal resistance, temperature uniformity, liquid fraction and Nusselt number. A good augmentation in the performance of PCM based MCHS with a maximum 7.3% decrement in thermal resistance and 15.26% increase in temperature uniformity was observed. 3-dimensional variation of the liquid fraction with Reynolds number and heat flux is also presented. Journal of Thermal Engineering Journal of Thermal Engineering 2023-07-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6805 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6805 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6805

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6879 2023-12-08T21:00:00Z 1

Mathematical Modelling of Evaporation Rate and Heating of Biodiesel Blends of Single-Component Droplets Madan Basnet, D. Senthilkumar, R. Yuvaraj diesel fuel droplet. Single component droplets. Evaporation rate. Heat/mass transfer Biodiesel serves as promising fuel and an optimal alternative for mitigating fuel scarcity and emission control in compression ignition engines. Several kinds of research have concluded that engine performance and its emission characteristics heavily depend on parameters like fuel droplet spray formation, atomization, evaporation, and combustion. These parameters depend on the thermophysical properties of biodiesel fuel. In this study, two biodiesel fuel samples Madhuca Indica and Radish oil, are used for creating the mathematical model for the evaporation rate. The thermophysical properties like normal boiling, critical properties, vapor pressure, latent heat of vaporization, liquid thermal conductivity, and gas diffusion coefficients are determined using standard correlation. An accurate mathematical model for estimation of evaporation rate and combustion of single component biodiesel droplet is framed and validated with single droplet setup experiment results for Jatropha Methyl Ester (JME), Karanjan Methyl Ester (KME), Mahua Methyl Ester (MME), Neem Methyl Ester (NME), Palm Methyl Ester (PME) oil and this model is further extrapolated to predict the evaporation and combustion behavior of two unexperimented oil, Madhuca, and Radish. It is found that Madhuca oil has the higher evaporation constant value of 0.1466mm2/s and, thus lowest lifetime among the biodiesel fuel studied. This value is attributed to lower molecular weight and higher molecular diffusivity. On the other hand, a reverse trend is observed in Radish with lower evaporation constant and higher lifetime. This study is a comprehensive methodology for estimating the behavior of biodiesel based on their composition and chemical structure and as a firm framework for combustion modeling in enhancing engine performance. Journal of Thermal Engineering Journal of Thermal Engineering 2023-12-08T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6879 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6879 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6879

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6684 2022-12-08T21:00:00Z 1

Numerical Simulation of Non-linear Film Variation and Heat Transfer Characteristics in Falling Film Evaporation Around in-line Horizontal Tubes Awdhesh Kumar Poddar, Nirmal Kant Singh Falling film; Horizontal tube; Film thickness; Heat transfer Numerical simulations of falling film evaporation around a horizontal tube are performed in this paper. Heat transfer phenomena occurring around the horizontal tube in falling film evaporation are highly unpredictable due to uncertainties in determination of film thickness around the tube, local dry out condition, geometrical configuration, tube spacing etc. Film thickness around the circumference of horizontal tube is investigated here and validated with Nusselt correlations and experiments carried out by researchers. The results are in good agreement with advance experimental investigations performed by various researchers. Influence of intertube spacing, film Reynolds number and variation of diameter on the formation of film thickness are studied and it is found that the film thickness is minimum around 100o-120o circumferential position, whereas Nusselt correlation predicted the minimum value at 90o circumferential position. A volume of fluid (VOF) technique is used for simulation. Wall shear stress and heat transfer are also studied around the horizontal cylinder. Film evaporation around the horizontal tube is simulated with single tube. It is seen that near the impingement zone, fluctuation of wall shear stress and heat transfer are very high showing abnormal behaviour in this zone. Journal of Thermal Engineering Journal of Thermal Engineering 2022-12-08T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6684 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6684 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6684

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7114 2024-09-10T21:00:00Z 1

The Effect of Operating Conditions and Climate Change on the Performance of the Photopholtaic Trombe Wall: An Empirical Estimate Abdullah A. ABDULLAH, Faris S. ATTULLA, Omer K. AHMED, Sameer ALGBURI, Raid W. DAOUD PV/Trombe wall; Performance; Dusty weather; Effect Photovoltaic Trombe Wall is considered a sustainable technology due to its importance and impact on interior spaces through the utilization of solar energy to heat the building and thus provide thermic comfort without the need to utilize cooling devices to lessen the power utilization. In addition to providing the building with electric power. Two experimental models were built to study the impact of climate changes and operating conditions on the PV/Trombe wall, one with DC fans and one without DC fans. A comparison was made between the two models. Operating conditions for dusty and non-dusty days have been tested to show their impact on system efficiency. In the case of the model using DC fans on a dust-free day, the electrical and thermic efficiency of the model reached 10.2% and 17.6%, respectively. In the case of the model without DC fans and on a dust-free day, the electrical and thermic efficiency of the model reached 8.4% and 40.1%, respectively. While the electrical and thermic efficiency of the two models on the dusty days was less than that, the model containing fans' electrical and thermic efficiency values were 6.6% and 11.9%, respectively. While the model without fans, the electrical and thermic efficiency values were 3.5% and 34.1%, respectively. This indicates that dusty days affect the electrical and thermic efficiency of the experimental system. Journal of Thermal Engineering Journal of Thermal Engineering 2024-09-10T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7114 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7114 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7114

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6880 2023-12-08T21:00:00Z 1

Numerical Analysis on Heat Transfer, Flow Structure and Exergy Loss of Combined Truncated and Circular Ribs in a Square Duct S. Mohamed Illyas , Kumaresan Vellaisamy, A. Muthumanokar Computational Fluid Dynamics; Heat transfer; Ribbed cooling; Exergy loss; Nusselt number; Friction factor The heat transfer, friction and exergy loss of a square duct with combined circular and truncated rectangular ribs are analyzed using computational fluid dynamics. The study is focused on the effect of rib arrangements on the flow and heat transfer performance. The analysis is carried out with six truncated rib angles varying between 15° and 90° and Re range of 12000 – 43000. The heat transfer is maximum in the middle part of the duct for 30° and 45° rib angles along span wise direction. The position of wake region is highly dependent on separation point over the circular rib as wake moves away radially from the axis of the duct for rib angles of 60°, 75° and 90°. The turbulent flow structures in large scale originates from side wall have marked effect on the heat transfer for the rib angles of 60°, 75° and 90° and with nearly with equal intensity for 15°, 30° and 45° rib angles. The exergy loss associated with friction is higher for 60° rib angle. While the normalized friction factor obtained with Fanning’s equation varied between 1.8 and 4.2 and thermal hydraulic performance varied between 0.2 and 1.3 for the range of Re examined. Journal of Thermal Engineering Journal of Thermal Engineering 2023-12-08T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6880 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6880 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6880

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6922 2024-02-06T21:00:00Z 1

Thermal Performance of Cocoa Pod Cook Stove Anak Agung Putu Susastriawan, Yuli Purwanto, Bambang Wahyu Sidhartha, Noval Siolimbona cocoa pod; gasifier; stove; utilization; waste Indonesia produces approximately 550.000 ton/year of cocoa pod waste from chocolate industry. The waste has a good potential to be used as a biomass feedstock of a cook stove. However, thermal performance of the conventional cook stove is low when using a high moisture content feedstock, such as a cocoa pod waste. In addition, conventional cook stove generates high pollutant when high moisture content feedstock is used. In other to encounter the problems, the present work develops gasifier based cocoa pod cook stove and investigates thermal performance of the stove at various equivalence ratios. The data collection is performed by varying equivalence ratio at 0.4, 0.5, and 0.6. Temperature of the stove, flame image, flame temperature, and water temperature are collected and used to analyze the thermal performance (i.e. useful heat and thermal efficiency) of the stove. The results reveal that a waste of cocoa pod can be used as a feedstock of gasifier based cook stove. Maximum useful heat of 1337.6 kJ and maximum thermal efficiency of 3.5% are obtained at optimum equivalence ratio of 0.5. To improve performance of the stove, the cocoa pod waste should be sun dried to reduce its moisture content and the porous burner may be applied as a burner of the gasifier based cook stove in the future work. Journal of Thermal Engineering Journal of Thermal Engineering 2024-02-06T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6922 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6922 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6922

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7072 2024-07-31T21:00:00Z 3

Advances in Solar Absorption Cooling Systems: An Overview S. C. Kaushik, Abhishek Verma, S. K. Tyagi Absorption refrigeration, solar energy, low grade thermal energy, alternative refrigeration, solar collectors The need for refrigeration and air conditioning plays a crucial role in energy consumption. It is one of the important aspects which plays a crucial role in the food, human comfort, and energy problems of any country. Rapid consumption of energy and fossil fuels depletion results in the onset of energy crises thus, the research on absorption refrigeration systems has been widely promoted because the input energy supply for the systems can be a low-grade heat available from solar, geothermal, and/or waste heat from Industries. Solar refrigeration and air conditioning is an attractive and promising applications of solar energy because the cooling demand and the availability of solar energy are in phase and solar cooling can be made cost-effective. The present work includes the solar energy option and the potential for cooling with various range of parameters such as availability of solar radiation, environmental effects, types of collectors, types of solar cooling systems in general, and closed/open/continuous/multistage/hybrid and advanced absorption refrigeration cycles in particular. A literature survey has been carried out for possible improvements in the performance of solar absorption cooling systems and different solar collection and storage options. The most suitable solar cooling option viz. absorption refrigeration with the solar operation, historical developments, and commercial products. Advanced absorption cycles and novel cooling systems have also been presented and discussed. Journal of Thermal Engineering Journal of Thermal Engineering 2024-07-31T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7072 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7072 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7072

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6833 2023-10-16T21:00:00Z 1

Extended Experimental Investigation of a Double-Effect Active Solar Still with a Paraffin Wax, in Owerri, Nigeria Ernest Nwosu, Kelechi Nsofor, Godswill Nwaji, Chibuike Ononogbo, Ikechi Ofong, Nnamdi Ogueke, Emmanuel Anyanwu Solar distillation; Double effect; Thermal performance; Productivity. PCM In this work, an experiment-based study of a double-effect, single-slope active solar still (SSASS) is presented. The system comprises an upper and a lower basin incorporated with a paraffin wax acting as a phase change material (PCM). The use of phase change materials is very important due to their high storage density and the isothermal nature of the storage process. Paraffin wax was selected based on its attractive thermo-physical properties. The thermal behaviors of the system during the diurnal and nocturnal phases in both compartments were explored. Experimental results showed that the upper basin’s yield contributed more to the overall distillate production over a 24-hour cycle while that of the lower basin predominated the diurnal production. Though the PCM served as an energy source during the nocturnal phase, it did not translate to significant improvement in the yield of the lower basin. The heat retention ability of the lower glazing retarded the condensation of the humid air in the lower compartment during the off-sunshine period. Thus, the nocturnal yield of the system was largely driven by the improved temperature difference between the upper saline water and the upper glazing, as well as the stored thermal energy in the saline water mass before sunset. The system achieved a maximum yield of 2,450 ml/day and a yield rate of 131 ml/h. A maximum monthly average yield of 1,787 ml/day was realized in May and a minimum of 692 ml/day in July. Nocturnal distillate production accounted for an average of 55% of the total distillate recovered from the still daily. The system achieved an efficiency range of 12.20 - 32.21%. The cost of freshwater production from the system is estimated at 0.0508 $/L with a payback period of 267 days. Thus, this system is economically viable and suitable particularly, for low-income earners. Journal of Thermal Engineering Journal of Thermal Engineering 2023-10-16T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6833 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6833 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6833

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6973 2024-03-22T21:00:00Z 1

Principal Parameters of Thermoelectric Generator Module Design for Effective İndustrial Waste Heat Recovery Wan Ahmad Najmi Wan Mohamed, Nur Faranini Zamri, Muhammad Fairuz Remeli thermoelectric generator, CHP, heat sink, waste heat, energy recovery In the sustainable energy agenda, thermoelectric generators (TEG) can be a central technology for low-cost combined heat and power (CHP) systems. TEG module (TEM) is the combination of TEG cells, heat pipes, heat sinks and copper blocks that produce electrical power and thermal energy for low temperature heating simultaneously. Two TEG cells were used in each TEM for CHP in a bakery factory with a reference waste heat temperature of 250°C. Different designs of TEM affect the heat transfer mechanics through the components. However, actual testing of each design requires high cost and time consuming. Identifying the principal parameters affecting the desired output is indeed important before investing in actual design fabrication. One-dimensional model is developed in this manuscript to evaluate the fundamental interactions between each component. Parametric variation for nine main parameters characterized the steady-state response of each parameter under four novel heat sink configurations. The parameter sweeps approach benefits in designing a novel TEM for optimum system output. An improved TEM with 6 TEG cells was designed and it increased the heat recovery ratio from an initial 14% to 38%. The Reynolds number of streams are the major operating parameter as it influences the heat sink effectiveness. Large heat exchanger frontal area and copper block housing surface area are also significant parameters. Identification of these principle parameters would assist in effective designs of TEM systems for industrial CHP. Journal of Thermal Engineering Journal of Thermal Engineering 2024-03-22T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6973 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6973 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6973

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6923 2024-02-06T21:00:00Z 1

Gas-Liquid Two-Phase Flow Pressure Drop in Flattened Tubes: an Experimental and Numerical Study Banipal Nanno Yaqob Flattened Tube Pressure Drop; Two-Phase Flow; Numerical Model; Aspect Ratio; Refrigerant Fluids Experimental, numerical and empirical research is carried out on pressure drop features of air-water two-phase flow in horizontal flattened tubes. Circular tubes of 10.5 mm I.D. made of copper were successively flattened into inner heights of 9, 8, and 6 mm (AR=1.27, 1.5, and 2.2, respectively). The experiment operation conditions were 200, 500, and 1000 kg/m2s for mass velocity, 6, 8, 10 LPM for flow rate, and 0 to 0.005 for gas quality. Also, the pressure drop for R134a and R410A was estimated numerically using ANSYS Fluent. The simulation test conditions were for vapor quality of 0.1 to 0.9 and saturation temperature of 40°C, while the conditions for mass velocity and flowrate are taken as that of the experiment test. The experimental data were examined to see how different factors affect on the pressure gradient. According to the outcomes and as compared to the circular tube, the pressure gradient was raised up to 27%, 95%, and 218% for tubes ?attened with aspect ratio of 1.27, 1.5, and 2.2, respectively. Moreover, the pressure drop for either air-water or refrigerant fluids is increased dramatically with increasing flow rate, but it decreases with increasing vapor quality. When compared to known circular tube correlations, a good agreement was achieved. Finally, the minimum difference between the experimental, numerical, and correlated results was less than 3% for gas quality of 0.0048 and aspect ratio of 2.2. Journal of Thermal Engineering Journal of Thermal Engineering 2024-02-06T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6923 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6923 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6923

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6924 2024-02-06T21:00:00Z 1

Experimental Investigation of Forced Convective Heat Transfer and Fluid Flow in a Mini Heat Pipe with Integrated Microgrooves Bassim Mohammed Majel, Zain Alabdeen Hussein Obaid Minichannel, Two-phase flow, Integrated circuits, Heat transfer coefficient In the present study, the convective heat transfer coefficient of water in a laminar flow regime under constant inlet temperature conditions inside a flat mini heat pipe was investigated experimentally. Heat flux ranged from 20-50Watt and various horizontal heat sink temperatures ranged from 15-35°C used during the experiments. The minichannels performance is evaluated in terms of the temperature profile, heat transfer coefficient, Nusselt number and pressure drop. The results emphasized that the mini heat pipe temperature gradients are less than the temperature of the copper plate and the heat resistance gradually decreases to its lowest value when the heat flux value reaches its highest value if it does not exceed the capillary limits. The data also demonstrated that the coefficient of heat transfer in the condensation zone is lower than in the evaporation zone at different heat sink temperatures. It has also been noted that there was a significant decrease in the source-sink temperature difference with an increase of 240% in the effective thermal conductivity in the horizontal position case of the flat mini heat pipe. A generalized regression equation is developed for the estimation of the Nusselt number valid for water in a flat mini heat pipe. Journal of Thermal Engineering Journal of Thermal Engineering 2024-02-06T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6924 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6924 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6924

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7206 2025-01-30T21:00:00Z 1

Nano-additive blends examination of performance and emission profile of CI engines fuelled with waste cooking oil based-biodiesel Samson K. FASOGBON, Sunday, O. OYEDEPO Aluminum Oxide Nanoadditive; Compression Ignition Engines; Emission; Performance; Waste Cooking Oil. Waste Cooking Oil (WCO) could become the alternative raw material for biodiesel production to sustain energy globally. Fossil diesel causes emissions of dangerous gases in compression ignition engines, and this had led to the use of biodiesel in the engines to reduce hazardous emissions. Researchers have also used nano additives with biodiesels to further improve CI engine performance and emission characteristics; behaviors are however Fuels-Nano additives combinations specific. This work therefore studied CI engines on the combination effects of blends of diesel, waste cooking oil-based biodiesel: B0 to B100 at 10 % incremental step, and aluminum oxide (Al2 O3) nanoparticles additive with dosages of 5 g/l and 10g/l on each fuel blends. The biodiesel was produced through the transesterification process in the presence of potassium methoxide as a catalyst. All mixtures containing nano additives were ultrasonicated at a frequency of 25 Hz to prevent agglomeration. The experiment was carried out in a fourstroke, single-cylinder, air-cooled compression ignition engine at engine speeds of 500, 1000, 1500, and 2000 rpm. The result showed a decrease in the CO emissions, brake-specific fuel consumption, and an increase in NOx emissions, brake power, and brake thermal efficiency when the percentage of biodiesel increased for pure biodiesel-diesel blend at higher engine speeds. Blends containing 5 g/l and 10 g/l aluminum oxide (Al2 O3) Nano-additive showed a significant increase in brake power, brake thermal efficiency and a significant decrease in brake-specific fuel consumption, CO and NOx emissions. For all blends tested, (B20+10 g/l) showed the best result for performance and emissions at all investigated speeds and torques; as it gave Highest BP of 8.5 % for low speed of 500 RPM and 9.7 % for high speed of 2000 RPM, Highest BTE of 19.4 % at high-speed of 2000 RPM and Highest NOx reduction of 42.9 % at low engine torque of 25 Nm and 32 % NOx reduction at high engine torque of 100 Nm; Highest CO reduction of 28.6 % at low engine torque of 25 Nm and 20.6 % NOx reduction at high engine torque of 100 Nm. In conclusion, for better performance and emission characteristics, waste cooking oil-based biodiesel blend with aluminum oxide; B20 +10 g/l can be used to fuel the compression ignition engine. Journal of Thermal Engineering Journal of Thermal Engineering 2025-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7206 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7206 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7206

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/5576 2022-05-25T21:00:00Z 9

Corrigendum: A Numerical Investigation of the Species Transport Approach for Modeling of Gaseous Combustion Upendra Rajak, Prem Kumar Chaurasiya, Prerana Nashine, Rohit Kumar, Tikendra Nath Verma Corrigendum Corrigendum Journal of Thermal Engineering Journal of Thermal Engineering 2022-05-25T21:00:00Z Editorial application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5576 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5576 Journal of Thermal Engineering, Year:2022, Vol:8, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=5576

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6912 2024-02-06T21:00:00Z 1

Hydrothermal Analysis of Archimedean Spiral Single and Dual Channel Heat Sink for CPU Cooling Hala M. Rashad, Younis Najim, Hatem H. Ismaeel heat sink, CPU liquid cooling, conjugate heat transfer, hydrothermal performance, computational fluid dynamics Engineering modeling and simulation represent a predominantly design tool in the modern manufacturing industry in which the actual system is reproduced using a mathematical and scientific model. This requires CPUs with higher computational capacities. However, increasing the computational capacities of CPU and GPU imposes challenges in the cooling process due to space limitations. CPU liquid cooling system has attracted more interest as an efficient heat dissipation tool. This work presents computational modeling of the conjugate heat and flow for the CPU liquid heat sink cooling. An Archimedean spiral channel is grooved into the coldplate of the heat sink. Single and dual channel passes are used in this work. The outer diameter of the coldplate is 105 mm and the channel depth is 5 mm for both single and dual-channel configurations. The conjugate heat sink model was constructed to have four different domains: CPU (alumina), glue layer (ethoxy), coldplate (copper), and liquid coolant (water). To incorporate the effect of turbulence, the flow rate varied to cover a range of Reynolds number from 3000 up to 15000 at a constant inlet temperature of 25 °C. The used turbulence model was the Shear Stress Transport (k-w) to better capture the viscous, high-frequency flow fluctuation in the near-wall region. The bottom surface of the CPU is subjected to 450 W of heat energy. The results showed that the channel configuration and Reynolds number have a decisive impact on controlling the CPU temperature. The CPU temperature decrease as Reynolds number increases, however, the pressure drop increases at an exponential rate. These findings are supported by Darcy–Weisbach equation for internal flow in which the pressure drop depends on the square of the average fluid velocity and it was noticed that the pressure drop in the dual channel was three times higher than that in the single channel. The hydrothermal performance of the Archimedean spiral channel rapidly decreased with Reynolds number and the single-channel had a slightly better performance compared with the dual-channel. Journal of Thermal Engineering Journal of Thermal Engineering 2024-02-06T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6912 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6912 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6912

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6925 2024-02-06T21:00:00Z 1

Multi-Objective Optimization of a Biomass Microchip-ORC System under Supercritical Conditions Panagiotis Kladisios, Athina Sagia ORC, supercritical, CHP, biomass, parametric analysis, multi-objective optimization, genetic algorithm, R124, isobutane, R245fa, isopentane ORC cycle is one of the most efficient technologies for the utilization of low-grade heat. ORC systems cover a wide range of heat sources and power outputs. Apart from increasing the overall efficiency, CHP systems contribute to the decentralization of energy production, the conservation of primary fuel, the reduction of the emission of greenhouse gasses and the reduction of the cost to the final consumer. This justifies the research activity around CHP-ORC systems. In the present paper, a steady-state thermodynamic model for a 50 ?kW?_el biomass microCHP-ORC was developed and five candidate fluids were selected: R124, isobutene, R245fa and isopentane. The multi-objective optimization under supercritical conditions was performed using the genetic algorithm. The thermal efficiency, the exergy efficiency and the total heat exchanger surface were selected as single objectives. The evaporation temperature and pressure and the pinch point temperature differences at the heat exchangers were selected as decision variables. Careful examination of the optimal results revealed a systematic tendency for high evaporation temperatures and pressures and low recuperator pinch point temperature differences. Recuperation was found beneficial in many aspects, especially at higher evaporation temperatures. Also, the use of cogeneration leads to overall system efficiencies that surpass 90 %, while simultaneously saving at least 20 % fuel. Lastly, isopentane was found to be the best-performing fluid. Journal of Thermal Engineering Journal of Thermal Engineering 2024-02-06T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6925 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6925 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6925

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6749 2023-05-16T21:00:00Z 1

Flow of Viscous Nanofluids across a Non-Linear Stretching Sheet Pradyumna Kumar Pattnaik, Shoeb Ahmed Syed, Sujogya Mishra, Swarnalata Jena, Sachindra Rout, Kamalakanta Muduli Nanofluids, Non-linear stretching sheet This article aims to demonstrate the flow of viscous nanofluid over a non-linear stretching sheet. Considering thermal radiation and dissipative heat in the heat transport phenomenon encourages the flow properties. In generally, nanofluids are employed in heat transfer equipment because they improve the thermal characteristics of coolants present in the equipment. Additionally, these fluids possess unique features that have the potential to be applied in a variety of applications, such as pharmaceutical procedures, hybrid power engines, household refrigerators, grinding, and microchips, among others. Consequently, the current model is built to allow for the optimal selection of thermophysical parameters such as conductivity and viscosity, which will enhance the overall effectiveness of the study. Appropriate transformation rules have been used to modify the highly non-linear PDEs into a couple of highly non-linear ODEs. An efficient built-in MATLAB bvp5C algorithm addresses the boundary value problem under consideration. Using the dimensionless parameters assumed in the problem, changes in the velocity as well as the temperature profiles are shown, and rate coefficients, by using numerical simulations are also employed in tabular form. The important outcomes which are exposed in the study are; that the particle concentration is used as a controlling parameter to reduce the nanofluid velocity, whereas it favours enhancing the fluid temperature and the radiating heat along with the coupling parameter due to the inclusion of dissipative heat also encourages to overshoot the temperature profile. Journal of Thermal Engineering Journal of Thermal Engineering 2023-05-16T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6749 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6749 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6749

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6759 2023-05-24T21:00:00Z 1

Experimental Analysis for Thermodynamic Characteristics of Municipal Solid Waste for Energy Generation with Environmental and Economic Assessment in Indian Scenario Ajay Kumar, Sujit Verma Solid waste; Incineration; Economic evaluation; Chemical exergy; Energy flux; Calorific value; Excessive energy use has caused a disturbance in the planet's life support system. It has created an adverse impact on water and natural resources. Power generation from solid waste can be an alternative to reduce waste volume and has an extra advantage in cleaning the surrounding with the gain of electric power supply. Innovative technologies and future perspectives of MSWI were highlighted. Moreover, the latest understanding of immobilization mechanisms and advanced characterization technologies were elaborated to foster the future design of treatment technologies and the actualization of sustainable management for MSWI. Solid waste to energy conversion provides economic and atmospheric benefits by introducing renewableenergy sources at minimum environmental influences.This analysis has focused on MSW to energy conversion system by incineration technique to generate electricity along with other bi-product and determines the system's financial feasibility. The experiment has been conducted to calculate the physio-chemical characteristics of municipal waste with a bomb calorimeter and incinerator for electricity generation. Solid waste characteristics like chemical exergy, entropy, higher heating point, energy flux, and potential have been analyzed for the incineration technique's viability. The thermal properties have been analytically described in the experiment. The result shows thatMSWhas a higher calorific value of 8.5-12.5 Mega Joule/kg, and charcoal has a higher calorific value of 27-32 Megajoule/kg. It also analyses that one-ton MSW can produce 600 kWh electricity with 360 gm CO2-eq/kWh generation. Journal of Thermal Engineering Journal of Thermal Engineering 2023-05-24T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6759 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6759 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6759

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6883 2023-12-08T21:00:00Z 1

Experimental Study on Heat Transfer from Rectangular Fins in Combined Convection Mehdi Basiri, Hamid Reza Goshayeshi , Issa Chaer, Hadi Pourpasha, Saeed Zeinali Heris Plate heat sink; combined convection; rectangular fin; Richardson number, empirical equation. Combined natural and forced convective heat transfer arise in many transport processes in engineering devices and in nature, which is frequently encountered in industrial and technical processes, including electronic devices cooled by fans, heat exchangers placed in a low-velocity environment, and solar receivers exposed to winds. In this study, the effects of design parameters have been experimentally investigated for the air-side thermal performance under combined (natural and forced) convection of the rectangular plate heat sinks, and the values of optimum design parameters were sought. Many ideas for improving cooling methods have been proposed, one of which is the heat sink. In this work, the average Nusselt number (Nu) and thermal resistance of a simple base rectangular plate and five vertical rectangular plate heat sinks with different numbers of fins under natural and combined convection were experimentally investigated to obtain the maximum average Nu and minimum thermal resistance for various Reynolds numbers (Re) from 2300 to 40000, Rayleigh numbers (Ra) from 1300000 to 13000000, and Richardson numbers (Ri) from 0.4 to 3. Also, in this experiment, fin spacing (P) was varied from 2.8 mm to 14.6 mm and the dimensionless P/H ratio was varied from 0.1 to 0.49. The flow velocity varied in the range of 2 to 8 m/s under combined convection. Based on the effects of Ri and Re, two empirical equations for natural and also for combined convection heat transfer were derived to calculate the average Nu. The average deviation for these two equations is about 7%. The outcomes of this research can be beneficial for engineers who work on electronics cooling systems. Journal of Thermal Engineering Journal of Thermal Engineering 2023-12-08T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6883 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6883 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6883

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7117 2024-09-10T21:00:00Z 1

Experimental and Computational Study of Heat Transfer and Flow Structure of Slotted Impinging Jet S. Mohamed ILLYAS, B. R. Ramesh BAPU, A. Muthu MANOKAR Thermochromic Liquid Crystal; Numerical Simulation; Heat Transfer Enhancement; Flow Structure; Slotted Jet The study is focused on the flow structure of the slotted impinging jet associated with its heat transfer performance. The analysis is performed for the circular and slotted jets of square, cross, and oval sections for flow exit to impinging plate distance of L/D = 1 to 4. The thermo-chromic liquid crystal sheet is used to visualize the heat transfer pattern on the impinging surface at Re = 12700 and 23000. The numerical analysis is carried out using CFD. The axial velocity peak (u/U0 = 2.124) is observed for the square jet corresponding to r/D = 0.33 at L/D = 1 and the peak reduces with increasing L/D distances. Higher intensity of average radial velocity (ur/U0 = 1.44) is observed close to the impinging plate for the slotted jet at L/D = 1 at 0.5 ? r/D ? 1.4 compared with radial velocity (ur/U0 = 0.91) of circular jet. Nusselt number distribution has little dependence for circular jet on the separation distance as the variation is marginal at L/D = 4 when compared to L/D = 1 and 2, the slotted jet however shows marked variation of Nusselt number (136.8 at L/D = 1, 135.2 at L/D = 2 and 113.5 at L/D = 4) in the region at X/D = 1.5. The highest values of turbulence intensity (TI = 0.206) is observed at r/D = 0.5 for the square jet at L/D = 3. Journal of Thermal Engineering Journal of Thermal Engineering 2024-09-10T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7117 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7117 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7117

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6765 2023-05-24T21:00:00Z 1

Toward Improving Thermal Behavior of Passive Solar Structures by Natural Ventilation and Extraction – Case Study – Hicham Lakrafli, Philippe ANDRE, Mohamed SENNOUNE, Khalid LEKOUCH, Yassin SADIKI Natural ventilation; Mechanical ventilation; Air renewal; Passive solar; Passive energy; Comfort temperature; Dynamic thermal simulation. Improving the energy performance of passive energy buildings is based on reducing their consumption. These reach very high levels in overheating periods because of the mechanical ventilation systems. This work proposes to implement ventilation strategies to reduce the indoor temperature of an academic building considered a passive solar structure and designed to benefit as much as possible from solar radiation. Using TRNSYS software, with its two components, TRNBUILD and TRNFLOW, different likely scenarios were tested and allowed to identify significant results. The mechanical extraction system is a solution if the extraction threshold temperature is 21-19°C to keep the Hall_1 temperature lower. While, to make the temperature of all areas of the building more comfortable, three natural ventilation scenarios were evaluated. Obtained results highlight that natural ventilation scenario (circuit 2) is the optimal scenario which makes the different zones very comfortable and lowers the temperature by an average of 4°C compared to mechanical ventilation. Thanks to the proposed ventilation scenarios, we have shown that we can, thanks to natural ventilation, renew the air inside the different areas of the building and maintain the comfort temperature. Natural ventilation can be an alternative to mechanical ventilation if we consider appropriate scenarios. This will strongly reduce energy consumption. Journal of Thermal Engineering Journal of Thermal Engineering 2023-05-24T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6765 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6765 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6765

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6909 2024-02-06T21:00:00Z 1

Investigation into the Heat Sink Performance of the Inline and Cut Cross Fins Types using Different Aluminum Alloys Ibrahim Thamer Nazzal, Thamer Khalif Salem, Saad Sami Farhan, Tahseen Ahmad Tahseen Inline, Cut Cross; Passive Heat Sink; Aluminum Alloys. In this study, two types of heat sinks are selected at similar dimensions. In addition, five types of aluminum alloys are used to find the optimum performance for both models' inline and cut cross heat sinks. These types of alloy materials were Al-1100, Al-3063, Al+25%Ni, and Al+25%Cu which are selected and compared with pure aluminum. The effectiveness results showed of the heat sink using Al- 25%Cu has the highest value compared to the other material types Al- 25%Ni, Al 1100, and Al 6063 respectively. While the lowest value of the fin efficiency was observed for pure aluminum. Moreover, the heat sink using Al- 25%Ni, Al 1100, and Al 6063 has moderate values. The results also indicated that the rate of heat-dissipated from the cut cross heat sink increases, as the fin thickness increases until reaches maximum value before it decreases with an increase in the fin thickness. While for the inline heat sink, the heat transfer increases as the fin thickness increase before stables at 2 mm approximately. Journal of Thermal Engineering Journal of Thermal Engineering 2024-02-06T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6909 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6909 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6909

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6975 2024-03-22T21:00:00Z 1

Experimental and Numerical Study for Assessment Indoor Air Quality by Adopting Mixing Ventilation with Different Occupants Density in Iraq Hot Climates Atheer Hmaizah Saber, Alaa Abbas Mahdi, Mohammed Wahhab Aljibory Thermal comfort, Mixing ventilation, Indoor air quality, Computational fluid- dynamics, occupied density. In this research, thermal comfort and air quality inside were examined for different numbers of persons (occupants' density) within a (3m × 2.5m × 2.5 m) office room. The office room is equipped with mixing ventilation system, temperature and air speed (17°C) and (2.5 m/s) respectively. The results of experimental experiments and results were compared with computational fluid- dynamics (CFD) analysis utilizing the turbulent (RNG, k-epsilon) model on a thermal manikin that represents the human body in a standing and sitting and position. The experimental study focused on measuring the velocity, air temperature, and carbon dioxide (CO2) concentration in different areas inside the room, in addition to taking measurements around the heat manikins and in the breathing area. In the numerical of analysis, thermal of comfort was assessed by air diffusion of performance Index (ADPI), predicted of percentage dissatisfied (PPD), and predicted of mean vote (PMV). The results indicate that thermal comfort and indoor air quality decline with more persons. Where the values of (ADPI), (PPD) and (PMV) change from (76.55 %), (6.325 %) and (0.021) to (64.25 %), (10.412 %) and (0.52) respectively, when the number of persons in the room increased from (two persons) to (four persons). Journal of Thermal Engineering Journal of Thermal Engineering 2024-03-22T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6975 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6975 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6975

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7017 2024-05-26T21:00:00Z 1

Numerical Simulation of Aerodynamic Performance of the Wing with Edge of Attack and Sinusoidal Escape Mustafa A. Mohammed, Marwah Ali Husain Wings, Aerodynamic Performance, Lifting Coefficient, Drag Coefficient, Edge of Attack and Sinusoidal Escape, Turbulence. Wings are one of the engineering components that play a vital role in the aerospace industry. Therefore, increasing the performance of the wings can improve the overall performance of the airplanes. One way to increase wing performance is to use sinusoidal curvature at the attack edge and wing escape, which delays the phenomenon of fatigue and improves aerodynamic performance at high attack angles. This study is to provide a better understanding of the aerodynamic characteristics of a finite NACA0012 wing with the performance of a wing with different types of wings with sinusoidal attack edge, sinusoidal escape edge, and compared them with simple wing. ANSYS FLUENT method has been used to simulate the wings. In addition to, the TRANSITION SST-4EQ method has also been used to solve the governing equations. The aerodynamic performance of a wing with the performance of different types of wings with sinusoidal attack edge, sinusoidal escape edge, and simple wing with NACA0012 cross section are investigated in Reynolds numbers of 5000, 15000 and 60,000 numerically. The kinetic energy distribution of turbulence on the wing body in these Reynolds numbers has been investigated. The amount of coefficients for and after different wings in Reynolds number 15000 with changing angle has been analysed. In unstable conditions, compressibility and non-viscosity have been compared. According to the present study, it was observed that the maximum pressure around the wing is sinusoidal and the wing with a combined design is higher than the simple wing. The drag is related to the wing with the combined design, although this geometry has the highest value of drag in the article with other types of wings. Journal of Thermal Engineering Journal of Thermal Engineering 2024-05-26T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7017 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7017 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7017

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6878 2023-12-08T21:00:00Z 1

Experimental and Theoretical Investigation of Thermal Efficiency and Productivity of Single Slope Basin Type Solar Distillation System using Honey-Comb Manish Kumar Chauhan, Akhilesh Kumar Chauhan, Yunis Khan, Abhendra Pratap Singh Solar still, thermal efficiency, productivity, honeycomb, single slope The aim of current research was to improve water quality by constructing a single slope basin type solar water distillation system with honeycomb, as well as to increase distilled water productivity. In this investigation, honeycomb structure of 2.25 cm and a diameter of 6 mm in a square section (100 cm*100 cm) have been proposed to enhance the efficiency of the solar still. An experimental analysis was done to investigate the performance of the honeycomb structure. Thermal efficiency of the standard solar distillation system was obtained approximately 18.48%, while the thermal efficiency and productivity of the solar distillation system with honeycomb was obtained 25.45% and 749.58 ml/m2 respectively. It was concluded that, the solar distillation system with honeycomb structure was more efficient that a simple conventional solar distillation system. The addition of honeycomb structure in simple solar desalination system increased the productivity and efficiency by 35.36% and 37.71% respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2023-12-08T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6878 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6878 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6878

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6756 2023-05-18T21:00:00Z 1

Design, Development, and Analysis of a Box Type Solar Cooker with Optimally Reflecting Side Walls Hemish Vaidya, Mamish Rathod, Salim Channiwala Solar cooker; Optimally inclined sidewalls; Figure of merit; Pot temperature; Plate temperature A novel inclined sidewall box-type solar cooker is constructed, and its performance is evaluated. The Opto-geometrical design of the cooker was designed for Surat, a city in India. The design is modified by optimizing the inclination angles of the sidewalls so that an optimal thermal response may be generated by reflecting sun rays from the sidewalls, and the performance of the solar cooker is enhanced. The optimized sidewall angles due south, due north, due east, and due west are designed to be 67.30, 22.690, 35.440, and 35.440, respectively and side walls are made reflective with reflecting Aluminium sheet. The results are compared with a conventional cooker. The thermal performance of the newly built solar cooker was evaluated, and the merit F1 for no-load circumstances and the merit F2 for various loading conditions were determined. The results show that the maximum plate temperature, the figure of merit F1, and the maximum pot temperature of the newly developed solar cooker with optimally reflecting sidewalls during load test are higher than that of a conventional cooker. The maximum plate temperature is found to be 760C and 650C in newly designed and conventional solar cookers, respectively. The temperatures are found to be about 16% more from 11:30 p.m. to 2:00 p.m. in the newly designed cooker compared to the conventional cooker. The maximum value of Figure of Merit F1 is found to be 0.15 and 0.11 in newly designed and conventional solar cookers. The maximum value of Figure of Merit F2 is found to be 0.59 and 0.30 in newly designed and conventional solar cookers. The maximum value of pot temperature is found to be 86 °C and 60 °C for newly designed and conventional solar cookers, respectively, during the load test, which is about 43% more in the newly designed cooker than the conventional cooker. The highest cooking temperature in the newly designed cooker was maintained at 90 0C for about 2 hours, and that in the conventional cooker was maintained at 60 0C for about 2 hours. In addition, the cooking test demonstrates that the food is thoroughly cooked in the newly built solar cooker, while it was discovered undercooked in the conventional cooker. Journal of Thermal Engineering Journal of Thermal Engineering 2023-05-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6756 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6756 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6756

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6926 2024-02-06T21:00:00Z 1

Effect of Modifying Bowl Geometry for IC Engine Fueled with Diesel and Biofuels - Review Bhavesh Pathak, Nikul Patel Bio fuels, Fluid Dynamics, IC engine, Bowl Geometry Bio-fuels are one of the most prominent, emerging, and promising fuels, which are aimed to replace diesel in the next decade. Though bio-fuels may not give the same performance as conventional diesel due to certain issues related to both technical and economic aspects, this fact leads to the need for alterations that are supposed to incorporate either changes in the shape of the combustion chamber or other critical factors that affect the performance of the engine. The shape of the top surface, which is known as the "bowl," in the piston plays a major role, and any slight modification in that shape leads to amplified effects on various combustion, emission, and performance parameters. This article shows the valid reason for accepting bio-fuels as fuel for CI engines by considering outcomes derived from experiments and numerical analysis with changes in the shape of the piston bowl. The results obtained are based on the attainment of various parameters, which leads to higher turbulence velocity distribution, better mixture fraction values, and lower soot formation distribution that can be obtained by modifying the shape of bowl. The pressure, temperature and heat release in the combustion chamber found to be changed due to the modification in bowl geometry. Journal of Thermal Engineering Journal of Thermal Engineering 2024-02-06T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6926 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6926 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6926

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6803 2023-07-31T21:00:00Z 1

A CFD Investigation of the Design Variables Affecting the Performance of Finned-tube Heat Exchangers Hussaini Syed Mujtaba, Tariq Feroze, Ahmad Hanan, Haider Ali Shams Heat Exchanger, Heat Transfer, CFD A wide variety of heating and cooling applications use heat exchangers. The increase in energy prices, the requirement for size reduction, and restriction on greenhouse gas emissions has led to the need for finding ways to develop efficient heat exchangers. A cost-efficient way to enhance the model of a heat exchanger by visualizing the effects of the design parameters is using Computational Fluid Dynamics (CFD). The reason for this exploration was to lead an examination of the varieties/changes in the general intensity move process for a Finned-Tube Heat Exchanger (FTHE), also known as Air Coil Heat Exchanger (ACHE) with a variety of plan boundaries like the quantity of tubes, course of action of tubes, and the material utilized for the intensity exchanger. The widely used heat exchanger that uses refrigerant R314a and air as the working fluids was simulated with different design modifications. The simulated results exhibited as to how the number of tubes, arrangement of coils/tubes, material of tubes, and density / spacing of fins, effects the pressure drop, temperature and velocities profiles, and heat exchangers’ transfer of a heat. The use of copper coils improved the heat transfer by approximately 61% as compared to aluminium coils. Journal of Thermal Engineering Journal of Thermal Engineering 2023-07-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6803 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6803 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6803

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7118 2024-09-10T21:00:00Z 1

An Experimental Study for a Single-Pass Solar Air Heater Integrated with Artificial Roughness Nabaa M. BADER, Khudheyer S. MUSHATET Artificial Roughness, Friction Factor, Solar Air Heater, Thermal Efficiency The use of solar air heaters is importance because of their capability to reduce the consumption of electricity that depends on fossil fuels, consequently reducing pollution and saving energy. Experimental simulations were conducted to analyze the thermal performance of a solar air heater with various artificial roughnesses (ribs, delta-winglet vortex generators, or combined ribs & delta-winglet) in a single-pass solar air heater. This work aims to determine the configuration that results in the greatest possible improvement in the thermal performance of a solar air heater. A consistent relative roughness height ratio of 0.6 and a variety of attack angles with the pitch ratio set at 10. This experimental examination was carried out at Reynolds numbers ranging from 5000 to 14000, with typical irradiance levels varying from a minimum of 330 W/m2 to a maximum of 850 W/m2. According to the findings, the mean bulk temperature of the combined roughened solar air heater was 37% higher than a smooth duct when the solar irradiation was peak. Compared to the other cases, the inclined ribs at a 60° provided a larger thermal efficiency that covered the most area and significantly improved the heat transfer convective rate. Journal of Thermal Engineering Journal of Thermal Engineering 2024-09-10T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7118 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7118 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7118

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6908 2024-02-06T21:00:00Z 1

Numerical Analysis of Coupled Fluid Flow and Natural Heat Transfer on a Vertical Flat Plate Mehdi Ghamati, Nematollah Askari, Morteza Abbasi, Morteza Morteza Moghimi, Seyed Masoud Khodadi, Mohammad Hasan Taheri Natural convection, Rung-Kutta method, Thermal boundary layer, Vertical plate This study aims to look into the temperature distribution on a vertical flat plate with a variable temperature boundary condition. As a novelty, the variable temperature is considered on the wall, and coupled momentum and energy equation are solved. Moreover, a novel variable change transforms the infinite boundary condition into the finite one. The partial differential governing equations were introduced and transformed into ordinary differential equations form using the similarity solution. The obtained equations were numerically solved and validated using previous research. The results showed that for a constant variable temperature index (n), increasing the Prandtl number (Pr) from 0.1 to 2 reduces the dimensionless maximum velocity by less than half and the skin friction coefficient by about 32%. In this case, the dimensionless temperature approaches zero faster; as a result, the thermal boundary layer thickness declines, and the Nusselt number (Nu) rises. Furthermore, for a constant Pr, when n increases from 0 to 1.5, the dimensionless maximum velocity and the skin friction decrease by about 38% and 23%, respectively. Since the dimensionless temperature continues to descending trend, Nu still rises in this case. Journal of Thermal Engineering Journal of Thermal Engineering 2024-02-06T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6908 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6908 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6908

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7173 2024-11-18T21:00:00Z 3

Thermal Management System of e-Vehicle Li-Ion Battery Modules: A Comprehensive Review Ajoy DEBBARMA Battery Thermal Management System; Battery Thermal Runaway; Cooling Enhancement Techniques; Hybrid Mode of Cooling Techniques; Single Cooling Techniques. Electric vehicles have the potential to address humanity’s issues of environmental deterioration and energy scarcity. Electric vehicles frequently use lithium-ion batteries as their power source. The heat is generated when the batteries are subjected to high-power charging and discharging loads. This results in a considerable loss in battery life and raises the possibility of a battery explosion. As a result, quick heat dissipation from the cells is required to ensure safe operation and longer battery life cycles. Air cooling is the most basic type of thermal management; yet, due to its poor thermal conductivity, it has its restrictions. Liquid cooling agents are superior to air cooling systems in terms of thermal control. Liquid cooling, on the other hand, added complexity to the working system, increased operating costs, and increased total system weight. A similar problem might be seen when applying the heat pipe concept of cooling systems. PCM provides several advantages over above mentioned three cooling technologies, but it also has a limited heat storage capacity and poor thermal conductivity. As a result, a hybrid BTMS paradigm emerges. However, research on hybrid techniques is still insufficient. To make effective hybrid BTMS technology, efforts are being undertaken, and earlier research on the hybrid is also summarized in this study. Journal of Thermal Engineering Journal of Thermal Engineering 2024-11-18T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7173 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7173 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7173

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6917 2024-02-06T21:00:00Z 1

Impact of Inclined Magnetic Field on Non-Orthogonal Stagnation Point Flow of CNT-Water Through Stretching Surface in a Porous Medium Issa El Glili, Mohamed Driouich Oblique stagnation point, nanofluid, stretching surface, non-linear thermal radiation, inclined magnetic field, porous medium, heat transfer. The magnetohydrodynamic (MHD) nanofluid flow at non-orthogonal stagnation point, with suspended carbon nanotubes in water on a stretched sheet in a permeable media with non-linear thermal radiation is studied. This work aims to explore the inclined magnetic field impacts on normal velocity, tangential velocity and temperature for both types of carbon nanotubes (CNTs). The governing flow equations which are continuity equation, momentum equation and energy equation are reformed into ordinary differential form with the proper boundary conditions using appropriate transformations. The computational solution of the nonlinear ODEs is obtained using the Bvp4c method. The graphs are presented to show the influence of certain physical factors which ranged as magnetic parameter (0.5 ? M ? 2.5), inclination angle of the magnetic field (?/2 ? ? ? ?/4), permeability parameter (0 ? ? ? 2), volume fraction of nanoparticle (0.03 ? ?? ? 0.07), stretching ration parameter (0.3 ? ?2 ? 0.7), Radiation parameter (0.5 ? Nr ? 0.9), the heating parameter (0.5 ? ?w ? 1.5) and Prandtl number (5 ? Pr ? 10). The normal and tangential velocity drops with the augmentation of (M), (?) and (?), while the temperature rise with enhance of (Nr) and (?w). This study’s findings may be used to manage the heat transmission and fluid velocity rate to achieve the required final product quality in numerous manufacturing processes such as electronic cooling, solar heating, biomedical and nuclear system cooling. Validation against previous research available in the literature in specific situations shows excellent agreement. Journal of Thermal Engineering Journal of Thermal Engineering 2024-02-06T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6917 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6917 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6917

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6914 2024-02-06T21:00:00Z 1

An Enhancement of Double Pipe Heat Exchanger Performance at a Constant Wall Temperature Using a Nanofluid of Iron Oxide and Refrigerant Vapor Saif Ali Kadhim, Ali Habeeb Askar, Ahmed Abed Mohammed Saleh Double pipe heat exchanger, Constant wall Temperature, Nanofluid, Turbulent Flow, Nusselt Number, Refrigerant Vapor, Convection Heat Transfer Coefficient. This study reports on experimentally enhancing the performance of a concentric double pipe heat exchanger using nanofluid and refrigerant vapor under constant wall temperature conditions. Ferro-nanoparticles with diameters of 80 nm are distributed in distilled water with volume concentrations of 0.1-0.7 % (nanofluid), which is used as hot fluid flowing turbulently inside the inner tube with Reynolds numbers ranging from 3900 to 11800, while refrigerant vapor produced from the refrigeration unit is used as cold fluid with counterflow through the annular tube. The results show that the convection heat transfer coefficient and Nusselt number in the inner tube increase proportionally with a rise in the mass flow rate of nanofluid and the ratio of nanoparticles in the fluid (concentration). Under Reynolds number 11900, the maximum enhancement for convection heat transfer coefficient and Nusselt number in the inner tube was 13.4% and 10.7%, respectively, when using the iron oxide nanofluid with volume concentration of 0.7% compared to pure water. The results of the test were also compared with an almost similar study that used water in the annular tube, and it was found that the use of refrigerant vapor in the annular tube gives better performance compared to water. Journal of Thermal Engineering Journal of Thermal Engineering 2024-02-06T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6914 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6914 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6914

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6907 2024-01-31T21:00:00Z 1

A Case Study on the Modeling and Simulation of UAVs Osman Kerem Koç, Ali Sertkaya, Alişan Gönül, Tolga Taner, Ahmet Selim Dalkılıç Flow Analysis; Structural Analysis; Unmanned Aerial Vehicles; Fluent; Design; ANSYS The current work presents the flow and structural analysis of the application design in unmanned aerial vehicles (UAVs) as well as indicates a case of the modeling and simulation study with the ANSYS Fluent and Mechanical programs. This research reveals the unmanned aerial vehicle's structural and mechanical design, structure configurations, energy-flow and structural analysis, propulsion and firing systems, prototype production and testing, and design flow models. This study aims to complete the unmanned aerial vehicle design by determining its aerodynamic configurations. Due to the complexity of the design, a preliminary preparation for flow analysis is performed with simplified geometry as well as flow analysis. The unmanned aerial vehicle is tested at different velocities by numerical analysis. In addition, different density flow analyses provide predictions about the aerodynamic forces of the UAVs at different heights and temperatures. The thrust results are 4240 g, power became 1711.62 W with 2.48 g/W efficiency, and 12179 [rpm] revolution for 22.2 V voltage and 77.1 A current, respectively. The 5 different analyses are performed in the range of 2.9-12 million elements, and the solution meshes with the lowest number of elements by performing parametric studies with the ANSYS program that gives the most accurate result. Journal of Thermal Engineering Journal of Thermal Engineering 2024-01-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6907 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6907 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6907

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6911 2024-02-06T21:00:00Z 1

Critical Investigation of Microchannel Design Effect on Thermal Performances of a Pem Fuel Cell Khaoula Khelaifa, Abdelmalek Atia, Hocine Ben Moussa, Ammar Naroura PEMFCs; CFD; Nanofluid, Cooling Plate; Microchannel; Heat Transfer. A major challenge for improving the characteristics of fuel cells is to obtain uniform temperature distribution during its operation, in which a major part of hydrogen chemical energy is converted to heat. If not properly exhausted, this exothermic chemical reaction causes overheating in the polymer electrolyte membrane fuel cells (PEMFCs), leading to a reduction in their performance. Hence, analyzing different techniques for PEMFCs cooling may be necessary for this kind of energy systems. In this study, four microchannel design effect on aluminum oxide (Al2O3) nanofluids thermal behavior in cooling plates with 1400×1800 mm2 was investigated using computational fluid dynamic (CFD) simulation. The performances of proposed microchannel designs were evaluated in terms of maximum and uniformity temperature. The suggested study has been validated by available published results from previous research studies. The obtained results depicted that the maximum temperatures have been 305.3K and 305.5K for S- character flow field and two stages coolant flow field microchannel designs, respectively. The results revealed that the multi-flow plate designs might greatly enhance the performance of PEMFCs in terms of temperature distribution in the cooling plate when compared to standard flow field designs. Another important finding was that the two stages microchannel and S-design are more thermal stable compared with other microchannels. Journal of Thermal Engineering Journal of Thermal Engineering 2024-02-06T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6911 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6911 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6911

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6916 2024-02-06T21:00:00Z 1

Energy, Exergy and Entropy Analysis with R1234yf as an Alternate Refrigerant to R134a of Automobile Air Conditioning System Bhaveshkumar Patel, Ashok Parekh R1234yf, R134a, Automobile air conditioning, COP, Exergy A major portion of the worldwide emissions arise from mobile air-conditioning systems with hydrofluorocarbon refrigerant as working substance and which is one of major cause for the greenhouse effect. R134a refrigerant having GWP of 1400 has been extensively used in car air conditioning. To reduce greenhouse gas emissions, the current R134a refrigerant must be phase out as per Kigali Amendment. The present study deals with cooling load calculation of car model by heat balance method as per ASHRAE standard using local climate condition. Further, thermodynamic analysis of R1234yf as an alternate refrigerant to R134a has been carried out for automobile air conditioning system. The required properties of refrigerants are extracted from Engineering Equation Software. The thermodynamic analysis is carried out to study the effect of operating parameters viz. condensing temperature, evaporating temperature, degree of superheating and degree of subcooling on COP, EDR, exergy efficiency and entropy generation. The previous literature reports mainly focus on separate study of either cooling load calculation or energy analysis or exergy analysis of R1234yf and R134a for automobile air conditioning system, while this paper presents the comprehensive study of new low GWP R1234yf as an alternate refrigerant to R134a in automobile air conditioning system with cooling load calculation including the concept of energy, entropy and exergy analysis. The percentage difference in COP between R134a and R1234yf system varies from 2.44 % to 4.78 % while percentage difference in EDR varies from 6.79 % to 2.87 % when evaporating temperature varied from -10 °C to 10 °C. With 12 °C of superheating at compressor inlet, the COP of R134a is 3.9 whereas COP of R1234yf is 3.75, which makes 3.85 % lower than that of R134a. The R1234yf has 4.78 % lower value of exergy efficiency as compared to that of R134a at evaporating temperature of -10 °C and it is found that maximum exergy destruction takes place in compressor. Journal of Thermal Engineering Journal of Thermal Engineering 2024-02-06T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6916 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6916 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6916

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6910 2024-02-06T21:00:00Z 1

Numerical Investigation of the Effects of the Bronchial Stenosis on Airflow in Human Respiratory Tract Ufuk Demir, Celal Satıcı, Filiz Koşar, Hasan Güneş Computational fluid dynamics (CFD) . Bronchial Stenosis . Airflow in human respiratory tract . Computed tomography . Patient-specific simulation Obstructive lung diseases are slowly progressing diseases that are characterized by a narrowing of airway diameter and make it harder to breathe. Although obstructive lung diseases have a high mortality rate, there are many clinical methods for early diagnosis such as impulse oscillometry, thorax computed tomography scans, and pulmonary function tests. The objective of this study is to investigate the effects of obstructions in main bronchitis on the airflow pattern and provide a better understanding to flow characteristics in healthy and obstructed (bronchial obstructions) human airways throughout a tidal breathing pattern. Seven-generation lung airway model of a healthy person was reconstructed from computed tomography (CT) images and additional models were created artificially for investigation of how obstructed airways affect flow characteristics, flow rate, tidal volumes, and air distributions. A person-specific non-uniform pressure inlet boundary condition for 12 breaths per minute was created as a time-dependent pressure profile and implemented in FLUENT software as a macro for distal airways and atmospheric pressure outlet boundary condition defined at the trachea exit. Numerical simulations were carried out in SST k-w turbulence model and validated with an experimental study. Various flow properties such as lobar distribution rates, maximum flow rate changes, and airflow characteristics at different flow rates (quiet breathing-15 L/min and intense activity level-60 L/min) in the carina region, mid-trachea and sagittal section of the trachea were obtained in the human respiratory tract by computationally. The results show that regardless of flow rate, the airflow characteristics are similar for healthy models and models with various stenosis grades during inhalation. In terms of maximum flow rate drop, for both inspiration and expiration phases 16%, 45%, and %80 decreases were observed in OM-I, OM-II, and OM-III, respectively. In line with the decrease in maximum flow rate similar drop, percentages were obtained for tidal volumes. Besides, with the increase of stenosis grade, the inhaled air volume distribution to the right and left upper lobes decreased between 15%-95%. Journal of Thermal Engineering Journal of Thermal Engineering 2024-02-06T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6910 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6910 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6910

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6970 2024-03-22T21:00:00Z 3

Recent Developments in Thermal Management of Light-Emitting Diodes (LEDs): A Review Ashish Khudaiwala, Rupesh L. Patel, Rakesh Bumataria Light Emitting Diode, Heat pipe, Nanofluid, Life span, Thermal Management Light Emitting Diodes (LEDs) is one of the newest ways to light up outdoor areas such as streets, stadiums, airports, military bases, harbors, and high mast towers. The main reason for the high focus is power consumption with better brightness. Even though LEDs have so many benefits, researchers should focus on better managing temperatures as the main reason behind the failure of LEDs is overheating. In this article, modern research trends like using heat pipes filled with nanofluids, ionic winds, spray cooling, use of fins, refrigerants, and oil cooling are focused on and discussed concerning LEDs, solar stills, electric vehicle batteries, and different heat transfer devices to develop a new way to handle the heat from higher-wattage LEDs. There is a research thrust in the field of more than one nanoparticle in the base fluid, and its proportions are not analyzed during LEDs cooling study using a heat pipe. It is necessary to control the heat using a more effective technique. Heat pipe with nanofluid is a more efficient, compact, and cost-effective cooling device o reduce LED failure due to higher heat flux. Hence, it is promising to use nanofluid-filled heat pipes to serve the purpose of the life span enhancement of LEDs. Journal of Thermal Engineering Journal of Thermal Engineering 2024-03-22T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6970 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6970 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6970

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6963 2024-03-14T21:00:00Z 1

MHD Boundary layer Micropolar fluid Flow over a Stretching Wedge Surface: Thermoforesis and Brownian Motion Effect Umme Hani, Mohammad Ali, Mohammad Shah Alam Micropolar fluid, MHD, stretching wedge surface, shooting method, Chemical reaction, radiation, micro-rotation To investigate the consequence effect of thermophoresis and Brownian diffusion on convective boundary layer micropolar fluid flow over a stretching wedge-shaped surface. The effects of non-dimensional parameters namely coupling constant parameter , magnetic parameter , Grashof number , modified Grashof number , micropolar parameter , vortex viscosity constraint , Prandtl number , thermal radiation parameter , Brownian motion parameter , thermophoresis parameter , heat generation parameter , Biot number , stretching parameter , Lewis number , and chemical reaction parameter on the steady MHD heat and mass transfer is investigated in the present study. The coupled non-linear partial differential equations are reduced into a set of non-linear ordinary differential equations employing similarity transformation. Furthermore, by using the Runge-Kutta method followed by the shooting technique, the transformed equations are solved. The main goal of this study is to investigate the numerical analysis of nanofluid flow within the boundary layer region with the effects of the microrotation parameter and velocity ratio parameter. The novelty of this paper is to propose a numerical method for solving third-order ordinary differential equations that include both linear and nonlinear terms. To understand the physical significance of this work, numerical analyses and tabular displays of the skin friction coefficient, Nusselt number, and Sherwood number are shown. The new approach of the present study contributes significantly to the understanding of numerical solutions to nonlinear differential equations in fluid mechanics and micropolar fluid flow. Micropolar fluids are becoming even more of a focus due to the desire for engineering applications in various fields of medical, mechanical engineering, and chemical processing. Journal of Thermal Engineering Journal of Thermal Engineering 2024-03-14T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6963 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6963 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6963

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7007 2024-05-26T21:00:00Z 1

Thermo-economic Evaluation of Solar Boiler Power Plant Mohammed Sh. Abed, Hussien S. Sultan, Falah A. Abood Solar power plant, Solar boiler, parabolic trough solar collectors Today, the world is turning to using renewable energy to solve the problems of fuel shortage and pollution due to CO2 emissions from the use of fossil fuels. In this study, parabolic trough solar collectors (PTC) with two types of heat transfer fluids HTF (PV1 and SYS 800) are used to investigate the performance of a retrofitted steam power plant using solar energy. A thermo-economic analysis was performed for a 10 MW simple steam power plant with different steam pressure from 10 to 100 bar located in the city of Basra in Iraq which receives high levels of solar radiation. Basra's weather condition is used to simulate the solar-assisted regenerative system using a parabolic trough collector (PTC). According to the system analysis, it was found that increasing the steam pressure reduces the total area required for PTC. For 10 bar operating pressure, the required PTC area is 64233,562 m2, while for 100 bar operating pressure, the required PTC area is 42907.59 m2. Also, it was estimated that the Levelized Cost of Energy (LCOE) decreased with increasing operating pressure. The decrease in LCOE is 43.16% for the pressure range from 10 to 100 bar. Journal of Thermal Engineering Journal of Thermal Engineering 2024-05-26T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7007 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7007 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7007

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6958 2024-03-14T21:00:00Z 1

Thermal Stress Analysis in Pin Fin Microchannel Heat Sink Mohammad Nazirul Syafiqaiman Jani, Nawaf H. Saeid Thermal stress, Conjugate heat transfer, Pin-fin microchannel, Numerical study. The conjugate heat transfer and the thermal stresses produced within a pin-fin microchannel heat sink are investigated numerically. The pin-fin microchannel heat sink is subjected to a constant heat flux from the bottom surface and cooled by water flow through the channel across the pin fins. Rectangular cross-section microchannel incorporating one raw of square pin fins are considered. The water flowing through the microchannel at Reynolds number varies from 200 to 800. The heat sink dissipates constant heat flux in the range of 75-175 kW/m2. The selected materials used for the solid substrate are Copper, Aluminium, Titanium, and Structural steel. The results are presented as contour plots for the temperature, thermal stress, and deformation distribution. It is found that the heat dissipation and the Nusselt number are increased with increasing Reynolds number, increasing the thermal conductivity of the material but remain constant throughout various heat fluxes. Thermal stresses are increased with decreasing Reynolds number, increasing heat flux, and increasing Youngs’ Modulus of the substrate material. The total deformation is increased with decreasing Reynolds number, increasing heat flux, and increasing the thermal expansion coefficient of the substrate material. Journal of Thermal Engineering Journal of Thermal Engineering 2024-03-14T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6958 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6958 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6958

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7013 2024-05-26T21:00:00Z 1

Numerical Investigation of Fluid Flow and Heat Transfer within Multilayer Wavy Microchannels Ali Yaghoobi, Masoud Kharati-Koopaee Microchannel; Friction factor; Nusselt number; Thermal performance In this research, the fluid flow and heat transfer phenomena within wavy multilayer microchannels comprising variable wavelength and amplitude are studied in laminar flow regime. In the present work, friction factor, Nusselt number and also overall performance of the multilayer microchannel are studied at different wavelengths and amplitudes and also Reynolds numbers. Numerical findings show that an increase in the number of layers results in the increase in the friction factor and Nusselt number. It is shown that the lowest and highest friction factors correspond to the cases of increasing amplitude and increasing wavelength, respectively. It is found that the decreasing wavelength and increasing amplitude cases result in the highest Nusselt number and increasing wavelength configuration leads to the lowest Nusselt number. Results exhibit that, with increasing the Reynolds number, the friction factor depending on the number of layers may increase or decrease whereas the Nusselt number increases. Numerical results show that for one-, two- and three-layer channels, the minimum relative friction factors are 0.1%, 3.7% and 4.7%, and maximum relative Nusselt numbers are 18.2%, 45% and 45.2%, respectively. It is also shown that an increase in the number of layers and Reynolds number causes the channel overall performance to increase. The lowest overall performances is associated to the increasing wavelength structure and the highest overall performance corresponds to the increasing amplitude configuration. It is shown that for one-, two- and three-layer wavy channels, the maximum overall performances are found to be 1.16, 1.43 and 1.43, respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2024-05-26T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7013 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7013 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7013

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7022 2024-05-26T21:00:00Z 3

Review of Various Solar Cavity Receivers of Parabolic Dish Concentrators with Design Aspects and Heat Loss Analysis Kushal S. Wasankar, Nitin P. Gulhane Parabolic dish collector; cavity receivers; convective heat loss; thermal efficiency; Nusselt correlation In a parabolic dish system, the heat losses from the cavity receiver significantly suppress the system’s efficiency and may increase its overall cost. Several existing researches have numerically and experimentally developed the different cavity receiver models by modifying their inclinations, design geometrics, and structure. The conductive loss does not occur much in the cavity receivers compared to the convective loss. So, the analysis of convective loss is more critical in the cavity receivers; however, the accurate prediction of convection loss is quite complex due to the temperature distribution near the cavity. This prime aim of the paper is to comprehensively review the existing literature related to design configurations of cavity receivers and heat loss analysis to set a platform for performance improvement via design modifications. The study emphasizes the effect of geometric parameters like the structure of cavity receivers, shape and sizes, and angle of inclinations with the ground. Structural configurations, especially the hemispherical, cylindrical, conical, and trapezoidal cavity receivers utilized for the solar dish collector (SDC), are investigated between the years 1980 to 2022. A comparison is made based on heat loss models and research outcomes. Besides, the Nusselt correlation model used for predicting heat losses is also carried out in this review by varying the effects such as inclination, aperture ratio, wind effect, etc. This review supports the solar cavity designers for experimentally investigating and simulating a new modified solar cavity receiver with minimization and accurately predicting convective losses. Journal of Thermal Engineering Journal of Thermal Engineering 2024-05-26T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7022 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7022 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7022

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6964 2024-03-14T21:00:00Z 1

Numerical Analysis of Turbulent Flow and Heat Transfer Enhancement using V-shaped Grooves Mounted on the Rotary Kiln’s Outer Walls Youcef Attou, Mohamed Bouhafs, Abdelkader Feddal Rotary ciment kiln, V-shaped groove, heat transfer enhancement, k -ω SST model Rotary kilns have been widely employed in various industrial uses, especially the cement production. This article deals with enhancing the thermal performance of a rotary kiln duct with V-shaped grooves mounted on the outer wall. Four V-shaped grooves with different depths h/D ranging from 0.1 to 0.4 were designed. The Reynolds Averaged Navier–Stokes equations (RANS) of two-dimensional steady-state flow are used to model the governing flow equations by using the finite volume approach (FVM) in FLUENT. k-? standard, k-? Realizable, k-? SST and k-? RNG turbulence models of the RANS approach and the k -? SST model has been adopted to validate CFD results. In this study, the numerical results have revealed that the increase in groove depth decrease the temperature of the rotary kiln’s outer wall than the smooth walls and gives the largest Nu number, especially for the groove with h/D =0.3 and 0.4 depths. Journal of Thermal Engineering Journal of Thermal Engineering 2024-03-14T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6964 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6964 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6964

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6969 2024-03-22T21:00:00Z 4

Convective Thermal losses of Long-Term Underground Hot Water Storage Milan Rashevski, Slavtcho Slavtchev viscous fluid, unsteady natural convection, heat transfer, closed cavern, vorticity-stream function formulation, FDM numerical solution A case of underground long-term hot water storage is investigated numerically. The study is based on the unsteady two-dimensional Navier-Stokes equations in Boussinesq approximation applied to a closed cavern with time-dependent temperature boundary conditions on the walls. The problem formulated in a vorticity-stream function statement is solved by finite difference method (FDM) for high values of the Rayleigh number and for the Prandtl number of water. Streamlines, velocity and temperature fields are presented graphically for given moments of time. The evolution of the thermocline thickness in the mid-section of the cavern is slow and illustrates that the hot water zone occupies more than the half of the cavern even after 6 months period. The Nusselt number on the walls shows that the convective thermal losses are small and after certain period of time tend to decrease due to the diminished temperature difference at the walls. The influence of the fluid convection on the thermal losses is evaluated quantitatively, showing high seasonal thermal efficiency of the insulated hot water storage. Journal of Thermal Engineering Journal of Thermal Engineering 2024-03-22T21:00:00Z Technical Note application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6969 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6969 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6969

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7120 2024-09-10T21:00:00Z 1

New Design for the Cold Part of Heat Pipes Using Functionally Graded Material in Heat Sink with Variable Thickness Fins: An Analytical Approach Mojtaba BABAELAHI, Mohammad Amin BABAZADEH, Mahdi SAADATFAR Heat pipe, Condenser, Heat sink, FGM, Analytical solution This study proposed a new design for the cold part of heat pipes that utilizes a Functionally Graded Material (FGM) in the heat sink with power-law fins. The heat transfer in the heat pipes was evaluated using the heat resistance method, and it was shown that the new design improves the performance of the heat pipe. A sensitivity analysis of geometrical and operational parameters was also conducted to examine their effects on the thermal management system. The results indicated that decreasing the inner radius and increasing the outer radius of the FGM fin with a power-law profile improves the thermal behavior by decreasing the absolute temperature of the fin by up to 1 Kelvin degree. It was also found that increasing the ambient air and the fin's inner temperature had a negative effect on the fin's performance by decreasing the amount of convection heat transfer and cooling. The study also showed that increasing the convection heat transfer coefficient and grading index reduces the absolute temperature by up to 1.5 Kelvin degrees, while decreasing the thickness profile coefficients, and conduction heat transfer coefficients positively affected the dimensionless temperature of the fin. The article concludes that using the new heat sink design improves the heat pipe's performance and allows for the quick evaluation of the heat sink's efficiency using an analytical solution. Journal of Thermal Engineering Journal of Thermal Engineering 2024-09-10T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7120 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7120 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7120

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6966 2024-03-14T21:00:00Z 1

Enhancement in Air--Cooling of Lithium-Ion Battery Packs using Tapered Airflow Duct Vivek Satheesh, Navneet Krishna, Prakhar Singh Kushwah, Ishan Garg, Sharmista Rai, Gurumoorthy S Hebbar, Dileep V. Nair Computational Fluid Dynamics, Battery Thermal Management, Lithium-ion Battery, Temperature Uniformity Temperature uniformity and peak-temperature reduction of lithium-ion battery packs are critical for adequate battery performance, cycle life, and safety. In air-cooled battery packs that use conventional rectangular ducts for airflow, the insufficient cooling of cells near the duct outlet leads to temperature nonuniformity and a rise in peak temperature. This study proposes a simple method of using a converging, tapered airflow duct to attain temperature uniformity and reduce peak temperature in air-cooled lithium-ion battery packs. The conjugate forced convection heat transfer from the battery pack was investigated using computational fluid dynamics, and the computational model was validated using experimental results for a limiting case. The proposed converging taper provided to the airflow duct reduced the peak temperature rise and improved the temperature uniformity of the batteries. For the conventional duct, the boundary layer development and the increase in air temperature downstream resulted in hotspots on cells near the outlet. In contrast, for the proposed tapered duct, the flow velocity increased downstream, resulting in improved heat dissipation from the cells near the outlet. Furthermore, the study investigated the effects of taper angle, inlet velocity, and heat generation rate on the flow and thermal fields. Notably, with the increase in taper angle, owing to the increase in turbulent heat transfer near the exit, the location of peak temperature shifted from the exit region to the central region of the battery pack. The taper-induced improvement in cooling was evident over the entire range of inlet velocities and heat generation rates investigated in the study. The peak temperature rise and maximum temperature difference of the battery pack were reduced by up to 20% and 19%, respectively. The proposed method, being effective and simple, could find its application in the cooling arrangements for battery packs in electric vehicles. Journal of Thermal Engineering Journal of Thermal Engineering 2024-03-14T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6966 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6966 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6966

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6790 2023-07-28T21:00:00Z 1

Entropy Generation of Al2O3 / Water Nanofluid in Corrugated Channels Leila Saoudi, Noredine Zeraibi Entropy generation; Laminar flow; Nanofluid; Sinusoidal and square channel. The flow of nanofluids in a corrugated channel has been shown to have a significant impact on heat transfer performance, and has therefore become an important area of research. The objective of this paper is to understand the thermal behavior of Al2O3/water nanofluid in a sinusoidal and square channel and to identify ways to optimize heat transfer performance in such configurations. For this purpose, a numerical simulation was conducted using ANSYS-Fluent software 16.0 on entropy generation and thermo-hydraulic performance of a wavy channel with the two corrugation profiles (sinusoidal and square). The analyses were carried out under laminar forced convection flow conditions with constant heat flux boundary conditions on the walls. The influence of various parameters, such as particle concentration(0–5%), particle diameter(10nm , 40nm and 60nm), and Reynolds number(200 < Re < 800) on the heat transfer, thermal, and frictional entropy generation, and Bejan number was analyzed. Moreover, the distribution of streamlines and static temperature contours has been presented and discussed, and a correlation equation for the average Nusselt number based on the numerical results is presented. One of the most significant results obtained is that the inclusion of nanoparticles (5% volume fraction) in the base fluid yielded remarkable results, including up to 41.92% and 7.03% increase in average Nusselt number for sinusoidal and square channels, respectively. The sinusoidal channel exhibited the highest thermo-hydraulic performance at Re = 800 and ? = 5%, approximately THP = 1.6. In addition, the increase of nanoparticle concentration from 0% to 5% at Re=800 and dnp=10nm, diminishes the total entropy generation by 28.39 % and 22.12 % for sinusoidal and square channels, respectively, but when the nanoparticle diameter decreases from 60nm to 10nm at ?=5% and Re=800, the total entropy generation in the sinusoidal channel decreases by 34.85%, whereas in the square channel, it decreases by 20.05%. Therefore, rather than using a square channel, it is preferable and beneficial to use small values of nanoparticle diameter and large values for each of ? and Re in the sinusoidal wavy channel. Overall, the study of nanofluid flow in a wavy channel can provide valuable insights into the behavior of nanofluids and their potential applications in a variety of fields, including manufacturing, energy production, mining, agriculture, and environmental engineering. Journal of Thermal Engineering Journal of Thermal Engineering 2023-07-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6790 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6790 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6790

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6961 2024-03-14T21:00:00Z 1

Towards the Use of Natural Thermal Insulations on Exterior of the Vertical Walls in the Desert Regions: Case Study the City of Bechar, Algeria Slimane Ziad, Imane Benoudjafer, Ibtissam Benoudjafer Thermal insulation system, energy consumption, natural base, residential building, energy efficiency, desert regions. The use of natural-based exterior thermal insulation systems constitutes a significant challenge for achieving energy efficiency of construction. The purpose of this article is to propose new exterior thermal insulation solutions based on natural materials such as wood wool, cellulose wadding, expanded cork, hemp fiber, and sheep's wool, in order to minimize energy consumption, address durability concerns, maintain thermal comfort, and promote the use of natural materials in thermal insulation system designs. The methodology followed consists of presenting a comparative numerical study of different exterior insulation techniques (ETI) using a dynamic thermal simulator for desert regions. The study evaluated ETI systems for vertical walls attached to a concrete block wall, including one EPS system with coating (wet process) and six systems with cladding (dry process). The results show that applying exterior insulation to walls using the two cladding systems based on hemp fiber and sheep wool resulted in a total reduction in building energy consumption of 42.21% and 42.81%, respectively. These results confirm the effectiveness of natural materials in improving the energy performance of buildings, particularly the system based on sheep wool. Journal of Thermal Engineering Journal of Thermal Engineering 2024-03-14T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6961 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6961 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6961

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7014 2024-05-26T21:00:00Z 1

Numerical Study on Heat Transfer and Fluid Dynamics in Plate Heat Exchangers: Effects of Chevron Angle and Aspect Ratio Sami Kaplan, Kubilay Bayramoğlu, Mehmet Sarıkanat, Lütfiye Altay Heat transfer, friction factor, Nusselt number, Chevron angle, plate heat exchanger Determination of the geometrical parameters of the heat exchanger has important effects on the thermohydraulic performance of heat exchanger. In this study, the effects of geometric parameters of a plate heat exchanger on thermohydraulic performance were comprehensively investigated using computational fluid dynamics (CFD). Parametric studies were carried out on 8 different corrugated channel geometries with various chevron angles (ß) and aspect ratios (2b/?) for Reynolds numbers ranging from 500 to 3000. An entire fluid channel was numerically studied using the same mass flow rate and the Reynolds number. As results of the study temperature distribution, pressure gradient, velocity, turbulent kinetic energy distribution, Nusselt number, friction factor, and flow characteristics were evaluated comparatively for each case. It was determined that the sinusoidal corrugations promote the turbulence intensity and the swirling flow which leads to thermal boundary layer mitigation and enhanced convection heat transfer in response to the increasing of aspect ratio. The results of the study show that the (CFD) model is a reasonable and effective technique for displaying 3D contour plots, streamlines, and determining performance parameters. Journal of Thermal Engineering Journal of Thermal Engineering 2024-05-26T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7014 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7014 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7014

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6885 2023-12-08T21:00:00Z 1

Determination of Optimum Insulation Thickness in Submarines Savas Durmaz, Andaç Batur Çolak, Hatice Mercan, Ahmet Selim Dalkılıç "Energy saving," "life-cycle cost analysis," "optimum insulation thickness," "submarine," "thermal insulation" One of the most effective ways to save energy for cooling and heating applications is thermal insulation. Because of this, determining the ideal insulation thickness is a popular topic for publications. The purpose of this study is to determine the appropriate insulation thickness needed for a submarine's external construction while it is cruising in various locations. Since seawater makes up a submarine's external environment, situations involving five distinct seawater temperatures from around the globe have been studied. There are five of them: the Mediterranean, Marmara, Aegean, Black Sea, and Sakhalin, which is in the North Pacific Ocean and has the coldest seawater on earth. By using the idea of degree-days, the annual cooling and heating needs of submarines in various regions have been computed. Based on life cycle cost analysis, optimization has been accomplished. In the beginning, the results of a study published in the literature supported the calculation methods utilized. The use of insulation materials such as rock wool, glass wool, polyurethane, expanded polystyrene, fiberglass, and foam glass, as well as fuel oil to run the generator, has been taken into account in a number of calculations, including the best insulation thickness, annual savings value, annual energy cost, and payback period. The findings indicate that depending on seawater temperatures and insulation materials, the ideal insulation thicknesses range between 2 and 12 cm, energy savings between 8.5% and 90%, and payback periods between 1.1 and 10 years. Journal of Thermal Engineering Journal of Thermal Engineering 2023-12-08T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6885 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6885 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6885

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7119 2024-09-10T21:00:00Z 1

Investigation of a Standard Gate Valve in Terms of Flow Rate, Opening Distance and Wedge Angle with CFD Soner ENEKCİ, Usame DEMİR, Kadir YILMAZ Gate valve, CFD analysis, wedge angle, pressure drop Gate valves provide sealing with metal-to-metal friction. When the right interior parts are selected and the production is not made according to the right design criteria, internal leaks occur in the valves in the medium term. Considering the ideal pressure, velocity equations and design suitable for the process can be realized by determining the nominal pressure and velocity curves. This study designed a standard gate valve with 8-inch connection dimensions. Computational Fluid Dynamics (CFD) method investigated split, flexible and solid wedge types of the designed valve, 0.5, 1, and 2 m/s flow velocities for 4 and 5-degree wedge closing angles and 20 mm, 40 mm, 60 mm, 90 mm, and 120 mm opening wedge positions. Ansys Fluent software was used for the analyses. Mesh optimization was performed for the ideal mesh number and analyzed according to the ideal mesh number. The k-Epsilon turbulence model was used for simulations. The same situations were repeated for a parallel wedge (0-degree wedge seating angle). The lowest pressure distribution and pressure loss occurred in the parallel wedge compared to the opening position of other types of wedges. The best gate type obtained from the analysis results was determined, and an experimental tightness test was performed. It can be said that the soft seat gate valve, designed according to the results of the sealing test, gives approximately 2.5 times more opening-closing life than the metal gate valve, thus reducing the maintenance-repair costs. Journal of Thermal Engineering Journal of Thermal Engineering 2024-09-10T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7119 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7119 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7119

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6713 2023-03-03T21:00:00Z 1

Enhanced Performance of a Microchannel with Rectangular Vortex Generators Alişan Gönül, Abdulkerim Okbaz Flow Control; Genetic Algorithm; Heat Transfer Enhancement; Microchannel; Vortex Generators Microchannel heat sinks and heat exchangers are widely used in the cooling of electronic systems. However, it is still important to enhance the heat transfer in the microchannel so that the intense heat generated can be removed. Vortex generators (VGs) create secondary flow structures in the flow, increasing the fluid mixing, thinning the thermal boundary layer, and ultimately boosting heat transfer. Here, we have controlled the flow structure and improved the heat transfer with the lowest possible pressure loss by placing VGs of different sizes, numbers, and angles of attack in a microchannel. The improvement in heat transfer is accelerated as vortex intensity increases. The angle of attack has a significant impact on vortex formation lengths, which reach high dimensions around 90°. Furthermore, increasing the VG length significantly increases the vortex formation lengths. The number of VG pairs has a significant impact on heat transfer and pressure losses. As the number of VG pairs increases, so does the area occupied by the secondary flow regions in the microchannel, increasing the fluid mixture and boosting heat transfer. The highest enhancement in heat transfer using VGs is obtained at around 230%, while the corresponding increase in pressure loss is 950%. According to the JF factor which we consider a performance evaluation criteria, the best result is around 1.38. The Genetic Aggregation Response Surface Methodology has been applied to numerical results. The related method is realized to produce results that are consistent with the numerical results within a ±5% error interval. All the input parameters considered in the sensitivity analysis have an impact of at least 10% on the output parameters. Journal of Thermal Engineering Journal of Thermal Engineering 2023-03-03T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6713 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6713 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6713

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7015 2024-05-26T21:00:00Z 1

Emerging Trends and Global Challenges to Predict Pressure Drop in Thermal Performance of WTG Gearbox K. Sunil Kumar, Raviteja Surakasi , A Mohan, B. T. Tharanisrisakthi, Sumathy Muniamuthu, Geetha N.B. LDD analysis; Master gear box; Bearing failures; Ims failures; Hss failures The most of the wind turbines in India has the limit of generating the active power through wind power plant. The main reason behind this is insufficient velocity of air at higher altitudes; improper maintenance at periodic levels such as change in oil sump; indoor and outdoor inadequate maintenance of oil at required levels; improper or lack of modern technology and fault diagnosis tools etc., which leads to failure of necessary active power generation, which is to be generated in that particular year. Hence the modern wind turbine requires highly advance gearbox and associated parts with latest technology monitoring sensors to monitor the LDD data’s frequently as well as to identify the sources of poor LDD data; identify the sources of common failures occurred during the rotation of gearbox. Utmost 70% of drop of efficiency in wind turbine is due to the weak in thermal properties of the gearbox. This research work provides the overall idea about the nature of failures occurred during the rotation of gearbox for the entire year and types of thermal behaviour occurrences, which predominantly drops the thermal performance of the gearbox and wind turbines in India. Journal of Thermal Engineering Journal of Thermal Engineering 2024-05-26T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7015 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7015 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7015

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6962 2024-03-14T21:00:00Z 1

Comparative Evaluation of Experimental Ejector Refrigeration System for Different Operating Configurations Batuhan Üğüdür, Mehmet Direk Ejector, cooling capacity, COP, dual evaporator In this study, a comparative performance evaluation of an experimental ejector refrigeration system was conducted for various operating modes. The experimental setup was operated in different modes: conventional vapour compression refrigeration (CVCR), conventional dual-evaporator system (CDES), and dual-evaporator ejector system (DEES). The system was tested under different operating conditions, including varying condenser temperatures and mass flow rates. The results of the evaluation showed that the highest total cooling capacity and coefficient of performance (COP) were achieved in the DEES mode, while the lowest total cooling capacity was observed in the CDES mode. The lowest compressor power was calculated when the system was operated in DEES mode. When the condenser temperature was 33°C, the compressor power obtained in the DEES was 22.7%, 5.4%, and 17.7% lower than that of the CVCRA, CVCRB, and CDES modes, respectively. In conclusion, the performance of the ejector-operated system was found to be superior to the other configurations, and the ejector contributed positively to the system performance. Journal of Thermal Engineering Journal of Thermal Engineering 2024-03-14T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6962 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6962 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6962

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7023 2024-05-26T21:00:00Z 3

Heat Enhancement in Solar Flat Plate Collectors – A Review Abinicks Raja G., Rajamurugu Natarajan, Pratik R. Gaikwad, Eleena Basil, Sahil D. Borse, Sundararaj M. Solar, Collectors, Heat transfer, Renewable Energy, Nano fluids This article provides an overview of recent advancements in the design and performance of flat plate solar collectors (FPSCs) for solar thermal power plants. The article highlights various strategies that have been explored to improve the efficiency of FPSCs, including the use of Micro Heat pipe Arrays, nano-materials, phase change materials, and novel tube geometries. The study emphasizes the importance of keeping costs low while improving overall collector efficiency and highlights the research gap in distinct aspects of FPSCs for heat enhancement. The article concludes that these advancements have the potential to significantly increase the use of solar thermal power, which could play a critical role in reducing our dependence on fossil fuels and mitigating climate change. This study examines the power potential and carbon emission reduction capabilities of solar collectors in India, taking into account the local climatic conditions and geographical location. The study also identifies major challenges and opportunities in the current research domain. Based on the analysis, the study highlights the opportunities for commercializing low cost solar plants in India. Journal of Thermal Engineering Journal of Thermal Engineering 2024-05-26T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7023 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7023 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7023

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7109 2024-09-10T21:00:00Z 1

Energy, Exergy and Performance Analysis of a 380 kWp Roof-Top PV Plant Assisted with Data-Driven Models for Energy Generation Abhijeet RATHORE, ALMAS, Sivasankari SUNDARAM energy efficiency, exergy efficiency, testing for non-trained location, deep-learning and 380 kWp PV plant. Energy and Exergy based performetric analysis integrated with deep learning assisted energy modelling for grid connected solar PV system, tested to non-trained location is proposed. The first objective is to perform an energy and exergy based performetric analysis for a realistic 380 kWp grid connected roof-top PV system whose performance parameter is used for testing the proposed energy prediction models. The second objective is to formulate a simple and an improved energy estimation method applicable for 34 locations in South India, without change in model-coefficients. So, a long-term annual performance analysis of a 380 kWp PV based distributed generator situated at 12.970N and 77.590E is performed which estimates the characteristic performance indicators like energy efficiency, exergy efficiency, performance ratio and capacity factor amounting to 8.49 %, 1.03%, 37%, and 8.03% respectively. The performance ratio of the plant is less as evident from the least exergy efficiency. The annual average losses in the system like thermal capture loss, array capture loss, system loss and miscellaneous loss amount to 0.46 (h/d), 2.51(h/d), 0.71 (h/d) and 2.97(h/d) respectively. The annual average energy generation of 380 kWp is 732.84 kWh/year. Furthermore, for realising the second objective, a total of four models are proposed namely linear, exponential, non-linear and deep learning based neural network model resulting in R of 0.933, 0.9071, 0.9386, and 0.9603 respectively is formulated. The proposed models are tested for non-trained locations where the R value justifying the closeness between the actual and the predicted value is as high as 0.8. The proposed models are then compared upon their performances and benchmarked against the reported models. Journal of Thermal Engineering Journal of Thermal Engineering 2024-09-10T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7109 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7109 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7109

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6804 2023-07-31T21:00:00Z 1

Parameter Optimization of Coriolis Mass Flow Meter in Laminar Flow Regime Using DOE-Taguchi Method Vikram Kolhe, Suyash Pawar, Vishal Chaudhari, Ravindra Edlabadkar, Sandipkumar Sonawane Coriolis mass flow meter, Error analysis, Analysis of variance, Taguchi approach, Laminar flow, Tube configuration The paper outlines the progression of a mathematical model using the Taguchi approach to analyze the performance of a Coriolis mass flow meter (CMFM). The sensor position, excitation frequency, and flow rate parameters were optimized using the Taguchi method for the meter's maximum time-lag output. An orthogonal array of experiments was designed, and the time lag results were obtained for two tube configurations (viz. Omega and Diamond) and parameter levels. The obtained data was analyzed using analysis of variance (ANOVA) to understand the relationship between the variables and the time lag. The results showed that the Omega tube configuration exhibited a lower percentage error compared to the Diamond tube configuration. Additionally, an increase in flow rate led to a decrease in the error. The regression models fitted the experimental data well, with high R2 values indicating a good fit. The ANOVA showed the factors' importance in affecting the time lag and the levels of interaction between the best individual parameters for maximizing the outcome. The most important factors affecting the Omega and Diamond tube configurations' maximum performance have been identified as the flow rate and sensor position, respectively. This study offers a systematic method for optimizing sensor parameters and provides light on how CMFMs behave in laminar flow. The experimental setup and mathematical model also serve as a basis for future research and advancements in CMFM design and functionality. Journal of Thermal Engineering Journal of Thermal Engineering 2023-07-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6804 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6804 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6804

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7024 2024-05-26T21:00:00Z 3

Thermodynamic Analysis of Solar Assisted Binary Vapour Cycle Using Ammonia-Water Mixture and Transcritical CO2 : A review Ayoushi Srivastava, Mayank Maheshwari Power cycle, Power generation system, SAPG, Binary cycle power plant The primary focus of this review article is to examine the power cycles employed for generating electricity from steam-dominated resources. It discusses the phenomenon of Transcritical CO2 (T- CO2) power cycles and the Rankine Cycle, which have been extensively studied by numerous academics. The article also briefly explores fuel-cell-based power plants using binary cycles, geothermal power plants, and solar-assisted power plants. The article presents information on power generation, thermal efficiency, energy efficiency, and exergy efficiency of these plants. The investigation reveals that geothermal power plants have thermal efficiencies ranging from 6.5% to 16.63% and exergy efficiencies ranging from 7.95% to 82%, producing power in the range of 199.1 kW to 19,448 kW. Solar power plants produce power ranging from 550.9 kW to 4500 kW, with energy efficiency between 21.93% and 57% and exergy efficiency between 50.5% and 64.92%. Fuel cell power plants using NH3+H2O as the working fluid generate power from 1015 kW to 20125 kW, with thermal efficiency between 25.4% and 70.3% and exergy efficiency between 12.1% and 36%. The article highlights the use of the Kalina cycle in these scenarios. Journal of Thermal Engineering Journal of Thermal Engineering 2024-05-26T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7024 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7024 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7024

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6965 2024-03-14T21:00:00Z 1

Enhancement in Thermal and Electrical Characteristics of Solar Photovoltaic Module through a Direct Contact Water Jacketed Cooling System Deepak kumar Sharma, Manish Rathod, Purnanand V. Bhale Electrical efficiency, PV/T, Solar cell, Temperature, Water jacketed cooling system Renewable energy resources are vital for addressing the universal concerns of air quality, energy security, and sustainable development. Solar energy has several benefits over other popular renewable energy sources, such as its accessibility and increased predictability. The device used for conversion of solar energy to electrical energy is known as photovoltaic panel, which is highly sensitive to the temperature. A significant reduction in efficiency is observed with an increment in temperature hence cooling of photovoltaic panel is highly desirable. Among the different cooling techniques, water cooling is attractive and widely used due to its good thermal properties and availability. Generally, panel cooling through water circulation in tubing is explored in past, however, these tubing structures are having some limitations such as heat transfer barrier, limited surface area, leakage issues, clogging and cost of material. These issues can be partially resolved by using direct contact water jacket cooling system. Therefore, the present study focuses on in enhancing the thermal and electrical characteristics of the solar photovoltaic module through a direct contact water jacketed cooling system. Initially, a 3D numerical model is developed and the outcome of the numerical model is compared with the experimental work. The results obtained are found in good agreement for solar cell temperature and water outlet temperature. The solar panel performance is investigated with different flow rates such as 0.01, 0.05, 0.1 and 1 cm/s. The direct contact water jacketed cooling system offers simplicity, light weight and cost effectiveness and is found promising over the indirect system. Temperature reduction up to 20 °C is observed over uncooled PV panel whereas enhancement in electrical efficiency up to 9.6 % is observed. The cooled PV solar cell maintain 40.2% low temperature compare to uncooled solar cell temperature. Journal of Thermal Engineering Journal of Thermal Engineering 2024-03-14T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6965 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6965 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6965

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6974 2024-03-22T21:00:00Z 1

Influences of Iso-Amyl Nitrate Oxygenated Additive on Mahua Methyl Ester/Diesel Blends Thermal Stability and CRDI Engine Performance Characteristics Putha Prasad Kumar, Srinivas Pendyala, S.K. Gugulothu Mahua oil, ignition improvers, optimisation, trade-off study and engine characteristics. Mahua oil is a remarkable fuel since it has a similar calorific value to diesel and has similar viscosity, flash point, and boiling points to diesel. However, since mahua oil has a lower cetane number than diesel when utilized as a blend, it displays a longer ignition delay and a greater peak heat release rate, resulting in higher NOx emission. To decrease the negative impact of mahua oil on NOx emission, an effort is made to introduce the ignition improver in different proportions (i.e., 5-20% by vol). Due to its higher latent heat, IAN shows some adverse effects on performance and emission outcomes. An investigation is conducted on a CRDI engine using mahua methyl ester blended with diesel by adding oxygenated additives to the engine characteristics. The emissions like HC, CO, and smoke were reduced by 16.32, 23.56, and 23.12%. The improved combustion process increases NOx and CO2 emissions by 13.62 and 19.89%. Also, an increase in HRR and CP values was noticed at full load operation. Additionally, it is observed that the engine's performance is enhanced using 15% Iso-amyl nitrate (IAN), indicating that the IAN blend is a useful ignition improver for mahua oil and diesel blends. Journal of Thermal Engineering Journal of Thermal Engineering 2024-03-22T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6974 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6974 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6974

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6881 2023-12-08T21:00:00Z 1

A Thermohydrodynamic Performance Analysis of a Fluid Film Bearing Considering with Geometrical Parameters Abdurrahim Dal, Mahir Şahin, Mustafa Kılıç Journal bearing, thermo-hydrodynamic analysis, bearing geometrical parameters Bearing performance characteristics such as stiffness, and load capacity, are related to the lubrication fluid circulating through the gap. In the fluid film bearings, the characteristic of the lubrication film also depends on the journal geometry and the viscosity. This study aimed to research the bearing geometry influences on the thermohydrodynamic performance of a circular journal bearing. The temperature distribution is modeled using a 3-dimensional energy equation. The velocity components are obtained on the pressure distribution governed by Dowson’s equation. Moreover, the heat transfer between the journal and oil is modeled with Fourier heat conduction equation, and the viscosity equation is derived for SAE10W30 commercial oil as a function of the temperature. An algorithm based on the finite difference method is developed, and a serial simulation is performed for different geometrical parameters such as bearing clearance, and bearing length-to-diameter ratio (L/D). When the radial clearance decreases from 150 µm to 100 µm, the maximum pressure grows up by 53%, and the maximum temperature decreases by 21%. On the other hand, when the L/D ratio rises from 0.8 to 1, the maximum pressure grows up by 22%, but the temperature distribution does not significantly change. The load capacity, and the stiffness are higher for low radial clearance. The load capacity, and the stiffness increase when the L/D ratio grows up. Journal of Thermal Engineering Journal of Thermal Engineering 2023-12-08T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6881 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6881 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6881

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7016 2024-05-26T21:00:00Z 1

Impact of Biodiesel Blends on Performance, Emissions and Waste Heat Recovery of Diesel Engine Driven Cogeneration System Saini Mahesh Chand, Jakhar Om Prakash, Khatri Rohit Diesel engine, Brake thermal efficiency, Biodiesel blends, Waste heat recovery, Emission characteristics. Due to the rapidly increasing energy demand, the world needs to focus more on identifying alternative energy sources like biofuels and energy conservation techniques that enhance the efficiency of various systems. A cogeneration (CHP) system is one of the most emerging techniques for achieving the goal of energy conservation by providing useful power (electricity) and heating simultaneously. So the current study proposes a diesel engine-driven CHP system that is fueled with different blends of biodiesel. The objective of the current study is to investigate the impact of Eureka Sativa oil biodiesel on waste heat recovery, performance, and emission characteristics of diesel engine driven combined heating and power generation system. The cogeneration unit is developed by connecting the exhaust pipe of a single-cylinder, four-stroke diesel engine with a heat exchanger. The pure diesel, along with 10%, 15%, 20%, and 25% by volume of biodiesel, was used as fuel for the cogeneration unit. The AVL DiGas 444N multi-gas analyzer was utilized to evaluate the engine exhaust gas emissions. Diesel fuel has the highest brake thermal efficiency and the lowest brake specific fuel consumption (BSFC). B20 has the highest brake thermal efficiency and the lowest BSFC among all blends of biodiesel. Also, B20 has better emission characteristics than all other blends of biodiesel. The exhaust gas temperature and waste heat recovery increase with the percentage of biodiesel in the blends. The B25 has the highest overall efficiency (38.49%) among all blends, which is 1.93 % lower than pure diesel. However, result analysis revealed that B20 is the best fuel among all biodiesel blends in terms of engine performance and emission formation. Whereas B25 is a better fuel in terms of WHR and overall cogeneration unit efficiency. Journal of Thermal Engineering Journal of Thermal Engineering 2024-05-26T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7016 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7016 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7016

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7210 2025-01-30T21:00:00Z 1

Numerical investigation on comparative performance assessment of solar air heater with different artificial roughness elements in a triangular duct Rafiuzzama SHAIK, Eshwaraiah PUNNA, S. K. GUGULOTHU Artificial Roughness; Renewable Energy; Solar Air Heater; Triangular Duct and Reynolds Number. In this study, various roughness geometries on the absorber plate are examined to analyze their effects on fluid flow and heat transfer characteristics, focusing on parameters like the Nusselt number and friction factor. These geometries were examined in solar air heaters with triangular passages. The modified duct with different artificial roughness geometries is compared with a conventional triangular duct. In contrast to a smooth SAH, an increase in Nusselt number of 7.42 times and friction factor of 6.12 times is observed. With the increase of Reynolds number from 4000 to 20000, average Nusselt number and thermal performance parameters are increased in the case of semi-circular rib by 15.23% and 16.23% compared with the other roughness elements. The frictional penalty is decreased by 23.43% at maximum Re compared with the other roughness elements. The increase in frictional losses at lower Reynolds numbers is attributed to the reduced velocity of the airflow. Also, using semi-circular intrusions as artificial roughness, the Nusselt number value increases considerably, proving our innovation’s capability. It is discovered that the suggested SAH with square and rectangular shaped rib performs better than traditional SAH under comparable shaped roughness components. However standard SAH is a superior choice for other roughness geometries. Journal of Thermal Engineering Journal of Thermal Engineering 2025-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7210 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7210 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7210

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6877 2023-12-08T21:00:00Z 1

Drying Model Based on the Relative Humidity Profile of Thin-Layer Tomatoes in an İndirect Solar Dryer Ahmed Alami, Lala Rajaorisoa, Mohammed-Hichem Benzaama, Abdeldjalil Benbakhti Drying model, experimental model, drying dynamics, dryer design. This work defined the development of a model for thin-film drying of tomatoes using an indirect solar dryer. Drying experiments were carried out and the drying model was approximated by a simplified model determined by the measurements collected during the experiments, in particular, the measurement of the relative humidity of the tomato during two days of drying coupled with the thermal behaviour of the drying device in free convection. The results show that with good measurements, it is possible to approximate the drying characteristic curve by a linear model with very high statistical performance indicators. The experiments also show that depending on the drying process adopted, the water behaviour of the tomato can change. In addition, the thin-film drying model adopted made it possible to assess the solar drying kinetics of the tomato variety studied. The results obtained finally show that the dryness of the tomato is reached after about 14 hours of drying. The drying temperature reaches an average of 80°C, and the final product water content after the optimal drying time is about 0.40 kg.water/kg.ms on a dry basis. Journal of Thermal Engineering Journal of Thermal Engineering 2023-12-08T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6877 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6877 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6877

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6871 2023-12-08T21:00:00Z 1

Analysis of Thermophysical Properties of Novel Hybrid Nanoparticles Based Vegetable Nanofluid Amol J. Asalekar, D.V. A. Rama Sastry, M. B. S. Sreekara Reddy, Surendra D. Barewar Hybrid nanoparticles, vegetable oil, thermal conductivity, ANN. Nano additive-based vegetable-oil fluids are play vital role to the conventional thermal applications due to their contribution to improved thermophysical properties. This work is focused on the synthesis and characterization of a novel ZnO-Ag hybrid nanoparticles-based sunflower oil for thermal applications. Firstly, the ZnO-Ag hybrid nanoparticles were prepared by a wet chemical approach and characterized using SEM and TEM. The synthesized hybrid nanoparticles were then mixed in the sunflower oil to prepare various nanofluids at different volume concentrations (?) ranging from 0.05 to 0.20%. The stability of the prepared nanofluids was investigated as a function of Zeta potential and visual examination. Further, the thermal conductivity and viscosity of prepared nanofluids was measured by the KD2-pro analyzer and Brookfield viscometer. The result showed that the thermal conductivity of prepared nanofluids was increased up to 21.01% at ? = 0.20% nanoparticles volume concentration. Finally, an artificial neural network model was developed to accurately predict the thermal conductivity of prepared nanofluids. Journal of Thermal Engineering Journal of Thermal Engineering 2023-12-08T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6871 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6871 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6871

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7018 2024-05-26T21:00:00Z 1

Effect of Steam Addition on the Combustion, Performance and Emissions Characteristics of an HCCI Diesel Engine Mushtaq Ahmad Rather, M. M. Wani EGR, HCCI, combustion efficiency, emissions,HCCI, Diesel engine, Steam addition, NOx emissions, Unburned hydrocarbons, Thermal characteristics Although homogeneous charge compression ignition (HCCI) diesel engines are the favored source of power with near zero oxides of nitrogen (NOx) and particulate matter emissions owing to a higher degree of homogeneity and elimination of diffusion phase combustion, the main drawback is the uncontrolled start of combustion along with high CO and unburned hydrocarbon emissions. In the present work, experimental investigations were carried out on a single cylinder diesel engine operating in HCCI combustion mode using external air-fuel mixture preparation. The regulated percentage of steam is added inside the mixing chamber and the effects on the combustion, performance and emission characteristics were reported for various steam injection rates at different brake mean effective pressures. The results obtained show that the brake thermal efficiency was improved to 21.048% with the addition of 20% steam addition and the NOx emissions were also reduced significantly. The emissions of CO and unburned hydrocarbon were found 0.7% and 93 ppm respectively at the steam addition rate of 20%, however a rapid increase was observed if the steam injection rate was increased further. Overall, the present work shows that by the addition of steam, the CO and unburned hydrocarbon emissions can be reduced significantly along with NOx emissions and also there is a greater potential to control the start of combustion. Journal of Thermal Engineering Journal of Thermal Engineering 2024-05-26T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7018 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7018 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7018

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6884 2023-12-08T21:00:00Z 1

Design and Development of Air Ventilated Air Bed for Hospitalized Patients Darshan Karanje, Sanket Hon, Shivroop Patil, Shivraj Gursal, Prafulla Hatte Air Ventilated Air bed, Hospitalized patients, bedsore, ventilation Proper ventilation is a critical consideration for the comfort of hospitalized patients. Dry skin, skin rashes, weariness, poor sleep, and other concerns caused by insufficient ventilation can all be avoided with proper ventilation. Air-Ventilated Air Beds are used to supply air to the major parts of the patient’s body. This air bed is constructed in such a way that air is circulated continually throughout the body of the hospitalized patient. It is especially beneficial for people who are bedridden and need to spend a significant amount of time in bed due to illness. Excessive heat generated between the bed and the patient is perhaps the common cause of bedsores. Sweating is the leading cause of bedsores. Air ventilation is included in the system to prevent sweating and reduce the incidences of bedsores. Dual compressors, rubber tubes, flow control valves, and anti-decubitus mattresses are among the components used. The rubber tubes are used to ventilate the space between the body of the patient and the upper surface of the air bed. Above the mattress, the rubber tube mesh is positioned. The air is first compressed in two compressors before passing through the distribution manifold and through the meshing. The tubes are altered by drilling holes at certain intervals. The air from the compressor is circulated through the pipes before passing through the openings in the pipes. The unrestricted passage of compressed air via a capillary tube lowers the temperature of the air. The air exhausted through the capillary tubes maintains the patient's body temperature stable for a while before lowering it. The air is ventilated throughout the bed in this manner. Bedsore can be avoided by reduction of sweat by using the air in close contact with the patient. Journal of Thermal Engineering Journal of Thermal Engineering 2023-12-08T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6884 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6884 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6884

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7125 2024-05-28T21:00:00Z 1

Numerical Simulation of the Shell Cooling of a Rotary Kiln Bouhafs MOHAMMED, Meghdir ABED, Bouchentouf Ikram MIMOUNA rotary kiln, shell, heat transfer, fins, efficiency The rotary kiln is considered the heart of cement manufacturing plants, so any malfunction can lead to significant losses for the company. These equipments are exposed to very high thermal stresses through the three modes of heat transfer, conduction, convection, and radiation. They are also subject to very important mechanical stresses at the level of the drum shell, the tires, the mass of refractory bricks, and the formation of the crust inside the kiln during start-up. The temperature of the flame is around 2000 °C, that of the internal material of the kiln can exceed 1450 °C, and the external temperature of the drum shell can reach 500 °C, particularly in the burning zone. These temperatures can lead to elastic and even plastic deformations. The aim of our study is to numerically simulate the cooling of the drum shell, in its burning zone over a length of 17 m, by placing 72 square-shaped fins on its external surface. This study is a continuation of another one that has already been published [1]. The numerical method used is the finite element method as implemented in the ANSYS Workbench calculation code. The results presented are based on the distribution of the external temperature of the drum shell in the burning zone for different cases. The results obtained show a decrease in the external temperature of the drum shell of about 40% in the case of a drum shell equipped with fins compared to one without fins. Journal of Thermal Engineering Journal of Thermal Engineering 2024-05-28T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7125 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7125 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7125

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7157 2024-11-18T21:00:00Z 1

Exergetic Performance Evaluation of a Phase Change Material Integrated Solar Still Sudeepthi A, Arun P. Double Slope Solar Still; Energy Storage; Exergy Efficiency; Phase Change Material (PCM); Thermal Efficiency; Volumetric Heat Generation. Solar desalination has a significant potential for addressing the increasing water scarcity of the world. Solar stills offer a sustainable solution for desalination of brackish water. Integration of Phase Change Material (PCM) in the still is one of the options for enhancing its productivity. Integration of PCM in solar stills has gained attention due to its capability to efficiently store and release thermal energy thereby enhancing its productivity. The present work proposes a modeling framework for the performance assessment of simple double slope solar stills integrated with PCM. The methodology is based on energy and exergy balance of the overall system. The exergy destruction associated with the still has been evaluated for the basic still and is compared with the case of PCM integrated still. The developed mathematical modeling framework is validated based on comparisons with the experimental observations for the south Indian location of Kozhikode. Lauric acid is considered as the representative PCM due to its favorable thermal properties for the application in solar stills. There is a reasonable agreement between the theoretical and experimental observations. With the incorporation of lauric acid as the PCM in the system, daily yield, daily thermal efficiency and exergy efficiency were found to be increased by 8.9%, 10.6%, and 3% respectively. A generic modelling framework for energy and exergy-based performance assessment of a PCM integrated still has been presented, which will be a useful tool for system optimization. Integration of different PCM with enhanced thermal properties are planned as future work for overall system optimisation for maximum energy efficiency. Journal of Thermal Engineering Journal of Thermal Engineering 2024-11-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7157 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7157 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7157

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7019 2024-05-26T21:00:00Z 1

Performance Analysis of a New Combined Cascading Absorption-Adsorption Refrigeration System to Improve Performance Majdi T. Amin Cascaded system, Adsorption; Absorption, Refrigeration, low grade heat source In this study, a new cascaded absorption-adsorption refrigeration cycle (ABS-ADS) is investigated under a variety of various operating conditions. Combined both absorption and adsorption refrigeration cycles can increase the overall energy performance. The condenser of the ABS cycle is cooled down by the evaporator of the ADS cycle. In this way, low-temperature cooling at low-grade heat source temperatures may be provided, and the benefit of each cycle can be utilized. Additionally, a comparison is also made between the performance of the proposed ABS-ADS and that of the standalone ABS and ADS cycles, as well as with other studies taken from the literature. Results demonstrated that, at heat source temperatures of 75oC, the cooling capacity of the proposed cascade ABS-ADS (25.5 kW) is greater than that of ABS and ADS by 16.8 and 177% with 0.644, 0.69, and 0.36 systems COP, respectively. In addition, it is superior to that of the ABS and ADS by 8.39% and 44%, respectively. The influence of mass flowrate of the heat source is high in the range lower than 1.0 kg/s; however, when the mass flowrate is more than 1.0 kg/s, the impact on the cooling effect and the COP is only marginal. When the flow rate of the solution pump is increased from 0.06 to 0.16 kg/s, the cooling capacity grows linearly from 16 to 44 kW, and the COP increases from 0.61 to 0.63. Increasing the temperature of the chilled water from 8 to 16oC raises the cooling capacity linearly from 20.6-36 kW and the COP from 0.58 to 0.622. In conclusion, the performance of the suggested cascade ABS-ADS cycle can operate effectively at low-grade heat sources and produce good thermal performance in comparison to other former studies. Journal of Thermal Engineering Journal of Thermal Engineering 2024-05-26T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7019 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7019 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7019

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6967 2024-03-14T21:00:00Z 1

Temperature and Salt Concentration Behavior of a Compact Rectangular Salinity Gradient Solar Pond DhandapaniSathish, Selvaraj Jegadheeswaran, Murugan Veeramanikandan, Seepana Praveenkumar, Raja Thirunavukkarasu Solar radiation, Thermal storage, Performance enhancement, Convection, Salinity gradient, Solar pond Design of economical and effective sola ponds which are useful thermal energy storage devices, remains a huge challenge. The present work aims at investigating the thermal performance of low cost mini salt gradient solar pond. The portable pond was fabricated as a rectangular configuration having a volume of 0.5m3. Polystyrene and high density polyethylene sheets were employed for insulating the walls. The top of the pond was covered with a slender glass so that the dust accumulation could be prevented without affecting the absorption of solar radiation. Sodium chloride salt was used as the medium and the three salt gradient regions namely lower convective, non-convective, and upper convective regions were established through injection filling technique. The temperature and salt gradient data were observed experimentally for a period of 20 days at Coimbatore, India. The pond could absorb significant amount of available radiation (around 65%) and the maximum temperature of the pond was observed to be 49oC. Frequent washing of the water surface is necessary to maintain stable salt gradient. Nevertheless, portable pond fabricated with low cost materials exhibited good potential of storing solar energy for solar thermal applications. Journal of Thermal Engineering Journal of Thermal Engineering 2024-03-14T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6967 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6967 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6967

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6968 2024-03-14T21:00:00Z 1

Study on Exhaust Gas Recirculation Diesel Engine using Karanja Oil Methyl Ester with Low Heat Rejection in Direct Injection Ravisankar Rajendran, V.S.K. Venkatachalapathy, K. Velmurugan, M. Elangovan, P. Balu KOME, LHR, EGR, BTE, HC, CO Energy is a fundamental necessity for man's life in the digital world today. The rapid depletion of fossil fuel resources forces rigorous alternative fuel analysis. Petroleum diesel can better replace vegetable oils edible or not edible. Karanja may be a possible supplier of diesel fuels for non-edible oil substitution. Current combustion surfaces for pistons and valve and cylinders have been filled with ceramic materials which make the engine totally adiabatic (LHR). The performance of biodiesel powered compressing ignition (CI) engine may be further boosted by utilising the engine's heat effectively and so increasing thermal efficiency. Exhaust Gas Recirculation (EGR) is actually one of the most important methods of limiting NOx emissions in internal combustion engines. Explore the output with and without exhaust gas recirculation on a retarded timing engine, with diesel and karanja oil methyl ester (KOME). The LHR with a retarded timing engine yielded improved thermal brake efficiency (TBE), decreased HC, smoke and CO emissions, while increasing KOME's NOx in comparison With a engine uncoated. As the EGR rate grew, the NOx and BTE were reduced marginally with increased HC, CO and smoke. 24.1 g/kw-hour CO, 10.1 g/kw-hour NOx and 0.55 g/kW-hour HC were registered at 20 percent of EGR Journal of Thermal Engineering Journal of Thermal Engineering 2024-03-14T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6968 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6968 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6968

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6959 2024-03-14T21:00:00Z 1

Performance Evaluation of Hybrid Nanofluid-Filled Cylindrical Heat Pipe by Machine Learning Algorithms K. Kumararaja, B. Sivaraman, S. Saravanan Hybrid nanofluid, Cylindrical heat pipe, Machine learning, Regression algorithms, Outlet temperature, Error The current study attempts to predict the outlet temperature of a hybrid nanofluid heat pipe using three machine learning models, namely Extra Tree Regression (ETR), CatBoost Regression (CBR), and Light Gradient Boosting Machine Regression (LGBMR), in the Python environment. Based on 7000 experimental data (various heat input, inclination angle, flow rate, and fluid ratio), different training (95%–5%) and testing (5%–95%) split sizes, a closer prediction was attained at 85:15. The three attempted machine learning models are capable of predicting the outlet temperature, as evidenced by the less than 5% deviation from the experimental results. Of the three attempted machine learning models, the ETR model outperforms the other two with a higher accuracy (98%). Further, the sensitivity analysis indicates the absence of data overfitting in the attempted models. Journal of Thermal Engineering Journal of Thermal Engineering 2024-03-14T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6959 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6959 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6959

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7011 2024-05-26T21:00:00Z 1

Energy, Exergy and Economic Analysis of Ammonia-Water Power Cycle Coupled with Trans-Critical Carbon Di-oxide Cycle Ayoushi Srivastava, Mayank Maheshwari Super critical carbon dioxide, Ammonia water mixture, Heat recovery vapor generator, Second law efficiency, First law efficiency, Irreversibility Power plant engineers today are primarily focused on maximizing the extraction of fuel energy. This objective involves improving the efficiencies of different thermodynamic elements and the overall cycle in terms of both first and second laws of thermodynamics. To achieve this, engineers are employing various techniques aimed at increasing these efficiencies. In the present work, one such technique being utilized is the substitution of water/steam with a different working fluid. By changing the working fluid, engineers aim to optimize the thermodynamic performance of the power plant. In this study, the analysis focuses on the utilization of an ammonia-water mixture combined with transcritical carbon dioxide in a heat recovery vapor generator. The results of this research reveal that the highest work output and second law efficiency achieved are 1192 kJ/sec and 81.68% respectively. These optimal values are obtained when the topping cycle pressure is set to 50 bar, and the turbine inlet temperatures are 500°C and 300°C for the ammonia-water mixture and transcritical carbon dioxide respectively. Furthermore, the maximum first law efficiency of 43.57% is observed when the topping cycle pressure is set to 50 bar, the bottoming cycle pressure is set to 160 bar, and the turbine inlet temperature is 300°C. The analysis also reveals that the heat source is responsible for the majority of exergy destruction, with a maximum of 1970 kJ/sec of available energy being destroyed at a temperature of 500°C. To achieve the highest values of thermodynamic performance parameters, it is recommended to maintain low pressure in the absorber and condenser. Additionally, the analysis indicates that the cost of electricity generation reaches its peak when the condenser pressure is set at 70 bar, amounting to 0.050 USD/kWh. Journal of Thermal Engineering Journal of Thermal Engineering 2024-05-26T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7011 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7011 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7011

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6976 2024-03-22T21:00:00Z 1

Thermal and Dynamic Characterization of a Multi-jet System with Different Geometry Diffusers Naas Zahout, Mohamed Braikia, Ali Khelil, Hassane Naji Dynamic homogenization; Circular jet; Lobed jet; Swirling jet; Experimental study; Numerical simulation; Turbulence Model SST k-ω. This paper proposed to use the impinging jets mixing process to improve the quality of residential heating and air conditioning. The main objective is to meet the requirements of occupants in terms of thermal comfort and air quality by proposing an optimal solution for the thermal homogenization improvement in the rooms by changing of the diffusers geometry and their arrangement in the ventilation and air-conditioning devices in blowing systems. This study involves both experimental and numerical studies of a three diffusers configurations composed of four peripheral jet with similar geometries and a central jet with a different geometry. All the configurations consist of four equidistant peripheral swirling jets, only the central jet that makes the difference between them. The configuration 1 includes a swirling central jet, on the other hand a circular central jet for the configuration 2 and finally a lobed central jet for configuration 3. The velocity and temperature distributions of the three configurations are investigated experimentally and numerically. Experimentally, the multifunction thermo-anemometer have been used to measure flow temperature and velocity. The dynamic and temperature features are more radially spread and get better homogeneity in configuration 3 and this is due to the energy distribution on the radial plane, which is relatively better than configuration 1 and configuration 2. The second part deals with numerical predictions of the dynamics and thermal fields of the three configurations considered. The study was realized using a RANS-based turbulence model. The numerical results are in reasonable agreement with our experiments for the three configurations. With this study, detailed information on the structure of the resulting flow is very useful to deepen the understanding of the physics of jet interaction and to validate turbulence models. The turbulence simulation is realized by the k-?-SST model. This model gives a satisfactorily predicts the axial drop in velocity and temperature over the entire study range, demonstrating its ability to handle the interaction between swirling and lobe jets. Our results show that the geometry of the central diffuser is essential. This allows the axial velocity to decrease faster than configurations 1 and 2. This increases lateral diffusion, resulting in better homogenization. Journal of Thermal Engineering Journal of Thermal Engineering 2024-03-22T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6976 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6976 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6976

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7009 2024-05-26T21:00:00Z 1

Dufour and Soret Effects on Unsteady MHD Mixed Convective Flow Across a Stretching Curved Surface with Thermal and Velocity Slip: A Numerical Study Temjennaro Jamir, Hemanta Konwar Unsteady; Curved surface; Thermal slip; Velocity slip; Soret effect; Dufour effect; heat and mass transfer The current research relates to numerical analysis of the unsteady MHD mixed convective flow over a curved stretching surface. The Dufour and Soret effects, chemical reaction and joule heating are accounted into the flow together with the thermal and velocity slip effects. The governing partial differential equations of the flow which are in curvilinear coordinates are transformed into ordinary differential equations by using suitable similarity transformations. The numerical results are obtained using the MATLAB built-in solver bvp4c. The stability of the numerical technique has been verified and compared with the available literatures. The resultant boundary layer flow field parameters and the parameters of engineering interest have been presented graphically along with tabular data. The results thus obtained show that the surface drag significantly drops by about 9.4% and 23.4% respectively upon enlargement of the curvature parameter (0.5?K?0.7) and velocity slip parameter (0.4???0.6) at the stretching surface. The thermal boundary layer thickness and heat transfer rate also tend to be drastically depleted as lesser heat gets transferred from the curve surface to the fluid. Incrementing the unsteadiness parameter (0.5???1) significantly improves the heat and mass transfer rates by about 13.5% and 13% respectively. It is also found that the rates of heat and mass transfer can be increased by enhancing the Dufour and Soret effects respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2024-05-26T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7009 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7009 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7009

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6920 2024-02-06T21:00:00Z 1

Effects of Intake Manifold Geometry in H2 & CNG Fueled Engine Combustion Rafaa Saaidia, Ons Ghriss, Hasan Köten, Mohammed M. Alquraish, Abdallah Bouabidi, Mamdouh El Haj Assad Gas engine; Intake manifold; Acoustic; Natural supercharging. This study attempted to identify the effect of optimized intake manifold geometry on the behaviors and emission level of hydrogen compressed natural gas (H2CNG) fueled engine. For this purpose, a commercial Hyundai Sonata spark ignition engine (SIE) is modified to operate with CNG and hydrogen blend. The optimal intake pipe length was predicted using an analytical acoustic method. New intake manifold is designed and implemented utilizing natural supercharging managed by over-pressure waves acoustic propagation. Several tests are conducted on the engine using the new manifold with a speed range from 1000 to 5000 rpm. Based on various engine speeds, the variation of brake torque (BT), in-cylinder pressure, NOx and CO emissions investigated by using gasoline, CNG and hydrogen CNG blend (HCNG) fueled engines via external mixtures. The first finding of the study is that the novel geometry improves the in-cylinder pressure by 10% at 3500 rpm. However, high engine speeds show a reduction of 14% in NOx and 40% in HC while speeds below 2000 rpm reduce CO by 40%. The second finding is that the new optimized geometry serves to get rid of both the auto-ignition and the back-fire for high ratio of hydrogen in the blend. Journal of Thermal Engineering Journal of Thermal Engineering 2024-02-06T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6920 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6920 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6920

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7056 2024-07-31T21:00:00Z 1

Using İnjected Additive Materials to İmprove Pipeline Transportation in Real-World Experiments and Computational Fluid Dynamics Ali Khalid Shaker Al-Sayyab, Mohammed A. Abdulwahid experiment; additive materials; crude oil; pressure drop;pipeline. In this paper, an experiment has been conducted where additive materials have been added to heavy crude oil to improve transportation. This is done on a pipeline length of 186 km. During the experiment, materials will be added to the inner pipeline to lubricate the heavy crude oil fiber and reduce the pressure drop. The additive materials, which are Drag-Reducing Agents (DRAs) (These are polymers that reduce the friction between the crude oil and the pipeline walls) are injected into heavy crude oil at different doses (two materials); the doses are 4, 6, 8, 10, and 12. A comparison between the cases before and after this additive has been obtained in the pipeline for velocity magnitude, vorticity magnitude, pressure drop, and wall shear stress. It can be observed that doses (8, 10, and 12) obtained a wide range of flow rates with fewer pressure drops than other dose points. The pressure at the city of Al-Faw has been found, and the maximum values are 1.482, 1.413, and 1.399 MPa for doses 12, 8, and 6, respectively. The simulation was done with COMSOL 5.4 Multiphasic software. Flow ranges increase as the dose increases. Shear stress increases with mass injection rate. Transporting heavy crude oil long distances is easier with additive materials. After the additive materials are added, crude oil will be transported for a long time without pressure drops, increasing the flow rate. The two turbines pump heavy crude oil through a 48 inches wide and 186 km long pipeline. These pipelines transfer heavy crude oil from the refinery to Al-Faw City. Journal of Thermal Engineering Journal of Thermal Engineering 2024-07-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7056 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7056 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7056

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7057 2024-07-31T21:00:00Z 1

Dynamics of Thermal radiation and Heat Generation/Absorption on a Viscous MHD Micropolar Fluid over a Stretching Sheet with Suction/Injection Comfort Ayomide Adeyemi, B. I. Olajuwon, Akinbo Johnson, M. T Raji Micropolar fluid, Thermal Radiation, Heat Generation/Absorption, Viscous Dissipation, Galerkin Weighted Residual This paper, analysed by computation, the behaviour of thermal radiation and heat generation/absorption in a viscous Magnetohydrodynamics Micropolar fluid through a porous medium of a stretching sheet with suction/injection. The investigation is done using the set of coupled nonlinear partial differential equations that describe the dynamics of the flow and heat transfer. These equations are transformed into a system of ordinary differential equations which are solved via the Galerkin Weighted Residual method. The behaviour of various embedded parameters adopted was presented graphically and discussed through tables accordingly. Aside from other major findings, the novel result shows that microrotation is a decreasing function of Magnetic and porosity parameters while increasing values of heat generation magnify the fluid molecules and strengthen the thermal effect on fluid at a far field. Also, higher variation of coupling constant depicts a lower viscosity nature and reduces the rotation of the fluid molecules. The validation obtained agreed with the literature. Journal of Thermal Engineering Journal of Thermal Engineering 2024-07-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7057 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7057 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7057

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7058 2024-07-31T21:00:00Z 1

Levelized Cost of Energy and Storage of Compressed Air Energy Storage with Wind and Solar Plants in Morocco Youness Masaaf, Youssef Ait El Kadi, Fatima Zahra Baghli compressed air, energy storage, LCOE, LCOS, LCOES, capacity factor To reduce greenhouse gas emissions and the environmental impact of fossil fuels, Morocco has decided to increase the use of renewable energy resources. The intermittent nature of renewable energy resources causes instability in the power grid. Energy storage is the appropriate solution to this problem. Compressed air energy storage is a technology that stores energy in the form of high-pressure compressed air in above ground tanks or underground caverns. Large-scale storage of compressed air energy requires the storage of large volumes in salt caverns or aquifers. The aim of this paper is to find out the benefits of integrating underground compressed air energy storage technology. A case study in Morocco is used to estimate the levelized cost of energy plus storage (LCOES). The annual capacity factor for solar and wind power plants and the potential of underground caverns in Morocco were analyzed. The results illustrate that for a system with 100 MW capacity installed in the Casablanca region, the combination of an adiabatic compressed air energy storage system (ACAES) with a wind turbine installation offers the lowest electricity price per kWh, with average LCOES of 0.04 $/kWh. Journal of Thermal Engineering Journal of Thermal Engineering 2024-07-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7058 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7058 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7058

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7059 2024-07-31T21:00:00Z 1

Adaptive Symbiotic Organisms Search Technique for Cost Optimization of Shell and Tube Heat Exchanger Jiten Makadia Optimization, nature inspired metaheuristics, STHX, Adaptive SOS, Alpha EHO, GSA, cost Nature inspired meta heuristics like swarm intelligence (SI), Artificial neural networks (ANN), evolutionary computing (EC) etc. have been used by researchers to solve single and multi-objective optimization problems of different fields. This work uses a novel ?-SOS (Adaptive symbiotic organisms search) algorithm for cost optimization of shell and tube heat exchanger. This algorithm is implemented for cost optimization of two benchmark STHX problem which are used by several researchers. Validation of the results is presented by comparing the geometric, flow and operational parameters of the same design problems when solved using particle swarm optimization (PSO), Alpha tuned elephant herding optimization technique (?-EHO) and Gravitation search algorithm (GSA). Result indicates a 4.73% and 11.3% reduction in cost for both the case study respectively when compared to same problems solved using PSO. Although when comparing with ?-EHO, results does not indicate any substantial difference. Furthermore, operational, and geometric dimensions are also calculated. This algorithm can be eventually applied to real world design engineering problems. Journal of Thermal Engineering Journal of Thermal Engineering 2024-07-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7059 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7059 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7059

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7008 2024-05-26T21:00:00Z 1

Numerical Investigation of a Direct Absorption Evacuated Tube Solar Collector Using Alumina Nanofluid Niloofar Shahini, Maryam Karami, Mohammad Ali Akhavan Behabadi Evacuated tube direct absorption solar collector; Nanofluid; Solar collector; Numerical simulation Direct absorption evacuated tube solar collectors are a new type of collector that has great potential to use in a solar system. In the present work, energy analysis of the direct absorption evacuated tube solar collectors incorporating Al_2 O_3 nanofluid is investigated numerically. A three-dimensional computational fluid dynamics simulation model is developed in ANSYS-Fluent software. Nanoparticles of Al_2 O_3 with two different volume fractions of 0.04% and 0.06% are selected to compare the thermal performance of the solar collector. In addition, two different base fluids (water and ethylene glycol) are chosen to scrutinize their effects on collector efficiency. The results show that 0.06% Al_2 O_3/water and 0.06% Al_2 O_3/EG nanofluids have the highest collector efficiency and outlet temperature difference, respectively. The outlet temperature difference of 0.04% Al_2 O_3/EG is improved by 19.34% with respect to 0.04% Al_2 O_3/water and for 0.06% Al_2 O_3/EG is improved by 16.45% with respect to 0.06% Al_2 O_3/water nanofluid, respectively. The results also reveal that the collector efficiency of 0.04% Al_2 O_3/water, 0.06% Al_2 O_3/water, 0.04% Al_2 O_3/EG, and 0.06% Al_2 O_3/EG nanofluids are 69.77%, 71.39%, 66.68%, and 69.43%, respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2024-05-26T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7008 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7008 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7008

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6831 2023-10-16T21:00:00Z 1

Energy and Production Analysis of a Dairy Milk Factory: A Case of Study Oznur Oztuna Taner Energy Analyses, Energy efficiency, Energy Consumption, Energy Performance, Production Analyses, Dairy Milk Plant This study illustrates the factory's production efficiency by demonstrating the energy efficiency in the dairy milk industry. Determining thermal energy in order to save energy enhances the factory's profitability. The study's aim is to carry out a thermal energy and production analysis of a dairy milk factory based on annual production. This study’s research is intended to make the conclusions more realistic by using production and energy data dependability analysis. The overall energy power consumption for the thermal and electric energy processes was determined to be 180,520 [W]. The target-specific energy consumption value was computed for Case 1 as 6,352.14 [MJ/t], Case 2 as 5,898.67 [MJ/t], and Case 3 as 5,445.21 [MJ/t]. The annual thermal (steam boiler) and electrical energy expenditures are obtained, with 315.87 [kW] of thermal (steam) energy and 80.98 [kW] of electrical energy. Total thermal and electrical energy reached 396.85 [kW]. Despite the factory's expenditures on thermal and electrical energy, the energy efficiency was determined to be 45.5%. The input energy was obtained to be 374.24 [kW] in Case 1, 356.33 [kW] in Case 2, and 342.08 [kW] in Case 3. The energy efficiency was calculated to be 48.2 [%] for Case 1, 50.7 [%] for Case 2, and 52.8 [%] for Case 3. This study, which is expected to inspire and model future research, is also likely to assist livestock and agriculture in the energy field. The novelty of this study is that optimizing product efficiency and energy consumption in the production of milk and dairy products will positively increase the energy efficiency of the factory. Journal of Thermal Engineering Journal of Thermal Engineering 2023-10-16T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6831 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6831 Journal of Thermal Engineering, Year:2023, Vol:9, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6831

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7060 2024-07-31T21:00:00Z 1

Thermo-Fluid Performance of a Heat Exchanger with a Novel Perforated Flow Deflector Type Conical Baffles Md. Atiqur Rahman, Sushil Kumar Dhiman Inclination angle; Conical baffle plate; Rectangular deflector; Swirl flow; Thermal efficiency, Volume goodness factor A study investigated how a new swirl airflow design could impact the heat transfer rate in a tubular heat exchanger with axial flow. A perforated conical baffle plate with rectangular air deflectors of different inclination angles was created to generate a swirl flow. The tubes in the heat exchanger were aligned longitudinally, and the heat flux across their surface was kept constant. Each plate had four deflectors with equal deflector angles and adjustable pitch ratios, which created a swirling airflow inside the circular duct containing the heated tubes. This increased turbulence and the rate of heat transfer across the tube surface. The Reynolds number stayed within the range of 93,500 to 160,500. The result indicates that the inclination angle and Pitch ratio profoundly impact the Nusselt number, while the pitch ratio has a greater effect on the friction factor. Furthermore, the conical baffle plate design resulted in an average improvement of 2.51 in thermal efficiency compared to a segmental baffle design with a deflector angle of 30° and a pitch ratio of 1, all under similar Reynolds number, pitch ratio, and blockage ratio conditions. Journal of Thermal Engineering Journal of Thermal Engineering 2024-07-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7060 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7060 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7060

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7055 2024-07-31T21:00:00Z 1

Drying Solanum lycopersicum (Tomatoes) in Greenhouse Solar Dryer : An Eco-Environmental Study Pringal Patel, Vikram P. Rathod, Divyesh Patel Greenhouse, Solar Dryer, Carbon Emission, Life-cost, Payback, Agriculture, Embodied Energy Fruits and vegetables are an important part of human diet. In the present study, the thermal performance of solar greenhouse dryer for drying Solanum lycopersicum (Tomatoes) was analysed. The drying pattern at various location of the drying chamber and different levels of the dryer was evaluated. The life cost analysis of the for drying the tomatoes in the dryer for 25 years of service was evaluated. The greenhouse solar dryer was developed with the structure base of galvanized iron pipes and covering of 2 mm thick polycarbonate sheet. The experiment was carried out for drying the tomatoes at various location in the dryer using the trays and trolley system. The maximum thermal efficiency of the dryer is 26.66 % while drying out 5.8 kgs of tomatoes in one day. The economic analysis of the greenhouse solar dryer shows that the payback period of such system can be attained in only 1.6 years which terms the dryer feasible and economically viable in the current agro-drying market. The embodied energy for the dryer was calculated 3154.71 kWh for the system. The CO2 emission for the greenhouse solar dryer was found around 6.62 tonnes for the lifespan of 25 years. The net CO2 mitigation was calculated around 41.62 tonnes which would generate an earning from 46766 INR to 62355 INR worth of carbon credits. Journal of Thermal Engineering Journal of Thermal Engineering 2024-07-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7055 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7055 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7055

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7208 2025-01-30T21:00:00Z 1

Numerical investigation to augmentation of heat transfer in solar air heater with arc shape ribs on absorber plate Ghaith Monem FADALA, Ahmed Hashem YOUSEF, Karrar S. HASAN Artificial Roughness; CFD, Fluid Flow; Heat Transfer; Solar Air Heater; Solar Energy. Using numerical methods, this paper investigates the heat transmission and friction factor of a SAH duct that has been intentionally roughened. The absorber plate of the duct is equipped with an arc-shaped structure that has three distinct angles of attack. This structure is Installed on the peak walls from the tray. The roughness parameters of this structure include a respective roughness factor (p/H) beginning from from 1.667 to 6.667, a respective rough height (e/H) of 0.271, an arc angle (α) beginning from from 30° to 60°, and a Re beginning from from 3000 to 15000. It has been determined that the efficiency of roughened SAH ducts surpasses that of smooth ducts within the range of roughness values examined. The numerical analysis indicates that the highest increase in Nu and f occurred at specific values: a respective roughness factor (p/H) of 3.33, a respective roughness height (e/H) of 0.271, an arc angle (α) of 60°, and a Reynolds number of 15000. The test runs for the roughened duct involved collecting data on various combinations of roughness parameters. The highest values observed were Nu = 215 and Nu ratio = 7.21. When compared to the conduit that is smooth had most possible value of f = 2.5 and f/fs = 3.39. The thermal performance factor is 3.88. Journal of Thermal Engineering Journal of Thermal Engineering 2025-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7208 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7208 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7208

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7123 2024-09-10T21:00:00Z 3

Biodiesel Production from Waste Cooking Oil: A Review on Production Methods, Recycling Models, Materials and Catalysts Atefeh AHMADBEIGI, Mahdi MAHMOUDI, Leila FEREIDOONI, Mojtaba AKBARI, Alibakhsh KASAEIAN Biodiesel; renewable energy; thermal process; recycling model; intensification techniques. The imperative for sustainable energy development has become increasingly evident, primarily due to the finite nature of fossil fuel reserves and the associated environmental apprehensions. In light of these concerns, biodiesel emerges as a compelling alternative. Its key attributes include renewability, reduced emissions, and the ability to be produced from a variety of sources, rendering it a promising candidate in addressing these energy and environmental challenges. Biodiesel holds significant promise as an energy source due to its lower environmental impact compared to traditional diesel fuels. This alternative fuel is non-toxic, safe, and biodegradable, primarily derived from renewable biological feedstocks like used cooking oils, making it an affordable and sustainable resource. This paper provides a comprehensive review encompassing biodiesel properties, feedstock options, diverse production techniques, catalyst variations, and the challenges associated with biodiesel production from WCO. Furthermore, this study delves into the evolution of biodiesel conversion processes and innovative approaches to enhance scalability. Detailed examinations of pivotal factors influencing transesterification, including catalyst weight percentage, temperature, alcohol-to-oil molar ratio, and reaction duration, are presented. Ultimately, this review concludes with future perspectives and suggestions. It emphasizes the importance of judiciously selecting catalysts, feedstock materials, and production methodologies to develop cost-effective, energy-efficient biodiesel solutions with reduced environmental impact and enhanced operational efficiency. Journal of Thermal Engineering Journal of Thermal Engineering 2024-09-10T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7123 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7123 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7123

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7061 2024-07-31T21:00:00Z 1

Accelerated Solidification of PCM via Al2O3/CuO Hybrid Nanoparticles in Triplex Tube Heat Storage Ibrahim E. Sadiq, Sattar Aljabair, Abdulhassan A. Karamallah Phase change material, Solidification, Triplex tube heat storage, hybrid nanofluid, PCM The thermal performance and heat transfer augmentation of paraffin wax as a phase change material (PCM) throughout discharging process within a triplex tube heat storage have been examined using a combined experimental and numerical analysis. The efforts of this research are focused on using a blend of two different types of highly conductive nanoparticles (Al2O3/CuO hybrid nano additives) to enhance the thermal characteristics of paraffin and improve the overall performance of TTHS, which is the originality of this study. Various volume concentrations (0.4, 0.8, 1.6, 3.2%) of hybrid nanoparticles were explored. Besides that, A set of tests were carried out to evaluate the impact of changing inlet temperature and mass flow rate of the heat transfer fluid (HTF) on the phase change phenomenon of the paraffin. The mass flow rates of HTF ranges from 3 kg/min to 12 kg/min while the temperatures of HTF varies from 30 °C to 40 °C. The calculations are included an iterative, finite-volume numerical technique that involves a domain enthalpy porosity model to simulate the phase transition process. The agreement between the experimental data and the numerical simulation is good. According to the results, reducing inlet temperature and/or increase the inlet mass flow rate of HTF speed up solidification rate. However, HTF inlet temperature has more impact on solidification rate than inlet mass flow rate. Moreover, the reduction in freezing duration caused by implementing hybrid nanoparticles has been observed for all volume concentrations investigated. However, adding 3.2% volume percentage of hybrid nanoparticles results in the highest overall freezing time reduction (about 23%). Journal of Thermal Engineering Journal of Thermal Engineering 2024-07-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7061 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7061 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7061

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7062 2024-07-31T21:00:00Z 1

An Experimental Assessment of Performance and Emission Analysis on a Green Microalgae Biodiesel di Engine with Bi2O3 Nanoparticles K. Sekharraj, P. Balu, R. Ravisankar, A.M. Saravanan Diesel Engine, Green Microalgae, Nanoparticles,B20, Performance, Emission A rapid growth in vehicles and population has resulted in a rapid rise in energy demand. Since fossil fuels are rapidly depleting, researchers are focused on finding alternative fuels for diesel as a result of climate change. The country imports 79% of its oil needs at the moment and plans to reduce that to 70% by 2024. To achieve this, alternative fuel sources that are non-toxic, renewable, and inexpensive are needed. It is emerging that algae-based biodiesel could be a viable alternative to diesel fuel. It has been found that microalgae oil can be used to produce biodiesel. The present study investigates the preparation of a biodiesel fuel blend of 80-20 (80 % diesel and 20 % biodiesel) using nanoparticles of Bi2O3. This research tests the fuels properties in accordance with ASTM standards. It is possible for nanoparticles to enhance fuel properties and overcome certain disadvantages in general by being adding as fuel additives. In this study, Green Microalgae blends and diesel blends containing Bi2O3 nanoadditives were compared for performance and emission characteristics. In experiments, the use of a biodiesel blend with nano-additives resulted in better performance characteristics and lower exhaust emissions. Journal of Thermal Engineering Journal of Thermal Engineering 2024-07-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7062 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7062 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7062

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7063 2024-07-31T21:00:00Z 1

Spark İgnition Engine Performance Analysis with Low Octane Gasoline and Methyl Tert-Butyl Ether Additive for Optimum Operation Obed Majeed Ali Octane number, Gasoline, Design of experiment, Fuel additives, Optimization, Methyl tert-butyl ether Fuel quality is considered an important indicator for ensuring maximum output power. Hence, using commercial fuel that didn’t meet the standard specifications may result in engine performance deterioration. In this study, Methyl tert-butyl ether additive has been introduced as an octane enhancer with local low-octane gasoline. Five samples were prepared by adding MTBE additive at 3%, 6%, 9%, 12% and 15% to commercial gasoline and tested at constant half load and increasing engine speed. Response surface method optimization and ANOVA analysis have been conducted using the obtained engine test results to indicate the optimum engine performance conditions and the significance of the variations respectively. Optimization results show that the output responses are linked statistically with the engine speed. The optimum operation conditions obtained at an engine speed of 3126 rpm and 3% additive ratio by 2356 W for brake power, 0.187857 g/W.hr for brake-specific fuel consumption and 38.3% for the brake thermal efficiency. According to the chosen significant level, ANOVA results shows significant influence of engine speed on the different obtained responses, On the other hand, the optimum response achieved at 3% additive ratio with insignificant influence for increasing additive ratio in the fuel mix. Journal of Thermal Engineering Journal of Thermal Engineering 2024-07-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7063 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7063 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7063

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7064 2024-07-31T21:00:00Z 1

Impact of Thermal İnsulation on Energy Consumption in Buildings Lemya Bentoumi, Touba Bouacida, Rachid Bessaih, Abdelouahab Bouttout Thermal insulation, energy consumption, thermal comfort, buildings, heat loss, thermal gain, renovation. This article analyzes the impact of thermal insulation on an existing house that did not comply with building regulations. The renovation involved adding layers to the ceiling and floor, the areas with the highest heat loss and gain. Results showed a 77% decrease in heat loss through the floor and a 59% decrease in surface losses, resulting in a 55% reduction in heating power and desired thermal comfort during winter. During summer, there was an 18% decrease in air conditioning power due to an 18% decrease in total thermal gain. Simulation using Design Builder software showed a 42% decrease in heating energy and 17% decrease in cooling energy after renovation. The TRNSYS software simulation showed a 500 [kWh] reduction in annual energy consumption. The renovation made the house compliant with thermal regulations for both seasons. Journal of Thermal Engineering Journal of Thermal Engineering 2024-07-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7064 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7064 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7064

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7073 2024-07-31T21:00:00Z 3

Heat Transfer Enhancement Techniques using Different Inserts in Absorber Tube of Parabolic Trough Solar Collector: A Review Pooja Raval, Bharat Ramani Inserts, Parabolic trough solar collector, Pressure drop, thermal enhancement Various collector technologies are prevalent for harnessing solar energy. Some of the most common types are flat plate and evacuated tube collectors. Parabolic trough collectors are not commercialized other than large industrial set-ups because these collectors occupy larger land areas with a higher installation cost. It becomes essential for the researcher to devise new technologies to reduce the cost and promote sustainable renewable energy technologies. Heat transfer enhancement techniques like tube turbulators, mainly twisted tape, wire coils, metal foam, corrugations, fins, and nanofluid are among the alternatives. The present review focuses on research on the enhancement of heat transfer rate in PTC using the above techniques, considering the work done from 2015-2023. An effort has been made to compare the output of such techniques after an exhaustive literature survey. The enhancement in heat transfer rate by dimensionless Nusselt number Nu/Nup. Nu is the Nusselt number for a PTC absorber tube when used with a turbulator, and Nup is the Nusselt number for a plain absorber tube. A similar comparison is made for f/fp, related to the friction factor encountered and when compared to a smooth tube. The literature shows that Nu/Nup ranges from 1.2-10 when using different turbulators, and f/fp ranges from 1.02-10.4, mainly dependent on geometry. These results prove the efficacy of tube turbulators in PTC absorbers, thereby promoting interest in further exploration, especially with an experimental investigation, which has yet to be reported in the literature. Moreover, previous research must be more comprehensive as a direct comparison of these techniques must be reported. This critical study reports a direct comparison of the above techniques. Journal of Thermal Engineering Journal of Thermal Engineering 2024-07-31T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7073 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7073 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7073

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7065 2024-07-31T21:00:00Z 1

Investigation of Thermomagnetic Gravitational Convection and Energy Distribution in a Vertical Layer of Ferrofluid Md. Habibur Rahman Convection, Energy, Ferrofluid, Instability, Magnetic Field The applied magnetic field and its inclination angle play important roles in flow stabilization and energy distribution in the flow domain. In this article, the linear stability characteristics and energy distribution due to the combined influence of thermal, magnetic, and gravitational forces in a vertical layer of ferrofluid enclosed by two differentially heated walls are investigated. The objective of this article is to investigate the combined effects of thermogravitational buoyancy and magnetic forces and provide parametric guidance for mixed magnetogravitational thermal experiments. The numerical results are obtained by the pseudo-spectral Chebyshev expansion method. It is found that the qualitative change in the shape of the instability boundaries and the area of flow stability expands significantly when the field inclination angle increases. The destabilizing magnetic field variation effect is most pronounced in the near-wall regions, especially near the cold wall. However, the viscous dissipation near the cold wall is also stronger than that close to the hot wall. Consequently, the overall instability pattern shifts toward the hot wall. The thermomagnetic perturbations arising in the layer of ferrofluid tend to make the magnetic and magnetization fields more uniform near the walls. The instability is mostly driven by gravitational buoyancy due to thermal effects compared to magnetic effects. The perturbed kinetic energy is lost due to viscous dissipation and modification of the applied magnetic field in the flow domain. Ferrofluids under the effects of thermal, magnetic, and gravitational forces have potential applications in cancer detection, MRI scanning, oil separation from water, tunable optical filters, digital data storage, vibration dampening, energy conversion devices, etc., and many other engineering branches. Journal of Thermal Engineering Journal of Thermal Engineering 2024-07-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7065 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7065 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7065

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7066 2024-07-31T21:00:00Z 1

An Experimental Study on Performance, Emissions, and Combustion Characteristics of a CI Engine Running on Citrullus Colocynthis Biodiesel Blends Chitradevi V., Balu Pandian Diesel Engine, Citrullus colocynthis, Performance, Emission, Combustion As an alternative to pure diesel, citrullus colocynthis oil, which has a larger proportion of triglycerides to monoglycerides, can be utilised to create a fatty acid alkyl ester. The purpose of the current study's experimental effort was to assess the characteristics, emissions, and performance of compression ignition engines running on various biodiesel blends made from Citrullus colocynthis. The present study compared the properties of pure Citrullus colocynthis oil (100% biodiesel) and pure diesel (100% diesel) to those of blended Citrullus colocynthis and biodiesel in different proportions (B20, B25, B50, B75, and B100).. The B20 biodiesel blend has been shown to be the best one due to its reduced emission content and improved brake thermal efficiency. Citrullus colocynthis oil and its blends have lowered in-cylinder pressure and heat release rates. In comparison to diesel fuel, B20 mix performs better and emits fewer pollutants. Journal of Thermal Engineering Journal of Thermal Engineering 2024-07-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7066 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7066 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7066

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7067 2024-07-31T21:00:00Z 1

Comparative Analysis of Modified Jet Diffuser Geometry for Evaluating the İmpact of Rounded Edges and Chamfered Design on Cooling Efficiency of Electronic Components in Cross Flow and İmpinging Jet Abdelhak Fellague Chebra, Ali Khelil, Mohamed Braikia, Mohamed Bedrouni Wall-mounted cube, Cooling electronic components, Impinging jet, lobed jet, Jet cross flow This article investigates the influence of altering the geometry of a jet diffuser and modifying the top corners of electronic components on cooling effectiveness. Computational simulations using the Shear stress transport turbulence model (k-? SST) are conducted. The study considers a cross-flow Reynolds number of 3410 and varying impinging jet Reynolds numbers (? = Rej/ReH = 0.5, 1, and 1.5). Results show a clear relationship between flow structure and cooling effectiveness. At ? = 0.5, cubes with rounded edges and chamfered corners have lower cooling efficiency. At ? = 1.0, chamfered cubes demonstrate enhanced cooling efficiency (4.7% increase in average Nusselt number). At ? = 1.5, rounded cubes exhibit superior cooling performance (3.7% higher Nusselt number). A lobed diffuser configuration achieves outstanding cooling effectiveness, with a Nusselt number 15% higher than a circular jet. These findings provide insights for improving cooling efficiency in electronic components under cross-flow and impinging jet conditions. Journal of Thermal Engineering Journal of Thermal Engineering 2024-07-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7067 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7067 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7067

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6918 2024-02-06T21:00:00Z 1

Thermodynamic Analysis of a Solar-Driven Vapor Compression Refrigeration System using R1234ze for Cooling Applications in Ghardaïa region (Southern Algeria) Ahmed Selloum, Zakaria Triki, Younes Chiba Solar energy, Vapor compression refrigeration, Low GWP refrigerant, Cooling applications, Performance, Comparison. This research paper presents a comprehensive analysis of a solar-driven vapor compression refrigeration (VCR) system intended for deployment in Ghardaïa, a region located in Southern Algeria with a desert climate featuring semi-arid conditions. The demand for cooling in this area is substantial, while the solar radiation available is abundant. The study compares the performance of two different working fluids: R134a, an HFC high GWP refrigerant that is being phased out, and R1234ze, a recently introduced low GWP HFO refrigerant. To assess the performance of the solar VCR system, a numerical model was developed in MATLAB software, employing the thermodynamic properties of R1234ze and R134a refrigerants. The outcomes indicate that the coefficient of performance (COP) and thermodynamic efficiency of the solar VCR system increase as the ambient temperature decreases due to greater power consumption by the compressor. Specifically, during the 21st day of July, the COP for R1234ze refrigerant falls within the range of 4.37-5.77, which is in close proximity to and surpasses 90% of the maximum COP value. On the other hand, the COP for R134a fluid ranges from 2.56 to 3.17. The lowest COP values occur around noon between 12:00 AM and 15:00 PM. Additionally, the highest PV power production for R134a and R1234ze refrigerants is observed at midday (12:00 PM), with respective values of 2.8 kWh and 1.6 kWh. Ultimately, the results strongly affirm that the utilization of solar energy and low GWP refrigerants offers a sustainable and economically viable solution for cooling applications in hot and arid regions. Journal of Thermal Engineering Journal of Thermal Engineering 2024-02-06T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6918 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6918 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6918

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7068 2024-07-31T21:00:00Z 1

An Experimental Evaluation of Chlorella Emersonii Biodiesel for Compression Ignition Engines Krishnan Rangasamy, Naveenchanandran Panchacharam, Balu Pandian Diesel Engine, Biodiesel, Chlorella emersonii, Performance, Emission, Combustion An increase in population count and a desire to reduce environmental hazards makes researchers search for fuel that can be eco-friendly and combat the setbacks of conventional fossil fuel. Chlorella emersonii is a common freshwater green algae found in India. This oil is transesterified and converted to chlorella emersonni methyl ester (CEME) biodiesel to mainly reduce viscosity and improve a few other properties. In the experiment, blending of CEME biodiesel with diesel was done on a volume basis and B10 (100% CEME and 90% diesel), B20(20% CEME and 80% diesel), B30(30% CEME and 70% diesel) and B100(100% CEME) were prepared for testing in a stationary single-cylinder diesel engine. Test results showed that B30 exhibited better results than others with high brake thermal efficiency, fewer emissions of HC by 24%, CO by 50%, smoke by 56%, and high in cylinder pressure and heat release rate (HRR). Thus, the obtained results are close to diesel. Journal of Thermal Engineering Journal of Thermal Engineering 2024-07-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7068 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7068 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7068

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7165 2024-11-18T21:00:00Z 1

Numerical and Experimental Study on the Collector and Chimney Modifications of a Solar Chimney Power Plant Rajamurugu NATARAJAN, Akhil Chandramohanan Kumari SUNI, Likhith Raj PEDASINGU, Yaknesh SAMPATH C-D Chimney; Generation Renewable Energy; Green Technology; Solar Chimney; Solar Power. The environmental hazard posed by global warming necessitates the development of sustainable, eco-friendly power production unit based on renewable energy principles. Solar Chimney Power Plants (SCPP) are the resource that fits this description. Here, the chimney is equipped with a larger roof at bottom, referred as collector, absorbs the sunlight to warm the air inside. This heat creates an upward draft, resulting a forward motion of air, which rotates the turbine. There is a better possibility of enhancing the performance of an SCPP with modification of factors such as chimney height, collector area, collector angular position. Hence, this research objective is to study the alteration in efficiency of an SCPP with collector angular modifications, such as completely slopped, intermediately sloped profiles, as well as the effects of various chimney designs with area ratios larger than one. An additional study of a semi divergent (SD) chimney with a completely slanted collector, positioned vertically. Initial analysis is performed using ANSYS-FLUENT, and a simulation environment is modeled to mimic the various chimney and collector configurations in preparation for the experimental work. The better model is chosen from these simulations and experimented in true environmental conditions. It was determined that the average increase in temperature within the SCPP was 17 K. The research found that the collector setup with a slope of 50% (case-2) resulted in a peak velocity 12% higher than that of the fully sloped configuration (case-1). Additionally, case-2 was 23% more productive than the Manzanares facility. On the other hand, case-3’s semi divergent chimney with a complete slopped collector outperformed the other two by 23% and 12%, respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2024-11-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7165 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7165 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7165

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6919 2024-02-06T21:00:00Z 1

Numerical Investigation of Forced Convection Flow of a Complex Bingham–Papanastasiou Fluid Between Two Concentric Cylinders with a Wavy Inner Wall Benhanifia Kada, Fares Redouane, Lakhdar Rahmani, Naveen Kumar Gupta, Mebarki Brahim, Hitesh Panchal, Saeed Nazari, Abhinav Kumar, Anand Patel forced convection; complex Bingham –Papanastasiou fluid ; concentric cylinder; finite element method. This research presents a numerical investigation of the flow field and heat transfer of a Visco-plastic fluid, The Bingham-Papanastasiou model is used to examine the flow field and forced convection heat transfer of a Viscoplastic fluid between two concentric cylinders with a wavy inner surface. By focusing on this particular configuration (wavy inner cylinder shape), where the inner surface exhibits as the hot wall while the outer surface is considered as the cold wall. This investigation is numerically achieved by using the Comsol Multiphysics, which is based on the finite-volume method, employing Galerkin's method for solving the governing equations. The parameters studied in this research are expressed with the following values: r/R=1/3, Reyn-olds number (Re=1, 10, 50), and undulation number (nu=0, 6, 12, 24). Increasing the inertia pa-rameter results in a higher intensity of thermal buoyancy, positively influencing heat transfer, particularly at Re=50. Furthermore, the acceleration of flow within the investigated space improves the hydrodynamic behavior, facilitating the exchange of thermal energy between the hot and cold walls. Additionally, it has been discovered that an undulating shape with a specific number of undulations (nu=6) maximizes hydrothermal performance within the investigated volume. The presence of these undulations enhances fluid mixing and disrupts the formation of stagnant regions ,which leading to improved heat transfer. Journal of Thermal Engineering Journal of Thermal Engineering 2024-02-06T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6919 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6919 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6919

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7069 2024-07-31T21:00:00Z 1

A Novel Modified JAYA Algorithm for Heat Exchanger Optimization Awadallah Ahmed, Osama Elmardi, Fathelrahman Elmahi, Obai Yunis, Mansour Abdelrahman Heat exchanger optimization; JAYA algorithm; Modified JAYA algorithm; Sine Cosine Algorithms; Grey Wolf Optimizer. In general, algorithm modification is changing or alternating some aspects of the original algorithms with improving their performances. This work aims to introduce and implement a novel modified Jaya algorithm (MJ) to optimize fins and tube heat exchangers. The objective functions used in the current work are to minimize total cost and maximize effectiveness. The optimization results of the MJ were compared with the standard JAYA algorithm and another two different algorithms, namely the Grey Wolf Optimizer (GWO) and Sine Cosine Algorithms (SCA), to examine the MJ performance improvement. A MATLAB in-house code was used to obtain the results of the different optimizing algorithms. Each of the four algorithms optimized the heat exchanger at three different values of population size, which are 25, 50, and 100, and three different numbers of runs, 20, 40, and 80, to determine the optimal solution. The results showed that MJ outperforms the standard JAYA algorithm and SCA in all cases studied. MJ performs better than GWO at low and medium populations,25 and 50. Still, at a population size of 100, MJ and GWO perform equally, with the advantage that MJ obtains less average execution time to find optimal solutions than GWO. The time increase of GWO over MJ is 450.56% at maximum and 52.86% at minimum. Journal of Thermal Engineering Journal of Thermal Engineering 2024-07-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7069 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7069 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7069

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7209 2025-01-30T21:00:00Z 1

Exploring low-GWP refrigerants for enhanced domestic refrigerator performance: A comprehensive investigation Mohammad Hasheer SHAIK, Srinivas KOLLA, Yellapragada Naga Venkata SAIRAM Domestic Refrigerator; HFC134a; HFC 1234yf; R152a. Our present investigation mainly focus on to identify the most appropriate refrigerants from various groups for replacing HFC-134a in a household refrigerator. The study involved conducting experiments using refrigerants from three different groups: Hydrofluoroolefin (HFO), Hydrofluorocarbon (HFC), and Hydrocarbon (HC). Among the tested refrigerants, R152a from the HFC group and HFC 1234yf from the HFO group showed the most potential. Compared to HFC-134a, both R152a and HFC 1234yf shows a reduction in refrigerating effect by approximately 4-7% and less power consumption in the compressor by around 5-7%.In conclusion, for replacing HFC-134a in a domestic refrigerator without needing alterations to the existing refrigeration system, two recommendable refrigerants are R152a and HFC 1234yf. These refrigerants are considered eco-friendly with zero ozone depletion potential (ODP) and low global warming potential (GWP) values. Journal of Thermal Engineering Journal of Thermal Engineering 2025-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7209 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7209 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7209

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7070 2024-07-31T21:00:00Z 1

Thermal Performance Analysis of Local Building Materials for Energy Efficiency in Iraq Riyadh Husni Aljawad, Atif Ali Hasan, Mahmood Hussain Khaleel, Omer Adil Zainal Keywords: Traditional materials, Aso brick factory production, thermal behavior, building thermal properties Abstract Due to the harsh climate in summer of the Iraq, the outer shell of buildings is exposed to heat flow from the outside ambient to the inside building space, and causes increase of heat gain in the space, so it requires the using of air conditioning units, which is led to consume electrical energy to remove that heat gain. The objective of this paper to reduce levels of electrical consumption by choosing best building materials. The best building materials which is has good resistance against heat flow that’s why the cost of building material difference each of other in the local market. While Aso Company for Bricks is considered one of the largest modern companies producing building materials and the most present in the entire area of Iraq. The aim of this study to focus was on its products, and five types models were selected and compared with the traditional model that is still used now. Therefore, heat gain test was experimentally conducted in a test room located in Baghdad city (zip code 10016, latitude of 33.2°N and longitude of 44°E) for one day from 6 a.m. to 7 p.m. and for the 21st day of each of the summer months (May to September) in 2021. The electrical energy consumed by the air-conditioning unit in the test room was measured, and the researchers concluded that the percentage of energy savings achieved within the limits (13.88–1.2%) depending on the type and thickness of the building material. Results shown the best building material is (Type IV), these blocks can be used to create walls with a thickness of 200 mm or 100 mm. Building blocks (the fourth kind), on the other hand, have a delay time of 6:30 hours and a thermal shrinkage coefficient of 0.63. They also have a density of 919 kg/m3. Therefore, the electrical consumption by A.C. units if used the blocks (Type IV) less than others. Journal of Thermal Engineering Journal of Thermal Engineering 2024-07-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7070 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7070 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7070

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7074 2024-07-31T21:00:00Z 3

Reviewing the Enhancement Optimum Performance Characteristics of Horizontal Axis Wind Turbine Blades using Add-On of Suitable Aerodynamic Properties Oluwaseyi Omotayo Alabi, Oyetunde Adeoye Adeaga, Ademola A. Dare Wind turbine horizontal axis, Add-on, Performance, Computational Fluid Dynamics, Turbulent model Standard horizontal-axis wind turbine blades are characterized by operational noise and low power output. Therefore, it is crucial to integrate mechanical components within the wind turbines to enhance their peak power output while simultaneously reducing their noise emissions. This article reviews enhancing optimum performance characteristics of horizontal axis wind turbine blades using various geometrical inbuilt Add-On mechanical devices of suitable aerodynamic properties. Evaluation of torque, thrust, and blades' aerodynamic properties, which enhance efficiency, were investigated to understand the performance of aerodynamic add-ons on rotor blades. The current work showed that adding aerodynamic add-ons to wind turbine blades can improve the performance and efficiency of the blades, as well as increase the power output of the blades. This study also considered the performance and efficiency of blades in turbulence and high wind speeds. Various turbulence-inbuilt models of numerical fluid dynamics modules were investigated and analyzed to predict the motion surrounding the horizontal axis wind turbine. Numerical outputs showed that Add-Ons on horizontal wind turbines significantly enhances the efficiency and performance with expected reduced noise. Journal of Thermal Engineering Journal of Thermal Engineering 2024-07-31T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7074 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7074 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7074

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7526 2026-01-30T21:00:00Z 1

Oscillating piezofan effects on natural and forced convection flow in a vertical channel with protruding heat sources Salim Ibrahim HASAN, Mehmet Akif EZAN, Serhan KÜÇÜKA Cantilever Piezofan; Discrete Channel; Electronic Cooling; Protruding Heat Source The current work investigates the flow characteristics and convective heat transfer performance of a vertically-oriented piezofan in a channel with wall-mounted protruding heat sources. A 2D numerical model is developed in COMSOL Multiphysics to simulate the temperature variations on the heated protrudes under forced and natural convection scenarios, with and without oscillation of the piezofan. A vertical channel with dimensions of Lch = 300 mm × S = 35 mm is considered with four protruding heat sources (Hhs = 25 mm × b = 7 mm), which are positioned on the same side of the channel, with a frontal surface heat flux of qw = 600 W/m2 . The results reveal that active and passive vortices generated by piezofan and protruding objects in the flow domain provide higher momentum and heat exchange. It was found that implementing piezofan inside the channel significantly enhances cooling performance and reduces the surface temperatures of the protrudes. Compared to the pure natural convection within the channel, the average convective heat transfer coefficient on the protrudes increased more than three times using piezofan. Besides, in the case of forced convection, the maximum increments in mean convective heat transfer are obtained as 74% and 59% at Reynolds numbers 1000 and 2000, respectively Journal of Thermal Engineering Journal of Thermal Engineering 2026-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7526 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7526 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7526

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7158 2024-11-18T21:00:00Z 1

Experimental Estimation of Radiation Heat Losses from a Fully Open Cylindrical Cascaded Cavity Receiver by Radiosity Network Method Kushal S. WASANKAR, Nitin P. GULHANE Cavity Inclination; Cavity Receiver; Heat Losses; Parabolic Dish; Radiosity Network; Solar Concentrators. The performance of solar thermal power systems using cavity receivers and parabolic dishes highly depends on the effective absorption of concentrated solar radiation by cavity receivers. Correct measurement of convection losses is challenging due to non-isothermal surface temperatures and unpredictable flow conditions inside the cavity. Correct prediction of radiation losses can help to predict convection losses. Effect of increasing the area ratio of normal cavity using cylinder in cylinder arrangement to increase the surface area for heat transfer, is studied experimentally. The specially designed heaters for model cavity size using nichrome wires sheathed between ceramic sheets were used to apply the thermal load, and the heat transfer rate was observed. Experimental temperatures were used for calculating the radiation heat losses using radiosity network method. Modified cavity surface is divided in parts and radiosity values for each part is calculated by solving simultaneous equation obtained by network method, using Gauss-Seidel method. Finally, the radiation heat loss from each surface is added to get total radiation heat loss. More heat transfer area for cylinder in cylinder arrangement and with the same heat input modified cavity shows higher surface temperatures. Network representation provides a better understanding of radiative interaction between different parts of the cavity. Radiosity network method predicts more accurate results than mean radiation heat loss calculations by calculating actual radiosity values for different parts of cavity. The difference in prediction is high at lower temperatures, emissivity and reduces with increasing temperature and emissivity. Effect of inner cylinder surface temperature was studied with three different cases and found that the radiation heat losses are less affected by inner cylinder surface temperatures. Effect of aspect ratio on radiation heat losses is presented in this work. Experimental results show that proposed cavity receiver design provide double surface area for heat transfer with increased surface temperatures for same heat input and total heat loss. Journal of Thermal Engineering Journal of Thermal Engineering 2024-11-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7158 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7158 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7158

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7121 2024-09-10T21:00:00Z 1

Experimental Investigation to Evaluate Thermal Performance of a Solar Cooker with Evacuated Tube Solar Collector Using Different Heat Transfer Fluids Yunis KHAN, Abhishek TEVATIA, D. APPARAO, Nagendra SINGH, Subhash MISHRA Evacuated tube solar collector, solar cooker, heat transfer fluid, phase change material, thermal performance In present research the impact of insulation on the discharge process of phase change material (PCM) and a comparison of the thermal performance of a solar cooker using two distinct types of heat transfer fluid (HTF) were experimentally investigated. The aim of this study is to select best performing HTF at the thermal performance point of view. In this experiment a solar cooker with an integrated PCM thermal storage unit was connected through connecting pipes to an evacuated tube solar collector. Separately, water and SigmaTherm–K were used as HTF to evaluate the thermal performance of a solar cooker. Acetanilide of commercial grade was utilized as thermal storage material in the solar cooker. Both charging and discharging of PCM were studied with insulation and without insulation. It was discovered that the temperature attained with PCM in an insulated cooker is 16.5 °C and 19.3 °C higher than without PCM using water and SigmaTherm–K as HTF respectively. It was concluded that using PCM with the SigmaTherm–K increased the amount of average energy by 29.11% compared to water. The temperature attained by water as cooking load increased from 22 °C to 77 °C and from 20.1 °C to 86.2 °C using water and SigmaTherm–K as a HTF respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2024-09-10T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7121 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7121 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7121

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7271 2025-03-23T21:00:00Z 1

Performance improvement of a decayed flow heat exchanger using spiral flow and nanofluid Walaa M. HASHIM, Faten N. AL-ZUBAIDI, Huda A. AL-SALIHI Decayed Flow and Nanofluid; Heat Exchanger; Spiral Flow; Swirl; Taylor Vortex. The demand for heat exchangers that have high performance is still a major challenge for the industrial field. In this work, a spiral flow of cold air and a 0.5% volume concentration of the nanoaluminum metal heat exchanger were used to analyze the Taylor vortex that forms in the hot nanofluid Al2O3. According to the experimental results, the effectiveness of the heat exchanger at the ratio Cmin/Cmax of 0.08 could be improved over that of the exchanger at the ratio Cmin/Cmax of 0.0. Additionally, at an inner cylinder rotational speed of 80 r.p.m, employing the spiral flow of cold air and nanofluid as a hot fluid to transfer heat increased its efficacy can reach up to 53.8%. Journal of Thermal Engineering Journal of Thermal Engineering 2025-03-23T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7271 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7271 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7271

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7108 2024-09-10T21:00:00Z 1

Thermal Analysis of Photovoltaic-Thermoelectric Hybrids Rida Y. NUWAYHID, Mohamad S. RAHAL, Yamen Z. MAKAREM, Roger R. ACHKAR Solar, Photovoltaics, Thermoelectrics, Hybrids, Temperature, Figure-of-merit, Efficiency There continues to be considerable research on the adverse effect of photovoltaic (PV) panel temperature on its power production. Aside from attempting to minimize heating up of the panel by providing heat sinks and the like, several studies looked into using the unconverted heat as an input to a Thermoelectric generator residing below the PV panel and questionably generating additional power. Using simple steady energy balances, simplified steady thermal models of PV panels, individually or thermally-in-series coupled to heat engines are studied. The nodal energy equations are solved to ascertain resulting temperatures and efficiencies under different insolations. After establishing a simplified model for a lone PV panel, a PV panel with an added thermoelectric generator attached to its back side is studied. Solving the associated steady energy equations, the photovoltaic-thermoelectric system is found to have a smaller than expected advantage in net power, no more than 4.15 %, over the lone PV panel and then only at high insolation’s and concentrations. The implication of this work is that hybridizing a PV panel by bottoming it with a thermoelectric generator is not quite attractive except possibly at higher solar concentrations. The margin to Increase the overall efficiency of a photovoltaic-thermoelectric hybrid by improving the Thermoelectric-Figure-of-Merit does not appear to be significant although further consideration of thermoelectric materials may be required. Journal of Thermal Engineering Journal of Thermal Engineering 2024-09-10T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7108 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7108 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7108

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7159 2024-11-18T21:00:00Z 1

Effect of Refrigerant Charge Variation on the Energy and Thermal Performance of a Domestic Refrigerator Diana PARDO-CELY, Juan M. BELMAN-FLORES, Armando GALLEGOS-MUÑOZ, David A. RODRÍGUEZ-VALDERRAMA Domestic Refrigerator; EER; Energy; Refrigerant Charge; Temperature. Inadequate refrigerant charges can affect the vapor compression refrigeration systems’ thermal and energy performance. To delve deeper into the subject, this study experimentally evaluated the performance of a domestic refrigerator operating at different refrigerant charges. Some of them simulate refrigerant leaks (70 and 80 g), and some others simulate an excess (100 and 110 g). Through a statistical analysis (Tukey test and control graphs), the temperature data with the greatest impact were analyzed, including the temperatures in the suction and in the compressor casing, the temperatures in the middle position and outlet of the condenser and evaporator, as well as the temperatures in the freezer. The operation of the refrigerator was affected to a greater extent when it worked with an overcharge of 110 g; here, the discharge pressure and the run time increased by 1.3 bar and 21%, respectively, compared to the conditions of the refrigerator operating with the reference charge (86 g). In addition, the excess charge also caused an increase in energy consumption of 0.56 kWh/day and a decrease in EER of 0.5 regarding the reference charge. Finally, the increase in energy consumption was projected to $0.03 USD per day with respect to the reference cost. Journal of Thermal Engineering Journal of Thermal Engineering 2024-11-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7159 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7159 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7159

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7160 2024-11-18T21:00:00Z 1

Numerical Analysis of Three-Dimensional Magnetohydrodynamics Non- Newtonian Free Stream Flow Induced by Permeable Stretching Surface Khyati DANG, Vinita MAKKAR, Naresh SHARMA Buongiorno’s Model; Casson Fluid; Chemical Reaction; Nanofluid; Shooting Method; Three-Dimensional Magnetohydrodynamics Flow. The modern research aims to explore the influence of free stream flow on the motion of MHD Non-Newtonian nanofluid through a permeable extending surface in a three-dimensional domain. The primary goal of this research is to examine the significance of distinct fluid parameters, including Casson fluid parameter β, free stream velocity parameter λ, Brownian motion parameter Nb, magnetic parameter M, Prandtl number Pr, thermophoresis parameter Nt, Lewis number Le on distribution of velocity, concentration of nanoparticle and temperature. When similarity variables are incorporated into the set of governing partial differential equations, the equations are modified into a set of ordinary differential equations. Runge–Kutta fourth order is employed with the help of shooting approach in order to achieve the computational approach of the model that has been reduced. Numerical values of physical characteristics, like that the Nusselt number, the Sherwood number, and skin friction, have been assessed contrary to numerous parameters and disclosed in tables for the subject of engineering. Results for distribution of temperature, velocity and concentration of nanoparticles are explored in detail, including their rate of convergence. The principal results of the research revealed that the influence of both Casson fluid and magnetic parameter on the distribution of velocity exhibits a pattern of decline. Additionally, the effects of Brownian motion parameter on temperature demonstrate a rising pattern, while its impact on concentration distribution shows a diminishing trend. The use of permeable materials has shown that the heat transport process along an expanding surface prevents thermal loss and promotes the cooling process, which is a significant outcome of the study. The findings of this research have numerous applications in biomedical engineering and are useful for the analysis of fluids that are not Newtonian under various conditions. The recent study in the three-dimensional extending region is important for the development of novel industrial processes involving nanoparticles and the idea of magnetohydrodynamics flow of non-Newtonian fluids in existence of free stream flow. Journal of Thermal Engineering Journal of Thermal Engineering 2024-11-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7160 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7160 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7160

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7171 2024-11-18T21:00:00Z 1

Comparative Analysis of Performance and Emission from Single Cylinder Diesel Engine Fuelled with Mango Kernel Biodiesel Dhananjay KHANKAL, Sarang HOLE, Hrishikesh GADEKAR, Ajaykumar JAGTAP, Amar PANDHARE Brake Thermal Efficiency; Emissions; Engine Load; Injection Pressure; Mango Kernel Biodiesel; Transesterification. Due to their efficiency and high power output, diesel engines find extensive use in the automotive, transportation, industrial, and agricultural sectors. However, these engines encounter several challenges, including the emission of pollutants such as nitrogen oxides and particulate matter, as well as their reliance on fossil fuels. As a result, the demand for alternative fuels has risen significantly. Biodiesel, derived from various sources, has emerged as a promising substitute for diesel fuel. Among these alternatives, mango kernel biodiesel is currently being investigated as a renewable fuel option for diesel engines. In this current research study, a single-cylinder diesel engine was used to investigate the effects of mango kernel biodiesel (B10) as fuel compared to conventional diesel fuel. The engine was operated under different loading conditions (25%, 50%, 75%, and 100%) and varying fuel injection pressures (400 bar, 500 bar, and 600 bar), while maintaining a compression ratio of 18. The research focused on conducting a comparative analysis of engine performance, and emissions between the two fuels viz. conventional diesel fuel and mango kernel biodiesel blend. For major test cases, the engine recorded higher brake thermal efficiency (BTE) and lower brake specific fuel consumption (BSFC) as compared to the biodiesel blend. At full load and higher injection pressure, the B10 blend increased BTE by 4.83% and decreased BSFC by 5.40% than diesel. The smoke formation, CO, HC emissions were notably higher with B10 blend. Journal of Thermal Engineering Journal of Thermal Engineering 2024-11-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7171 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7171 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7171

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7211 2025-01-30T21:00:00Z 1

Numerical investigation of improved metal foam heat sink with Fe3O4-H2O nanofluid T. BOUACIDA, R. BESSAIH Electronic Cooling; Forced Convection; Heat Sink; TwoPhase Eulerian Model; Porous Media. The reliability and efficiency of electronic systems can be improved by removing their high thermal flux. Integrating porous media and nanofluids as working fluid within a heat sink (HS) is an effective strategy to dissipate the heat of electronic devices. To cool a CPU, a three-dimensional numerical simulation is carried out to investigate the characteristics of Fe3O4-H2O nanofluid flow, heat transfer, and entropy production in the proposed heat sink equipped with enhanced metal foam. The two-phase Eulerian model is implemented in Ansys Fluent software to predict the behavior of the turbulence flow of nanofluid. The simulation results are validated with experimental and numerical existing data, good agreement is achieved. The impact of pore permeability (10−4 ≤ Da ≤ 10−1), nanoparticle diameter (10nm ≤ dn ≤ 50nm), nanoparticle concentration (0.1% ≤ φ ≤ 0.5%), and flow velocity (2600 ≤ Re ≤ 3800) on heat exchange and entropy generation/production are carried out. The results showed that the application of reinforced foam enhances the average Nusselt number by 5.79% compared to aluminum foam and reduces thermal entropy generation/production by 47.58% at Re = 2600. Moreover, the performance evaluation criteria (PEC) increase by 56% when the pore permeability and flow velocity are raised. Journal of Thermal Engineering Journal of Thermal Engineering 2025-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7211 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7211 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7211

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7110 2024-09-10T21:00:00Z 1

Optimizing the Thermal Performance of a Double-Pipe Heat Exchanger Using Twisted Tapes with Variable Cuts and Fe3O4 Nanofluid K. P. V. Krishna VARMA, N. S. NAVEEN, P. S. KISHORE, Satish PUJARI, Krishna JOGI, V. Dhana RAJU cut twisted tapes, Nanofluid, Taguchi, friction factor, Nusselt number, Reynolds number, ANN This research work aims to optimize double pipe heat exchanger performance using Taguchi, ANOVA, and ANN. Experimental trials involved varying ferric oxide nanoparticles, cut radius, and volume-based flow rate. Twisted tapes with ratios of 3, 5, and 7 were placed within the tube. Assessed heat transfer characteristics included h, Nu, ff, and thermal performance factor. Taguchi, ANOVA, and ANN optimization techniques were applied to the experimental data. A Taguchi optimization using an L9 orthogonal array focused on input attributes (Vol % of nanoparticles, flow rate, radius of cut), with output attributes being heat transfer co-efficient (h), Nusselt number (Nu), friction factor(ff) and thermal performance factor. Results revealed a notable flow rate effect on enhancing h, Nu, and ff, while the addition of nanoparticles significantly influenced thermal performance. Taguchi and ANOVA were conducted using MINI Tab and ANN was implemented through MATLAB. Test data demonstrated that nanoparticle dispersants in nanofluid significantly improved heat transfer properties, consistent with the noteworthy improvement indicated by optimization techniques. The convective heat transfer coefficient parameter showed improvement with a coolant flow rate of 50.29% and a volume of nanoparticles at 27.32%. The enhancement of Nusselt number (Nu) was influenced by a coolant flow rate of 50.34% and a volume percent of nanoparticles at 34.25%. The thermal performance factor was significantly influenced by the volume percent of nanoparticles (79.75%) and the radius of cut (3.83%).The experimental data aligned well with findings from Taguchi and ANN. Journal of Thermal Engineering Journal of Thermal Engineering 2024-09-10T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7110 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7110 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7110

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7161 2024-11-18T21:00:00Z 1

Investigations on the Pyrolysis Behavior of Sapindus Mukorossi Based on Kinetic and Thermodynamic Parameters Karunakarareddy LOMADA, Suraj POYILIL, Arun PALATEL, Muraleedharan CHANDRASEKHARAN Biomass; Iso-Conversional Methods; Model-Free Methods; Pyrolysis; Reaction Mechanism; Sapindus Mukorossi. Sapindus mukorossi (SM) is a fast-growing deciduous tree found extensively in tropical and sub-tropical regions of Asia. The conversion of SM seed shell (left over after extracting the pulp and kernal) to value added products through pyrolysis needs in-depth knowledge about its thermal degradation behavior. The present work studies the physicochemical properties, pyrolysis behavior, and kinetics of this less explored biomass feedstock for thermochemical conversion. The elemental composition, gross composition and higher heating value (HHV) of the SM shell is found to determine its energy potential. The kinetics of the pyrolysis reaction influence the breakdown of solid biomass into final products. Thermogravimetric analysis (TGA), wherein the sample is heated at various heating rates (5, 10, 20 °C/min) at inert condition reveals the thermal degradation profile of SM seed shell. Three important isoconversional model-free techniques, notably Friedman, Ozawa-Flynn-Wall (OFW), and Kissinger-Akahira-Sunose (KAS) approaches, are employed to obtain the kinetic triplet data, the thermodynamic parameters are also determined. The C, H, N, S and O content of the SM shell was found to be 39.82%, 4.64%, 0.64%, 0.64% and 54.26% respectively. The SM seed shell had a volatile matter, fixed carbon and HHV of 68.5%, 20.9% and 16.6 MJ/kg respectively which revealed its energy potential for thermochemical conversion. From the TGA curve, the maximum thermal degradation was observed between 200 °C and 500 °C. The values of average activation energy determined using models Friedman, OFW and KAS are 152.28 kJ mol-1, 140.05 kJ mol-1 and 138.14 kJ mol-1, respectively. The frequency factor was found to vary widely between 103 and 1015. The variation in activation energy and frequency factor as the conversion progresses indicated complicated processes during the thermal deterioration of SM. The biomass degradation occurs by diffusion and nucleation mechanisms when the conversion value is between 0.2 and 0.5, and for conversion values in the range of 0.6–0.8, the degradation occurs by diffusion mechanisms. The physicochemical characteristics of SM are found to be comparable with that of the commonly available biomasses. The detailed investigations presented in this paper have clearly demonstrated the viability of SM seed shell as a viable feedstock for the pyrolysis process. Journal of Thermal Engineering Journal of Thermal Engineering 2024-11-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7161 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7161 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7161

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7162 2024-11-18T21:00:00Z 1

A Three-Velocity Three-Temperature Three-Concentration Description for MHD Double-Diffusive Free Convection in a Cavity Occupied by a Tridisperse Porous Medium Iman ZAHMATKESH Free Convection; Heat Transfer; Magnetohydrodynamics; Mass Transfer; Tridisperse Porous Media (TDPM). This work proposes a three-velocity three-temperature three-concentration (3V-3T-3C) model to describe the momentum, energy, and mass transfer in the macro-pores, meso-pores, and micro-pores in a tridisperse porous medium (TDPM), in the attendance of magnetic field imposition. Thereafter, the system of these highly coupled equations is solved numerically to scrutinize MHD double-diffusive free convection heat transfer in a square cavity occupied by a TDPM, for the first time. Finally, features of the pertinent parameters on the flow strength as well as heat and mass transfer are disclosed through contour plots and tables. The simulation results suggest that the elimination of the magnetic field as well as increase in the double-diffusion ratio boosts up the flow strength and embellishes the heat and mass transfer, in all scales of porosity of the TDPM. It is also scrutinized that rise in the Lewis number is accompanied by small declination in the flow strength and the heat transfer and substantial elevation in the mass transfer, in all scales of porosity. Meanwhile, the consequences of the magnetic field imposition, the double-diffusion ratio, and the Lewis number are detected to be more intense in the macro-pores, as compared with the other scales of porosity of the TDPM. Additionally, it is elucidated that change in the macro-porosity is more likely to alter the heat and mass transfer performances, as compared with the meso-porosity or micro-porosity. Journal of Thermal Engineering Journal of Thermal Engineering 2024-11-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7162 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7162 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7162

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7112 2024-09-10T21:00:00Z 1

Effect of Compression Ratio and Load on Performance and Emission Behavior of VCR-CRDI Engine Fueled with Moringa Oleifera Biodiesel Vasant PATEL, Vyomesh BUCH Non edible Moringa Oleifera biodiesel, CRDI-VCR type diesel engine, Performance and emission characteristics. The preliminary objective of the present work is to evaluate the performance and emission characteristics for different CR and engine loads using diesel and Moringa Oleifera biodiesel blends as fuel. In the present work mono cylinder, 4-stroke, CRDI-VCR type, CI engine tested using diesel and Moringa Oleifera biodiesel blend MB10, MB20, and MB30to investigate the performance and emission behavior of an engine concerning CR at the different loading conditions (0.88, 1.75, 2.66 and 3.5 kW). The experiment was performed at four different CRs 15:1, 16:1, 17:1, and 18:1 at fixed IT 230bTDCand IP 600 bar. The results of the experiment show that the highest BTE for diesel and biodiesel blend MB30 is reported at 27.26% and 28.26% at the higher CR of the present investigation 18:1 and 100% load condition. The increase in load and CR shows the reduction in the BSFC and BSEC of an engine for all tested fuels and the minimum BSFC and BSEC reported among the entire fuel blend is 0.30 kg/kWh and 12.9 MJ/kWh for MB30 fuel blend at higher CR of present investigation 18:1 and 100% load condition. The minimum emission of CO and HC reported for MB30 fuel at higher CR of present investigation 18:1 and 100% load condition is 0.04 % vol and 8 ppm. In the present investigation, the highest CR of 18:1 and 100% load condition offers the minimum emission of NOx reported as 522 ppm for the biodiesel blend MB20 among entire fuel blends. The results reveal that the NOx emission of the MB20 fuel blend is about 11.97% less than recorded for diesel. The emission of smoke is almost zero for all the fuel blends at the higher CR 17:1 and 18:1 up to 50% loading condition. The highest emission of smoke was observed at lower CR 15:1 and 100% loading conditions for all the tested fuel blends. Moringa Oleifera biodiesel blend MB30 shows an enhancement in thermal performance by increasing BTE and decreasing BSFC while improving emission characteristics by reducing emissions of pollutants such as CO, HC, smoke, and NOx. Journal of Thermal Engineering Journal of Thermal Engineering 2024-09-10T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7112 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7112 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7112

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7172 2024-11-18T21:00:00Z 1

A Recapitulation of Solar Dryers in Realm - Evaluating Geometry, Modes, Thermal Energy Storage, and Applications in Agricultural Produce Yogesh D. KOKATE, Prasad R. BAVISKAR, Sanjeev D. SURYAWANSHI Agricultural Produce; FEA Analysis; Heat Storage Materials; Mathematical Models; Modes of Solar Drying; Shapes of Solar Dryers. Waste of agricultural produce attributed poor post-harvest management practices. To resolve this problem now days solar drying system gained hegemony to preserve and process the agricultural produce. The study systematically analyses the experimentation conducted on different factors of solar dryer, including its geometry, modes, agricultural produce, heat storage materials, mathematical models, and validation through Finite Element Analysis (FEA) analysis, providing valuable insights for future study. In the reviewed literature, the desiccation of agricultural produce commonly occurs within the air temperature range of 28°C to 86°C. It was found that the most effective desiccation of agricultural produce in solar dryer cabinets takes place within the air temperature range of 50°C to 65°C, leads to reduce drying time. In the majority of studies aimed at improving the desiccation rate, air circulation is achieved through the use of blowers or fans, with velocities typically rang of 0.5 m/s to 2 m/s. Additionally, the air flow rates employed in these studies vary from 0.003 kg/s to 0.09 kg/s. However, further research and investment are needed to enhance solar drying technologies, exploring new geometries, intermittent air circulation, desiccants to reduce air humidity and make them available to more farmers across the world. Journal of Thermal Engineering Journal of Thermal Engineering 2024-11-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7172 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7172 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7172

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7163 2024-11-18T21:00:00Z 1

Performance Study of Sub-Cooled CO2 Trans-Critical Air Conditioning Cycle: The Combined Effect of Vapor Quality and Compressor Efficiency Ahmad Bani YASEEN, Mohammad TARAWNEH, Hussein N. DALGAMONI, Khaleel AL-KHASAWNEH Airconditioning; Efficiency; Simulation; Trans-critical CO2; Vapor Quality. Carbon dioxide, one of the most critical potential refrigerants, has little impact on the environment. CO2 trans-critical cycles are an essential topic in air conditioning. The current study investigates the performance of the CO2 trans-critical air conditioning cycle for various parameters. The distinct contribution of this work arises from its emphasis on the interrelated nature of the combined effect of compressor efficiency and vapor quality at the evaporator inlet on the overall performance of the CO2 trans-critical cycle; by filling this knowledge gap, the research endeavours to comprehensively understand the system’s behavior under a wide range of operation conditions. The cycle has been modelled using Engineering Equation Solver (EES) and MATLAB codes and validated against an experimental study. The results showed that the cooling capacity increases by 66% when gas-cooling pressure rises from 100 to 150 bar. Raising vapor quality from 0.1 to 0.5 and lowering the degree of superheat from 12 to 0 °C reduces the cooling capacity by 52.4% and increases the coefficient of performance by 87%. Power consumption of the compressor decreases by 50% by increasing compressor efficiency from 70% to 100% and lowering gas cooling pressure from 110 to 80 bar. While the coefficient of performance of the cycle increases by 111.7% by increasing compressor efficiency from 70 to 100% with a degree of sub-cool from 0 to 6 °C and a degree of superheat from 0 to 12 °C. Journal of Thermal Engineering Journal of Thermal Engineering 2024-11-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7163 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7163 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7163

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7212 2025-01-30T21:00:00Z 1

Performance enhancement of thermal energy storage system using ZrO2 doped paraffin wax Shri Krishna MISHRA, Mukesh Kumar GUPTA, Rahul KUMAR, Abhishek SHARMA Characterization, Nanomaterial; Paraffin Wax; Synthesis; Thermal Energy Storage. The present work focused on the application of zirconium dioxide (ZrO2), a metal based nano material in a helical tube heat exchanger. A novel nano enhance phase change material (NEPCM) passes through a series of test to explore its energy storage capacity. The aim of the study is to determine the effect of varying amounts of ZrO2 on the thermal performance of energy storage systems through experiments, and based on the results, to identify the optimal concentration. The scanning electron microscopy (SEM) results indicated that the ZrO2 physically bonded with paraffin wax without disturbing the chemical stability and structure of the NEPCM samples. It was noticed that ZrO2 successfully stabilized surface temperature, solidification and melting of paraffin wax. Experiments with ZrO2 doped with paraffin wax also helped to establish the optimum value of charging and discharging time. The most significant enhancement in charging rate was observed with a mere 0.1–0.3% (vol.) increase, but this enhancement rapidly declined with increases beyond 0.3% in volume concentration. NEPCM with 0.3% concentration in volume was identified as ideal sample. When the mass flow rate increased from 1 to 5 LPM, the exergy efficiency dropped from 21.4% to 15.3%. Compared to other PCM and NEPCM samples, ZrO2-doped PCM samples exhibited a more favorable thermal response. Journal of Thermal Engineering Journal of Thermal Engineering 2025-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7212 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7212 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7212

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7213 2025-01-30T21:00:00Z 1

Modeling and co-simulation of an integrated solar heating system and direct contact membrane distillation module Mouad BOUSMAHA, Ahmed REMLAOUI, Driss NEHARI Co-simulation; Desalination; Direct Contact Membrane Distillation; Solar Heating. This study investigates the use of a solar heating system and a direct contact membrane distillation module to produce pure water. The study employs co-simulation techniques that combine TRNSYS and MATLAB. The integrated system consists of a flat sheet membrane module for purification, a hot water storage tank with an internally regulated auxiliary heater, and a flat plate collector for thermal energy supply. A novel membrane distillation module was used, allowing the liquid to make direct contact with the membrane. The module was developed in MATLAB, reprogrammed, and then integrated into the TRNSYS framework. The TRNSYS-MATLAB co-simulation assessed the integrated system’s long-term efficiency. This novel solar desalination technique also improves prediction flexibility for various membrane distillation scales and configurations (such as co-current and counter-current). The current study used and validated the use of Polyvinylidene fluoride flat sheet membrane distillation in both co-current and counter-current arrangements at small and large scales, comparing the results to previously published research. Increasing the collector area from 2 m² to 8 m² in Ain Témouchent’s weather conditions reduces the auxiliary heating rate by 14% in December and 44.27% in August. In the summer, solar fraction and solar collector efficiency are 71% and 63%, respectively. The current integrated system can collect approximately 54.28 l of water flux through the membrane per day, resulting in a membrane production rate of 13.57 kg/ m².hr. The findings show that the use of modern co-simulation techniques is highly inventive, producing environmentally friendly water in a sustainable and efficient way Journal of Thermal Engineering Journal of Thermal Engineering 2025-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7213 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7213 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7213

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7214 2025-01-30T21:00:00Z 1

Thermal behavior and evolved gas analysis for pyrolysis of olive pomace, coal, and their blends using TGA/FTIR Hasan MERDUN, Balkis YAHYAOUI Coal; Co-pyrolysis; Olive Pomace; Synergistic Effect; TGA/FTIR. This study analyzed the thermal behavior and evolved gas for pyrolysis of olive pomace (OP), coal, and their five blends at five different heating rates using TGA/FTIR. Furthermore, synergistic effects were investigated during the co-pyrolysis of OP and coal. Mass loss (ML) systematically increased in the second stage of all samples from pure coal toward pure OP, but the corresponding temperatures and temperature ranges decreased. The synergistic effect was observed for ML and maximum differential thermogravimetry (DTGmax) in the blends of 60% OP + 40% Coal and 80% OP + 20% Coal. The absorbances of CO and CO2 were similar, but the absorbances of CH4, NOx, and SO2 showed similar and clear trends with a single peak at temperatures of 200-600o C as in TG and DTG curves. The peak intensity and hence the contribution to CH4, NOx, and SO2 emission increased as the OP content increased in the blend. The highest peak intensity with the largest contribution to CO emission was observed in the pure OP sample, whereas the lowest peak with the least contribution was observed in the 40% OP + 60% Coal sample. Similar behavior was observed in the CO2 absorbance. The results of this study with different thermal behavior, synergistic effects, and gas emissions during pyrolysis of OP, coal, and their blends suggest conducting further studies under different experimental conditions to understand better and get useful knowledge for the design of industrial pyrolysis reactors. Journal of Thermal Engineering Journal of Thermal Engineering 2025-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7214 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7214 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7214

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7115 2024-09-10T21:00:00Z 1

Thermodynamic Entropy of a Magnetized Nanofluid Flow Over an Inclined Stretching Cylindrical Surface Mahesh GARVANDHA, Nagaraju GAJJELA, Vamsikrishna NARLA, Dewendra KUMAR Bejan number; Entropy generation; Inclined stretching cylinder; Nanofluid; Variable thermal conductivity In the fluid transport processes extent of irreversibility causes entropy generation that leads to degrading the life span of any engineering system. The main objective of this investigation is to enhance the span of the system by analyzing the effects of various physical parameters. A nanofluid flow over an inclined stretching cylinder is studied to measure entropy generation due to thermal conductivity, Soret, and Dufour effects along with viscous dissipation and internal heat source. Buongiorno model is considered as a base structure. The mathematical equations so formed are solved by shooting technique with Gill’s fourth order method. Numerical results are validated with Homotopy analysis method through Bvph2.0. Effects of various parameters have been investigated on transport processes like axial velocity, temperature profile, and nanofluid concentration profiles. It seems that higher intensity of the applied magnetic field (M = 0, 1, 2), variable thermal conductivity (? = 0.1, 0.3, 0.5), and Brinkman number (Br = 0.35) generates more entropy that degrades the system’s life. Magnetic parameter and group parameter (1?Br/?_1?3), changing thermal conductivity all leads to a rise in entropy. In the study, group parameter reducing Bejan number that makes system more sustainable that full fills the aim of the study. Such physical situations generate more entropy must be reduced or avoided to make the system more efficient and long-lasting. Journal of Thermal Engineering Journal of Thermal Engineering 2024-09-10T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7115 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7115 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7115

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7106 2024-09-10T21:00:00Z 1

Performance and Fluid Flow Analysis of Double Pipe Heat Exchanger using AL2O3-Nanofluid Azhar Hussain SHAH, Liaquat Ali MEMON, Muhammad Ramzan LUHUR, Qadir Buksh JAMALI, Sajjad Hussain BHANGWAR, Umair Ahmed RAJPUT Heat transfer, Heat exchanger, Nano fluid, Nanoparticle, Convective heat transfer coefficient Heat exchangers play a vital important role in industries and processing equipment’s. Among them, the double pipe heat exchanger facilitates the exchange of heat between two fluids through surface tubes. This study aimed to investigate various thermal performance parameters of baseline water and Aluminum oxide nanofluid at various volume concentrations and flow rates. The results were compared between baseline water and Aluminum oxide nanofluid using a test rig at the temperature range of 60 °C for industrial applications. The nanofluid sample was prepared by adding very small-sized (20nm) Al2O3 nanoparticles in the baseline water within the range of 0.10% to 0.175% using a standard two step method for the sterilization process. The nanoparticle and baseline water were under set by a hot plate mechanical stirrer for approximately 2 hours to ensure the proper dispersion before the tests, rendering the nanofluid stable for 12 hours. The Laminar-Transition flow double pipe heat exchanger (test rig) operated at flow rates ranging from 1.6×10-5-3.3×10-5 m3/sec (1-2 LPM) within the range of Reynolds number from 1700 to 3400 at volume concentration of 0.10% to 0.175% Moreover, an addition of 0.175% of Al2O3 nanoparticle in the baseline improved the average heat transfer coefficient from 140% to 155%, thermal conductivity of 21.6% and, 5.94% efficiency in counter flow direction and also showed higher friction factor i.e. 2.81% than baseline water. The results suggest that Al2O3-nanofluid at 0.175% could function very well as working fluid for industrial requirements compared to the conventional baseline water. Journal of Thermal Engineering Journal of Thermal Engineering 2024-09-10T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7106 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7106 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7106

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7122 2024-09-10T21:00:00Z 1

Estimation of Wind Speed by Artificial Intelligence Method: A Case Study Enas F. AZIZ, Raid W. DAOUD, Sameer ALGBURI, Omer K. AHMED, Khalil F. YASSEN Wind energy; Assessment; Artificial intelligence; Iraq. Wind speed changes from one region to another due to several influencing variables. In this article, a software method has been proposed to determine the future wind speed at any time and under any conditions. Neural Networks were used with engineering data regarding the method of education, training algorithms, and different activation functions between the input and output layers, each according to the nature of the data that will be generated. Backpropagation Neural were used with three variables chosen to be the inputs for the learning and training network (wind speed, humidity, and time), which are considered the most important in determining the proposed or expected speed at the relevant time and place. The hidden layer consists of 10 neurons which are determined according to the precision of output. After comparing the measurements from the weather system with the expected values, a very tiny percentage of error was found, since these readings are regarded as acceptable and aid in the problem-solving process for running companies and researchers. The error rate recorded in this work ranged between (3 * 10-3 and 3 * 10-5), and the average number of attempts for the training and examination process reached 33 attempts, as it is known that neural networks carry out the training process based on specific mathematical functions and closed loops that depend on the lowest possible error rate. Journal of Thermal Engineering Journal of Thermal Engineering 2024-09-10T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7122 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7122 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7122

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7216 2025-01-30T21:00:00Z 1

Numerical analysis of nanofluid flow over a radiating oscillating plate with hall current and MHD at enhanced temperature S. SARALA, E. GEETHA Alumina; Radiation; Magnetic Field Parameter; Primary Velocity; Secondary Velocity; Variable Temperature. The study investigates the impact of various factors, including magnetohydrodynamics (MHD), alumina nanofluid flow, thermal radiation, Hall current, and harmonic oscillations on convective heat generation at enhanced temperatures on a plate. The plate experiences harmonic oscillations while maintaining a uniform temperature, and dimensional equations are converted into non-dimensional ones using specific parameters. Through Laplace transformation, an exact solution is derived. Analysis of velocity and temperature considers the Prandtl number, Grashof number, Hall parameter, magnetic parameter, radiation, solid volume fraction, and phase angle. Graphs illustrate the impact of primary and secondary velocity, showing increased velocities with higher Grashof numbers and decreased velocities with rising Hall parameters. Moreover, the temperature rises in line with the solid volume fraction. Effective heat transfer is crucial for improving energy efficiency in industrial processes, HVAC (heating, ventilation, and air conditioning) systems, and thermal management setups. Engineers utilize the Nusselt number to optimize heat transfer equipment design. For instance, at Nu = 0.9258 (at t = 0.5, Pr = 0.71, solid volume fraction = 0.26, R = 1). and In magnetohydrodynamics (MHD), the presence of a magnetic field alters the fluid flow behavior. At higher magnetic field strengths, the fluid flow becomes more constrained or influenced by the magnetic forces, which can lead to increased frictional resistance along the surface of the plate. The skin friction coefficient values increase for both velocities as the magnetic field parameter reaches 4, 5, and 6. Graphical representations of mathematical findings enhance comprehension of temperature and velocity variations, emphasizing the importance of heat transfer efficiency. Journal of Thermal Engineering Journal of Thermal Engineering 2025-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7216 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7216 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7216

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7105 2024-09-10T21:00:00Z 1

Influence of Buoyancy Forces in MHD Non-Newtonian Convective Nanofluid Utilizing Buongiorno’s Model Induced by 3D Exponential Sheet Saloni GUPTA, Parmod Kumar SHARMA, Sanjay KUMAR, Chinta Mani TIWARI Casson Fluid, Shooting Method, Nanofluid, Chemical reaction, Buongiorno's Model, Buoyancy forces The designation of this research is to scrutinize the influence of convective nanofluids over a three-dimensional exponential surface with chemical reactive species in a free stream fluid flow by following Buongiorno's model. The continuity, momentum, energy, concentration and motile microorganism density partial differential equations that make up the physical governing equation problems are simultaneously transformed into ordinary differential equations system. By using MATLAB programming, the RKF approach has been followed in order to implement the shooting technique to solve this system that explores how changing fluid parameters affect the profile of physical quantities of interest. A parametric analysis has been done in the current study. The effects of fluid parameters such as chemical reaction, Brownian motion, free stream velocity, Lewis number, thermophoresis, and Prandtl number on concentration, temperature, and velocity profiles are graphically represented. Moreover, Contour plots are also drawn against computational fluid parameters to get desired results. Furthermore, calculated results are correlated with already existing outcomes along with residual error. It is inferred that; thermal and concentration fields increase for higher thermal and concentration Biot numbers serially. Additionally, it is found that skin friction coefficient declines with inclination in thermophoresis Nt (1.0?Nt?3.0) and Prandtl number Pr??(1.0?Pr?4.0)?. The present investigation aims to support production businesses in achieving the desired level of quality of their products by effectively managing the transport phenomena. Journal of Thermal Engineering Journal of Thermal Engineering 2024-09-10T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7105 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7105 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7105

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7215 2025-01-30T21:00:00Z 1

Numerical investigation of hydrothermal performances of minichannel heat sink using porous media Rajesh KUMAR, Mohammad ZUNAID, Radhey Shyam MISHRA Electronic Cooling; Heat Sink; Hydrothermal Performances; Minichannel; Nanofluids; Porous Media In the present study, 3-D CFD simulations have been performed to examine the hydrothermal performance of a circular-shaped minichannel heat sink. The heat sink is composed of aluminum with dimensions of 40mm×40mm×10mm and it is designed for Reynolds numbers less than 1300. A uniform heat flux of 66 KW/m2 is applied to the bottom wall of the heat sink, while other surfaces have been insulated. The finite volume approach was utilized in Ansys-Fluent to solve the system governing equations and associated boundary conditions. Magnetite-water nanofluid has been used as a coolant and examined the variations of mass flow rate and nanofluid concentration on cooling potential. A bronze porous material has been inserted throughout the channel space at various porosity levels. The performances of the heat sink have been further investigated at various channel counts by varying the hydraulic diameter in a manner that the total flow area of the channels remains constant. The results show that the number of channels and their dimensions have a substantial effect on heat transfer efficiency. This investigation reveals that using porous media is very significant relative to nanofluid at any concentration and the maximum augmentation in heat transfer by the incorporation of porous media along with nanofluid is 5.54 times. Moreover, the heat sink's practical utility is optimized through Figures of Merit and heat transfer efficiency. As a result, the optimum hydrothermal performance of this present study is achieved at six channels with a lower volume flow rate, higher volume fraction of nanofluid, and a lower porosity level. Journal of Thermal Engineering Journal of Thermal Engineering 2025-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7215 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7215 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7215

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7217 2025-01-30T21:00:00Z 1

Fe3O4, Au nanoparticles influence on bio-nanofluid thermal conductivity Ali J. ALI, Bahaa E. EDDIN, Sanaa T. Mousa AL-MUSAWI, Hasan Shakir MAJDI, Miqdam T. CHAICHAN Bio-nanofluid; Glioblastoma; Hematocrit; Hyperthermia; Nanoparticles; Thermal Conductivity. Hyperthermia therapy is one of the new technologies emerging from nanotechnology. This study examines the relationship between bio-nanofluid thermal conductivity and hematocrit differences. In the treatment of cancer, researchers have used several types of nanoparticles. The bio-nanofluid used in this study was created by adding two types of nanoparticles (Fe3O4 and Au) to blood for the first time. Based on the results, thermal conductivity was found to be significantly affected by the shape of nanoparticles, and the proposed thermal conductivity models agreed with the literature. According to the nanomaterial and the age and gender of the participants, as well as the nanoparticles’ shape, analysis of the study results is presented. For each group of men, women, and children, the effective thermal conductivity values of Plasma-Au nanoparticles and plasma-Fe3O4 nanoparticle fluids changed with the thickness of the interlayer. In comparison to iron nanoparticles (magnetite oxide Fe3O4), gold nanoparticles improved the thermal conductivity more. Nano-layer thickness increases with radius at the same time as thermal conductivity increases. A bio-nanofluid composed of plasma, nano-Fe3O4, or nano-Au was calculated by Yang’s model. In addition, the thermal conductivity of nano-biofluid, consisting of plasma nano-Fe3O4, nano-Au, and red blood cells, was calculated using the Maxwell model. As a result of varying hematocrit values, nano-biofluids improve at a different rate of thermal conductivity. Depending on the gender and age of the patient, the rate of improvement varies. Au nanoparticles (5 nm) increased the bio-nanofluid thermal conductivity for children by 0.623% and 0.306% more than that for men and women, respectively, at nano-layer thickness (t=1 nm). Using Fe3O4 NPs of 25 nm diameter, the children thermal conductivity of nano-biofluid increased by 0.58% and 0.268% higher than men and women, respectively, at nano-layer thickness (t= 5 nm). Journal of Thermal Engineering Journal of Thermal Engineering 2025-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7217 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7217 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7217

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/6960 2024-03-14T21:00:00Z 1

Evaluation of the Thermal Efficiency of Nanofluid Flows in Flat Plate Solar Collector Adnan Hussein, Afrah Turki Awad, Hussein Hayder Muhammed Ali Experimental Study; Nanofluid; Copper Oxide Nanoparticles; Thermal Performance; Efficiency. In this research, flat plate solar collectors (FPSC) were studied due to their simplicity, low maintenance, and cost-effectiveness. The study focused on comparing FPSC thermal performance using CuO/H2O nanofluids. Experiments were conducted over three months during the Iraqi weather conditions (January, February, and March) with carefully selected nanoparticle concentrations. Data was collected from 9 A.M. to 3 P.M., using various mass flow rates (ranging from 0.003 to 0.076 kg/s). Results showed a direct correlation between temperature and nanoparticle concentrations, with the highest outlet temperature (50°C) observed at 3 P.M. for 1% CuO-water nanofluid. Notably, at 1 P.M. in March, the 1% CuO-water nanofluid exhibited a 32% increase in collector thermal efficiency, surpassing pure water by 11.3%. This would improve the performance of FPSC by achieving higher efficiency increments. These improvements were attributed to the unique physical properties of nanoparticles, their increased surface area, and higher thermal conductivity. The study determined that the optimum nanofluid concentration for superior collector efficiency was 1%. Journal of Thermal Engineering Journal of Thermal Engineering 2024-03-14T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6960 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6960 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=6960

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7218 2025-01-30T21:00:00Z 1

Investigation on Delonix regina biodiesel blends on diesel engine with 1-butanol-diesel blends to test engine performance, combustion and emission characteristics Sumathy MUNIAMUTHU, K. Sunil KUMAR, S. DEEPA, Muniyandi ELANGOVAN, Amit VERMA, Mahesh M. SONEKAR Brake Thermal Efficiency; Energy; Delonix Regina Blends; Specific Fuel Consumption. The need for automobiles is rapidly increasing all over the world. The biofuel requirement has also increased due to the need to avoid the nonpolluted atmosphere and improve performance. This work, with its innovative use of nonedible Delonox regina blends with limited proportions of butanol alcohols has practical implications for the automotive industry. The novelty of this research lies in the investigation of 1-butanol additives on Delox regina blends with the lowest proportions followed by 5%,12%, and 14% as a best-boosting ignitor. This limited butanol proportions proved that the engine’s thermodynamic performance was better when fuelled with Delonox regina blends and subjected to different loads. The results obtained from the Delonox regina blends and diesel in terms of performance, owing to combustion and owing to emissions for every stage, are compared with diesel. Higher thermal efficiency is obtained for the blend D90DR05B05, and the least BSFC is also attained for the blend D90DR05B05 than diesel, But the emissions are very low for the blend DR 100 followed by CO emissions, which is 34.5% superior to diesel. CO2 emissions are 14.5% decreased for the blend D70DR16B14 than diesel, HC emissions for blend DR100 are less than 42.5%, and NOx emissions for blend DR100 are less than 23.53% compared to diesel. Journal of Thermal Engineering Journal of Thermal Engineering 2025-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7218 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7218 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7218

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7219 2025-01-30T21:00:00Z 1

An experimental study on the impact of porous media in improving the heat transfer performance characteristics of photovoltaic-thermal system Amjad H. HAMZAWY, Qahtan A. ABED Efficiency; Improvement; Performance; Photovoltaic; Porous; Thermal. Photovoltaic (PV) systems are characterized by their efficiency and performance decreasing as the operating temperature increases. The maximum available tested efficiency of the PV module decreases by up to 0.8% with each 10-degree temperature increase. To perform better PV, it is necessary to extract the heat, and thus decrease its temperature. In the context of this particular research investigation, a series of empirical investigations were conducted at Al-Rumaitha Technical Institute situated in Iraq (31°42' - 45°12'). These experimental endeavors were undertaken to analyze the performance and characteristics of photovoltaic thermal (P`VT) collectors. It is noteworthy to mention that one of these solar panels was effectively incorporated into a photovoltaic/thermal (PV/T) module, while the other panel was employed independently without any cooling mechanism. It is essential to underscore that the induction and maintenance of airflow were achieved through the utilization of an air intake fan. It is important to highlight that these experimental investigations were undertaken over a diverse array of days throughout the year, thereby ensuring the thorough coverage of various atmospheric conditions and scenarios. The results show the maximum electrical efficiency achieved was found to be a commendable 19%, representing an impressive improvement of 5.1% when compared to the PV panel without porous. Moreover, it is important to highlight that the maximum output power attained was an astounding 330.7W. Also, the thermal characteristics of the system showed that the maximum amount of heat gain reached a notable 707.1 W. It is also worth noting that the thermal efficiency of the system was calculated to be 29.57%. Lastly, it is pertinent to mention that the overall efficiency of the system, encompassing both electrical and thermal aspects, amounted to an impressive 46.8%. Journal of Thermal Engineering Journal of Thermal Engineering 2025-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7219 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7219 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7219

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7220 2025-01-30T21:00:00Z 1

Studying the influence of using metal foam baffles on the performance of double-pipe heat exchanger Zuhair S. FRABEEAH, Abbas J. JUBEAR, Hussain R. AL-BUGHARBEE Copper Foam Baffles; Heat Transformer Rate Enhancement; Local Thermal Equilibrium; Numerical Investigation. The enhancement of the thermal performance of heat exchangers has a great importance to the researchers. This is because improving the performance will lead to increasing the efficiency of the application where the heat exchangers are used. In this study, the thermal and hydraulic performance of a double heat exchanger with open-cell copper foam baffles inside was investigated numerically and experimentally with water as operating fluid. The numerical simulation was conducted using ANSYS FLUENT 2020 R2 to simulate the water flow and temperature distribution in the heat exchanger at different configurations. These configurations included the completely and partially filled with metal foam with different foam properties such as pore density, baffle angle, and baffle thickness. The experimental work included the designing and building of the test rig and obtaining the temperature recordings which were used for comparison purposes. Results were obtained for temperature contours, velocity streamlines, Nusselt numbers, effectiveness, pressure drops, and friction factors at variable baffles angles (β = 60°, 120°, 180°), variable baffles thickness (t =10, 20, 30mm), and variables pore density (PPI=10, 20, 30, 40, 50PPI). They showed that as the volume of metal foam increases, the heat transfer rate (Qave) and the pressure drop (∆p) increases. In addition, the performance of the heat exchanger with a partially filled core was better than that in the completely filled case. On the other hand, when the metal foam volume decreases, the pressure drop decreases. Furthermore, it was observed that the heat transfer rate increases with the increase in pore density. Experimental results showed an enhancement in heat transfer rate in a double-pipe heat exchanger by 32.4% at 40PPI and β=180°. There was also an enhancement in the Nusselt number value (Nuave) by 117% due to the use of copper foam baffles. Journal of Thermal Engineering Journal of Thermal Engineering 2025-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7220 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7220 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7220

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7164 2024-11-18T21:00:00Z 1

Characterization of NACA 2412 and NACA 4412 Airfoils: Effects of Angle of Attack on Aerodynamics Coefficients Dilsad AKGUMUS GOK, Khaled Nimer Mohammad AL-NIMER Angle of Attack; Drag Coefficient; Lift Coefficient; NACA 2412, NACA 4412. The angle of attack plays a pivotal role in determining the performance of an aircraft wing, a critical component of its overall design. This angle, defined as the angle between the chord line of the wing and the relative wind direction, has a profound impact on the lift and drag forces experienced by the wing. When the angle of attack is low, the wing generates lift with minimal drag. However, at higher angles of attack, the wing encounters increased drag and may reach a stall condition. Understanding the influence of the angle of attack on an aircraft wing is crucial in both design and operation, significantly impacting the aircraft’s capabilities in takeoff, climb, navigation, and landing. Therefore, a comprehensive comprehension of the relationship between the angle of attack and wing performance is imperative for ensuring safe and efficient aircraft operation. This study is dedicated to elucidating the effect of the angle of attack on aircraft performance, focusing on the variation in aerodynamic coefficients for two distinct airfoils. Employing Computational Fluid Dynamics (CFD) analysis via SolidWorks, the research examines NACA airfoil types, specifically NACA 2412 and NACA 4412, each featuring different cambers. The selected angles of attack for the investigation range from 0° to 20°, with a constant flow rate of 43 m/s. The findings reveal that the NACA 2412 airfoil exhibits a higher lift-to-drag ratio near to 20 compared to 6 in NACA 4412 airfoil. This insight provides valuable information for optimizing the aerodynamic performance of aircraft wings, contributing to the enhancement of overall efficiency and safety in aviation. Journal of Thermal Engineering Journal of Thermal Engineering 2024-11-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7164 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7164 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7164

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7010 2024-05-26T21:00:00Z 1

An Experimental Study on Supersonic Jet Control Using Shifted Air Tabs Mahendra Perumal Govindan, Aravindh Kumar S. M., Elangovan S., Sundararaj M. Supersonic jet; Air tab; Injection Pressure Ratio; Nozzle Pressure Ratio; Shadowgraph. This experimental study investigates the impact of two diametrically positioned sonic air tabs on the mixing characteristics of a Mach 2.1 circular jet. Positioned at an axial distance of 0.25D from the convergent-divergent nozzle exit, the air tabs' injection pressure ratio was systematically varied from 3 to 6, while maintaining nozzle pressure ratios of 3, 4, 5, and 6. Through Pitot pressure measurements and flow visualization, the study reveals that the sonic air tabs effectively reduce the core length of the Mach 2.1 jet across all nozzle pressure ratios. The accelerated mixing of the Mach 2.1 jet with the ambient fluid, facilitated by the air tabs, results in shorter core lengths. Importantly, the mixing enhancement by air tabs intensifies with increasing injection pressure ratio for all nozzle pressure ratios, with the maximum reduction in core length consistently occurring at an injection pressure ratio of 6. The observed maximum reductions in core length for nozzle pressure ratios 3, 4, 5, and 6 at an injection pressure ratio of 6 are 41.3%, 60.8%, 43.7%, and 43.5%, respectively. Visualization results confirm the air tabs' effectiveness in attenuating waves within the jet core, with the weakening of waves increasing with higher injection pressure ratios. These findings contribute valuable insights into optimizing supersonic jet performance through fluidic control techniques. Journal of Thermal Engineering Journal of Thermal Engineering 2024-05-26T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7010 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7010 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7010

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7174 2024-11-18T21:00:00Z 3

Environmental Studies for Various Simple and Hybrid Solar Still Configurations: A Comprehensive Review Khaoula HIDOURI, Hussein TOGUN, Farhan Lafta RASHID, Azher M. ABED, Ahmed Kadhim HUSSEIN, Bagh ALI, Sachindra Kumar ROUT, Mohamed Bechir Ben HAMIDA, Uddhaba BISWAL CO2 Mitigation; Conversion Efficiency of Life Cycle; Embodied Energy; Energy Payback Time; Environmental. In this review article the results for the last three years are given with regard to the energy payback time, the embodied energy, the emissions of carbon dioxide (CO2), conversion efficiency of life cycle, attenuation of the CO2 and the carbon credit earned (CCE). The study parameters are relatively difficult to follow their evolution according to the experimental prototype studied and the materials used. All depend on the nature of the design and the economic part. The findings demonstrated that embodied energy ranges from 30 to 100 percent of the total life cycle consumed. EPT typically depends on the location and the equipment used, and it has the least negative environmental effects when used in products with an average shelf life of 10 years or less, regardless of the type of solar still. Desalination methods attain their optimum efficiency very quickly in terms of sustainability, according to LCCE. CO2 mitigation is more likely to occur with active systems than with passive ones. The system (CSS + WM + PTC) with the highest embodied energy value among the systems under study has a value that is approximately 54% greater than that of CSS. Journal of Thermal Engineering Journal of Thermal Engineering 2024-11-18T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7174 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7174 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7174

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7207 2025-01-30T21:00:00Z 1

Effect of lower rate of exhaust gas recirculation on CI engine characteristics fueled with Prosopis juliflora biodiesel: An experimental study B. MUSTHAFA, B. SARAVANAN, S. Senthur PRABU, Asokan M. A., S. SUJAI Biodiesel, CI Engine, EGR, Juliflora, NOx Emission. The enormous rise in energy demand with the strict emissions regulations has put together in search of the finest alternative fuel that meets the various emission norms of the vehicles made worldwide. Nowadays, researchers all around the globe aims to reduce the amounts of emissions from the compression ignition (CI) engine. Biofuel resembles the qualities of fossil diesel while it is also proven to be a greener fuel and viable alternative. However, the primary challenge of using biodiesel was higher emissions of Nitrogen oxides (NOx). Hence to minimize the NOx, an exhaust gas re-circulation (EGR) system could be utilized which could resolve the challenges associated with this higher NOx emissions. In this study, juliflora biodiesel was selected and blended with diesel at 20% by volume (B20) and three different EGR percentages 5%, 10%, and 15%, were investigated on the characteristics of CI engine. Based on the test outcomes, a drop in NOx has been observed with a 15% rate of EGR which is 6.1% lower than conventional diesel. Moreover, brake thermal efficiency increased by 11% as compared to diesel. However, a slight increase in other exhaust emissions was noticed with EGR. The results conclude that, lower rate of EGR (15%) with B20 blend of juliflora biodiesel provides the optimum performance in the engine with least NOx emission. Journal of Thermal Engineering Journal of Thermal Engineering 2025-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7207 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7207 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7207

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7221 2025-01-30T21:00:00Z 1

Effect of diethyl ether and isobutanol as fuel additives on the diesel engine attributes fueled with subabul seed biodiesel K. YAMINI, P. S. KISHORE, V. DHANA RAJU DEE; Engine Characteristics; Isobutanol; Subabul Biodiesel. In recent years, biodiesel has emerged as a renewable and eco-friendly alternative to traditional diesel fuel, garnering significant attention. This research investigates the viability of utilizing subabul seed biodiesel in diesel engine applications. The process involves mechanically pressing crude oil from subabul seeds and subsequently extracting subabul seed methyl ester through transesterification. The physical and chemical properties of subabul seed biodiesel are compared with those of diesel. To enhance the performance of the biodiesel, fuel additives such as diethyl ether (DEE) and isobutanol (ISOB) are introduced to a 20% concentration of subabul seed methyl ester (SSME 20) at varying levels. At full load, SSME 20, with the addition of 10% DEE, demonstrates a 7.4% increase in Brake Thermal Efficiency (BTE) compared to SSME 20 alone. Furthermore, emissions from the diesel engine are significantly reduced—hydrocarbon by 24.39%, carbon monoxide by 4.6%, nitrogen oxide by 9.33%, and smoke emissions by 8.84%—compared to conventional diesel fuel. Similarly, the incorporation of 10% isobutanol into SSME 20 results in a 4.71% higher BTE than SSME 20 alone. Engine tailpipe emissions show a noteworthy reduction of 20.73%, 4.12%, 6.42%, and 6.62% for hydrocarbon, carbon monoxide, nitrogen oxide, and smoke, respectively, compared to diesel fuel at full load. The addition of isobutanol and diethyl ether to SSME 20 is found to increase the Heat Release Rate (HRR) over SSME 20 biodiesel. Diesel exhibits the highest HRR at 73.55 J/°CA, followed by SSME 20 with 10% DEE at 72.15 J/°CA, and SSME 20 with 10% isobutanol at 71.85 J/°CA. In conclusion, biodiesel, particularly from subabul seeds, shows promise in reducing greenhouse gas emissions and fostering sustainable energy systems. The blending of subabul biodiesel with fuel additives like DEE and isobutanol positions it as a viable standard fuel for diverse applications such as transportation, agriculture, and electricity generation. Journal of Thermal Engineering Journal of Thermal Engineering 2025-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7221 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7221 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7221

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7222 2025-01-30T21:00:00Z 1

Thermal conductivity of porous plastics manufactured by 3D printing: Controlling the design of the cavities and corresponding effects Ahmed K. MUHAMMAD, Tawfeeq W. MOHAMMED, Kadhim K. RESAN 3D Printing; Additive Manufacturing; Cavities; Insulation; Thermal Conductivity. This study examines factors associated with the cavities formed in 3D-printed porous thermoplastics, and establishes their relationship with the thermal conductivity of bulk material. The research has examined two porous thermoplastics, specifically poly-lactic acid (PLA) and acrylonitrile butadiene styrene (ABS). Certain categories have been used for the cavities based on their shapes (sphere, cube and diamond), sizes (0.5 to 1.9 mm), numbers (200 to 500), and distributions (in-line or staggered). Specific findings indicate that the optimal thermal conductivity value can be achieved by utilizing samples with 500 pores of 1.5 mm pore diameter. It is shown, the pores could be in the shape of diamonds and distributed in a staggered manner in order to have minimum thermal conductivity. The thermal conductivity values for the most favorable specimens were determined to be 0.13 W/m·K for PLA and 0.12 W/m·K for ABS. The observed values demonstrate a decrease of 40-45% in comparison to the non-porous samples of the same materials. Journal of Thermal Engineering Journal of Thermal Engineering 2025-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7222 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7222 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7222

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7223 2025-01-30T21:00:00Z 1

Impact of memory and long-range interaction in a two-dimensional semi-infinite solid cylinder Navneet Kumar LAMBA Caputo Fractional Derivative; Integral Transformation; Mittag-Leffler Function; Riesz Fractional Derivative; Solid Circular CylinderTemperature; Thermal Stresses; Two Dimensional. Space fractional differential operators are used to study long-range interactions, and time differential operators handle memory effects. A semi-infinite circular cylinder is taken into consideration to analyse both effects in a two-dimensional thermoelastic situation where heat conduction is influenced by internal heat generation. A prescribed jump function is applied to the bottom of the semi-infinite circular cylinder, and the time-dependent heat flux happens at the curved edge of the cylinder. The transformative approach of Laplace, Fourier, and Hankel was used to solve the governing equation of heat transfer with Caputo and the finite fractional derivatives of Riesz. The outcomes are expressed in terms of the Bessel function series. The numerical calculations are performed with the material properties of pure copper, and the graphical representations of the thermal distributions are successfully plotted. Journal of Thermal Engineering Journal of Thermal Engineering 2025-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7223 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7223 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7223

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7107 2024-09-10T21:00:00Z 1

Heat Transfer Characteristics of Magnetohydrodynamic Casson Stratified Hybrid Nanofluid Flow Past a Porous Stretching Cylinder Jintu Mani NATH, Ashish PAUL, Tusar Kanti DAS Heat source/sink, Casson hybrid-nanofluid, vertical cylinder, thermal stratification, porous space In the existence of a thermal source, this study examines the impacts of thermal stratification on the heat transmission characteristics of magnetohydrodynamic water-based copper/molybdenum disulfide Casson hybrid nanofluid flow across a vertical cylinder which is linearly stretching. A magnetic field with an inclination is applied along the stretched vertical cylinder. The driving forces for the flow are due to the stretched cylinder and natural convection. With appropriate similarity transformations, non-linear ordinary differential equations are obtained from the collection of mathematically modeled partial differential equations. The numerical findings are obtained by utilizing the MATLAB bvp4c approach. The consequence of protuberant factors on the thermal and velocity curves is also studied and is depicted pictorially. The outcomes of the friction drag and the thermal transmission rate are summarized in the table. The important contributions highlight that water-based copper/molybdenum disulfide Casson hybrid nanofluids have superior thermal conductivity than water-based copper Casson nanofluids. The water-based Casson hybrid nanofluid fluid has a noteworthy influence on enhancing thermal procedures. Thermal exchangers, solar power systems, automotive cooling down and precision manufacturing are among their beneficial functions. The friction drag for Casson hybrid nanofluid has been found to improve by up to 32.3% when contrasted to water-based Casson nanofluid. While contrasting the Casson hybrid nanofluid with the Casson nanofluid, the thermal transport rate is increased by almost 6.6%. The rate of thermal transmission at the solid surface is negatively impacted by thermal stratification. This finding has practical implications in the areas of bettering materials for thermal insulation and energy-effective designs for buildings. The outcomes reflect a significant enrichment in the discipline of fluid dynamics and nanofluid research since they offer promising potential for heat transfer optimization in various commercial environments. Journal of Thermal Engineering Journal of Thermal Engineering 2024-09-10T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7107 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7107 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7107

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7224 2025-01-30T21:00:00Z 1

Synergy of non-uniform heat source/sink and variable thermal conductivity on stagnation point flow of Casson fluid over a convective stretching sheet C. Arruna NANDHINI, S. JOTHIMANI, Ali J. CHAMKHA Casson Fluid; Convective Stretching Sheet; Non-Uniform Heat Source/Sink; Stagnation Point and Constructive/ Destructive Chemical Reaction; Variable Thermal Conductivity. A novel approach is formulated to scrutinize the stagnation point flow of chemically reacting Casson fluid past a convective stretching sheet. Additionally, the combined impact of a non-uniform heat source/sink and variable thermal conductivity on the fluid flow is examined. With the aid of a suitable similarity transformation, the governing partial differential equations are transmogrified into corresponding ordinary differential equations. bvp4c, an in-built technique of MATLAB, is implemented to acquire the numerical solutions. The appurtenant parameters that exert influence on the concentration distribution, temperature distribution, and velocity profile are depicted graphically. The effects of various physical parameters such as Casson fluid parameter, magnetic field parameter, Prandtl number, Schmidt number, Eckert number, Biot number, variable thermal conductivity parameter, non-uniform heat source/sink parameters and velocity slip parameter are shown in plots for several ranges of values. In a constrained scenario, the accuracy and validity of the numerical technique utilized are justified by analogizing the procured outcomes with the pre-existing results in the literature. The influence of pertinent parameters that regulate the Nusselt number, skin friction coefficient, and Sherwood number is presented in tabular form. An upsurge in the variable thermal conductivity parameter reduces the temperature for internal heat generation, but for internal heat absorption, it diminishes the temperature adjacent to the wall and skyrockets the temperature far away from the wall. This current study is of immediate interest in the field of the aerospace industry due to the indispensability of variable thermal conductivity in lunar soft lander technology. Journal of Thermal Engineering Journal of Thermal Engineering 2025-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7224 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7224 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7224

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7225 2025-01-30T21:00:00Z 1

Experimental and numerical study of fluid flow and heat transfer in the impinging of inline round jets B. Venkata Sai Raghu VAMSI, P. RAVEENDIRAN, Malladi R. Ch. SASTRY Multiple Impinging Jets; Nusselt Number; Pressure Coefficient; SST K-Ω, Static Pressure, Streak Line Visualization. The effect of pitch-to-diameter ratio, dimensionless nozzle-to-plate spacing, and Reynold’s number on fluid flow behavior and heat transfer from the heated surface is studied numerically for three inline circular impinging jets. The dimensionless nozzle to distance varies from 1 to 6, the pitch-to-diameter ratio from 2 to 4, and Reynold’s number from 3512.69 to 9532.71. The streak lines plotted numerically are validated by experiments using the Oil flow visualization technique. As the inter-jet spacing increases, a shift in the direction of the resultant fluid flow on the target surface is observed with a symmetrical distribution of fluid flow and heat transfer at P/D=4.Correlations for the maximum static pressure, maximum coefficient of pressure, and average Nusselt number on the target surface are proposed by performing regression analysis at a confidence level of 98% with an R2 value of 99.53%, 99.60%, and 99.21%, respectively. In addition, it has been observed that the jet-to-jet distance, distance between the nozzle and target plate, and Reynold›s number play a crucial role in the augmentation of heat transfer and distribution of air in the multiple impinging jets. Journal of Thermal Engineering Journal of Thermal Engineering 2025-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7225 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7225 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7225

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7071 2024-07-31T21:00:00Z 1

Numerical Study of Flow Behavior and Heat Transfer of Ternary Water-Based Nanofluids in the Presence of Suction/Injection, Stretching/Shrinking Sheet Gul M. Shaikh, Abid A. Memon, M. Asif Memon, Ubaidullah Yashkun, Adebowale Martins Obalalu , Hasan Köten Stagnation point, Suction/injection, Stretching/shrinking sheet, Slip flow boundary conditions, Ternary nanofluid. This article investigates the stagnation point flow considering suction/injection, a stretching/shrinking sheet, and slip flow boundary conditions. A ternary hybrid nanofluid comprising titanium oxide, silver, and zinc oxide is employed to study the velocity field and thermal characteristics. The Tiwari Das nanofluid model, along with the boundary flow equations in two dimensions, is utilized for analysis. Initially, the governing equations are transformed into a system of ordinary differential equations (ODEs) using a similarity transformation. Subsequently, the obtained ODEs are solved using a finite element method. A parametric study is conducted, varying the stretching/shrinking parameter, suction/injection parameter, slip flow parameter, and total volume fraction of the ternary nanofluids within the ranges of -1 to 0.5, -1 to 1, 0 to 1, and 0.03 to 0.3, respectively. The percentage change in temperature relative to the ambient temperature consistently decreases with the increase in normalized distance from the stagnation point, whether it is a stretching or shrinking sheet. The temperature decline is faster in the case of a shrinking sheet. In cases involving injection, converting sheet shrinking to stretching has a more significant impact on the percentage change in temperature due to ambient temperature compared to the suction case. Journal of Thermal Engineering Journal of Thermal Engineering 2024-07-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7071 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7071 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7071

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7268 2025-03-23T21:00:00Z 1

Experimental study of temperature changes in a solar chimney Ammar SEMANE, Razika IHADDADENE, Elhouas BEDJEGHIT, Belhi GUERIRA, Nabila IHADDADENE Absorber Temperature; Ambient Temperature; Collector Temperature; Mathematical Models; Solar Chimney; Solar Radiation The purpose of the current study is to conduct an experimental investigation into the effects of ambient temperature and solar radiation on the mean temperature of the absorber and collector of the solar chimney. To achieve this goal, a solar chimney prototype with a collector diameter of 0.79 m, a collector height of 0.105 m, a chimney diameter of 0.075 m, and a chimney height of 1.39 m was constructed at M’sila University. The experiments were conducted in a arid climate at the Biskra University. The results show that the mean absorber temperature was higher than the mean collector temperature. The absorber and collector temperatures are correlated by a polynomial law. The ambient temperature and solar radiation have a significant impact on the mean temperature changes of the absorber and collector. Mathematical models that depict how the mean collector and mean absorber temperatures change with respect to solar radiation and ambient temperature have been proposed. Journal of Thermal Engineering Journal of Thermal Engineering 2025-03-23T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7268 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7268 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7268

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7167 2024-11-18T21:00:00Z 1

Techno-Economic Analysis of the Feasibility of a Hybrid Power Plant with Photovoltaic Panels a Water Treatment Station and Compressed Air Energy Storage. A Case Study: Casablanca-Morocco Youness MASAAF, Youssef Ait El KADI, Fatima Zahra BAGHLI Compressed Air; Energy Storage; LCOS; Storage Temperature; Water Treatment. Due to the growth of population, the energy needs have increased. To address this rise of demand, the increase of share of renewable energy in the energy mix is the solution since it is a sustainable, unlimited and zero greenhouses’ emissions source. However, these resources are characterized by their intermittency. To solve this problem, we need to store the additional energy. One of the most promising technologies is compressed air storage, it has proven useful to store energy during off-peak hours and to reproduce it during peak hours. This paper investigates the feasibility of a hybrid power generation system consisting of a photovoltaics system combined with a compressed air energy storage. The hybrid power system address to compare the system feasibility with and without the energy storage option. The hybrid system is intended to supply power to a water treatment plant. The analysis of the energy profile including consumption, generation, and storage, was performed. The influence of the air storage temperature on the levelized cost of storage and the dependence on the grid energy was studied. The effects of ambient temperature and compressor pressure ratio on various system parameters, such as mass air flow in and out, and system efficiency, have been investigated. The result shows that when the storage temperature is increased from 300 to 800°C, the levelized cost of storage benefit is 0.025$/kWh. The system efficiency decreased from 70% to 28% when increasing the pressure ratio from 2 to 30, while keeping the ambient temperature constant at 300°K. Conversely, it increased from 60% to 64% when raising the ambient temperature from 295°K to 320°K while maintaining the pressure ratio at 3. Journal of Thermal Engineering Journal of Thermal Engineering 2024-11-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7167 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7167 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7167

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7358 2025-07-30T21:00:00Z 1

Effects of radiation and chemical reaction due to graphene oxide nanofluid flow in concentric cylinders Jagadeeshwar PASHIKANTI, Susmitha PRIYADHARSHINI D. R., Santhosh THOTA Buongiorno Model; Entropy Generation; Graphene Nanofluids. Aggregated studies on thermal radiation effects in nanofluid flow are important for the effective utilization of its striking thermophysical properties and extensive industrial applications such as coolants in automobile radiators, heat exchangers, propulsion systems, atomic plants, etc. Particularly in concentric cylinders, the nanofluid flow has a wide range of applications, including medicine such as stenosis treatment. This investigation is one such computational study to explore the radiative flow between two concentric cylinders due to graphene oxide nanofluids. The flow is modeled, including the impacts of radiative heat flux, chemical reaction effects, thermophoresis, and Brownian motion. The spectral method is used to solve the system of complex nonlinear coupled equations under convective conditions. The influence of implanted parameters on skin friction, concentration, and temperature profiles of the nanofluid and their impacts on entropy are studied. From the tabulated values of the Sherwood and Nusselt numbers, it is observed that convective heat and mass transfer can be enhanced by the thermophoresis parameter and the Brownian motion parameter, whereas diffusive mass transfer is enhanced by the chemical reaction parameter. A comparison table shows good agreement between the literature and the obtained values. Also, the results obtained are graphed and discussed in detail, along with entropy generation. Journal of Thermal Engineering Journal of Thermal Engineering 2025-07-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7358 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7358 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7358

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7273 2025-03-23T21:00:00Z 1

Enhancing flat plate collectors’ efficiency by minimizing optical losses through vacuum glazing and ethylene glycol-diamond-alumina nanofluid Muhammad SHEHRAM, Muhammad Najwan HAMIDI, Aeizaal Azman A. WAHAB, M. K. Mat DESA Efficiency Enhancement; Hybrid Nanofluids; Solar Collectors; Thermal Stability; Vacuum Glazing. This study addresses the critical need to improve the efficiency of solar flat plate collectors (FPC) where the key factors influencing their performance include the choice of working fluids, exposure to sunlight, and minimizing heat loss. Carbon-based nanofluids, known for their exceptional thermal stability and heat transfer properties, emerge as a promising solution. This research presents an innovative approach by combining carbon-based (ethylene glycol-diamond) and metal-oxide-based (alumina) hybrid nanofluids to boost collector efficiency. Additionally, a two-step strategy is employed to reduce reflection losses. A triple glaze is applied to the collector’s top surface, followed by vacuum glazing. The latter, consisting of three layers of low-iron glass with an emissivity of 0.20 and a solar transmittance of 0.87 which reduces the glass thickness. This integration of vacuum glass and hybrid nanofluid results in an 82% increase in FPC efficiency. The nanofluids, with nanoparticles sized between 100 and 200 nm and material volume fractions of 0.3% for carbon-based and 0.1% for metal-oxide-based components, circulate at 4 L/min. Ethylene glycol has an energy efficiency of 58%, alumina 68%, and diamond nanofluids 71.8%. Heat transfer coefficients are 0.88 for ethylene glycol, 0.93 for alumina-based nanofluids, and 0.98 for diamond-based fluid. The hybrid nanofluids also exhibit heat loss ranging from 2.4 W/m.K to 4.0 W/m.K. Triple glaze vacuum layers achieve an efficiency peak of 82%, significantly reducing heat loss to 700W compared to single and double layers. The study utilizes Python in an Anaconda Jupyter notebook for detailed system modeling, facilitating thorough simulation of the system. Journal of Thermal Engineering Journal of Thermal Engineering 2025-03-23T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7273 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7273 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7273

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7169 2024-11-18T21:00:00Z 1

Effects of Electric Field, MHD Micropolar Hybrid Nanofluid Flow with Mixed Convection and Thermal Radiation Across a Flat Surface Aruna J., H. NIRANJAN Electric Field; Hybrid Nanofluid; Micropolar Fluid; Mixed Convection; MHD; Thermal Radiation. Hybrid nanofluids significantly impact the thermal properties of pure fluids. This study examines the flow of a micropolar electrically conducting hybrid nanofluid in a mixed convective MHD environment over a flat surface. The enclosed fluid is a specialized water-based mixture of hybrid nanoparticles containing silver and alumina, uniformly dispersed to fill the enclosure. Suction and injection effects are applied to the vertically positioned plate within a permeable material. Further considerations include Joule heating, electrical effects, thermal radiation, and viscous dissipation. The nonlinear PDEs are converted into a dimensionless form and subsequently solved numerically using the bvp4c function in MATLAB. Results show increased fluid mobility with magnetic and mixed convection factors, declining under micropolar component presence. Micropolar parameters enhance fluid micro rotational velocity. Thermal behavior diminishes with the higher electric field and rises with increased magnetic effects, heat source, radiation, Eckert number, and micropolar parameter. The velocity curve elevates with a higher electric field factor. The Nusselt number and dimensionless skin friction coefficient values are computed and graphically represented. The research finds applications in engineering and medicine, including Heat Exchangers, Microfluidics, Medical Imaging, Electroplating, and Electrokinetic Pumps. Electric field effects are pivotal in electrothermal thrusters for spacecraft propulsion, leveraging principles of magnetohydrodynamics (MHD) and hybrid nanofluid flow to enhance performance in the vacuum space. Journal of Thermal Engineering Journal of Thermal Engineering 2024-11-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7169 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7169 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7169

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7266 2025-03-23T21:00:00Z 1

Evaluation on fire incident of electric vehicle spaces onboard ferries with using fire dynamics simulations Tolga AYCI, Baris BARLAS, Aykut I. OLCER Electric Vehicles; Fire Dynamics Simulation; Fire Onboard Ferry; Fire Safety. This study brings a unique perspective of electric vehicles (EVs) transportation via maritime with using performance-based design of fire safety management. In the recent years, due to the increase of production and transportation of EVs, this study is highlighted the fire safety management. The integration of electric vehicles (EVs) into maritime transport, particularly via ships and ferries, brings about unique challenges, notably concerning fire safety management. Given the increasing prevalence of EVs and their potential fire hazards, it’s crucial to address these risks comprehensively. The fire safety management of electric vehicles in ferry transport is dealt with, as this form of maritime transport is becoming increasingly important due to the increased production of this type of vehicle, which develops a complex chemical reaction mechanism and dangerous properties such as initial exothermal temperature, self-heating speed, pressure increase speed, etc. Therefore, relevant rules and regulations should be considered to ensure a safe journey. This study brings novelty to the fire safety analysis of EVs transportation onboard ships with using performance-based design and fire dynamics simulation tools to predict temperature level of the case incident. The Fire Dynamic Simulator was used for the simulations for the prediction of temperature distributions during an electric vehicle fire inside a ferry. The presented case study demonstrates how fire simulations could predict conditions for performance-based design of ferries that transport electric vehicles. Depending on simulations, temperature at initial times approximately 40s of fire incidents caused by EVs is around 1200°C and this cause severe results in terms of life and asset safety. In conclusion, this paper presents a brief insight to find an effective method for simulating and mitigating EV fires on ships to ensure crew safety and minimize fire damage. Journal of Thermal Engineering Journal of Thermal Engineering 2025-03-23T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7266 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7266 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7266

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7267 2025-03-23T21:00:00Z 1

Stability analysis of the mixed convective flow of Jeffrey nanofluid through a porous medium Harsha S. V, Chandra Shekara Guruva REDDY, Hemanth Kumar C. Horizontal Pressure Gradient; Instability; Jeffrey Fluid; Mixed Convection; Nanofluid; Porous Layer. This study investigates the stability of a mixed convective flow of a nanofluid through a horizontal porous layer using an unsteady Jeffrey-Darcy model. Linear stability theory is employed to assess the stability of a system, where the base fluid is modeled as a Jeffrey fluid with dispersed nanoparticles in a state of thermal equilibrium. The stability equations are derived as an eigenvalue problem using Fourier decomposition, solved using the higher order Weighted Residual Galerkin Method (WRGM), and validated analytically. The results are presented in terms of critical values of the Darcy-Rayleigh number, wave number, and wave speed over nondimensional parameters. Further, the impact of nondimensional numbers like horizontal pressure gradient, thermal diffusivity ratio, and nanoparticle volume fraction has stabilizing effects, whereas the Jeffrey parameter and the Vadasz number have the opposite effect. Moreover, it has been observed that the increase in the Jeffrey parameter reduces the stability region. The variation Jeffrey parameter causes a change in the flow and thereby discards the analytical proof of stability even under the limit of an infinite Vadasz number. The inquiry into the stability or instability of the fundamental flow is addressed by solving the eigenvalue problem numerically over a finite range of the Jeffrey parameter and horizontal pressure gradient. These results indicate that the oscillatory convection mode is advantageous for estimating the required volume fraction of nanoparticles in the base fluid to improve the thermal efficiency of Jeffrey nanofluids. Numerical and graphical analyses explore the impacts of dimensionless parameters on physical systems, providing insights into the system’s stability properties under varying conditions. Journal of Thermal Engineering Journal of Thermal Engineering 2025-03-23T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7267 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7267 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7267

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7012 2024-05-26T21:00:00Z 1

Developing the Analytical Solution for the Nonlinear Bioheat Transfer Equation through Homotopy Analysis Method along with an Optimal Convergence Control Parameter Rouhollah Ostadhossein Pennes' Bioheat Equation, Homotopy Analysis Method (HAM), Convergence-Control Parameter, Mean Squared Error. Homotopy Analysis Method (HAM) is an effective technique to achieve the analytical solution of a broad range of problems, mainly with nonlinear governing equations. The solution of Pennes' bioheat equation in nonlinear form arising from the linear temperature-dependent nature of specific heat capacity of a biological tissue using Homotopy Analysis Method has been obtained analytically and validated with the numerical results obtained from the Finite Difference Method (FDM) the first time in this study. The analysis demonstrated that considering the various values of the convergence parameter and computing the Mean Squared Error (MSR) to achieve the optimum values ensures accurate results even at the low-order approximations of the solution. Investigating the effect of the nonlinear term's magnitude on the solution indicated a direct relationship; However, the effect was not remarkable even at the major values, thus it is possible to consider the specific heat capacity of a living tissue, a constant value through thermal simulations. According to this research, Homotopy Analysis Method can be a proper method to derive the analytical solution of either the linear or nonlinear form of Pennes' bioheat equation. Journal of Thermal Engineering Journal of Thermal Engineering 2024-05-26T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7012 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7012 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7012

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7324 2025-05-15T21:00:00Z 3

Heat transfer performance of Lithium-ion battery pack using Composite phase change material: A Review Vinayak Mandlik, Sandipkumar Sonawane, Milind Patil Composite Phase Change Material (CPCM); Flexible Phase Change Material (FCPM); Heat Transfer Performance; Li-ion Battery; Phase Change Material (PCM) Electric Vehicles (EVs) rely on Li-ion batteries (Li-ion), which perform best in an operating temperature range of 15°C to 40°C. However, in regions where ambient temperatures are higher, EVs can catch fire even with thermal management systems. To address this issue, researchers are exploring the use of phase change materials (PCM) in battery thermal management systems (BTMS). PCM-based BTMS can maintain operating temperatures within the standard range for a long time without additional power, thus improving battery lifespan. Various types of PCM, such as Composite phase change material (CPCM) and Flexible phase change material (FCPM), have been proposed for BTMS to address existing issues like overheating, internal heat generation, and optimization. Battery Thermal Management Systems (BTMS) in Electric Vehicles (EVs) have issues like overheating during running and charging, internal heat generation, optimization, and battery life. The maximum temperature difference (∆Tmax) is achieved between 2°C to 20°C for different discharge rates. This reduces the battery surface temperature by 24% to 70% and improves battery lifespan. Journal of Thermal Engineering Journal of Thermal Engineering 2025-05-15T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7324 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7324 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7324

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7323 2025-05-15T21:00:00Z 3

The use of turpentine as additive for diesel oil. A review Robert Mădălin CHIVU, Jorge MARTINS, Florin POPESCU, Ion V. ION, Uzuneanu KRISZTINA, Michael FRATITA Biofuel; Diesel Engine; Engine Efficiency; Fuel Consumption; Pollutant Emissions; Turpentine. This paper reviews research on the effects of substituting diesel oil with mixtures containing turpentine on the performance and emissions of internal combustion engines. Studies have shown that turpentine-diesel blends offer several potential benefits when used as fuel. In some cases, significant reductions of up to 10% in fuel consumption have been observed. Overall, pollutant emissions decreased, with reduction in smoke opacity exceeding 40%, as reported in some studies. Certain blends exhibited increased engine performance, potentially due to improved fuel atomization from the lower viscosity of the mixture. Additionally, studies have documented thermal efficiency gains exceeding 3% in specific cases. However, the effectiveness of these blends is highly dependent on several factors, including the source of the turpentine (its geographic origin can significantly impact its properties and suitability for blending); the injection pressure (which is crucial for maximizing the benefits of the blend) and the proportion of the turpentine in the mixture (which significantly influences the observed effects). Journal of Thermal Engineering Journal of Thermal Engineering 2025-05-15T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7323 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7323 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7323

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7272 2025-03-23T21:00:00Z 1

Thermal analysis and energy requirement of wall and window components for buildings with different orientations Meral ÖZEL, Serhat SENGUR Climate Zones; Energy Requirements; Heat Gain and Losses; Noninsulated Wall and Insulated Wall; Single-Glazing and Double-Glazing. This research highlights the importance of wall insulation, type of glazing and glazing area to reduce energy consumption and to ensure thermal comfort in residential buildings. With the appropriate combination of design parameters such as window glass area, glazing type, wall orientation and wall insulation, heating and cooling loads and therefore energy requirements can be substantially reduced. The main goal of this research is to analyze the thermal performance and energy requirements of the wall and window components that can make residential buildings energy efficient, considering building orientations for four cities of Türkiye. Firstly, heat gain and losses through walls and windows are numerically researched. The heat transmission loads through wall are computed employing an implicit finite difference procedure. Secondly, the ratio of window to wall area is also investigated from the transmission loads point of view. Then, heating and cooling energy requirements and costs are also separately determined for walls consisting of single and double-glazed windows. Consequently, it is observed that the orientation, climate conditions, geographical location, type of glazing and insulation have a notable effect on heat transmission and energy requirement. The results also show that the highest heating energy requirement and cost are acquired for the north orientation in Kars, where the heating load is dominant while the highest cooling energy requirement and cost are acquired for the west (or east) orientation in Antalya, where the cooling load is dominant. It is revealed that the double glazing significantly reduces these energy requirements. The results show that this reduction in heating need for Kars is 61.91%, 45.81%, 49.01% and 49.01% for South, North, East and West orientations, respectively. On the other hand, it is seen that this decrease in cooling need for Antalya is 30.45%, 33.30%, 25.17% and 25.17%. Also, the double glazing appears to be more effective at reducing heating demand than at reducing cooling demand. The results acquired in this work will be very beneficial in the selection of glass type and the glazing area, taking into account the wall direction, when designing exterior walls of residential buildings in different climatic zones. Journal of Thermal Engineering Journal of Thermal Engineering 2025-03-23T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7272 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7272 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7272

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7306 2025-05-15T21:00:00Z 1

Assessment of student thermal comfort perception of spaces in education building with different ventilation strategies after COVID-19 Resul OZLUK, Turkan GOKSAL OZBALTA, Kubra GUNGOR Educational Buildings; Heat Balance and Adaptive Thermal Comfort Model; Questionnaire Based Survey; Statistical Models; Thermal Sensation. Environmental comfort directly affects student learning. With the rapid increase in educational buildings, thermal comfort conditions, student performance, and work efficiency are very important. The impact of COVID-19 has changed comfort expectations in assessing indoor air quality. This study investigates the thermal comfort of students from different regions in classrooms with different ventilation systems in summer and winter. The research presents statistically the results obtained from questionnaires and measurements of environmental variables. Surveys and field measurements were conducted from February 2021 to June 2022. The measurements included indoor environmental parameters, such as dry bulb and globe temperature, relative humidity, indoor airflow speed and CO2 concentration. The subjective investigation was carried out using 635 particular questionnaires regarding their thermal senses, thermal preferences and the comfort conditions of the environment to determine the percentages of dissatisfaction. Approximately 82% of students in the naturally ventilated classrooms and 80% in the air-conditioned classrooms were comfortable. The average indoor comfort temperature estimated by the adaptive comfort method in naturally ventilated spaces was found to comply with ASHRAE 55 standards in both summer and winter. Another important finding is the differences in the thermal sensations of the students, especially for the winter period, as they come from various climatic regions of Türkiye. Journal of Thermal Engineering Journal of Thermal Engineering 2025-05-15T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7306 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7306 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7306

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7274 2025-03-23T21:00:00Z 1

Hydrothermal investigation of a nanofluid flow in a compound microchannels Sarab Salih SHEKHO, Ahmed Fouad AL-NEAMA Al2O3; Compound MCHSs; CuO; Nanofluid; Reentrant Microchannels. In this research, CFD modelling was employed to quantitatively investigate the influence of laminar forced convective heat transfer employing Al2O3/water and CuO/water nanofluids as working mediums, with a volume concentration (φ) of 4%, in three distinct compound microchannel heat sinks (MCHSs). Each MCHS features a bottom circular cavity and a narrow slot (namely rectangular, trapezoidal, or semicircular reentrant) attached to the circular cavity's crest. Their cooling efficacy was compared to that of a traditional straight rectangular MCHS. Both nanoparticles had a diameter of 47nm, and the nanofluid's thermophysical properties were temperature-dependent. The fluid inlet temperature was maintained at 20°C, whereas the volumetric flow rate (Qin) ranged from 20 to 100ml/min. The results demonstrated that employing a hybrid heat transfer augmentation technique with CuO/water nanofluid at Qin=100ml/min increased the average Nusselt number (Nuavg) of the rectangular reentrant MCHS by 7.1% and decreased the total thermal resistance (Rth) of the semicircular reentrant MCHS by 16.8%, compared to using water in a traditional MCHS. However, this improvement in Nuavg was accompanied by a 45.8% increment in the total pressure drop (ΔPt) when the rectangular reentrant MCHS within CuO/water nanofluid was used instead of the traditional MCHS with pure water. This improved heat transfer is attributed to flow separation, fluid acceleration in the main flow, and intensified fluid mixing in the three newly proposed MCHSs. Journal of Thermal Engineering Journal of Thermal Engineering 2025-03-23T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7274 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7274 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7274

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7372 2025-07-30T21:00:00Z 3

Recent advancements, challenges in recycling of waste plastic using microwave assisted catalytic co-pyrolysis of biomass and waste plastic for production of value added chemicals: a review Hafiz Miqdad MASOOD, Javeed ASHRAF, Khurram SHAHZAD, Rafi Ullah KHAN, Nida IMRAN, Zeeshan ZAFAR Bio-fuel; Catalyst; Corn Cob; DTG; HDPE; TGA. The endeavor aim to addressed environmental issues by converting biomass and plastic waste into high-value products such as bio-oil, syngas, and biochar, consequently encouraging sustainability and energy saving. Our goal is to investigate the efficacy of an amalgamation of processing technologies and microwave irradiation, which has resulted in noticeable increases in reaction productivity as well as significant reductions in processing time, emphasizing its importance in addressing the environmental crisis caused by plastic waste accumulation. Microwave processing provides greater yields and cleaner profiles when contrasted to pyrolysis, high temperature carbonization and gasification techniques. This is indicative of its exceptional thermal and non-thermal effects, which distinguish it from other methods of heating. The use of catalysts in co-pyrolysis promotes product selectivity and quality, with different catalysts such as biochar, activated carbon, and zeolites being employed to enhance yields and product composition. The results indicate that the optimal yields of bio-oil are 72.1% from 95:5 weight percent corncob and high density polyethylene without catalyst, and 67.1% from 90:10 weight percent corncob and high density polyethylene with a catalyst. The optimization of microwave treatment settings, establishing large-scale continuous processing technology, and undertaking techno-economic assessments for commercial production are all challenging. Microwave pyrolysis is an effective process for producing fuels with high calorific value. Future recommendations, given the numerous benefits of microwave pyrolysis, should be optimized on an industrial scale. Journal of Thermal Engineering Journal of Thermal Engineering 2025-07-30T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7372 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7372 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7372

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7307 2025-05-15T21:00:00Z 1

An experimental investigation of an inclined solar chimney integrated into residential buildings with different materials construction for natural ventilation in a hot-arid climate Benali OUSSAMA, Dobbi ABDELMADJID, Hassini NOUREDDINE, Mohamed El-Amine SLIMANI, Hadjadj ABDESSAMIA Building Materials; Performance; Solar Chimney; Thermal Comfort; Thermal Inertia; Ventilation. Solar chimneys are used to ventilate residential buildings, helping reduce infections caused by the recent COVID-19 pandemic. An experimental investigation was conducted to evaluate the efficiency of rooftop solar chimneys by assessing the thermal performance of two small rooms constructed from the two most commonly used building materials in the region: local stone and hollow brick. The study examined the effects of building materials, chimney inclination (angles of 30°, 45°, and 60°), and air gaps (0.15 m and 0.25 m) on the chimney’s performance under real climatic conditions at the University of Ouargla, Algeria, known for its dry and hot climate, from May 8 to 13, 2021. The results showed that installation factors significantly affect the performance of solar chimneys. The inclination angle had the most significant impact, potentially enhancing performance by up to 20%. Additionally, selecting suitable building materials, such as local stone, for specific geographical areas can improve performance by at least 15% during peak times. The air gap, as a configuration factor, contributes to a 14% improvement in performance. The analysis revealed that the highest indoor air velocity in the living area can be achieved using a solar chimney with specific dimensions of 1 m x 0.65 m, an air gap of 0.25 m, and an inclination angle of 45°. At average solar radiation levels of 550, 800, and 950 W/m2, the solar chimney can achieve air change rates of 5, 6.5, and 7.8 air changes per hour (ACH), respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2025-05-15T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7307 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7307 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7307

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7423 2025-09-29T21:00:00Z 3

Novel approaches to zeolite deactivation mitigation and regeneration in biomass gasification Imron ROSYADI, Suyitno, Zainal ARIFIN, Tata SURARDI Biomass Gasification; Catalyst Regeneration; Deactivation Mechanisms; A Mitigation; Environmental Applications; Zeolite Catalys. The comprehensive study delves into the intricate realm of zeolite catalyst deactivation within the context of biomass gasification, aiming to provide a thorough understanding of deactivation mechanisms, innovative strategies for mitigation and regeneration, and potential applications for deactivated zeolites. Key findings reveal reversible and irreversible deactivation processes, heavily influenced by physical and chemical interactions with contaminants such as nitrogen, sulfur, and heavy metals. Empirical data-driven mitigation strategies showcase the effectiveness of metal modifiers like nickel and cobalt in reducing coke yield, alongside novel approaches such as core-shell zeolite structures and the integration of redox metal oxides to maintain catalyst basicity and stability. Moreover, successful regeneration methods including thermal regeneration, chemical washing, and steaming demonstrate the restoration of catalytic activity post-deactivation. Despite reduced efficiency, deactivated zeolites exhibit promises in environmental remediation, achieving heavy metal removal efficiencies surpassing 90%, and enhancing durability while reducing permeability in construction materials and concrete additives. Furthermore, the review emphasizes the necessity for refined strategies adaptable to diverse conditions, promoting sustainable catalyst utilization in biomass gasification and beyond. Key contributions highlighted include the identification of deactivation processes, recognition of pivotal factors affecting zeolite catalysts, validation of data-driven mitigation strategies, demonstration of novel approaches, successful application of regeneration methods, and exploration of potential applications for deactivated zeolites. These findings signify significant progress in addressing zeolite catalyst deactivation mitigation and regeneration challenges and enhancing efficiency and sustainability in biomass gasification technologies. Journal of Thermal Engineering Journal of Thermal Engineering 2025-09-29T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7423 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7423 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7423

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7375 2025-07-30T21:00:00Z 3

A review on enhancement of solar photovoltaic (PV) system performance with water-based nano-fluid cooling systems Vimukthi Vithanage PRIYADARSHANA, Ashan INDURANGA, Chanaka GALPAYA, Amalka INDUPAMA SAMARATHUNGA, Kaveenga KOSWATTAGE Nanofluid Cooling Systems; Nanofluids; Photovoltaic Systems; Solar Photovoltaic Cooling. Photovoltaic cooling systems are emerging as an interesting research area globally with the increasing demand for solar photovoltaic power generation. As the operating temperature of solar photovoltaic modules negatively impacts the efficiency of solar panels, the demand for efficient PV cooling technologies is increasing. As a result, researchers are focused on developing efficient PV solar photovoltaic cooling technologies by utilizing nanotechnology, especially using water-based nanofluids as an enhanced heat transfer fluid for solar PV cooling systems. In this review, initially, a comparative analysis of electrical efficiency enhancement was conducted between nanofluid-based PV cooling systems and other PV cooling technologies such as water spray, nanofluid cooling, floating solar systems, heat pipe type cooling systems, forced air, etc. Also, the enhancement of thermo-physical properties of water-based nanofluids was reviewed to study the applicability of different water-based nanofluids for solar photovoltaic cooling applications. This study focuses on the challenges of using nanofluids for solar photovoltaic cooling systems, such as nanofluid’s stability, pressure drop, and friction factor, which are considerable obstacles when using nanofluids as the heat transfer fluid in commercial solar photovoltaic cooling systems. This study reveals the potential of nanofluid-based cooling systems to fulfill the increasing demand for high-performance cooling solutions for PV panels. Journal of Thermal Engineering Journal of Thermal Engineering 2025-07-30T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7375 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7375 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7375

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7321 2025-05-15T21:00:00Z 1

Numerical modelling of 3D magnetohydrodynamics chemically reacting permeable sheet influenced by free stream convection nanofluid flow Smita YADAV, Sanjay KUMAR, Parmod Kumar SHARMA, Vinita MAKKAR, Khyati DANG Chemical Reaction; Magnetohydrodynamics; Nanofluid; Non-Newtonian Casson Fluid; Permeable Sheet. The effects of a chemical reaction on mixed convective nanofluid flow along a permeable stretched surface in the presence of free stream flow are demonstrated. The impact of multiple non-dimensional characteristics on different gradients and profiles is investigated. Through appropriate transformations, governing coupled partial differential equations become ordinary differential equations, which are then solved numerically. Through MATLAB programming, Runge Kutta Fehlberg method by following shooting technique yields the numerical solutions. Influence of fluid parameters especially free stream velocity, thermal Biot number, concentration Biot number, heat generation parameter, chemical reaction parameter, stretching ratio parameter, permeability parameter, magnetic parameter, Prandtl number, Brownian motion parameter, Lewis number has been investigated that makes this research novel one. The calculated results are presented in the form of tables and contour plots. Furthermore, examined are the thermal transfer strength (Nusselt number) and the mass exchange strength (Sherwood number). According to our research, the velocity distribution gets smaller as the magnetic parameter increases, but the corresponding profile gets increases for free stream velocity flow. With rise in the values of stretching ratio parameter from 2.0-10.0, heat transfer rate falls down by 7.24%. Heat transfer rate falls down by 22.37% with rise in the values of Prandtl number within the range 0.2-1.0. Additionally, temperature enhances with enhancement in thermal Biot number. Comparing its latest findings to prior outcomes and accomplishing convergence criteria supports this technique’s validity. Current research in this domain has diverse applications, encompassing power plants, refrigeration systems, medical science, ranging from transportation to energy production and in wide variety of industries, Micro-Electro-Mechanical Systems and in the field of biotechnology. This research attempts to help industrial companies achieve product quality by regulating transport phenomena. Journal of Thermal Engineering Journal of Thermal Engineering 2025-05-15T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7321 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7321 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7321

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7124 2024-09-10T21:00:00Z 3

A State-of-the-Art Review on Thermo Fluid Performance of Brazed Plate Heat Exchanger for HVAC Application Madhu Kalyan Reddy PULAGAM, Sachindra Kumar ROUT, Sunil Kumar SARANGI Plate heat Exchangers, Heat transfer, fluid flow, friction factor, CFD Plate heat exchangers have served various industrial applications for decades, with brazed plate heat exchangers (BPHE) emerging as preferred choices due to their favorable operating conditions. While extensive research has been conducted on flow patterns in gasketed plate heat exchangers, similar studies for BPHE have been lacking, given their analogous geometry. However, recent years have witnessed a surge in research focusing on single and multi-phase flow dynamics. Advancements in computational fluid dynamics (CFD) have furthered our understanding by providing insights into flow and heat transfer patterns, while also reducing the need for costly experimental tests of different geometries. This has facilitated the adoption of parametrization, bolstered by the feasibility and accuracy of numerical models. Nevertheless, substantial research remains to be undertaken to develop comprehensive models capable of integrating multiple geometric and flow parameters. This article examines existing research on BPHE and outlines potential areas for future exploration to address current research gaps. Journal of Thermal Engineering Journal of Thermal Engineering 2024-09-10T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7124 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7124 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7124

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7313 2025-05-15T21:00:00Z 1

Effect of higher alcohol on injector deposit and wear in compression ignition engine Faheem Ahmed SOLANGI, Liaquat Ali MEMON, Saleem Raza SAMO, Muhammad Ramzan LUHUR, Umair Ahmed RAJPUT, Ali Murtaza ANSARI, Ali Raza SOLANGI Ansys Fluent; Autodesk Inventor; Emission Level; Radial Injection; Silencer; Temperature Level; Simulation. The effectiveness of engine exhaust silencers in reducing noise is crucial for addressing environmental and regulatory concerns. In this study, the effects of radial air injection at pressures of 2, 2.5, and 3 bar on temperature, sound pressure levels, and emissions are assessed to optimize the silencer performance. To investigate this, the study employs ANSYS for detailed 3D modelling of the silencers. This model is then carefully constructed to enable simulation studies to examine the impacts of radial air injection and temperature distribution. Experimental validation is carried out to validate simulation results to verify robustness and reliability. The findings show that three radial air jets effectively reduce carbon monoxide (CO) emissions and temperature. The most promising results are observed at 3 bar of radial air injection, where a temperature reduction of 217 K, a 2.94% decrease in CO emissions, and a 7.84 dB reduction in sound pressure levels are achieved. The agreement between simulation and experimental data demonstrates the potential of radial air injection in improving silencer performance, providing insights for developing more efficient and environmentally friendly exhaust systems. Journal of Thermal Engineering Journal of Thermal Engineering 2025-05-15T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7313 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7313 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7313

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7590 2026-03-31T21:00:00Z 1

Investigation of thermal and hydrodynamic performance of a plate compact heat exchanger with Levenberg-Marquardt artificial neural network method Aykut BACAK Artificial Neural Network; Compact Heat Exchanger; Heat Transfer Coefficient; Levenberg- Marquardt; Pressure Drop. Compact heat exchangers are an essential device for efficiently transferring thermal energy between fluids. In contrast to larger objects of the same kind, they do this by optimizing the surface area for heat transmission inside a more compact space. This study theoretically calculates the heat transfer coefficient and pressure drop of a plate compact heat exchanger using design parameters such as air flow rate (1-4 kg/s), inlet air temperature (300-350 K), outlet air temperature (400-450 K), passage width (0.003-0.05 m), divider width (0.001-0.005 m), and heat exchanger length (0.15-1 m) at atmospheric pressure (101325 Pa). The study uses the Levenberg-Marquardt artificial neural network method to investigate heat transfer coefficients in compact heat exchangers. Results demonstration that the coefficient increases with mass flow rate doubling and 93% tripling. The maximum coefficient increases by 7.9% with a divider width of 0.001 m, while it decreases with shorter route lengths. The investigation revealed that pressure decreases exhibit a more pronounced rise in relation to the width of the divider. The factors increased by 1.04, 1.08, 1.13, 1.17, and 1.22 for divider widths of 0.001 m and 0.005 m, respectively, at varying temperatures. The change in the width of the divider had little effect on the pressure decrease at constant average temperatures. The Mean Squared Error (MSE) for heat transfer was -0.1787, whereas the MSE for pressure drop was 3.988. The training phase of the ANN was flawless, achieving projected values over 200 W/m2K and a pressure decrease surpassing 5000 Pa. Journal of Thermal Engineering Journal of Thermal Engineering 2026-03-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7590 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7590 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7590

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7422 2025-09-29T21:00:00Z 1

Parametric study and performance evaluation of a multi-layered twin pcmbased vertical thermal energy storage system Amit Kumar GHOSH, Pabitra HALDER Alternating Arrangement; Multilayer; Phase Change Materials (PCMs); Thermal Energy Storage (TES); Twin-PCM. This study illustrates an ingenious approach to thermal energy storage using multi-layer twinphase change materials (PCMs) alternately arranged inside a vertical shell and tube energy storage system. A complex conjugate heat transfer and fluid flow problem is numerically solved, and the effects of different parameters on energy storage performance are evaluated. This study highlights the impact of the number of layers, radius ratio, and flow Reynolds number in the melting and solidification process of PCMs. It also includes the comparison between multi-layer twin PCMs over single-layer individual PCM. The melting and solidification rate improves approximately by 44.3% and 19%, respectively, as the number of layers (n) increases from 2 to 8. Additionally, an 8-layer twin PCM-based system accelerates energy storage and retrieval efficacy, attaining a 33.2% enhancement in stored energy and a 5.3% increase in retrieved energy at a fixed time compared to a 2-layer configuration. It is also observed that in the 8-layer-PCM-1&2 alternating arrangement, the melting rate improved by about 33.65% and 55.84% compared to the 1-layer-PCM-1 and 1-layer-PCM-2 respectively. Similarly, the solidification rate is also promoted in the multi-layer system as compared to the single-layer system. Moreover, it is evident that a lower R/r ratio (R/r = 2) significantly decreases both melting and solidification times by about 78.6% and 89%, respectively, compared to a higher ratio (R/r = 4). Similarly, an increase in the HTF flow Reynolds number correlates with reductions in melting and solidification times by approximately 5.8% and 1%, respectively. This study also facilitates the expedited advancement of both the melting and solidification processes of PCMs with distinct physical justifications that can enable a clear understanding of the improvement of thermal energy storage systems. Journal of Thermal Engineering Journal of Thermal Engineering 2025-09-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7422 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7422 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7422

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7257 2025-03-23T21:00:00Z 1

Performance optimization of oxy-fuel combustion diesel engine with EGR based on fuel injection parameters using response surface methodology (RSM) Raghavendra UGRARAM, R. Meenakshi REDDY, B. Chandra Mohana REDDY Optimization; Oxy Fuel Combustion Diesel engine; Performance; Response Surface Methodology. The interest in research on diesel engine emission reduction is on the rise. A novelistic combustion technique called Oxy-Fuel Combustion (OFC) with 40% of Exhaust Gas Recirculation (EGR) is studied experimentally on a diesel engine at 25% engine load conditions. Although, in OFC nitrogen oxides (NOx) emissions are eliminated and CO, HC emissions are reduced, there is a considerable reduction in Brake Thermal Efficiency (BTE) and increased Brake Specific Fuel Consumption (BSFC) than the Conventional Air Combustion (CAC). In the present study Response Surface Methodology (RSM) Optimization technique is used to optimize the fuel injection parameters of OFC to improve its performance. Start Of Injection (SOI), Duration Of Injection (DOI) and Mass Of Fuel Injected (MFI) are the factorial variables considered for the optimization. To examine the impacts of the selected factorial variables on BTE and BSFC, regression models were formulated and verified to be statistically significant. The Multi-Objective Genetic Algorithm results reveal that the optimum conditions are SOI at 358 CAD, DOI at 15.8 degrees, and MFI at 0.0106 g. The validity of the model was confirmed through the experimental results and demonstrated that the prediction error is below 5%. The experimental results of OFC diesel engine with the optimum conditions indicate that BTE is improved from 14.8 to 24.1% and BSFC reduced from 527.7 to 402.3 g/kW-h. According to the observations of this study, it is concluded that OFC with EGR can be deployed in a diesel engine with no design modifications and the drop in performance in comparison with CAC can be recovered with the RSM optimization. Journal of Thermal Engineering Journal of Thermal Engineering 2025-03-23T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7257 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7257 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7257

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7308 2025-05-15T21:00:00Z 1

Investigation on gasification of waste textile using advanced thermodynamic equilibrium model to address textile waste pollution Mohd ZEESHAN, Rohan R. PANDE, Purnanand V. BHALE Gasification; MSW; Producer Gas; Textile; Thermodynamic Equilibrium Modelling; Waste to Energy. This study investigates the application of gasification as a thermal conversion technology for converting textile waste into a viable energy source. Waste of either form has significant potential as a source of alternate energy, but there is a deficiency of research specifically studying the gasification of textile waste or textile-based refuse-derived fuel. This study intends to develop a specific thermodynamic model for analyzing the conversion of textile-based refuse-derived fuel, which is a unique knowledge. The study synthesizes three RDF compositions using textiles and significant components of municipal solid waste as complementary materials. A parametric analysis is performed utilizing the thermodynamic model derived from the principle of minimizing Gibbs free energy. The findings indicate that gasification can provide a valuable fuel gas composition, demonstrating its viability as a waste-to-energy technique for addressing the particularly concerning textile waste. The investigations suggest that the influence of the equivalence ratio on gas composition is more substantial compared to that of the reaction temperatures. In the gasification process, the composition of the gas and its total heating value are more critical when dealing with a mixture of municipal waste and textile waste compared to the gasification of a sample consisting solely of textile waste. Among the three compositions, the composite sample exhibits the highest hydrogen and carbon dioxide concentration in the product gas. The investigations conducted in this study reveal that the product gas contains hydrogen in the range of 11.11% to 19.92% by volume and carbon dioxide in the range of 17.73% to 43.53% by volume. The highest energy value of the producer gas, 10.29 MJ/kg of feed, is achieved when the reaction temperature and equivalence ratio values are at their minimum. The investigations offer a comprehensive analysis of the gasification of a particular waste stream, providing valuable insights that could potentially enhance waste-to-energy processes for sustainable energy sources. Journal of Thermal Engineering Journal of Thermal Engineering 2025-05-15T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7308 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7308 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7308

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7314 2025-05-15T21:00:00Z 1

A novel method for forced convection heat transfer in 2D skewed cavities using a non-orthogonal mesh Khaled Fawzi SHATNAWI, Saad Bin MANSOOR, Bekir Sami YILBAS Cavity; Convection; Lid-Driven; Non-Orthogonal; Skewed; Tensor Calculus. A novel approach is introduced to study a lid-driven, skewed cavity flow via utilizing a non-orthogonal, body-fitted coordinate system, employing the primitive variables. The Navier-Stokes equations are fully transformed in the new coordinate system while including the independent variables, the velocity components as well as the directions in which the momentum equations are applicable. A non-staggered grid system is used for all variables by substituting the continuity equation with the Pressure Poisson Equation and its appropriate boundary conditions. The flow problem is solved for various skew angles of the cavity. The transformed energy equation is also numerically solved to predict the temperature field in the skewed cavities for different heating conditions at the cavity walls. The present study provides simplifications in numerical modelling of the flow system in cavities without large skewness. In addition, a good agreement is found with previously reported results for skew angles equal to or closer to 90 degrees. Journal of Thermal Engineering Journal of Thermal Engineering 2025-05-15T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7314 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7314 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7314

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7309 2025-05-15T21:00:00Z 1

Computational investigations of perforated annular fins under natural convection heat transfer Md. Shaukat ALI, Naveen SHARMA, Bhongiri Sai GANESH Circumferential Fin; Conjugate Heat Transfer; Heat Transfer Enhancement; Natural Convection, Perforated Fin. The cylindrical shape of objects has always been preferred by thermal engineers as a means of transferring heat, owing to their compact design and high surface-to-volume ratio. Additionally, fins were commonly used over the surface of a cylinder to enhance heat transfer even further by providing a larger surface area for heat dissipation. Therefore, this work investigates the effect of perforated annular fins, protruded from a hot vertical cylinder, on heat transfer performance due to free convection. This conjugate heat transfer study was performed for three Rayleigh numbers (Ra = 0.68 × 107, 1.37 × 107, and 1.8 × 107) in a laminar flow regime. The study involved varying numbers of fins (ranging from 3 to 7) along the cylinder height, resulting in different fin pitch to cylinder diameter ratios (S/d = 2, 2.4, 3, 4 and 5.8). The fluid flow and energy equations were solved using ANSYS Fluent to understand the correspondence between heat transfer and flow behavior. The grid dependence test and the data validation with published work were successfully performed. The Nusselt number is observed to increase with the increase in Rayleigh number, up to 41.75%, irrespective of the number and type of fins used. The heat transfer enhancements due to perforated fins are found to be higher than those without perforations. The maximum augmentation in Nusselt number is found to be 49% in case of the highest number of perforated fins as compared to solid fins, corresponding to an S/d ratio of 2 and a Ra of 1.8 × 107. Conversely, the minimum enhancement in augmented Nusselt number is 20% for an S/d ratio of 5.84 and Ra of 0.68 × 107. The flow characteristics are found to be in commensurate with the heat transfer results. Journal of Thermal Engineering Journal of Thermal Engineering 2025-05-15T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7309 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7309 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7309

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7310 2025-05-15T21:00:00Z 1

Numerical investigation of mixed convection in a square lid-driven cavity with influence of orientation and nanoparticle addition on heat transfer characteristics: Multi-objective optimization approach T. Ravi Kumar REDDY, D.R. SRINIVASAN Cavity; Dimensionless Number and RSM; Horizontal; Liddriven; Vertical Blocks. Response surface methodology is employed to optimize the operating variables (i.e., Reynolds number (150 ≤ Re ≤ 2500), Grashof number (103 to 106) and Richardson number (0.01 ≤ Ri ≤ 12) with different orientations (horizontal and vertical) blocks with mixed convection heat transfer is analysed. Initially, numerical investigations are carried out on a lid-driven cavity with different orientations by employing a laminar mixed convection phenomenon. Optimized results are considered for defining the new models to reduce computational time and effort. Obtained optimized results are validated with numerical results (Nusselt number) and found to be in good agreement. The present work analysis is carried out on a rectangular cavity with different geometries inserted horizontally and vertically by varying the distance (0.2 ≤ W/L ≤ 0.8). As the distance between the blocks varied, the Nusselt number was affected. Also, it is observed that with higher Ri and Re, an enhanced Nu number is observed with vertical compared to horizontal models. In the case of vertical model, maximum Nu is observed at a W/L distance of 0.5 and Ri of 0.043; however, in case of horizontal models at a W/L distance of 0.2 and Ri of 0.043. Ultimately, novel relationships between the Nu number with other dimensionless parameters (Gr, Re) with different orientations (W/L) have been established, with the intention of potentially using them in engineering design. Journal of Thermal Engineering Journal of Thermal Engineering 2025-05-15T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7310 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7310 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7310

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7315 2025-05-15T21:00:00Z 1

Optimization of biodiesel powered CI engine process parameters using AHP and Taguchi grey method – A hybrid approach Krishnamoorthy NATARAJAN, Saravanan SUBRAMANI, Ravi GOVINDASAMY, Paul Durai KUMAR AHP; Anti-Oxidants; Biodiesel; Diesel Engine; Injection Timing; Taguchi Grey Approach. Blends of algae oil with diesel can act as a substitute for diesel are expected to provide organized efficiency and better emission characteristics by controlling the parameters of the compression ignition engine. The addition of antioxidants like pyrogallol and butylated hydroxy toluene can make biodiesel more effective. An Analytical Hierarchy Process and the Taguchi-Grey method are combined for the first time in the compression ignition engine process to optimize the parameters for better performance and reduce toxic emissions. For analytical hierarchy process analysis, an expert’s opinion is collected for the response variables to assign the weightage to the variables. For better performance and reduced emissions, the optimum process parameters are found to be injection timing at 23°, pyrogallol at 0 ppm, and butylated hydroxy toluene at 500 PPM. Furthermore, a confirmation test was conducted to confirm the obtained results from the optimization process, and the results showed that the brake thermal efficiency is enhanced by 3.6 % and NOx is reduced by 6 %. However, the smoke from the CI engine is increased by 10.4 %. Journal of Thermal Engineering Journal of Thermal Engineering 2025-05-15T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7315 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7315 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7315

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7311 2025-05-15T21:00:00Z 1

Experimental and simulation study to evaluate effect of radial air injection on performance of motorcycle silencers Nilaj N. DESHMUKH, Kishor V. MANE, Jebastin NADAR, Reuben PEREIRA, Rahul SHELAR, Rickson DAVID Ansys Fluent; Autodesk Inventor; Emission Level; Radial Injection; Silencer; Temperature Level; Simulation. The effectiveness of engine exhaust silencers in reducing noise is crucial for addressing environmental and regulatory concerns. In this study, the effects of radial air injection at pressures of 2, 2.5, and 3 bar on temperature, sound pressure levels, and emissions are assessed to optimize the silencer performance. To investigate this, the study employs ANSYS for detailed 3D modelling of the silencers. This model is then carefully constructed to enable simulation studies to examine the impacts of radial air injection and temperature distribution. Experimental validation is carried out to validate simulation results to verify robustness and reliability. The findings show that three radial air jets effectively reduce carbon monoxide (CO) emissions and temperature. The most promising results are observed at 3 bar of radial air injection, where a temperature reduction of 217 K, a 2.94% decrease in CO emissions, and a 7.84 dB reduction in sound pressure levels are achieved. The agreement between simulation and experimental data demonstrates the potential of radial air injection in improving silencer performance, providing insights for developing more efficient and environmentally friendly exhaust systems. Journal of Thermal Engineering Journal of Thermal Engineering 2025-05-15T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7311 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7311 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7311

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7316 2025-05-15T21:00:00Z 1

Heat and mass transfer analysis of unsteady MHD Carreu nanofluid flow over a stretched surface in a porous medium with Stefan blowing condition R. GEETHA, B. REDDAPPA, A. SUMITHRA, B. RUSHI KUMAR, B. PRABHAKAR REDDY Carreau Nanofluid; Heat Transfer; MHD; Porous Medium; Stefan Blowing; Unsteady Flow. This study delves into the magneto-hydrodynamic (MHD) flow of a non-Newtonian nanofluid over an unstable stretched surface, focusing on the effects of suction and Stefan blowing. Employing innovative approaches, such as modeling the nanofluid as a two-phase system and using the Carreau fluid model for non-Newtonian behavior, the research generates a numerical solution for heat and mass transfer analysis of unsteady MHD Carreau nanofluid flow in a porous medium under Stefan blowing conditions. By applying similarity transformations, the Carreau fluid flow equations are converted into dimensionless non-linear ordinary differential equations, which are then solved using MATLAB›s bvp4c function. The study meticulously examines the influence of various dimensionless parameters on mass transfer, temperature, concentration, friction factor, and dimensionless velocity, with results presented through comprehensive graphs and tables. Key findings indicate that both temperature and fluid velocity increase with higher Stefan blowing/suction parameters, while temperature decreases with rising fluid velocity and Weissenberg number. These insights are crucial for enhancing the performance and longevity of critical machinery, such as bearings, sliding components, and engines. The study highlights Stefan blowing›s potential to boost heat transfer efficiency by reducing thermal resistance and improving the heat transfer coefficient. The synergistic effects of Carreau nanofluid and Stefan blowing offer promising applications in cooling systems, thermal management tools, and lubrication within the oil and gas industry. The findings advance thermal management technologies and provide a new perspective on engineering applications across various sectors. The range of some physical parameters which are used in this study are: The power-law index (0<n<2), Weissenberg Number (0< We< 100), Magnetic Parameter (0<M< 100), Prandtl Number (Gases: 0.7<Pr< 1, Liquids: 1<Pr<100, Oils: 100<Pr<10,000), Lewis Number (0.01<Le<10). Journal of Thermal Engineering Journal of Thermal Engineering 2025-05-15T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7316 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7316 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7316

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7263 2025-03-23T21:00:00Z 1

Enhancing heat efficiency in arid environments using a PVT collector for revealed facade shelter Mohamed Cherif BENZID, Boubebeur DOKKAR, Abdelghani BOUBEKRI Desert Climate; Discovered Façade Shelter; Heating; PVT Collector. In Ouargla neighboring (Algeria), the harsh climate conditions and the isolation of agricultural areas pose some difficulties for developing agriculture. For lightening climatic constraints, thermal comfort in farmer homes is required. The present study investigated the thermal behavior in a 3D model of an existing earth-sheltered room using Ansys Software. To improve room heating on the coldest winter day, different room designs are investigated. The variant equipped with a photovoltaic-thermal (PVT) solar collector shows significant thermal comfort, where for an ambient temperature of around 4°C, the indoor temperature in the living space reaches about 24°C. Also, the PVT system has a low initial cost compared to a heat pump, where the gap reaches 1460 euros. In addition, the long-term exploitation of discovered façade shelters achieves an appreciable benefit against the mode of farmers’ transportation between the city and the farm.. Journal of Thermal Engineering Journal of Thermal Engineering 2025-03-23T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7263 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7263 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7263

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7259 2025-03-23T21:00:00Z 1

Experimental investigation of convective heat transfer performance using sporadic flow divider type inserts Suryaji S. KALE, Sanjaykumar S. GAWADE Flow Divider Type; Heat Transfer Enhancement; Inserts; Reynolds Number. The depletion of conventional energy resources highlights the growing need for efficient utilization of available energy sources. Heat exchangers play a vital role in transferring heat between two or more fluids, and enhancing their performance is crucial for improving energy efficiency. Various techniques, categorized as active, passive, or hybrid methods, can be employed to augment heat transfer in heat exchangers. This experimental study investigates the use of innovative sporadic flow divider inserts as a passive method for heat transfer enhancement. The experiments were conducted using inserts with different twist angles of 90°, 60°, 45°, and 30°, over a range of Reynolds numbers from 7000 to 21000. The effect of spacing between the inserts was also analyzed using different space ratios (0.19, 0.39, 0.59, 0.78) in combination with the various twist angles. The results indicated that higher Reynolds numbers led to increased Nusselt numbers, a decrease in the Thermal Enhancement Factor (ψ), and a reduction in the Friction Factor (f). Among the tested configurations, the 45° twist angle insert exhibited the highest Thermal Enhancement Factor (ψ) and Overall Performance Criteria (η) across most conditions. Conversely, the 30° twist angle resulted in a significantly higher friction factor, impeding fluid flow. The optimal performance was achieved with a 45° twist angle and a space ratio of 0.59, yielding a 23% improvement in Thermal Enhancement Factor (ψ) and a 55% increase in Overall Performance Criteria (η) compared to a plain tube. These findings demonstrate that sporadic flow divider inserts can effectively enhance convective heat transfer with a moderate increase in friction, ultimately improving the Overall Performance Criteria (η). Journal of Thermal Engineering Journal of Thermal Engineering 2025-03-23T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7259 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7259 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7259

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7166 2024-11-18T21:00:00Z 1

Effects of Gas-Liquid Flow and Dehumidification Performance of a Liquid Desiccant Dehumidifier: A Numerical Approach for Vertical Smooth & Rough, and Inclined Rough Plates Md. Tamzid SHAHARIER, Dipayan MONDAL, Md. Abdul HASIB, Md. Ashraful ISLAM Dehumidifier Performance; Heat and Mass Transfer; Liquid Desiccant; Moist Air; Vertical and Inclined Plates. This study investigates the dehumidification performance and the gas-liquid flow of a falling film liquid desiccant dehumidifier with different plate configurations: vertical smooth, vertical rough, and inclined rough. Utilizing ANSYS Workbench 2020 R1, the Re-Normalization Group (RNG) k-ε turbulence model has been utilized to simulate the gas-liquid flow, and the volume of fluid model is employed to track the interface patterns between the gas and liquid phases. This model takes into account the effects of the two-dimensional turbulent flow which is performed for various plate configurations under situations of unstable gas-liquid flow. The 30% LiCl solution is used as an absorbent and hence, the performance has been evaluated using a constant mass transfer rate of 50 mol/s. Furthermore, the LiCl solution’s mass concentration is taken into account as 30%, 33%, 36%, 40%, and 44%, respectively, for the justification of the influence of various concentrations of LiCl solution. The study analyzes the fields of mass fractions and the mechanisms that lead to the enhancement of dehumidification. The research examines the influence of inlet desiccant concentration and air velocity on mass transfer properties, revealing that an inclined ribbed plate significantly enhances dehumidification up to 10.8% compared to the smooth plate particularly at 1.5 m/s inlet air velocity by generating liquid film waves and increasing contact time between the liquid desiccant and moist of air. Lower inlet air velocities and higher inlet desiccant concentrations resulted in a decreased outlet mass percentage of water vapor. The optimal LiCl concentrations for water vapor absorption are 30-40%, with efficiency stable above 36%, though benefits may plateau beyond a certain level. The study concludes that the inclined rough plate enhances mass transfer performance at various inlet air velocities and desiccant concentrations by increasing the contact time between the liquid desiccant and moist air, increasing the rate of water vapor absorption. These findings provide valuable insights for researchers and engineers aiming to optimize liquid desiccant dehumidification systems for various applications, especially in the hybrid liquid desiccant-vapor compression systems. Journal of Thermal Engineering Journal of Thermal Engineering 2024-11-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7166 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7166 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7166

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7168 2024-11-18T21:00:00Z 1

Impact of Air Flow, Temperature Distribution, and Heat Transmission in a Refrigerator Compartment with and without Shelves: A Numerical Approach Md. Ahsanul BARI, Dipayan MONDAL, Md. Abdul HASIB Air Flow; ANSYS Workbench 2020 R1; Heat Transmission; Refrigerator Compartment (with and without shelves); Temperature Distribution. This study explores the impact of shelf configurations on airflow, temperature distribution, and heat transfer within a refrigerator’s compartment, aiming to optimize natural convection for enhanced energy efficiency and preservation. This analysis assumes a steady-state and laminar air flow to maintain a constant heat transfer rate, where the flow is to be stable with a consistent two-dimensional pattern. Computational fluid dynamics simulations are conducted with ANSYS Workbench 2020 R1 to model airflow patterns, temperature gradients, and heat transfer mechanisms under various shelf configurations. The effect of shelves on airflow and temperature distribution inside the refrigerant compartment are investigated and compared the results of temperature and air-flow distribution by altering the number of glass plates. The analysis reveals significant temperature stratification: colder air tends to settle at the bottom, while warmer air accumulates at the top. Glass shelves are found to disrupt the primary airflow along the walls, but they also enhance heat transfer by improving airflow near the walls. This results in higher temperatures in the upper sections of the refrigerator compared to the average, which presents challenges for storing temperature-sensitive items regardless of the shelf configuration. The lowest temperature in the compartment is 272.55 K at 0~10 cm from the bottom wall, and the highest is 279.75 K at 95~100 cm, due to the upward rise of hot air and downward sink of cold air. The pressure ranges are from -7.11 × 10-3 to 2.88 × 10-1 Pa for without shelves and -7.95 × 10-3 to 3.07 × 10-1 Pa with four shelves, respectively. Maximum air velocities are 1.87 × 10-2 m/s for without shelves and 1.61 × 10-2 m/s for with shelves. By measuring temperatures, pressure, and air velocities at various points within the compartment maintained at the optimal temperature, the study highlights the impact of air density changes on airflow and temperature distribution. The findings underscore the importance scope of shelf design and placement in minimizing temperature differentials and improving cooling efficiency. The originality of this work lies in advancing beyond conventional forced convection models by exploring temperature stratification and natural convection effects to optimize shelf layout and improve energy efficiency. This study integrates detailed air flow analysis with practical implications for refrigerator design, advancing beyond conventional forced convection systems. Future research could explore alternative shelf materials, optimal configurations, and consumer behavior to further refine refrigeration technologies for sustainable household use. Journal of Thermal Engineering Journal of Thermal Engineering 2024-11-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7168 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7168 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7168

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7312 2025-05-15T21:00:00Z 1

Effect of various reactor temperatures for mixed metallic oxides in chemical looping combustion system for carbon capture Mit Manojbhai SHETH, Atal Bihari HARICHANDAN, Rameshkumar BHORANIYA Bubble Hydrodynamics; Carbon Capture; Chemical Looping Combustion; Mixed Metal Oxides; Operating Temperature. Chemical looping combustion (CLC) is an innovative technology designed to address the growing concerns related to carbon dioxide (CO2) emissions from fossil fuel-based power plants. As the world grapples with the challenges of climate change, the development of efficient and cost-effective carbon capture technologies has become imperative. CLC emerges as a promising solution, offering a unique approach to capturing CO2 while maintaining energy efficiency in power generation. The study of bubble hydrodynamics within the fuel reactor of a CH4–fueled CLC system has been incorporated into the present research work. The reaction kinetics have been incorporated into the reactive system of the fuel reactor by a user-defined function (UDF) during numerical analysis. The present study uses CuO and NiO as mixed oxygen carrier materials in various proportions and CH4 as a fuel in combustion processes. The various proportions of mixed metallic oxides have been considered as 30% CuO and 70% NiO, 50% CuO and 50% NiO, and 70% CuO and 30% NiO by volume. The bubble hydrodynamics in terms of development, growth, rise, and burst are visualized and analyzed in the solid-gas molar fraction inside the fuel reactor. In the recent work, authors have chosen different operating temperatures varying from 923 K to 1323 K. The fuel conversion rate has been observed to increase with the increased temperature. Journal of Thermal Engineering Journal of Thermal Engineering 2025-05-15T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7312 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7312 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7312

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7317 2025-05-15T21:00:00Z 1

Magnetohydrodynamic natural convection of complex fluids in a square porous cavity: A numerical simulation S. VIGNESHWARI, B. REDDAPPA, B. RUSHI KUMAR Galerkin Finite Element Method; Jeffrey Fluid; Magnetohydrodynamics; Natural Convection; Porous Cavity. The primary objective of the present study is to investigate the influence of magnetohydrodynamic (MHD) flow and heat transfer behavior of Jeffrey fluid under natural convection within a square cavity filled with a permeable matrix. This investigation is significant because enhancing heat transfer capabilities in systems such as nuclear reactor cooling is crucial for ensuring efficient thermal management. The cavity is configured with cold vertical walls, an adiabatic top surface, and a heated bottom surface, while a constant vertical magnetic field is applied at the left wall. The momentum transfer in the permeable matrix is modelled using the Darcy– Forchheimer approach, and the Galerkin finite element method (GFEM) is employed within COMSOL Multiphysics 6.1 to solve the governing equations. The study examines a range of Rayleigh numbers (10³ ≤ Ra ≤ 106 ), Darcy numbers (10-5 ≤ Da ≤ 10-3), and Hartmann numbers (10 ≤ Ha ≤ 40), providing a detailed analysis of the Nusselt number, velocity distribution, isocontours, isotherms, temperature profiles, and stream functions. Key findings of the study reveal that as the Hartmann number increases, the velocity distribution exhibits a monotonic rise which indicating the strong influence of the magnetic field on flow dynamics. Numerical results of the study demonstrate that with an increase in the Hartmann number (Ha) from 10 to 40, the average Nusselt number on the hot wall decreases from 13.645 to 12.380 at a Rayleigh number (Ra) of 106 indicate a reduction in heat transfer efficiency due to the damping effect of the magnetic field. For lower Rayleigh numbers (Ra = 103 ) the Nusselt number remains nearly constant around 5.728 across varying Hartmann numbers which shows that the magnetic field’s impact is less significant under weaker convective conditions. The results of the study show a high degree of consistency with previous studies, demonstrating the robustness of the numerical approach. This work advances the understanding of MHD natural convection with Jeffrey fluids by offering specific, quantitative insights that go beyond previous literature, particularly in the context of optimizing heat transfer in engineering applications. The novelty of present findings are particularly relevant to geophysical applications, such as modeling the movement of magma in volcanic cavities, as well as industrial processes like polymer mixing. Journal of Thermal Engineering Journal of Thermal Engineering 2025-05-15T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7317 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7317 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7317

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7322 2025-05-15T21:00:00Z 1

Experimental performance evaluation of a solar powered evaporative cooling system for preservation of agricultural produce in tropical region Mfon O. UDO, Sunday O. OYEDEPO, Sunday A. AFOLALU, Samson O. ONGBAL, Oluwaseun KILANKO, Richard O. LERAMO, Bahaa SALEH, Joseph O. DIRISU, James A. OMOLEYE, Gbolahan ODEWOLE, Philip O. BABALOLA, Samson K. FASOGBON, Ejike C. SOLOMON, Blessed BOLARINWA-ODUNAYO, Idemili O. UCHECHUKWU Ambient Temperature; Cooling Efficiency; Cooling Pad; Evaporative Cooling System; Rate of Evaporation; Relative Humidity; Solar PV. Lack of suitable power supplies and storage facilities are major contributors to post-harvest loss of fruits and vegetables in low- and middle-income nations. The problem of food security can be greatly alleviated by solar-powered cooling systems that store agricultural produce in a decentralized manner. In addition to decreasing food loss and waste, this approach promotes green economic growth by lowering greenhouse gas emissions. In view of this, a direct active solar-powered evaporative cooling system is developed and its performance was assessed. In this investigation, the temperature and humidity within the evaporative cooling system were recorded using a Floureon RC-4HC data logger. The data logger was configured to capture data every half an hour for six to seven hours. The wet and dry bulb temperatures of the surrounding area were recorded using a combination wet bulb and dry bulb hygrometer. To determine the relative humidity values, a psychometric chart was utilized in conjunction with the hygrometer data. To measure the air velocity entering the evaporative cooling system, a digital anemometer was employed. Readings were taken consecutively over four days with varying pad thicknesses (from 20mm to 80mm) under no load conditions and for eight days under load conditions. Results of the study shows that the temperature of the cooling chamber reduced to 25o C with a drop range from 3 to 10o C and the highest relative humidity of 88.2% was recorded inside the cooling chamber while relative humidity of 66.5% was recorded for the surroundings. The cooling efficiency of the cooling chamber was found to vary from 61.4 to 87.5% under no load conditions and 47.06 to 91.1% under load conditions. Moreover, the rate of evaporation, cooling capacity and saturation efficiency vary respectively from 0.00116 kg/s to 0.00198 kg/s; 5.284 kW to 7.736 kW and 61.40% to 87.50%. Additionally, it was observed that agricultural produce such as tomatoes, peppers, and okra stored in the evaporative cooler retained their freshness and color after 8 days, whereas those stored under room conditions lost both after 3 days. This demonstrates effectiveness of the developed solar-powered evaporative cooling system to preserve agricultural produce. Small-scale farmers in rural areas, which account for about two-thirds of all farm produce losses, the private sector, Non-Governmental Organisations and some government agencies working to promote decentralized cold-storage facilities are expected to find great value in this study. Journal of Thermal Engineering Journal of Thermal Engineering 2025-05-15T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7322 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7322 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7322

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7260 2025-03-23T21:00:00Z 1

Unsteady magnetohydrodynamic free convection flow of Al2O3–Cu/water nanofluid over a permeable linear stretching sheet through a porous medium with viscous dissipation and heat source/sink Joel MATHEWS, Hymavathi TALLA Heat Source/Sink; Magnetohydrodynamics (MHD); Nanofluids; Permeable Sheet; Thermal Radiation; Viscous-dissipation. This paper examines the effect of Copper and Aluminium oxide nanoparticles on the MHD water-based flow over a permeable linearly stretching sheet through a porous medium. The objective of the present work is to exhibit the impact of magnetic field, viscous dissipation, thermal radiation, and heat source/sink with the metallic and oxide nanoparticles due to permeable stretching sheet. The significance of a new advanced nanofluid with two kinds of nanoparticle materials (Copper and Aluminium oxide) stems from the fact that in the design of various equipment, such as nuclear power plants, gas turbines, propulsion devices for aircraft, missiles, etc. Similarity variables were used to transform the nonlinear partial differential equations into ordinary differential equations. To solve the obtained ODEs, the MATLAB bvp4c solver is used. The behavior of velocity and temperature profiles is discussed through graphs. Also, the physical quantities, such as Skin friction coefficient and Nusselt number, for both fluids are calculated and presented via tables. We have compared the velocity profiles of nanofluids and pure fluid and observed that Copper and Alumina nanofluids perform more efficiently than the base fluid. Moreover, the numerical results are compared with the existing results and found to have good accuracy with the present results. Journal of Thermal Engineering Journal of Thermal Engineering 2025-03-23T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7260 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7260 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7260

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7275 2025-03-23T21:00:00Z 3

Demolition wastes in the global construction industry: An overview of research perspective from 2001 to 2020 Abubakar Sadiq MAHMOUD, Mahmoud Hijab ABUBAKAR, Zulfikar ADAMU, Jamilu ADAMU GARKUWA Bibliometric Analysis; Construction Industry; Demolition Wastes; Sustainable Practices; Systematic Literature Review. Construction Demolition and Renovation Wastes (CDRW) are produced in large amounts in many countries, with the construction industry serving as a primary catalyst for both infrastructure development and socioeconomic progress. Global calls for action have been sparked by the threats that CDRWs represent to human health, safety, and the environment. The objectives of this review are to provide a bibliometric analysis and a thorough literature assessment of DWC-related publications, key players, and scientific advancements using data from the Scopus database. The analysis shows a 20-year rise in publications of 1725%, with significant improvements in CDWR treatment, disposal, management, and valorization. These highlight how crucial sustainable practices are to the construction industry and offer a pathway for further study. Practical applications of these results include the development of more effective recycling programs and the creation of policies aimed at reducing construction waste. The findings will be useful to researchers to guide future research towards inventive approaches as well as policymakers and stakeholders to promote sustainable practices for waste management and valorization. Journal of Thermal Engineering Journal of Thermal Engineering 2025-03-23T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7275 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7275 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7275

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7318 2025-05-15T21:00:00Z 1

MHD stream past an inclined surface with diffusion-thermo and viscous dissipation sequels Bhaskarjyoti DEKA, Rita CHOUDHURY Boundary Layer; Diffusion-Thermo; MHD; Thermophoresis; Viscous Dissipation. The steady-state MHD (Magnetohydrodynamics) incompressible free convective boundary layer stream over an inclined surface, moving continuously in the existence of heat along with mass transfer is studied. The interpretation of Diffusion-thermo, Viscous dissipation, and Thermophoresis has been emphasized. To decompose the heat and mass transport, a two-dimensional steady flow model formed by appurtenant boundary conditions is created. The equations that govern the system are solved using numerical techniques, specifically the bvp4c solver in MATLAB, with appropriate boundary conditions. Numerical constellations are also plotted to validate the results and the acquired relevant parameters are effectively analysed. This incorporation expands on prior investigations and enhances our comprehension of these intricate interrelations. Adequate validation has been performed against previously published articles and positive agreement has been observed. The Nusselt number and temperature profile decrease with increasing Dufour number, while a noticeable change in behaviour is observed in the concentration profile and Sherwood number. The research is significant as it provides insights into improving heat and mass transfer mechanisms, which are essential in a variety of engineering challenges, including Chemical Industries, Nuclear Reactors, and Metallurgical Industries. The findings from the study of MHD flow through inclined surfaces with diffusion-thermo and viscous dissipation effects have broad applicability and implications in various engineering fields. This research has the potential to significantly impact process optimization, control flow patterns in metallurgical furnaces, enhance heat transfer, and improve energy efficiency. It also contributes to the design and analysis of liquid metal-cooled nuclear reactors. Journal of Thermal Engineering Journal of Thermal Engineering 2025-05-15T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7318 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7318 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7318

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7319 2025-05-15T21:00:00Z 1

Heat transfer enhancement by laterally impinging air jet on semi-circular grooved surface A. M. RATHOD, Chandrashekhar K. JADHAV, Rohit S. TARTE, Nitin P. GULHANE, Jan TALER, Dawid TALER, Pawel OCLON Cooling Rate; Jet Impingement; Local Nusselt Number; Reynold Number; Semicircular Groove Surface. This study experimentally investigates the cooling rate of a jet impinging on a semi-circular grooved surface. The experiments aim to determine the magnitude of convective heat dissipation on this grooved surface, which is 6mm thick and features six evenly distributed circular grooves. The investigation considers various factors, including Reynolds numbers ranging from 4000 to 12000, clearance (z/d) between nozzle outlet to target plate, varying from 1 to 6, and the surface roughness of the plate. Local and average Nusselt numbers were calculated using experimental data on airflow behaviour in different areas of jet impingement. Compared to a smooth flat plate, the grooved surface showed a significant increase in both local and average Nusselt numbers, with the local Nusselt number increased by 11% and averaged Nusselt number by 15.23%. Heat transfer across various regions, including stagnant, transition, and wall jet, was studied under a uniform heat flux over a flat plate. Experimental results show that maximum heat dissipation occurs in the transition region for semi-circular grooved surfaces, while for smooth flat plates, it occurs in the stagnation region. The maximum percentage deviation was recorded as 15.23% with Reynolds number of 12000. Journal of Thermal Engineering Journal of Thermal Engineering 2025-05-15T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7319 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7319 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7319

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7325 2025-05-15T21:00:00Z 3

Soiling mechanics of solar photovoltaics: A review Kudzanayi CHITEKA, Christopher C. ENWEREMADU Dust Adhesion; Dust Characteristics; Environmental Characteristics; Solar Collector Soiling; Solar Installation Geometry; Soiling Mechanics The widespread deployment of solar energy, while promising sustainable and renewable power generation, is affected by various factors, with soiling being a significant concern. This review provides an in-depth exploration of the complex mechanisms underlying the soiling of solar photovoltaic (PV) surfaces, which has become a pressing concern in the face of the rapid expansion of solar energy deployment worldwide. The deposition, accumulation, and detachment processes, including rebounding, resuspension, and cementation, are examined in detail, highlighting their interplay with various environmental factors and installation parameters. Emphasis is placed on the critical role of airflow dynamics, such as wind speed and direction, in influencing soiling rates and adhesion forces. Moreover, the impact of geographical location and climatic conditions on soiling mechanisms is thoroughly analyzed, considering factors like dust particle characteristics, surface roughness, and moisture content. Although research has advanced understanding, comprehensive studies integrating all soiling variables are still needed, highlighting the need for further investigation. Journal of Thermal Engineering Journal of Thermal Engineering 2025-05-15T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7325 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7325 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7325

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7320 2025-05-15T21:00:00Z 1

Strategic design and optimization of ultra-high-frequency regenerators for miniature pulse tube cryocoolers: A roadmap to achieve high efficiency and compact Chetan O. YADAV, P. V. RAMANA Miniature Pulse Tube Cryocooler; REGEN3.3; Regenerator; Ultra-High Frequency. Infrared sensors on small satellites require a miniature pulse tube cryocooler to operate efficiently at ultra-high frequencies. This study focuses on optimizing the regenerator of a miniature pulse tube cryocooler, which is crucial for enhancing performance in terms of low vibration, improving reliability, and increasing the system’s lifespan. Using the software tool REGEN 3.3, we conducted numerical simulations to analyze the geometrical and operating parameters that impact the performance of the ultra-high frequency regenerator. A comprehensive investigation was performed across a wide range of ultra-high frequencies (100 to 200 Hz), charge pressures (3.5–7.0 MPa), and pressure ratios (1.15–1.3), while considering operating temperatures from 300 K to 80 K and cooling power of 1 W. The optimized regenerator dimensions of 4 mm diameter and 25 mm length at 100 Hz achieve a coefficient of performance of 0.0819, while at 200 Hz, dimensions of 4 mm diameter and 20 mm length produce a coefficient of performance of 0.07491, demonstrating frequency-dependent performance variation. The Key results show that variations in regenerator length by up to 20% (from 25 mm to 20 mm) result in only a 5.093% decrease in coefficient of performance, while a 30% increase (from 25 mm to 30 mm) leads to a 14.91% reduction. The findings indicate that operating frequency minimally influences the optimal diameter; however, the optimum regenerator length decreases with frequency. An increase in frequency from 100 Hz to 200 Hz results in a 20% reduction in regenerator length and an 8.51% decrease in COP. Charge pressure has a limited effect on optimal dimensions, whereas higher cold-end pressure ratios significantly reduce the overall dimensions of the regenerator. An increase in charge pressure reduces pressure drop loss by up to 73% with no significant effect on regenerator losses, while the variations in the pressure ratio have no significant impact on pressure and regenerator losses. The novelty of this work lies in its systematic numerical optimization of an ultra-high frequency regenerator for miniature pulse tube cryocoolers, providing insights that extend beyond previous literature by demonstrating the importance of broad tolerances in design parameters and the significant impact of geometry and operating parameters on performance. This study outlines a roadmap of the ultra-high-frequency regenerator in miniature pulse tube cryocoolers, facilitating efficient operation and miniaturization, thereby enhancing the capabilities of satellite systems. Journal of Thermal Engineering Journal of Thermal Engineering 2025-05-15T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7320 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7320 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:3 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7320

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7175 2024-11-18T21:00:00Z 3

A Comprehensive Investigation of Solar Panel Cleaning Technologies: A Review Study Mustafa Tahir AKKOYUNLU, Yousef ABDALLATIF Cleaning Techniques; Photovoltaic Panels; Dust Accumulation; PV Efficiency; Solar Energy. This article explores the evolution and importance of photovoltaic (PV) panels, spanning from their inception to contemporary variations, emphasizing their critical role in addressing global concerns regarding climate change and carbon emissions. It underscores the necessity of maintaining clean photovoltaic panels to optimize efficiency and examines factors affecting dust accumulation and mitigation methods. The literature review highlights the substantial impact of dust accumulation on PV panel efficiency, documenting power output declines due to dust deposition globally. It also discusses the evolving landscape of cleaning methodologies, including robotic systems and surface treatments, to enhance solar PV performance in dusty environments. Dust’s multifaceted role in environmental processes, affecting climate, atmospheric interactions, and human health, is acknowledged. The complexity of dust deposition on PV systems, influenced by various factors, underscores the challenge of maintaining optimal panel efficiency. The diverse characteristics of dust, including size, composition, adhesion, and density, complicate understanding and emphasize the need for comprehensive research. Various cleaning techniques, from traditional methods to advanced ones like electrostatic precipitators and coatings, are explored, addressing dust accumulation with considerations for water conservation and energy efficiency. Innovative dust mitigation approaches like super-hydrophilic and super-hydrophobic coatings are presented. This article provides a comparative analysis of solar panel cleaning methods, emphasizing their advantages and limitations, to aid in method selection based on installation needs and environmental conditions. It also delves into active and passive self-cleaning techniques, assesses automated cleaning systems, underlines the role of these methods in obtaining the highest efficiency of photovoltaic panels shows the different mechanisms by which these methods are built, and reviews the latest studies in this area. Journal of Thermal Engineering Journal of Thermal Engineering 2024-11-18T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7175 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7175 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7175

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7366 2025-07-30T21:00:00Z 1

Thermo-hydrodynamic analysis and exergy destruction minimization in a three- dimensional corrugated channel working with a ferrofluid and an external magnetic field Abdelaziz BOUMAIZA, Mahfoud KADJA, Cherif Ould LAHOUCINE, Zakaria KOREI Heat Transfer; Hydrodynamic Behavior; Magnetic Field; Numerical Modeling; Ferrofluid; Exergy Destruction The ever-increasing consumption of limited energy sources has forced researchers and engineers to produce more efficient energy systems in order to use energy sources effectively. Among the existing energy systems, those which are made of corrugated configurations play an important role in heat transfer enhancement in many engineering applications such as heat exchangers, microchannel heat sinks, solar collectors, etc. This paper analyses the influence of an electromagnetic field on the hydrodynamic and thermodynamic behaviours of Fe3O4-water flow in a corrugated channel in order optimize its performance. Such analysis has not been thoroughly investigated by other researchers. Three-dimensional numerical modelling was used to conduct this study. It consisted in solving the governing equations for continuity, momentum, and energy using the finite volume method. The following boundary conditions have been imposed in the study: the non-corrugated parts of the channel are thermally insulated, whereas the top and bottom corrugated surfaces receive a uniform heat flux. An external and uniform magnetic field is applied perpendicular to the flow in the corrugated section. This study examines the effects of the magnetic field strength, the Reynolds number (Re), and the nanofluid volume fraction on the channel’s heat transfer performance. The analysis of the results reveals that heat transfer is significantly affected by the magnetic field at low Re numbers (less than 400). The presence of a magnetic field, particularly at B = 300G, prominently features the appearance of eddies at Re = 200 and Re = 400. Entropy generation decreases with increasing magnetic field, which is more evident in the B = 200G and B = 300G cases. The Nusselt number increases by more than 80% with B = 300G at a low Reynolds number (Re = 200). Both the thermal and total exergy destruction decrease as the Reynolds number and magnetic field strengths increase, especially in the cases of Re = 200 and Re = 400 with B = 300G. However, an increase in frictional exergy destruction is observed. The minimum total exergy destruction is achieved at Re = 1200, B = 300 G, and a volume fraction of 2%. The thermal exergy destruction and total exergy destruction in the case of B = 300G decrease by 37% compared to water Journal of Thermal Engineering Journal of Thermal Engineering 2025-07-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7366 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7366 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7366

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7264 2025-03-23T21:00:00Z 1

Heat transfer intensification of ethylene glycol dispersed with nano alumina in a spiral tube heat exchanger for application in solar thermal systems Ardhani Satya Bhanu PRASANNA, Koona RAMJI, Manepalli SAILAJA, D. ASIRINAIDU Aluminium Oxide Nanoparticles; CFD Analysis; Double Flow Spiral Tube Heat Exchanger; Ethylene Glycol; Nanofluids The study investigates the heat transfer properties of ethylene glycol-alumina nanofluids in a double-tube spiral coil heat exchanger operating under laminar flow conditions. The present study is related to solar thermal systems and discusses the effects of surface modification of nanomaterials before dispersion in ethylene glycol. Further, the study compares the experimental values with a computational fluid dynamics model. The fluid used consists of ethylene glycol with dispersed nano-alumina (Al2O3) with a diameter of 50 nm in concentrations of 1%, 0.5%, 0.25% and 0.125%. The aluminum oxide nanoparticles were surface modified with the surfactant hexadecyl cetyl trimethyl ammonium bromide to improve the dispersion stability. To determine the thermal conductivity and dynamic viscosity at different concentrations, C-Therm thermal analyzer and a Brookfield viscometer were employed. The heat transfer intensification studies were conducted in a double-tube spiral heat exchanger. The dispersion of nanoparticles leads to an increase in thermal conductivity of up to 20 %. The results show that adding alumina nanoparticles to ethylene glycol resulted in an increase in the heat transfer coefficient by up to 32% compared to base ethylene glycol. The heat transfer coefficients of the test fluids increased by 22%, 27%, 30% and 32% when nanofluids with alumina concentrations of 0.125%, 0.25%, 0.5% and 1%, respectively, were used. The validity of the results was confirmed by comparing the experimental data with computational fluid dynamics models. The validation of the mesh confirmed the accuracy of the numerical flow model. The deviation between the experimental data and the values predicted by the flow model is negligible. Journal of Thermal Engineering Journal of Thermal Engineering 2025-03-23T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7264 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7264 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7264

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7359 2025-07-30T21:00:00Z 1

Analysis of energy and exergy of a thermal storage system using multiple phase change material Jayaprakash V, Ganesan S, Beemkumar N, Sunil Kumar M Charging-Discharging Process; Exergy; Heat Transfer Fluid (HTF); Phase Change Material (PCM), Thermal Energy Storage (TES). A practical method for balancing supply and demand in renewable energy is cascade latent thermal storage. Thermal energy storage (TES) systems with phase change material (PCM) store energy at different temperature levels. This study aims to present the comparative energy and exergy efficiency analysis of single PCM and multiple-temperature PCM TES using different PCM in a temperature range of 100-200°C. The analysis is carried out in three configurations: 1) single PCM with Hydroquinone, 2) single PCM with Catechol, and 3) Multiple-temperature PCMs with Hydroquinone and Catechol. In the first and second configurations, heat transfer fluid, i.e. therminol-66, flows in their respective individual PCM tanks and analysis is carried out. In the third configuration, i.e. multi-temperature PCMs, heat transfer fluid (HTF) flows in descending order of respective melting point. Energy and exergy efficiency were analysed regarding temperature and time during the charging and discharging cycles. From the analysis, the overall exergy efficiency using Hydroquinone and Catechol as PCM in the TES system in cascading is 38.57%, which is relatively higher than the exergy values of the single PCM, which indicates that by providing multi-grade thermal energies, multiple PCMs can increase thermal performance while also expanding the thermal energy’s application scope. Journal of Thermal Engineering Journal of Thermal Engineering 2025-07-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7359 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7359 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7359

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7369 2025-07-30T21:00:00Z 1

Kinetics and mathematical model of sugarcane bagasse drying in laboratory scale rotary dryer Melvin Emil SIMANJUNTAK, Paini Sri WIDYAWATI Bagasse; Drying; Mathematical Models; Moisture Ratio; Rotary Dryer. Sugarcane is the primary source of natural sweeteners that are always needed. North Sumatra is a province in Indonesia with a population of 14.8 million. It consumes as much as 144,323 tons of sugar per year. The existing sugar factory can produce 47,122 tons. One of the by-products of sugar factories is bagasse, which is used as fuel in boilers and has a moisture content of about 50%. Dried bagasse can be used for various purposes, such as fuel, paper, particle board and feedstock. On the other hand, the boiler exhaust gas in a sugar mill has a temperature of around 150-200 °C. This bagasse can be dried before being used in a boiler to save consumption. Theoretically, this heat can be used to dry bagasse. The study aimed to obtain a drying kinetic model, the occurrence of changes in the drying stage of the falling rate, effective moisture diffusion, and errors between the kinetic model and the experiments on drying with the rotary dryer method. Things like this have been difficult to find until now. This study was conducted through an experiment of drying sugarcane bagasse using a rotary dryer on a laboratory scale. The temperatures used were around the exhaust gas temperature, namely 140, 160, 180, and 200 °C and the drum rotation was 3 rpm. The sample masses are 100, 125, and 150 gr, with a length of 3 cm. The results show that the Wang and Singh model is the most appropriate kinetic model due to the highest correlation coefficient and the lowest Root Mean Square Error and chi-square (χ2 ) values. Another result obtained was that since drying, only the drying rate of the first and second stages can be seen. The change in drying rate from the first to the second stage is faster when the temperature is higher and the sample mass is less. This change occurred around the 12th to 22th minute. The effective moisture diffusion definition for 100, 125, and 150 gr sample masses at 200 °C drying temperature were 2.72 x10-5, 2.60 x 10-5, and 1.93 x 10-5 m2 /s, respectively. The error between the experimental results and the Wang and Singh model mainly were below 5% Journal of Thermal Engineering Journal of Thermal Engineering 2025-07-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7369 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7369 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7369

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7374 2025-07-30T21:00:00Z 3

Recent trends in the development and growth of solar technologies: a review K. Sunil KUMAR, Raviteja SURAKASI, Kumar GOVINDHASAMY, S. SUDHA, Grynal D'MELLO, B. T. THARANISRISAKTHI Cleaner Technologies; Hybrid Systems; Solar Photovoltaic, Solar Thermal. The generation of power from solar-based power plants has wide issues in terms of less solar radiation throughout the year. One more issues pertaining the solar power plants is solar panel costs are very high and the power generation per unit is Rupees twenty, In this research study, methods used for the generation of solar panels and the various types of literature concerning the generation of power, maintenance of panels and solar radiation intensities parameters are deeply investigated and the minimal land requirements for installing the solar power plants has been discussed. The important findings from the various kinds of investigations that have recently been conducted on solar photovoltaic, solar thermal and solar photo voltaic thermal systems is inclination angle varying from 20 degrees results in achieving 1200 W/m2 followed by solar Photovoltaic systems gives enormous power attainment of 10 kWh/m2 /day. But Solar Photovoltaic and solar thermal give the very least power generation than solar photovoltaic thermal systems range of 2 kWh/m2 /day to 4 kWh/m2 / day. The novelty from various findings and literature gaps involved in a research study is design of solar photo voltaic thermal systems is very simple and requires very little space compared to solar photo voltaic and thermal systems. Journal of Thermal Engineering Journal of Thermal Engineering 2025-07-30T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7374 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7374 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7374

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7521 2026-01-30T21:00:00Z 1

Thermo-diffusion effects on mhd casson blood flow in an inclined muti-stenosed artery Harshad PATEL, Snehal PATEL, Nilesh PATEL Casson Fluid; Fractional Derivative; Magnetic Particles; MHD; Multi-Stenosed Artery; Thermal Radiation The current study investigates the effects of thermos-diffusion on Casson blood flow in the presence of a magnetic field. We consider the flow in an inclined multi-stenosed artery with an oscillating pressure gradient. By using the similarity transformation, the governing equations are transformed into a dimensionless form. For more effective study of the fractional time derivative, the Caputo-Fabrizio time derivative is adopted. Using the tools provided by the Laplace transform and the finite Hankel transform, the analytical solution to the aforementioned problem is derived. We gather numerical findings and display them through graphs to help you better comprehend the effects of various physical parameters. Data visualization shows that the external magnet-controlled blood flow’s turbulence. These results suggest that high magnetic field impacts are harmful to health. Additionally, it is observed that thermal radiation commonly enhances the heat distribution procedure. Journal of Thermal Engineering Journal of Thermal Engineering 2026-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7521 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7521 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7521

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7256 2025-03-23T21:00:00Z 1

An experimental and numerical analysis on the effective utilization of waste heat from a ladle preheating system through a heat exchanger system Baji KATTA, Manjini SAMBANDAM, M. PREMLATHA, Saravanan CHANDRASEKARAN CFD; Green Energy; Heat Exchanger; Sustainability; Waste Heat Recovery. Steel-making industries use preheated ladles to transfer molten steel from primary to secondary facilities. The preheating process removes moisture, reduces thermal shock, protects the refractory lining, and minimizes temperature drop, but it emits substantial heat through the flue gas. This study introduces a novel, low-cost heat exchanger designed specifically for waste heat recovery in ladle preheating systems, contributing to a circular economy and substantial carbon dioxide reduction. We designed and analyzed a shell-tube heat exchanger using the Kern method and performed experiments and numerical analyses for thermal behavior with commercial ANSYS 19.0. We assessed waste heat utilization through an experimental setup, leveraging insights from computational fluid dynamics modeling and mathematical modeling. We reduced liquefied natural gas consumption from 224 kg/hr to 197 kg/hr. This method saved energy, cutting consumption from 5855 Gcal/yr to 5149 Gcal/yr and lowering carbon dioxide emissions from 1372 TCO2/yr to 1207 TCO2/yr. Our findings suggest that a waste heat recovery system effectively reduces greenhouse gas emissions and offers a practical, cost-effective way to recover energy from the ladle preheating system. Journal of Thermal Engineering Journal of Thermal Engineering 2025-03-23T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7256 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7256 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7256

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7367 2025-07-30T21:00:00Z 1

The impact of electrode design parameters on the thermal behavior of a lithium-ion battery Ahmed Fouad AL-NEAMA, Harvey Morpeth THOMPSON 18650-type NMC Battery; Discharge Rate; Electrode Thickness; LiB; State of Charge. The main objective of this study is to develop an accurate simulation methodology for the temperatures in cylindrical lithium-ion batteries (LiBs), while they are being continuously charged and discharged, that can be used to ensure they remain within safe operating limits. A comprehensive 3D simulation methodology for air-cooled cylindrical LiBs is developed and applied to the specific case of an 18650-type NMC LiB. The battery cell chemistry is modelled using a Pseudo 2D electrochemical model, while the temperature within the battery is represented using a 3D axisymmetric heat transfer model. The electrochemical and thermal behaviours are modelled by coupling the heat source produced from the electrochemical model with the average temperature from the thermal model. This study’s key novelty lies in its detailed investigation into how multiple electrode design parameters affect the LiB’s thermal characteristics. To verify the model’s accuracy, the simulation outcomes are compared with experimental data on discharge voltage and surface temperature of LiBs at different discharge rates, and good agreement is obtained. The model is then used to explore the impacts of the electrode thickness, positive electrode particle size, charge-discharge rate (C-rate) and inlet airflow velocity on battery thermal behaviour. The numerical results revealed that increasing the C-rate, electrode thickness, and positive electrode particle size increases the LiBs’ temperature rise rate; however, increasing inlet airflow velocity reduces the temperature rise of the battery cell. At inlet airflow velocity of 0.1 m/s, the maximum temperature roughly increases by 31.7 o C (at 6 C-rate) compared to the 1 C-rate case. At 4 C-rate and inlet airflow velocity of 0.2 m/s, the numerical results predict that increasing the negative electrode thickness from 25 to 70 µm increased the maximum temperature from 31.8 to 48.1 o C, while raising positive electrode particle size from 1 to 7 µm increased the maximum temperature from 32.06 o C to 38.74 o C (at time of 2000 s). The research method and conclusions can provide valuable references for further research on the thermal characteristics of the LiB. Journal of Thermal Engineering Journal of Thermal Engineering 2025-07-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7367 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7367 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7367

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7156 2024-11-18T21:00:00Z 1

An Experimental Investigation of Liquid Jets under Low-Speed Crossflows Hatice MERCAN, Mehdi NABATI, Hasan BEDIR, Gunay ANLAS Droplet Formation; Gaseous Crossflow; Liquid Jet; Momentum Flux Ratio; Shadow Graph; Spray Penetration; Weber Number. This study presents the breakup mechanisms and droplet features of a liquid jet introduced into a low-speed cross air flow. The main aim of this study is to investigate the spray behavior of water when exposed to a uniform crossflow of air at very low velocities. A shadow sizing system is employed to collect comprehensive data for analyzing the interactions between liquid jets and crossflowing air. Three different nozzles were used to examine the distribution, penetration, and breakup characteristics of water jets in an air crossflow. It is worth highlighting that the Weber number in this experiment was maintained at a very low level. Both the jet Weber number (1.3 < Wej < 119) and the gas Weber number (0 < Weg < 1), along with the momentum flux ratio (2 < q < 14400), are crucial dimensionless parameters significantly affecting various droplet properties such as size, velocity, shape, and breakup behavior. This study investigates the structural features, trajectory of the jet, and duration of breakup near the nozzle. Subsequently, the experimental results are tabulated for future numerical and analytical studies. As the air crossflow velocity increases, the liquid jet bends in the direction of the airflow. The breakup length decreases with increasing air velocity. The nozzle with medium diameter shows the maximum dimensionless breakup length. At a constant air velocity, the breakup length initially increases and then decreases with an increasing momentum flux ratio. Higher liquid flow rates result in a higher density of smaller droplets. The liquid jets shift upstream with increasing q values; however, due to the wide range of q values, existing empirical relations in the literature fail to accurately predict this behavior. Journal of Thermal Engineering Journal of Thermal Engineering 2024-11-18T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7156 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7156 Journal of Thermal Engineering, Year:2024, Vol:10, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7156

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7371 2025-07-30T21:00:00Z 1

Thermal transmittance analysis in Tehran residential units with an approach to building roof insulation simulation Ashkan HASSANI, Shooka Khoshbakht BAHRAMANI Building Roof Heat Transfer; Building Thermal Transmittance; Building Thermal Transmittance Simulation; Thermal Insulation Analysis. This study focuses on the impact of building thermal insulation on the energy consumption issue, which highlights the importance of reducing energy usage through efficient heat transfer management, especially in building roofs. The reviewed literature was categorized according to thermal transmittance, material properties, and simulation techniques. The identified gap is the lack of a numerical framework for insulation materials in building construction in Iran, which architects and building designers can use. The main method of investigation is a simulation-based approach using Design Builder software that follows the procedure from building modeling to the configuration of roof layers. Eight types of thermal insulation layers were simulated to evaluate their influence on improving the thermal balance of the roof. This research emphasizes a common roof detail used in Tehran residential buildings. This study evaluates the heat balance factor to identify the most suitable frameworks based on the insulation type. The findings of this study present a numerical framework that categorizes roof insulation materials and their thickness in terms of enhancing the thermal performance in Tehran’s buildings, which is a considerable result of this study. Based on the results, architects and building designers in Tehran have the possibility to use the framework in their first design phase, which can choose the most efficient insulation based on their project calculations. This is counted as the novelty point of the current research. As a numeric point, high-rate insulations like polystyrene (HFC) and polyurethane demonstrate remarkable flexibility in enhancing thermal balance with coefficients ranging from 0.03 kW, to +0.06 kW which is considered based on the thickness increasing. Journal of Thermal Engineering Journal of Thermal Engineering 2025-07-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7371 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7371 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7371

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7418 2025-09-29T21:00:00Z 1

Experimental investigation of the impact of electronic expansion valve opening on vcr system performance: comparative analysis with capillary tube and thermostatic expansion valve Ankitsinh CHAUHAN, Ashok PAREKH, Vimal PATEL VCR System, Expansion Devices, Performance Analysis of VCR System, Comparison of Expansion Devices, EXV Openings. The Electronic Expansion Valve controls the amount of refrigerant flow into the evaporator. The percentage opening of the electronic expansion valve significantly impacts the performance of the vapor compression refrigeration system as it controls the refrigerant flow to the evaporator which alters the superheating temperature and thus providing different cooling loads. In order to protect the compressor from damage from the liquid refrigerant, it is essential to vaporize all refrigerant before it leaves the evaporator. The experiments were conducted with an air-cooled condenser, a compressor frequency of 45 Hz, and a water pump frequency of 50 Hz. The experiments ran until the cold water temperature reached 10°C. R- 134a refrigerant was used as the working fluid in all experiments. The conditions were kept similar for the capillary tube, thermostatic expansion valve, and electronic expansion valve. The performance parameters including cooling load, compressor power, and cooling coefficient of performance, were investigated by varying the electronic expansion valve percentage opening. The best performance achieved was that of a cooling load of 6560 W and COP of 4.56, with a 60% electronic expansion valve opening. In comparison to the capillary tube, the 60% electronic expansion valve opening provides an increase of 65% of the cooling load and increase of 39% of the coefficient of performance, respectively, and compared to thermostatic expansion valve, it provides an increase of 35% of the cooling load and increase of 10% of the coefficient of performance, respectively Journal of Thermal Engineering Journal of Thermal Engineering 2025-09-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7418 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7418 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7418

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7361 2025-07-30T21:00:00Z 1

Temperature evolution within a solar panel using a cooling source of varying sizes and shapes in the presence of a hybrid nanofluid Boubekeur GHAZI, Syham KADRI, Razli MEHDAOUI Hybrid Nanofluid; Circular Cold Cylinder; Square Cold Cylinder; Temperature Solar Panel; Natural Convection; Finite Element Method; Triangular Cavity. A triangle space with a submerged cold cylinder of varying sizes and shapes is the subject of this computational investigation of spontaneous thermal convection. The (Al2O3-Cu-water) hybrid nanofluid fills the triangle space using an aspect ratio and the geometry of the cold source immersed in the solar panel. The objective of this project is to enhance the performance of the panel by increasing the evacuation rate of convective heat transfer. The second goal is to conduct digital research that will enable a reliable selection of data for the panel future design. Therefore, this work has significance since it allows for lowering the temperature and boosting the solar panel efficiency despite the challenging conditions in our dry border region (south-west Algeria). With a Rayleigh number of 106 and based on information from our dry location (southwest Algeria), with the solar panel angled at 30°, we tested three distinct cases: one with SL=0.04, another with SL=0.06 and the last one with SL= 0.08. The coupling of the flow-governing equations in our investigation is solved by a quadratic Lagrange interpolation utilizing the finite element approach. Following the establishment of the optimal dimension, five distinct shapes of the cold source are examined to ascertain the best shape for the evacuation of convective heat transfer within a triangle cavity. Temperature profiles, average Nusselt number, streamline and isotherm patterns are all part of the collected data. Based on the findings of this experiment, the convective transfer mode can only be dominant when the source is circular with a diameter of SL= 0.08. Near the source, it has been found that the temperature of the solar panel is reduced, which is a significant result. There is a strong agreement when we compare the average Nusselt number of our code to that of Keramat. Journal of Thermal Engineering Journal of Thermal Engineering 2025-07-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7361 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7361 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7361

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7364 2025-07-30T21:00:00Z 1

Machine learning in flow boiling: predicting bubble lift-off diameter despite data limitations Atta Heydarpour TABRIZI, Mousa MOHAMMADPOURFARD, Mostafa MOHAMMADPOURFARD Bubble Size; Machine Learning Techniques; Predictive Model; Regression Model. This study concentrates on applying machine learning techniques to flow boiling in order to predict the bubble lift-off diameter. This prediction is critical because the diameter plays a key role in understanding boiling dynamics and calculating heat transfer rates. Additionally, accurately predicting this diameter is essential for optimizing thermal systems and enhancing energy efficiency. By evaluating the performance of three different machine learning algorithms: M5 tree, multilinear regression, and random forest, we aimed to assess their effectiveness in providing reliable predictions even with limited experimental data. This research is essential as it demonstrates the potential of machine learning to enhance predictive accuracy in scenarios where obtaining extensive datasets is challenging. Our findings show that these machine-learning techniques are effective for accurate predictions. The results show that the coefficient of determination ranged from 0.64 to 0.94, indicating how well the models fit the data. The root mean square error was between 0.009 and 0.02, and the mean absolute error ranged from 0.0004 to 0.02. Based on the findings, it can be inferred that the machine learning algorithms used in this study are reliable for predicting bubble lift-off diameter. This reliability also extends to other experimental parameters, suggesting that these techniques can be effectively applied in various contexts with limited data. This study demonstrates the potential of machine learning to predict experimental parameters and advances previous research by identifying key factors that influence bubble lift-off diameter. Journal of Thermal Engineering Journal of Thermal Engineering 2025-07-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7364 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7364 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7364

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7370 2025-07-30T21:00:00Z 1

Numerical investigation of slip flow and temperature jump of nanofluid in a microchannel with square obstacles using lattice Boltzmann method Habib KARIMI, Kourosh JAVAHERDEH Heat Transfer; Lattice Boltzmann Method; Microchannel; Nanofluid; Square Obstacles. This study investigated a forced convection of nanofluid in a microchannel with the presence of square obstacles using lattice Boltzmann method. The slip boundary conditions for velocity and temperature jump are considered for microchannel. The study is conducted in three volume fractions of nanoparticles, two Knudsen numbers and two Reynolds numbers. The results is shown that with enhancing the volume fraction of nanoparticles, the heat transfer coefficient increases more than two times. It is observed that by increasing the Knudsen number, the velocity slip and also temperature jump increases, but the heat transfer coefficient and the friction coefficient decreases. The first obstacle in the microchannel is more effective which is due to the creation of the vortex and the vortex characteristics in dissembling the hydraulic and thermal boundary layers. Also, increasing the nanoparticles volume fraction, the heat transfer coefficient rises noticeably. Journal of Thermal Engineering Journal of Thermal Engineering 2025-07-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7370 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7370 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7370

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7419 2025-09-29T21:00:00Z 1

Thermal performance of drying mango slices using a baffled-type hybrid solar dryer with exhaust hot air recirculation Debashree Debadatta BEHERA, Shiv Sankar DAS, Ramesh CHANDRA MOHANTY, Raj Kumar SATANKAR Solar Drying, Forced Convection, Development of Hybrid Solar Dryer, Experimental Investigation, Performance Analysis, Uncertainty Analysis. In this research, a hybrid solar dryer has been designed for day and night operation through forced convection for drying mango slices and preparation of bread toast. As studied from the literature, enough research is not done on the use of recirculation of exhaust hot air and baffle in a solar dryer. The thermal and economic performance of the dryer has been assessed by calculating collector efficiency, drying efficiency, drying rate, payback period and cost-benefit ratio. It is found that the maximum collector efficiency is 74.1% and 66.96% with and without the use of exhaust hot air recirculation. Performance parameters such as drying rate (0.95 kg/ hr), drying efficiency (32.89%), payback period (1.4394 years), and cost-benefit ratio (2.08) have been evaluated. An effective drying effect is produced by using an electric coil for night operation of dryer. An increase in the solar radiation increases the temperature of air inside the collector, thereby increasing the collector efficiency, drying efficiency and drying rate. The coefficient of determination for outlet collector temperature during consecutive three days is estimated above 95%, thus signifying a higher order of fit. Performing an uncertainty analysis of measurement, the uncertainty error is calculated below 10% exhibiting a reliable experimental result. Solar drying is considered as a sustainable food preservation method without negatively impacting the environment and finds wide applications in the fruit and food processing industries, domestic purposes etc. Journal of Thermal Engineering Journal of Thermal Engineering 2025-09-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7419 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7419 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7419

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7261 2025-03-23T21:00:00Z 1

Mitigating solar heat gain through windows of buildings by reflective films: A case study in Iraq Tawfeeq W. MOHAMMED, Dalmn Y. TAHA Cooling; Radiation; Retroreflective; Shading; Window. The current work evaluates thermally the role of shading films in mitigating the heat gain through regular glazing unit, as an energy saving application. The study used experimental data collected in an actual building, and theoretical models used to calculate the heat gain and cooling load. The study served several reflective films with different colors, manners and shading rates. The measurements included the values of temperature (indoor and surface), solar radiation and light intensity. The results manifested the potential of these sheets to eliminate the solar radiation by more than 70%, and decrease the heat gain via up to 50% in comparison with the conventional clear window. A film with medium shading rate (50%) reduces the heat gain through the window up to 40%, which reduces the corresponding energy consumption by 290, 400, 480 and 540 W, in cases of using gray, red, black and retro-reflective films, respectively. This will save the energy by 3.7, 5.1, 6.2 and 6.9%. Furthermore, the use of very dark films leads to undesired rise in the internal surface temperature, as well as weak light indoor. The use of retro-films elucidates suitable light indoor and doesn’t show that rise in the surface temperature owing to the ability in reflecting the rays right back without diffusion. The novelty is presenting findings of a realistic and actual investigation for the effect of shading films in the reduction of heat passed through the glass of a building in an extreme hot area. However, the study can be considered as an effective passive technique to withstand the overheating due to global warming and assigned within adaptation and mitigation policy. Journal of Thermal Engineering Journal of Thermal Engineering 2025-03-23T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7261 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7261 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7261

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7368 2025-07-30T21:00:00Z 1

Enhancement of thermal efficiency of a wet cooling tower using magnetite nanofluid with different stabilizers Berkman ISCI, Abdulgani ELMAKSUR, Kıymet YILDIRIM, Nurettin ELTUGRAL, Kamil ARSLAN Cooling Tower; Iron Oxide Nanoparticle; Nanofluids; Stabilizers; Thermal Efficiency. Nanofluids have gained increasing attention because of their superior thermophysical properties compared to the base fluid. However, the environmental impact of the nanofluids has raised concerns together with their potential use in practical applications. This study aims to explore the impact of using Fe3O4 nanofluids stabilized by synthetic and natural stabilizers (CTAB and gelatin) to enhance thermal efficiency while minimizing environmental impact. The Fe3O4 nanoparticles were synthesized by using a hydrothermal method with an average particle size of 200 nm. The nanofluids were prepared by dispersing the nanoparticles (0.1 wt% Fe3O4) in the presence of the stabilizers with concentrations between 0.2 and 1.0 wt% in deionized water. The impact of stabilizer type and concentration on the nanofluids’ stability was monitored through visual inspection. The thermal efficiency of the nanofluids was investigated experimentally on a laboratory-scale cooling tower at 45°C, with a 0.06 m3 /h volume flow rate, and between 0.02 and 0.07 kg/s air mass flow rates. The results show that nanofluid with 0.8 wt% gelatin achieves maximum stability for up to three weeks, significantly outperforming the nanofluid with the CTAB, which stabilized for only up to one week. The nanofluid with 0.8 wt% gelatin achieved a higher efficiency of 47 % at the air mass flow rate of 0.04 kg/s, consistently outperformed its CTAB counterpart. These results show that gelatin, a natural polypeptide, is more suitable than CTAB for nanofluid formulations, offering both thermal efficiency enhancement and environmental benefits due to its non-toxic and low-cost nature. Journal of Thermal Engineering Journal of Thermal Engineering 2025-07-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7368 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7368 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7368

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7360 2025-07-30T21:00:00Z 1

Computational investigation and exergy analysis of swirling flow in vortex tube Hitesh R. THAKARE CFD; Cold Mass Ratio; Exergy Analysis; Exergy Efficiency; Temperature Separation; VT. A vortex tube is very useful in several process industries to solve the spot cooling problem. Owing to its very small size and high pressure of working fluid, experimental analysis and determination of flow parameters of vortex tube becomes very difficult task. The present work attempts to explore and utilise the philosophy of computational fluid dynamics in an effort to overcome the limitations of experimental investigations. Simulation has been performed for turbulent, swirling, compressible flow of air at various inlet pressures using Standard k–ε turbulence model. The results of the computational model are validated against experimental results as well as computational results of previously published works through comparison of temperature separation magnitude on % basis as well as non-dimensional basis. The variation between experimental and computational results is about 8%. Thereafter, grid independence of solution is checked to circumvent the errors pertaining to grid’s coarseness. Previously, many of the research works on exergy analysis of vortex tube have been conducted for constant values of cold mass ratio, whilst in the present work, performance has been checked for different cold mass ratios as well as inlet pressure values. The inlet pressure values are selected pertaining to common scenario in process industries. It is inferred from the results that the computational model is able to replicate the exergetic behaviour of vortex tube with good agreement. As hypothesized at the beginning of this research, cold mass ratio is found to be indeed an important parameter from both energy as well as exergy analysis point of view. The amount of inlet total exergy is 559 W at 200 kPa, 966 W at 300 kPa, 1352.71 W at 400 kPa, 1538.86 W at 486 kPa, 1732.29 W at 500 kPa and 2174.54 W at 600 kPa inlet pressure. Maximum cold exergy efficiency of 27.77% and hot exergy efficiency of 39.39% is observed at inlet pressure of 600 kPa. Total exergy efficiency shows minimum value for cold mass ratios in the range of 0.4 to 0.6. Cold-end exergy efficiency is observed to be more affected due to inlet pressure than hot-end exergy efficiency Journal of Thermal Engineering Journal of Thermal Engineering 2025-07-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7360 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7360 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7360

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7373 2025-07-30T21:00:00Z 3

Advances in passive heat transfer enhancement for heat exchangers: a comprehensive review Muhammad Ali KHAN, Muhammad lLYAS, Khalid WAHEED, Inamul HAQ, Fatih AYDOGAN Air Bubble Injection; Extended Surfaces; Heat Transfer Enhancement; Micro-Surfaces; Nanofluids; Passive Methods; Phase Change Materials; Printed Circuit Heat Exchangers; Tape Inserts; Vortex Generators. This paper reviews the latest advances in passive heat transfer enhancement techniques, addressing the gap in the literature regarding recent developments. Heat exchangers are crucial in improving energy efficiency in various industrial applications, including power plants and nuclear reactors. Various heat enhancement techniques such as geometric modifications, air bubble injection, vortex generators, tape inserts, micro-surfaces, baffles, printed circuit heat exchangers, and phase change materials are studied. These techniques are evaluated based on heat transfer rate, pressure drop, and performance evaluation criteria. It is found from this review that the air bubble injection in shell and tube heat exchangers demonstrates the highest performance evaluation criteria of 4.5. However, its application is limited by process constraints. On the other hand, the Y-shaped tape inserts with a trapezoidal configuration though having a slightly lower performance evaluation criteria of 3.68 is easier to implement in existing and new designs. In printed circuit heat exchangers, zigzag channels exhibit a 50% improvement in thermal performance compared to straight channels. The study also highlights the potential of gyroid structures for application in high-pressure and high-temperature systems, such as advanced nuclear reactors. The comprehensive evaluation of heat enhancement techniques provides designers and engineers with a practical insight into designing heat exchanger for specific system requirements. Journal of Thermal Engineering Journal of Thermal Engineering 2025-07-30T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7373 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7373 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7373

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7406 2025-09-29T21:00:00Z 1

Enhancing VCRS performance: A study of R134a and refrigerant blends with spiral condensers and series evaporators Saurabh KULKARNI, Shriramshastri CHAVALI, Shruti VEDPATHAK R134a; Refrigerant Blends; Series Evaporator Arrangement; Spiral Condenser; Vapor Compression Refrigeration System (VCRS). The purpose of this work will be the improve the vapour compression refrigeration system, taking into account the usage of environmentally friendly refrigerants. This is important because the alternative solution for achieving a minimal invasion into the environment with maximum energy efficiency is urgently needed. The method used here, namely, system redesigns with spiral condensers and series evaporators, was validated using CoolPack software. Major outcomes are that the coefficient of performance is increased by 77% and power consumption is reduced by 19% when a spiral condenser is used instead of the conventional systems. The hydrocarbon blends of propane and isobutane were found to be possible substitutes for R134a, and using nanofluids of Al2O3 or ZnO was shown to increase the coefficient of performance up to 137%. The research does not only add a source of enhancing literature but also provides a practical framework for developing more sustainable and ef ficient refrigeration technologies. Journal of Thermal Engineering Journal of Thermal Engineering 2025-09-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7406 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7406 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7406

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7362 2025-07-30T21:00:00Z 1

An in-depth numerical investigation of a solar latent heat storage unit incorporating phase change materials Kenza OUDAOUI, Mustapha FARAJI Heat Discharge; Heat Exchangers; Heat Transfer; Latent Heat Storage; Phase Change Materials; Solidification Process; Solar Energy; Water Heating. The energy storage method is very important for many engineering domains, providing multiple benefits for a variety of fields. The requirement for an effective way to store heat generated during times of high solar radiation and, recover it later when there is no sun is one of the most frequent issues that solar power systems encounter. Therefore, storing energy using phase change materials (PCM) is an important solution for overcoming the mismatch between the energy supply and demand in solar thermal systems. We study a new heat storage system based on 3 different phase change materials and not on a single one. Most of the previous studies focus on charging or storing heat in a PCM. But crucial problems arise during discharge. Given the low thermal conductivity of the phase change materials, are we able to recover all the energy we have stored and how? This is the major objective of this study. The novel heat storage unit uses three different phase change materials instead of one. These phase change materials are located at variable positions to optimize the performance of the latent heat storage unit. The main purpose of the present paper is to numerically study the discharge process of multiple phase change materials in a coaxial solar water/PCM heat exchanger. Different configurations, including the phase change material position and PCM thickness are analyzed. These materials were selected according to their thermophysical properties (melting temperature, thermal conductivity and latent heat of fusion). For this purpose, a cylindrical two-dimensional mathematical model based on energy conservation equations was developed. The governing equations were discretized over finite volume controls using the enthalpy method and several numerical simulations were conducted to study multiple PCM/water heat exchangers behaviour. The impacts of the phase change material position and radius are experienced to evaluate the thermal performance of the heat exchanger. The optimal configuration for solidification is determined. It was found that, the heating time can be extended by properly moving the various phase change materials within the tube. Numerous cases are examined. The two cases that offer both advantageous heating choices have a heat delivery time to water that exceeds 138 minutes. When the impact of tube radius is examined, it is discovered that, in the case of a very thin PCM layer, the water records a high temperature of 60°C for 40 minutes before declining somewhat but staying above 42°C until t=56 minutes. For about 53 minutes, the water outlet temperature stays above 40°C when the phase change materials cylinder thickness reaches 17 mm. During the heat discharge, a comparatively improved heat evacuation capability is noted. Nevertheless, 28 kJ of heat are not utilized in total. The heat exchanger is unable to release the remaining energy. Journal of Thermal Engineering Journal of Thermal Engineering 2025-07-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7362 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7362 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7362

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7424 2025-09-29T21:00:00Z 3

Factors affecting and methods of reducing thermal stratification in cryogenic storage tanks of launch vehicles: review article Krish V. RAIBOLE, Puskaraj D. SONAWWANAY Cryogenic Propellants; Launch Vehicles; Liquid Rocket Engines; Thermal Insulation; Thermal Stratification Contemporary launch vehicles of the past few decades primarily implement liquid rocket engines, which in turn employ cryogenic propellants stored in sub-zero conditions in highly sophisticated cryogenic storage tanks. These tanks are usually deprived of any thermal insulation in order to prioritize the payload capacity, and thus they are prone to a substantial amount of heat in-flux that leads to a rise in the temperature of the cryogenic liquid, leading to thermal stratification. This paper presents a comprehensive review of the various factors affecting the rate of thermal stratification in cryogenic propellant storage tanks, along with numerous experimental and numerical techniques developed for controlling or mitigating this stratification through geometrical modifications, varying surface properties, and bubbling of gases through the bulk liquid. Out of the techniques reviewed, simple geometrical modifications showed substantial results, with ribs reducing stratification by up to 30%. On the other hand, complex techniques like bubbling of gases destratified the bulk liquid within 25 to 35 s. A special focus has also been placed on reviewing the numerical modelling and simulations of this phenomenon, particularly those developed in recent years. Journal of Thermal Engineering Journal of Thermal Engineering 2025-09-29T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7424 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7424 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7424

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7365 2025-07-30T21:00:00Z 1

Performance and emissions assessment of a spark-ignition engine fueled with ethanol-, methanol- and acetone-gasoline blends Mehrez GASSOUMI, Fakher HAMDI, Zouhair BOUTAR, Mahdi DHAWI, Zouhaier KHALFET, Aliya FAZAL, Raja Mazuir Raja Ahsan SHAH, Ridha ENNETTA, Hakan Serhad SOYHAN Acetone; Blend; Engine; Ethanol; Experimental Study; Gasoline; Methanol Alternative fuels have the potential to reduce exhaust emissions in the transportation sector. This research investigates the use of oxygen-enriched fuel mixtures as practical alternatives to pure gasoline in spark-ignition engines. Unlike previous studies that only focused on individual or paired oxygenated fuel comparisons, this study analyzes simultaneously three oxygenated fuels (ethanol, methanol, and acetone) at identical blending ratios. Experiments were performed with an engine testing rig under full load conditions at varying engine speeds. The tested fuel blends included pure gasoline and blends, with 10% ethanol, acetone, and methanol by volume. The results indicated that all the tested fuel blends led to slight improvements in engine performance. The methanol blend provided the highest increases in brake torque, power, and mean effective pressure, with enhancements of up to 19%. Meanwhile, the ethanol blend notably enhanced fuel consumption and thermal efficiency by 25% and 40%, respectively. Regarding the exhaust emissions, it was observed that all the oxygenated fuel blends reduced the carbon monoxide and carbon dioxide emissions. The best achievement was obtained with the ethanol blend, which reduced carbon monoxide and carbon dioxide emissions by 35% and 15%, respectively. However, nitrogen oxide emissions increased with both alcohol blends. On the other hand, it decreases with the acetone blend across all engine speeds. Thus, this work proposes innovative pure gasoline alternatives that can reduce hazardous emissions without requiring technical interventions or loss in engine power. Journal of Thermal Engineering Journal of Thermal Engineering 2025-07-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7365 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7365 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7365

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7408 2025-08-31T21:00:00Z 1

On the role of biomimetics shark skin flow control in the aerodynamic characteristics of leading-edge protuberanced wing section S. SMRITHIKA, S. ARUNVINTHAN Aerodynamic Force Coefficients; Biomimetics; Flow Control; Leading-Edge Protuberances; Surface Pressure Distribution; Time-Series Data; Wind Tunnel Testing An experimental investigation of the effect of shark skin flow control structures on the aerodynamic characteristics of novel bio-inspired Leading-Edge Protuberanced wing section is presented in this paper. NACA 63(4)-021 airfoil based leading-edge protuberanced wing featuring an Amplitude of 0.12c and wavelength 0.5c is utilized in this study. Short-fin Mako’s scale structure as outlined in the previous literature were 3D Printed and they act as the base geometry of the shark scale structure. Two different sets of shark scale geometries, varying in chord length, span, amplitude, and wavelength were chosen based on the literature. Additionally, to assess the significance of the alignment of these 3D Printed shark scale structures on the aerodynamic characteristics, different patterns like Staggered non-overlapped, linear non-overlapped, linear overlapped were considered. This study merges two biomimetic ideas such as leading-edge protuberances and shark scales which renders aerodynamic benefits. The focus of this study is to assess the influence of the shark scale structures as an effective flow control means for biomimetic Leading-Edge Protuberanced Wing section. Further, all the works related to shark scale were only carried out over conventional straight wing airfoil sections. The present study is the first of its kind to investigate the influence of shark scale structures on the aerodynamic characteristics of Leading-Edge Protuberanced wings. All the series of experiments were conducted at wide range of angles of attack ranging from 0°≤α≤70° in an increment of 5° at two different Reynolds number 32066 and 69488. Surface pressure measurements were obtained over the test models with the help of Miniature Pressure Scanner 4264 Scanivalve pressure scanner pneumatically connected to the 50 pressure taps equi-distributed over the upper and the lower surface of the test model. Results reveal that the use of shark scale structures as a means of flow control renders aerodynamic benefit in terms of lift increment, drag reduction and stall delay. The modified LEP model with Shark scale structures exhibit 34.6% increment in lift coefficient, 29% decrement in drag coefficient and 42.8% stall delay. The modified shark scale model fitted Leading-Edge Protuberanced wing is effective and outperforms conventional Leading-Edge Protuberanced wing especially at low Reynolds number and hence could be used as a viable solution for Micro-Aerial Vehicles and Nano-Aerial Vehicles operating in this regime. Journal of Thermal Engineering Journal of Thermal Engineering 2025-08-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7408 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7408 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7408

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7528 2026-01-30T21:00:00Z 3

Phase change materials (PCMs) used in buildings: A critical review Soukaina TOUMZINE, Hanane MOULAY ABDELALI Building Envelope; Thermal Energy Storage;Thermal Comfort; Latent Heat; PCM The construction sector deserves special attention due to its energy efficiency potential, high energy consumption, and environmental impact. Indeed, reducing energy consumption in buildings means reducing the carbon footprint and mitigating climate change. Phase change materials (PCMs) have garnered significant attention in recent years because to their potential to enhance comfort and mitigate environmental impact by reducing greenhouse gas emissions. Between 2013 and 2023, research in this area experienced a substantial increase of 231.45%. This considerable rise reflects the technology›s notable advancements and growing interest among researchers. This article provides a comprehensive assessment of recent scientific studies investigating the effects of PCMs integrated into building envelopes to reduce heating and cooling energy consumption. The main characteristics and properties of PCMs, selection criteria, and integration methods are reviewed and discussed, then the main numerical tools as well as a method for determining the main thermo-physical properties of PCMs based on the results of previous studies are presented. Thus, all the recent research carried out locally (Morocco) was described, and finally, a thorough assessment was conducted to identify deficiencies and offer suggestions for future research. Journal of Thermal Engineering Journal of Thermal Engineering 2026-01-30T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7528 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7528 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7528

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7357 2025-07-30T21:00:00Z 1

Integrated absorption refrigeration and gas turbine power plant system: Performance enhancement through intake air cooling Layth Abed Hasnawi AL-RUBAYE, Loay M. MUBARAK, Ahmed AL-SAMARI Absorption Refrigeration; Gas Turbine Power Plant; Intake Air Cooling. Meeting the world’s electricity demands relies significantly on gas turbine power plants; however, extremely hot ambient temperatures can seriously affect these plants. In this study, a gas turbine power plant and an absorption refrigeration cycle for intake air cooling are proposed as a new integrated system. The unique aspect of this setup is that the gas turbine’s exhaust gases power the absorption chiller’s generator. The chiller’s evaporator cools the atmospheric air before entering the compressor. This leads to a reduction in the compressor’s work and an enhancement in the power plant’s thermal efficiency. The study investigates the impact of inlet air temperature variations on the power generated, energy efficiency, and exergy efficiency of a power plant to reduce greenhouse gas emissions. Also, mathematical modeling and analysis of both Brayton and absorption cycles are reported utilizing EES software. The findings assess that the power generated, energy efficiency, and exergy efficiency enhance considerably as the compressor inlet air temperature drops. The highest net generated power reaches about 61.91 MW at an inlet air temperature of 15°C, while the lowest value of about 57.22 MW is recorded at 50°C. In addition, at 15°C inlet air temperature, the cycle energy efficiency and exergy efficiency are increased by about 8.2% and 50.5%, respectively, compared to 50°C inlet temperature. Therefore, the novelty of the current work is enhancing system efficiency without more fuel consumption. Journal of Thermal Engineering Journal of Thermal Engineering 2025-07-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7357 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7357 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7357

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7409 2025-09-29T21:00:00Z 1

Highly viable nanoparticle based Thermal Interface Materials (TIM) for electronics device cooling applications S. Uma MAHESHWARI, A. Brusly SOLOMON, G. THILAGAVATHI, Madhukar HEMAMALINI, D. ILLAKKIAM Bond Line Thickness; Effective Thermal Contact Resistance; Heat Transfer Applications; Nanoparticles; Thermal Interface Material. High performance interface materials (TIMs) were developed using various nanoparticles and paraffin wax. An indigenous test set up was fabricated using aluminium heat sink and copper plates as heating plate for measuring effective thermal contact resistance (Rth, eff) of prepared TIMs to evaluate their thermal performance. Chrome-Alumel thermocouples were used for measuring the temperature. Furthermore a relative study of effective thermal contact resistance of prepared (TIMs) was carried out to evaluate their performance. The nanoparticle chosen for present distinctive study were SiO2, Al2O3, CuO, GO, rGO. The TIM samples were synthesized by blending 6 wt% of assorted nanoparticles in 5 ml base fluid of paraffin wax. They were uniformly mixed using ultra sonicator to create a smooth and fine paste based TIM. The resulting paste (TIMs) was applied as an ultra-thin layer between the copper heater and aluminium sink of the indigenously designed and fabricated test rig. Power inputs for experiments were 25, 50 and 75W. Experimental studies were done at reduced pressure (RP) and full pressure (FP) applied by completely loosening and tightening the screws of the aluminium heat sink. . Addition of (SiO2, Al2O3, CuO, GO and rGO) nanoparticles to the base fluid paraffin wax significantly decreases the effctive thermal resistance to a large extent as the added nano parcticles helps in better heat conduction due to their enhanced total surface area leading to more effcetive heat evacuation. Enhanced results are observed at full pressure, at reduced pressure drastic increment in (Rth, eff) occurs due to improper gap filling. These results significantly depicts the importance of bondline thickness in performance of TIM. Interestingly siliica based TIM gives the best performance of heat transference to ambience at 50 W power input (Rth, eff = 0.460 C/W) and slightly becomes inferior to GO at higher power input. GO based TIM shows the best results at higher power of 75 W, its Rth, eff being 0.510 C/W. Journal of Thermal Engineering Journal of Thermal Engineering 2025-09-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7409 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7409 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7409

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7410 2025-09-29T21:00:00Z 1

Performance of Mylar and Teflon as compound parabolic concentrators in solar desalination system Shridhar KEDAR, Deepak WATVISAVE, Prerna MISHRA, Ganesh Vijay MORE, Adarsh Abi MATHEW, Neeta MANDHARE, Sumedh INGLE Compound Parabolic Concentrator; Evacuated Tube Collector; Reflectivity; Solar Energy. The water-energy nexus is an important and difficult issue and must be resolved for present and also for the future. The process of producing freshwater requires a lot of energy, therefore a workable solution to this issue is crucial. In the current situation, solar energy is one of the best options for desalination as it is inexpensive, environment friendly, and widely accessible. In general, flat plate collectors and evacuated tube collectors have been used as solar collector for desalination. In this study, a single-stage hybrid groundwater solar desalination system has been used for experimental investigation. Compound parabolic concentrator is positioned to gather solar radiations and transfer heat to evacuated tubes, for improving the performance under various weather conditions in Pune, India. The ideal distance between evacuated tube collector and compound parabolic concentrator was 20 mm. The current study primarily focuses on the performance of two polymeric materials, Teflon and Mylar, as reflector, on the rate of soft water production. It was observed that when mylar was used reflecting material the rate of soft water production amounts to be 3.5 litres per day whereas teflon was used as reflecting material the rate of soft water prodcution amounts to be 3.0 litres respectively. As per the validation of results for hybrid solar desalination system gives better results than solar-wind hybrid energy system. Thus Mylar shows more promising result than Teflon for production of soft water. It shows 20 % increase soft water production using mylar material on compound parabolic concentrator as comparied to the teflon. Journal of Thermal Engineering Journal of Thermal Engineering 2025-09-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7410 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7410 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7410

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7262 2025-03-23T21:00:00Z 1

Numerical analysis of spiral tube heat exchanger circulated with zinc oxide nanofluids K. P. V. Krishna VARMA, Kavati VENKATESWARLU, Teku KALYANI, S. HEMALATHA, P. Vijaya KUMAR CFD; Heat Transfer Coefficient; Helical Coil Heat Exchanger; Reynolds Number; ZnO Nanofluids. Helical tube heat exchangers differ from ordinary heat exchangers in that they have special qualities that enhance heat transmission since the fluid flows from straight to coiled channels as curved streams instead of linear ones, leading to the increased momentum and heat transmission rates. However, there is still scope for research on improving heat transfer characteristics for a helical coil heat exchanger with conjugate heat transfer employing various configurations of internal longitudinal fins. Thus, in this work, numerical study was conducted to explore the flow behaviour and thermal performance of water-ZnO nanofluids (nanofluid) in a spiral tube heat exchanger. The mass flow rate (ṁ) of the water-ZnO nanofluids was varied from 0.025 kg/s to 0.125 kg/s, while the mass flow rate of the hot fluid (water) was maintained constant at 0.0091 kg/s. The concentrations of the nanofluid in water used were 1%, 2%, and 3%. Simulations in three dimensions were analysed for the turbulent stream regime, and governing equations for the turbulent stream were solved using the k-epsilon (k-ε) for Reynolds numbers ranging from 4000 to 12000. The temperature, velocity and pressure contours were analysed with respect to the variation in the concentration and flow rate of the ZnO nanofluids. Finally, the results confirmed that by applying ZnO nanofluids, the heat transfer coefficient as well as the friction factor increased by 43% and 1.12 times respectively when compared with the plain tube. Journal of Thermal Engineering Journal of Thermal Engineering 2025-03-23T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7262 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7262 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7262

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7258 2025-03-23T21:00:00Z 1

Effect of the design variables on the vortex water turbine performance Hussein M. ZINAL, Omer K. AHMED Experimental; Performance; Water Vortex; Water Vortex Power Plant. The water vortex power plant has become of more interest to researchers due to its important role in renewable energy technologies, allowing it to operate with low heads and flow rates. The novelty of the work compared to previous efforts is that a group of variables studied together that have an important role in increasing the efficiency of the system, such as the increase and decrease in the number of blades, the effect of weight through changing the type of metal, and the height of the turbine from the bottom of the basin. Therefore, this article evaluated the performance of the water vortex plant, in which several variables were studied: the number of turbine blades, turbine weight, and turbine height from the basin floor where the water vortex system was designed and tested by using four turbines: one of them had six blades and another four blade are made from carbon steel alloy and two other turbines, which one of them six blades the other four blades are made of galvanized alloy. Practical tests also concluded that the four-blade turbine, made of carbon steel alloy, achieved an efficiency of up to 69%. The weight of the turbine plays a vital role in determining the system efficiency when a six-blade turbine made of carbon alloy with a higher weight and a height of 3 cm reaches 64% as the maximum efficiency. Also, the experiments found that the highest efficiency reaches the turbine at a height of 3 cm from the bottom of the basin after different heights were chosen for the turbines used from the bottom, which included (1.5 cm, 3 cm, 5 cm, 8 cm). Journal of Thermal Engineering Journal of Thermal Engineering 2025-03-23T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7258 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7258 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7258

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7269 2025-03-23T21:00:00Z 1

Techno-economic analysis of solar still with nano-phase change material and heating coil: A novel approach for sustainable development Anand KUSHWAH, Abdhesh KUMAR, M. K. GAUR Economic; Heating Coil; Nanoparticles; PCM; Solar Still. A worldwide shortage of drinkable water has resulted from the rapid rise of industrialization and population, prompting researchers to find an alternative method to fulfil this requirement. Solar still systems are powered by solar energy that can provide drinkable water. However, it has a low production issue. This study investigates the performance of two types of solar stills: a conventional solar still and an advanced solar still. Modifications such as an external condenser, a water heating coil, and nano-phase change material (ZnO-PCM) were employed to enhance the productivity of the advanced solar stills. The results demonstrated that the advanced solar still with a heating coil achieved a thermal efficiency of 46% and a yield improvement of 77%, the advanced solar still with an EC achieved a thermal efficiency of 53% and a yield improvement of 119%, and the advanced solar still with ZnO-PCM achieved a thermal efficiency of 51% and a yield improvement of 113%. The productivity of the advanced solar still was enhanced by approximately 36% with ZnO-PCM and by 42% with an external condenser. Economic analysis revealed the cost of desalinated freshwater to be $0.030 per litre for the conventional solar still, $0.023 per litre for the advanced solar still with ZnO-PCM, and $0.021 per litre for the advanced solar still with an external condenser. Journal of Thermal Engineering Journal of Thermal Engineering 2025-03-23T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7269 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7269 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7269

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7411 2025-09-29T21:00:00Z 1

Thermal design and CFD simulation of an internal heat exchanger with R1234yf as an alternate refrigerant to R134a B. K. PATEL, A. D. PAREKH Automobile Air Conditioning; COP; CFD; R1234yf; R134a; Internal Heat Exchanger. The most widely utilized refrigerant in car air conditioners today is still R134a, particularly in developing nations, but its global warming potential is very high (1430). The use of high global warming potential working substances is progressively prohibited and restricted by the F-gas act and the Kigali Amendment in developing and developed nations. R1234yf has been the subject of thermodynamic research as a potential replacement for R134a in vehicle air conditioning systems. Compared to R134a, R1234yf performs somewhat inferior, that can be improved by incorporating an internal heat exchanger into the existing system. Refereeing to the literature available, computational fluid dynamics analysis of the internal heat exchanger for an automobile air conditioning system with refrigerant R1234yf is rarely observed. Hence the novel concept of computational fluid dynamics analysis of thermally designed internal heat exchanger is focused here. This study analyzes the thermal design of an internal heat exchanger and its impact on the coefficient of performance for R1234yf and R134a. And computational fluid dynamics analysis of the thermal designed internal heat exchanger is performed to finalize the dimension of the internal heat exchanger. For similar cooling capacity, the system with refrigerant R134a performance is not much affected by the application of an internal heat exchanger. Its COP increases from 3.636 to 3.676, i.e., only 1.09%. While the performance gap of the system with refrigerant R1234yf as compared to the system with R134a without an internal heat exchanger is 5.17%, while the gap is decreased up to 3.16% with an internal heat exchanger. Identical results are obtained in computational fluid dynamics analysis, with an increment in the internal heat exchanger length, heat transfer increases as well, and the outlet temperature meets the necessary level within a tolerable pressure drop Journal of Thermal Engineering Journal of Thermal Engineering 2025-09-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7411 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7411 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7411

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7265 2025-03-23T21:00:00Z 1

Enhancing aerodynamic efficiency with a moving surface panel on a NACA 2412 airfoil Ravichandrakumar Kumar BHASKAR, Ganapathy Subramanian L. R. Airfoil; Flow Control Techniques; Flow Separation & Aerodynamic Performance; Fluid Flow; Moving Surface Boundary. This study investigates the application of a moving surface boundary on a NACA 2412 airfoil using a belt mechanism with two pulleys to enhance aerodynamic efficiency. By accelerating the airflow, the moving surface helps delay flow separation, which typically limits aerodynamic performance. Previous computational works simplified the moving surface as a flat panel, often neglecting the gap between the panel and airfoil, as well as the complexities introduced by the belt-pulley mechanism. Building on earlier research, this study models a belt mechanism that spans 20% of the airfoil’s chord length, evaluating its aerodynamic impact at different chord-wise locations. Numerical analysis was conducted at varying belt speeds and panel positions. Results showed that placing the panel at 20% and 40% of the chord, as well as near the leading edge, yielded the best performance, increasing aerodynamic efficiency by 153%, 159%, and 166%, respectively. These enhancements were particularly evident at lower angles of attack, especially around 4 degrees. The novelty of this work lies in its realistic representation of the belt mechanism, accounting for gaps and flow disturbances caused by the pulleys. This approach provides a more accurate simulation of real-world applications, with findings suggesting that placing the moving surface at 20% chord length offers optimal aerodynamic gains, offering valuable insights for future flow control applications. Journal of Thermal Engineering Journal of Thermal Engineering 2025-03-23T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7265 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7265 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7265

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7517 2026-01-30T21:00:00Z 1

Exergy, energy, exergoenvironmental assessment of a novel combined helium Brayton cycle and transcritical CO2 cycle for solar power tower applications Yunis KHAN, Deepak SINGH, Shailendra SINHA, K.S. BHOLE, D. APPARAO Energy Analysis; Exergy Analysis; Exergoenvironmental Analysis; Helium Brayton Cycle; Parametric Analysis; Performance Comparison; Solar Power Tower; TCO₂ Cycle This study introduces a combined cycle that captures solar energy from a solar power tower for power generation. The system couples a helium-based Brayton cycle (topping cycle) with a transcritical carbon dioxide cycle (bottoming cycle), where the latter recovers and uses the waste heat released from the Brayton process. A detailed investigation was carried out, incorporating energy, exergy, and exergoenvironmental evaluations, to assess the overall performance of the combined power plant. The findings demonstrated a significant improvement of 12.05% in the energy efficiency of the helium-based Brayton cycle when the transcritical carbon dioxide cycle was incorporated as a bottoming configuration. The plant’s optimal operating parameters were identified, giving peak values of 23.2% for energy efficiency, 24.83% for exergy efficiency, and 14,930 kW for power output. A detailed examination of the solar subsystem components (receiver and heliostats) revealed the maximum exergy destruction occurs in these parts of the solar plant, totalling around 37,578 kW. The total exergy destruction across the plant was calculated to be 45,164 kW. The exergoenvironmental impact coefficient exhibited a substantial value of 4.028, primarily attributed to the lower exergy efficiency of the plant. Additionally, the energetic stability factor was found to be 0.2483. This research contributes to solar power tower integration, enhancing efficiency, and achieving a simplified system with fewer components compared to previous studies. Journal of Thermal Engineering Journal of Thermal Engineering 2026-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7517 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7517 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7517

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7412 2025-09-29T21:00:00Z 1

A novel approach to augment stepped solar still productivity using the heat storage characteristics of water J. S. D’COTHA, P. R. SURESH, P. SAJEESH Feed Water; Heat Storage; Nocturnal Yield; Stepped Still. Improvement in freshwater productivity by minimizing the carbon footprint is the main goal paving way to the development and modification of solar stills. The primary objective of this study is to enhance the productivity of the solar still while optimizing construction and maintenance costs. In contrast to other phase change materials and heat storage materials, this study utilizes water as the sensible heat storage medium. This investigation deviates from established protocols by implementing a feed water addition strategy that exceeds evaporated water quantities. The still’s performance was enhanced by using a dynamic water depth strategy, where lower depths during morning hours boosted daytime yield, and higher depths later in the day improved night-time output. This process optimizes the use of incident energy, converting it into specific heat energy while minimizing the impact on temperature increase. Experiments in Kochi, India, revealed that the solar still’s overall yield, without feed water addition, decreased with increasing initial water depth, yielding 5290 ml/m², 5140 ml/m², and 4800 ml/m² at depths of 0.5 cm, 1.0 cm, and 1.5 cm, respectively. Adding 100 ml of feed water to each tray at the three initial water depths resulted in productivity increases of 2.3%, 2.5%, and 2.9%, respectively, compared to no feed water additions. Furthermore, adding 200 ml of feed water led to more significant improvements in productivity, with increases of 5.9%, 8.2%, and 7.5%, respectively. A solar still with an initial water depth of 0.5 cm and a feed water inlet of 400 ml per tray achieved the highest distillate output of 6330 ml/m²/day, corresponding to a maximum daily efficiency of 66.45%. Experimental values were validated against theoretical energy balance equations, with a deviation of less than 6%. The cost of distillate produced was $0.03, which is approximately one-tenth the price of water available in the regional market. Solar stills offer a viable solution for producing potable water, addressing the drinking water needs of communities and urban areas facing water scarcity. The low cost, simplicity, and eco-friendliness of this desalination process make it ideal for household use. Future research should focus on developing intelligent feed water systems that adapt to solar radiation and ambient temperature fluctuations, optimizing feed water quantity and maximizing daily still output. Journal of Thermal Engineering Journal of Thermal Engineering 2025-09-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7412 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7412 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7412

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7473 2025-11-25T21:00:00Z 1

Investigation on performance and emission studies of variable compression ratio engine using neem oil biodiesel Hardik A. PATEL, Bhavesh P. PATEL Biodiesel; Diesel Engine; Emissions; Neem Oil; VCR Engine. Biodiesel, particularly Neem oil-based biodiesel, has emerged as a promising eco-friendly alternative, offering reduced greenhouse gas emissions, lower sulphur content, cleaner combustion, and biodegradability. Variable Compression Ratio (VCR) engines further enhance performance, fuel efficiency, and emissions reduction across various fuels. This study focuses on experimenting with Neem-based biodiesel in VCR engines and conducting a parametric study to address the challenges of fossil fuel use. The experimental study revealed several key findings. CO emissions decreased with higher biodiesel blending and compression ratios, achieving a 28% reduction with NB50 at 6 N-m load and CR 22. CO2 emissions are reduced by 20% using B40 at CR 22 under full load (12 N-m). A 27% reduction in HC emissions is noted with B30 at CR 20 under full load. NOx emissions increased by 20% at full load and CR 22:1 with pure diesel. Brake Thermal Efficiency increased by 16% with NB30 at 6 N-m load and CR 22. SFC significantly decreased under no-load conditions with NB50.Optimal results from AI-TLBO with NB40 fuel and a compression ratio of 22 at no-load showed reductions of 20.20% in CO, 23.84% in CO2, 24.5% in HC, and a 23.1% NOx increase. Journal of Thermal Engineering Journal of Thermal Engineering 2025-11-25T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7473 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7473 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7473

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7519 2026-01-30T21:00:00Z 1

Residential building thermal transmittance simulation-based analysis in Tehran city with an approach to assess wall insulation Ashkan HASSANI, Shooka Khoshbakht BAHRAMANI Building Energy Efficiency; Simulation-Based Analysis; Tehran Urban Buildings; Thermal Insulation; Wall Insulation Materials The article deals with the study related to thermal insulation of building walls in Tehran through energy consumption reduction, aiming to contribute to sustainability of the urban environment. In Iran, more than 40% of total energy consumption is related to the construction and housing sector, so optimization of the building thermal performance has a high relevance. Insulation materials are increasingly being used in Tehran; however, there is still a lack of a comprehensive quantitative framework embracing local materials and building typology. In this regard, the equivalent of ten different insulation configurations has been simulated for thermal performance using Design Builder software in order to study their respective effects on energy efficiency. Each configuration includes variations in insulation types and thicknesses. The results highlight that insulation materials, including polyurethane, fiberglass board, and mineral wool, are excellent thermal performance enhancers, while the high level is normally achieved by growing the heat balance. Besides, finding the optimal range of insulation thickness- 2-6 cm-provides practically the maximum energy economy. This quantitative framework will help architects and designers make informed choices about appropriate wall insulation materials in Tehran’s buildings. The novelty of the present research is that, for the first time, such a study will focus on the specific climatic condition of Tehran and its local construction practice. These findings have broader implications for further research and urban planning, since this laid framework may be applied to the multiple Iranian cities with diverse climate zones, hence guiding sustainable building designs throughout the nation. Journal of Thermal Engineering Journal of Thermal Engineering 2026-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7519 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7519 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7519

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7466 2025-11-25T21:00:00Z 1

Comparative performance of different solar still configurations P. VELMURUGAN, K. KUMARARAJA, R. S. HARISIVASANKARAN, S. SARAVANAN Black Cloth; Configuration; DNN; Performance; Solar Still; Water Collected. This study evaluates the performance of three solar still configurations: the conventional solar still, the pyramid solar still with fins, and the pyramid solar still with fins covered in black cotton cloth. The variation in absorber plate, glass plate, water temperature, and the quantum of water collected in the attempted configurations was determined at identical conditions. Of the three solar still configurations, the pyramid shaped solar still having fins covered with a black cloth exhibited better efficiency and produced 3.7 liters of potable water. The pyramid shaped solar still having fins closely follows with a water production of three liters. The superior performance is due to the better heat absorption and heat transfer following the enhanced area and the capillary effect of the black cloth. In addition, a deep neural network model with better accuracy, having an R² value of 0.96, was created in the Python environment to predict the glass, absorber, and water temperatures along with the water collected. The novel integration of experimental and artificial intelligence in the optimization of solar still provides room for potential seawater-to-potable-water conversion and is suitable for remote or hilly areas. Journal of Thermal Engineering Journal of Thermal Engineering 2025-11-25T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7466 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7466 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7466

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7522 2026-01-30T21:00:00Z 1

Experimental study of parabolic dish collector based solar cooker with different thermal energy storage system M.K. GAUR, Amit SHRIVASTAVA, Pawan AGRAWAL, R. K. PANDIT, Parul SAXENA Solar Concentrator; Phase Change Material; Solar Energy; Parabolic Disk The study focuses on the performance of a parabolic dish collector-based solar cooker integrated with different phase change materials (PCMs) to address the challenge of improving solar cooking efficiency. Conducted under the climatic conditions of Gwalior (M.P.), India, the experimental setup featured a parabolic concentrator with an area of 5.908 m². Erythritol and Paraffin Wax were tested as PCMs for solar-assisted rice cooking with water under varying solar radiation levels. Results show that Erythritol outperformed Paraffin Wax in terms of heat retention and cooking efficiency. With Erythritol, the maximum PCM temperature reached 107°C under solar radiation of 649 W/m², achieving a cooking time of 45 minutes and a peak food temperature of 96°C. In comparison, Paraffin Wax exhibited limitations, providing insufficient heat for proper cooking under similar conditions. The average exergy efficiency was 2.6% for Erythritol and 1.1% for Paraffin Wax. This study demonstrates the superior thermal performance of Erythritol as a PCM, highlighting its potential to enhance solar cooking technologies. The novelty of this work lies in its comparative evaluation of PCMs under real-world conditions, providing practical insights for optimizing solar thermal systems. Journal of Thermal Engineering Journal of Thermal Engineering 2026-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7522 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7522 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7522

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7413 2025-09-29T21:00:00Z 1

Experimental adsorption studies of atmospheric water vapor by clay based composite sorbents in vertical fluidized bed C. R. HIREMATH, Ravikiran KADOLI, R. J. TALAPATI Adsorption; Clay; Calcium chloride; Fluidization; Horse dung; Humidity ratio; Sawdust. Transient adsorption characteristics of atmospheric water vapor with clay and clay-additives-based calcium chloride composite desiccants in vertical fluidized beds are studied experimentally. The different clay-based composite sorbents considered in the study are clay-calcium chloride, clay-horse dung-calcium chloride and clay-sawdust-calcium chloride adsorbents. The influence of bed mass and air superficial velocity on transient change in bed inlet air humidity ratio and air temperature for different desiccant clay-based composite sorbents is experimentally studied. It was noted that the thermo-physical properties of different adsorbents, bed mass and air inlet velocity significantly influence the fluidized bed performance in the adsorption system. The linear porosity distribution in fluidization shows the availability of increased adsorption capacity for clay-based desiccants in comparison to clay-additive desiccants, as indicated by higher total adsorption capacity. For the similar conditions of bed weight (300 g) and inlet air velocity (2 m/s), the total quantity of water adsorbed is 30.09 g, 21.84 g and 27.02 g for clay-calcium chloride, clay-horse dung-calcium chloride and clay-sawdust- calcium chloride fluidized adsorbent beds. The results reveal heat load reduction of clay-calcium chloride vertical fluidized bed dehumidification system is 62% and 52% higher compared to clay-horse dung-calcium chloride and clay-sawdust-calcium chloride desiccant dehumidification systems. For all the dehumidification systems, the reduction in latent load is higher than the increase in sensible heat load, which will reduce the overall heat load of the cooling system. Journal of Thermal Engineering Journal of Thermal Engineering 2025-09-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7413 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7413 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7413

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7414 2025-09-29T21:00:00Z 1

Performance optimization of low-head vertical axis impulse turbine runners for nozzle angle, nozzle diameter, and nozzle standoff distance using response surface methodology H. N. LAKDAWALA, V. K. PATEL, G. P. BAKHRU, D. N. MODI 3D Printed Buckets; Hydraulic Nozzles; Pico Hydro; Response Surface Methodology; Turgo Turbine. Pico-scale turbines, such as Turgo and Pelton, are site-specific and show variable performance under various operating and design parameters. Experimental investigation and response surface methodology were combined to optimize the geometrical parameters of Pelton and Turgo turbine runners in the present study. Low-cost, lightweight hybrid runners with 3D-printed buckets and aluminum runner discs with a vertical turbine axis were designed for low-head applications. Multivariate statistical evaluation and response surface methodology were conducted using Design Expert 13.0 software, with a central composite design applied to analyze results and optimize parameters through 80 test runs. Quadratic models describing the hydraulic efficiency characteristics of impulse turbine runners were developed via ANOVA. The study examined nozzle diameters (10-14 mm), angles (90°-95°), numbers (1 or 2), and standoff distances (40-60 mm). The optimized condition for the Turgo turbine runner was achieved with a 95° nozzle angle, 14 mm nozzle diameter, and a 40 mm standoff distance. The hydraulic efficiency of 66.19% is found, with significant model parameters having P-values below 0.0001. The findings indicated a maximum efficiency of 66.55% under optimized conditions, closely matching the proposed model with an error of 0.54%. Thus, the Turgo turbine is highly efficient and suitable for Pico hydro off-grid applications. Journal of Thermal Engineering Journal of Thermal Engineering 2025-09-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7414 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7414 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7414

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7415 2025-09-29T21:00:00Z 1

Advanced thermal management in aircraft lithium-ion battery packs: optimization of heat dissipation using heat spreaders and phase change materials Srinivas MALLIMOGGALA, K. Rama DEVI Aluminum Heat Spreaders; Battery Safety; Cooling Strategies, COMSOL Multiphysics; Heat Dissipation; Lithium-Ion Batteries; Thermal Management . Lithium-ion battery packs are essential in aviation, particularly for aircraft like the Cessna, Cirrus, and Piper models usually with 24V, and 16Ah to 35Ah capacities, depending on the specific model and avionics package installed, due to their high energy density and weight efficiency, which are critical for optimizing performance and fuel economy. This paper makes an exploration when it comes to spreading the heat from Auxiliary Power Unit (APU) battery packs with various cooling methods. This study addresses thermal management challenges, including the risk of thermal runaway, which can jeopardize safety challenges by optimizing heat dissipation in a 7s4p battery pack used in these aircraft, employing cooling techniques such as air cooling, phase change materials (PCMs), and aluminum-based heat spreaders (Al 3003-H18 and Al 6063-T83) to meet typical aviation requirements for reliability and efficiency. The simulations proved by COMSOL Multiphysics® pointed out that the aluminum variants especially the Al 3003-H18 significantly reduced peak temperatures (64.27 °C) compared to air cooling (82.36°C) at 8C, thus offered best thermal regime capability and managed the peak temperature as well as the voltage across the different rates of discharged. Pearson’s correlation coefficient analysis also showed positive higher order linear regression between aluminum-based models highlighting their efficiency in dealing with the heat generation or thermal runaway. This work extends existing literature by applying aluminum heat spreaders for aviation-specific applications, offering new insights into the relationship between thermal properties and cooling strategies under high discharge conditions, thereby enhancing both safety and battery longevity in critical aviation operations. Journal of Thermal Engineering Journal of Thermal Engineering 2025-09-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7415 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7415 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7415

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7525 2026-01-30T21:00:00Z 1

Assessment of combustion, performance, and emissions in a direct injection compression ignition engine using blends of jatropha, karanja, waste cooking, sunflower, and palm oil methyl esters with diesel Venkata Ramesh MAMILLA, G. Lakshmi Narayana RAO Performance; Combustion; Emission; Compression Ignition Engine; Diesel; Biodiesel As prospective alternative fuels for diesel engines, the current study examines two edible oils, namely sunflower and palm oil, and three non-edible oils namely jatropha, karanja, and waste cooking oil. The transesterification process was used to produce methyl esters from Karanja oil, Jatropha oil, Sunflower oil, Palm oil, and Waste cooking oil. The physical properties of these methyl esters met the specifications of IS biodiesel standards and were found to be similar to those of conventional diesel. An experimental setup used a single-cylinder, air-cooled, fourstroke direct injection diesel engine with a power output of 4.4 kW to assess the fuels performance, emission and combustion characteristics with varying blends of the methyl esters (20%, 40%, 60%, 80%, and 100%). Peak pressure, ignition delay and heat release rate were assessed in the combustion analysis. The performance metrics assessed included brake thermal efficiency, while the exhaust emissions analyzed were nitrogen oxides, hydrocarbons, smoke, and carbon monoxide. The experimental outcomes were compared to baseline data from diesel fuel. The findings indicated that the low blends of 20% biodiesel of Jatropha oil methyl esters (JTME), Karanja oil methyl esters (KME), Palm oil methyl esters (POME), Sunflower oil methyl esters (SFOME) and Waste cooking oil methyl esters (WCOME) served as the effective alternative fuel for performance and emissions under full load conditions among all fuels tested. Journal of Thermal Engineering Journal of Thermal Engineering 2026-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7525 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7525 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7525

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7459 2025-11-25T21:00:00Z 1

Ultrasound-assisted desulfurization of crude oil using sodium hydroxide Anfal H. SADEQ Crude Oil; Desulfurization, Optimization; Sodium Hydroxide, Ultrasound-Assisted Desulfurization (UADS). To meet the required standards on air quality and emissions from engine exhaust, several countries have instituted policies to set and reduce the limit of crude oil and petroleum product sulfur concentration to very low levels. This research studies the effectiveness of combining the assisted ultrasound desulfurization, and the traditional sodium hydroxide desulfurization methodologies, to lower the amount of sulfur contained in fuels produced even further. The sample in question was 25mL of crude oil obtained from the East Baghdad Oil Field in Iraq, containing 4.31 wt.% sulfur. The main underlying parameters of the UADS process; sodium hydroxide concentration, (temperature, 20-80 C0), reaction time (10-30 min), and intensity (30-60%) of ultrasound. The study contrasted the ultrasound desulfurization of crude oil performing the sodium hydroxide process with ‘standard’ caustic desulfurization, using the same parameters. The synergy of NaOH and ultrasonic irradiation in desulfurization of crude oil has surpassed their individual capabilities. The experimental data also compares the ultrasonic assisted empirical and reaction measures of the crude oil deuteron capture. She concluded that the maximal sulfur concentration deduced from the system was close to 68% at optimal conditions of 3M NaOH concentration, reaction temperature 60 C0, 30 minutes, with 40% of collimated ultrasound. Journal of Thermal Engineering Journal of Thermal Engineering 2025-11-25T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7459 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7459 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7459

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7416 2025-09-29T21:00:00Z 1

Comparative performance analysis of the Andasol-1 power plant in M'sila (an Algerian province) Khaled BOUCHAREB, Nabila IHADDADENE, Razika IHADDADENE, Khellaf BELKHIRI Andasol-1 Power Plant; Climatic Conditions; Parabolic Trough Concentrated Solar Power; M’Sila; Performance Assessment; SAM Software. Within the field of environmentally friendly electricity generation, parabolic trough concentrated solar power (CSP-PT) technology is acknowledged as one of the most efficient and practicable options. The current research employs the System Advisor Model (SAM) software to assess the viability of establishing a CSP facility utilizing parabolic trough technology, akin to the Andasol-1 power plant in southern Spain, within the M’Sila region of northern Algeria. It also statistically identifies the meteorological factors that most significantly influence Andasol-1’s performance in M’Sila and models its operation based on them. Furthermore, it compares Andasol-1’s performance across a range of locations reported in the literature. When the Andasol-1 power plant with a capacity of 50 MW is installed in M’Sila, it generates electricity year-round from 11:00 a.m. to 5:00 p.m., with an average output ranging from 25 MWe to 52 MWe. It can reach 17 hours of production, or even more, from March to September due to the favorable weather conditions and energy storage system (TES). The electricity generation increases with Direct Normal Irradiance (DNI) and ambient temperature, while it decreases with relative humidity. These variables collectively explain 98.2% of the electricity production variance in M’Sila (R² = 0.982), underscoring the significance of the linear regression model proposed. When Andasol-1 is erected in Kuwait, Tataouine (Tunisia), or at its true site (Spain), it produces less electricity annually than M’Sila, Tajoura (Libya), and Ma’an (Jordan). Furthermore, M’Sila’s climate is the second most favorable for Andasol-1, after Jordan’s, since it can generate 177.22 GWh of power annually there, exceeding its actual location. Climate change allows for the installation of solar power plants in northern regions as well. Journal of Thermal Engineering Journal of Thermal Engineering 2025-09-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7416 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7416 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7416

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7420 2025-09-29T21:00:00Z 1

Experimental investigations on performance improvement of multi point sequential fuel injection engine by reducing back pressure Chandrakumar PARDHI, Anshul GANGELE, Sanjay CHHALOTRE, C. P. JAWAHAR Exhaust Pipe; Backpressure; Volumetric Efficiency; Exhaust Emission; Throttle Position. Substantial developments in automotive technology have led to the recent explosion in the availability of high-performance vehicles. One of the most important components of internal combustion engines for reducing fuel consumption and exhaust emissions. Exhaust back pressure, a critical engine characteristic regulates the amount of internal exhaust gas trapped in the cylinder, affecting emissions and engine performance. The present work is focused on improving the performance of a multipoint sequential fuel injection engine by reducing the back pressure. The performance tests were carried out on a Hyundai i10 engine (1200 cc, multi-cylinder, 3000 rpm maximum speed). This study includes introducing fresh jet air at various flow rates into the exhaust system to reduce the concentration of exhaust gas contaminants and provide the desired backpressure while accounting for changes in engine speed. The effect of backpressure on various engine performance parameters at different engine speed conditions has been analyzed. It is inferred from the present study that at 2000 engine rpm, the temperature of exhaust gas drops between 50o C and 90°C and there is a marginal increase in the volumetric efficiency from 4.5 to 6.25%. The engine power increased about 6 to 8.2% at this operating condition. Journal of Thermal Engineering Journal of Thermal Engineering 2025-09-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7420 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7420 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7420

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7513 2026-01-30T21:00:00Z 1

Improvement of the thermal performances of a parabolic trough solar concentrator with concentric receiver tube and nanofluid Djemaa GUERRAICHE, Kamel ZOUGGAR, Khelifa GUERRAICHE, Antar TAHIRI, Zied DRISS, Cherif BOUGRIOU, Aya YAHA CFD; Heat Transfer; Nanofluid; Parabolic Trough Collector; Solar Energy; Trough Collector Parabolic trough solar concentrators (PTCs) encounter significant challenges arising from Non-Uniform Heat Flux (NUHF) around the receiver, which causes local overheating and pronounced circumferential temperature gradients. This study proposes the solution to this problem by uniforming the heat flux distribution, minimizing the temperature gradient, and improving performance. A numerical analysis is carried out on a novel small-scale PTC model featuring a concentric absorber tube design. The study compares the heat recovery performance of conventional, concentric, and eccentric absorber configurations using two heat transfer fluids enhanced with nanofluids: water and Syltherm-800 oil. A three-dimensional simulation model was presented by coupling Monte Carlo Ray-Tracing (MCRT) with (CFD) in ANSYS Fluent to predict the thermo-hydraulic response of parabolic trough receivers. Furthermore, Particular attention is given to the effects of is given to the effects of critical operational factors, namely inlet fluid temperature, mass flow rate, and nanofluid concentration on heat transfer and overall efficiency. The results confirm that the concentric parabolic trough receiver (PTR) operates with lower peak wall temperatures and smaller circumferential thermal gradients, which lessen thermal stresses and supports higher overall efficiency. When compared to the reference design, the concentric and eccentric receiver tube configurations lower the absorber tube’s temperature gradient by roughly 45% and 60.6%, respectively. These new configuration enhance heat collecting efficiency by up to 2.62% and 3.26% relative to the smoothe PTC tube. Moreover, the use of nanofluids added significant enhancements of efficiency, by 6.12% and 8.23% for the concentric and eccentric arrangements, respectively. This work highlights the promise of novel receiver designs and the use of nanofluids to boost both thermal and mechanics performance of PTCs and contributes knowledge beyond earlier work in the literature and serves toward improving solar therma. Journal of Thermal Engineering Journal of Thermal Engineering 2026-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7513 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7513 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7513

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7356 2025-07-30T21:00:00Z 1

Evaluation of energy efficiencies in a varied steam release domestic pressure cooker Hesborn R. AYUB, Willis J. AMBUSSO, Daudi M. NYAANGA Automated Cooker; Modified Pressure Cooker; Insulated Cooker; Pressure Cooker Efficiency; Zero-Steam Release. Despite its efficiency, pressure cooking is characterized by two primary energy losses: direct steam release during whistling and convection heat loss to the surroundings. The study focused on reducing energy losses during pressure cooking. The study experimented to determine the effect of each modification on pressure cooker energy efficiency. Ceramic wool insulation and automation for zero steam release modifications to an ordinary pressure cooker were used interchangeably. The experiment’s controls were an ordinary induction-powered pressure cooker and an electric pressure cooker powered with a resistive element. The energy consumption and standby cooking time were measured, and efficiency was calculated. Insulation improved standby cooking time and energy efficiency by 100% and 3.3%, respectively, whereas automation alone increased energy efficiency by 196%. Combining insulation and automation increased energy efficiency by 200%. The insulated automated pressure cooker had an efficiency of 93%, which was close to the electric pressure cooker’s 95%; both combined insulation and automation. It was discovered that a combination of insulation and automation eliminates major pressure-cooking losses, including convection and direct steam thermal energy. This reduces the amount of energy consumed while cooking, thereby increasing energy efficiency. This will significantly reduce the cooking carbon footprint, reducing the demand for fuel wood from forests. This will save forests, thereby combating climate change and improving environmental sustainability. The novel aspect of this study is that it investigated each effect of zero-steam release and thermal insulation pressure cooker modification on energy efficiency. This has reduced thermal energy waste and increased energy efficiency, adding to the body of research knowledge in the field of thermal engineering. This study is significant because it will spur efforts to improve energy efficiency in cooking, lowering the carbon footprint. Journal of Thermal Engineering Journal of Thermal Engineering 2025-07-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7356 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7356 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7356

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7417 2025-09-29T21:00:00Z 1

Effect of bristled shark scale structures on the aerodynamic characteristics of leading-edge protuberanced wing section S. SMRITHIKA, S. ARUNVINTHAN Aerodynamic Force Coefficients; Biomimetics; Flow Control Leading-Edge Protuberances, Time-Series Data, Wind Tunnel Testing, Surface Pressure Distribution. The present paper focuses its attention on assessing the influence of bristled shark scale structures over biologically inspired leading-edge protuberanced (LEP) airfoil section. It is worth noting that utilization of bristled shark scale structures as an effective flow control method remains untouched to date and this paper aims to study the same. NACA 63(4)-021 airfoil has been utilized as the baseline model in this study as it is closely reminiscent of the flippers of the Humpback whales. The test models include a baseline LEP model and two modified models M1 and M2 fitted with a single strip of shark scale structures at 0.6C and consecutive strips placed between 0.6 and 0.8C respectively. All the sets of experiments were conducted in the low-speed subsonic wind tunnel facility. The leading edge protuberanced wing utilized in the present study features an amplitude of 0.12C and wavelength of 0.5C based on the foundation developed by the previous researchers. The bristled shark scale structures inspired by the short-fin mako as well as the test model were 3D printed using PLA material at a resolution of 100µ/m. The test models were experimentally evaluated for a wide range of angles of attack ranging from 0°≤α≤70° in increments of 5° at Re=1.71x105 . Surface pressure measurements were obtained over the test models with the help of MPS4264 Scanivalve pressure scanner which are pneumatically connected to the pressure tapings. Aerodynamic forces and force coefficients were then estimated using pressure integration technique from the surface pressure measurements. Results reveal that the bristled shark scale tends to improve the aerodynamic characteristics in terms of lift increment and delay in flow separation. In other words, the modified models are effective as flow control means over the leading-edge protuberanced airfoil section. M1 and M2 improve the lift coefficient by 44% and 18.6% respectively when compared against the LEP baseline model. The prevailing spanwise gradient in the LEP baseline model is reduced around 85% in the modified model M1. Journal of Thermal Engineering Journal of Thermal Engineering 2025-09-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7417 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7417 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7417

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7515 2026-01-30T21:00:00Z 1

Turbulent forced convection of hybrid nanofluids in a three-dimensional L-shaped channel: Modeling, analysis, and regression model development Amanullah PHULPOTO, Abid A. MEMON, M. Asif MEMON, Ubaidullah YASHKUN, Adebowale Martins OBALALU Convection; Darcy; Kinetic Energy; L-shaped Channel; Turbulent The study explores turbulent forced convection of hybrid nanofluids in a three-dimensional L-shaped channel using COMSOL Multiphysics. The hybrid nanofluid comprises copper and aluminum oxide particles dispersed in water, with volume fractions of 0.01 (1%), 0.04 (4%), 0.07 (7%), and 0.1 (10%). Simulations are conducted for forced convection under Reynolds numbers ranging from 10,000 to 40,000. The partial differential equations of the Navier- Stokes, κ − ε model of the turbulence, and the three-dimensional energy equation are employed to model the system. The turbulence kinetic energy and dissipation rates for the turbulent flow range from 2.99E-3 to 1.53 (m2 / s2) and from 0.2136 to 2524.1913 (m3 / s3), respectively. This research is significant for advancing efficient heat transfer mechanisms, which are crucial for applications in cooling systems and energy devices. Key findings include the observation that the minimum temperature at the channel edges decreases with an increasing volume fraction of aluminum oxide and improves with copper addition. Copper consistently enhances the minimum temperature across all scenarios. The Nusselt number calculated using aluminum oxide is nearly ten times greater than that obtained using copper. The friction factor initially increases along the channel length and then decreases, showing minimal sensitivity to variations in the volume fractions of copper and aluminum oxide. Using multiple linear regression, predictive equations for the average temperature and Nusselt number at the outlet were developed based on the Reynolds number and the nanomaterial volume fractions. The novelty of this work lies in the exploration of a three-dimensional L-shaped channel to analyze its thermal behavior, offering significant insights for engineering applications and design improvements. Furthermore, the study provides a novel contribution by deriving linear regression equations for the average Nusselt number and average temperature, which have not been addressed in previous literature. The absolute error for the average temperature equation ranges from 0.005 to 1.6, while for the Nusselt number, it varies between 0.368 and 1.6, ensuring high accuracy of the regression model. Journal of Thermal Engineering Journal of Thermal Engineering 2026-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7515 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7515 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7515

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7467 2025-11-25T21:00:00Z 1

Prediction of dual-axis solar tracking of the PV system for optimal power output using GA, DE, TLBO, Jaya, and Rao-3 algorithms Mukesh KUMAR, PRABHANSU Dual-axis Solar Tracker; Electrical Power; Simulation; Tilt Angle; Azimuth Angle. In this study, novel algorithms approach that forecast the sun’s movement more accurately, even in bad weather, and optimize for additional characteristics besides solar tracking. It was investigated through comparative analysis by using standard optimization methods, i.e., the JAYA algorithm, Teaching Learning Based Optimization algorithm, Rao-3 algorithm, Genetic algorithm, and Differential Evolution algorithm for a dual-axis solar tracking of a Photovoltaic system. This dual-axis tracking involves rotation of two-axis, i.e., tilt angles and azimuth angles, to maximize the total available solar radiation at optimized tilt angles and azimuth angles for varying time from sunrise to sunset. The reason for obtaining optimum angles is to align the solar PV panel with the incoming solar radiation to get the maximum output. A non-linear and constrained optimization problem is employed to evaluate the optimum tilt angle and optimum azimuth angle trajectories. As in this case, the objective function is in an explicit form that is not known, the optimization methods are employed to evaluate the objective function, and that method calculates the available total solar radiation tracked and carried out in MATLAB software. The optimization results for the considered algorithms showed that the output electrical energy with the dual-axis tracker is far greater than that of the fixed system. It was found that for summer days, the electrical power generation by different optimization algorithms are as follows: TLBO-16.1713 kWh, JAYA-16.1436 kWh, Rao-3-16.1125 kWh, DE-16.2079 kWh, and GA-16.1969 kWh, and measured fixed system-13.2610 kWh. The obtained results for various optimization algorithms, in comparison to a measured fixed system, demonstrated significant enhancements in power generation. Journal of Thermal Engineering Journal of Thermal Engineering 2025-11-25T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7467 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7467 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7467

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7514 2026-01-30T21:00:00Z 1

Opposition-based algorithm for the optimization of shell-and-tube heat exchangers Elaheh KHOSRAVIAN, Mohammad B. AHMADI Aspen-EDR Software; Optimization Methods; Optimizing Based Opposition; Shell and Tube Heat Exchanger Shell-and-tube heat exchangers are widely used across various industries due to their high efficiency in energy recovery, drying, and cooling processes. However, optimizing these exchangers presents significant challenges due to the discrete nature of the design variables and the complexity of the governing equations, which are discontinuous and non-differentiable. To address these challenges, metaheuristic algorithms such as Genetic Algorithm, Particle Swarm Optimization, and Differential Evolution are commonly applied. This study introduces two enhanced optimization algorithms: Opposition-Based Differential Evolution and Comprehensive Opposition-Based Learning. These methods incorporate the concept of opposition both in generating initial solutions and in iterative optimization processes, enabling the efficient identification of optimal solutions. The optimization process focuses on key design variables, including tube diameter, shell diameter, and baffle spacing, which directly determine the complete geometry of the heat exchanger. The performance of these algorithms was evaluated across two case studies from prior research. Results showed an 18.88% improvement in cost reduction for the first case study and a 16.37% improvement for the second compared to conventional methods. Additionally, these algorithms outperformed Aspen EDR, a commercial heat exchanger design software, in identifying cost-effective and geometrically feasible solutions. Since Aspen EDR has limited modules for heat exchanger design and fails to provide solutions for complex geometries, such as helical or coiled tube configurations, the proposed algorithms offer a reliable and efficient alternative in such scenarios This research demonstrates the potential of these enhanced optimization algorithms to overcome traditional design limitations, providing a more versatile and effective approach for designing shell-and-tube heat exchangers with improved performance and cost efficiency Journal of Thermal Engineering Journal of Thermal Engineering 2026-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7514 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7514 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7514

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7506 2026-01-30T21:00:00Z 1

Performance assessment of solar based trigeneration system using organic rankine cycle and ejector refrigeration system Yunis KHAN, K.K. SIVAKUMAR, P. M.G. Bashir ASDAQUE, D. APPARAO, Rajesh KUMAR, Kumar GAURAV, Lalit BATRA Exergy; Exergoenvironmental Impact; Solar Power Tower; Helium Brayton Cycle; Ejector Refrigeration System In this study, a novel trigeneration system was developed to harness high-temperature solar energy from a solar power tower, enabling simultaneous generation of power, heating, and cooling effects. The system comprises a Brayton cycle utilizing helium as the working fluid, complemented by an organic Rankine cycle with an ejector refrigeration system to recover waste heat from the Brayton cycle. Energy, exergy, and exergoenvironmental analyses were conducted on the proposed system using engineering equation solver software. The heating and cooling effects were generated at 50°C and 10°C, respectively for building applications such as hospitals and hostels. The proposed plant was obtained the exergy and energy efficiencies of 25.12% and 23.30%, respectively. Additionally, cooling loads, heating loads and power output were obtained as 8.25 kW, 60.52 kW and 14998 kW, respectively. Moreover, the exergoenvironmental impact coefficient has a high value of 4.028 due to the lower exergy efficiency of the plant. The exergetic stability factor was determined to be 0.2483. Journal of Thermal Engineering Journal of Thermal Engineering 2026-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7506 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7506 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7506

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7470 2025-11-25T21:00:00Z 1

Numerical analysis of thermo-hydraulic performance of molten salt coolant flowing through a louvered-fin compact heat exchanger Bahadır DOĞAN, Mehmet Mete OZTURK, Latife Berrin ERBAY Compact Heat Exchanger; FLiBe; Louvered Fin; Molten Salt. New types of nuclear reactors have been proposed in recent years to meet the growing energy demand. These reactors operate at high outlet temperatures, which must be efficiently removed from the system. For this purpose, compact heat exchangers are considered important candidates. The study examines the thermohydraulic behavior of LiF-BeF2 (FLiBe) molten salt in a compact heat exchanger with multi-louvered fins as a part of a Molten Salt Reactor’s cooling loop at the steady state. This numerical benchmark study aimed to collect data for both baseline scenarios and cases of slow coolant circulation within the reactor for the first time in the literature. Numerical tests were conducted for low Reynolds numbers ranging from 100 to 500, over a flow region characterized by varying fin pitches and louver angles to compare FLiBe’s performance as a coolant in a Molten Salt Reactor. The findings indicate that as the louver angle increases, the molten salt flow becomes more directed through the louvers, enhancing heat transfer between the fins and the molten salt. Conversely, increasing fin pitches directs the flow more towards the ducts, reducing interaction with the FLiBe and diminishing thermal performance. As regard to outcomes, the highest heat transfer coefficient is determined to be about 27 kW/(m2K) at the smallest fin pitch of 1.5 mm, the biggest louver angle of 36o and a molten salt inlet velocity of 0.8 m/s. Under the same conditions, the heat transfer coefficient is calculated as 24.7 kW/(m2K) and 24.2 kW/ (m2K) for the pitches of 2.0 mm and 2.5 mm, respectively. The louver angle has a significant effect on the pressure drop especially for the fin pitch of 1.50 mm. At 0.8 m/s molten salt inlet velocity and fin pitch of 1.5 mm, the pressure drop with a louver angle of 36o is 58% higher than with a louver angle of 20o. Journal of Thermal Engineering Journal of Thermal Engineering 2025-11-25T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7470 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7470 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7470

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7512 2026-01-30T21:00:00Z 1

Pyrolysis, kinetics, and thermodynamic analysis of neem seed cake for the sustainable resource recovery Manisha RANI, Rohan R. PANDE, Kamalesh A. SORATE Activation Energy; Bioenergy; Endothermic Behavior; Kinetics; Seedcakes; Thermodynamics Pyrolysis has considerable potential for the monetization and management of neem seedcake by producing value-added compounds. The decomposition of neem seedcake (NSC) was analyzed, occurs in three stages: moisture removal (30–220°C), active decomposition (220– 550°C), and slow char formation (550–800°C). The activation energies for seedcake pyrolysis were calculated using the Starink, Kissinger-Akahira-Sunose (KAS), and Ozawa-Flynn-Wall (OFW) methods, yielding values 235.985 kJ/mol, 235.918 kJ/mol, and 228.026 kJ/mol, respectively. The product exhibited highest activation energy 429.335 kJ/mol. The reaction rate increases exponentially as activation energy decreases. The isoconversional methods were used to predict activation energy of neem seedcake with coefficient of determination (R2 ) greater than 0.90. The reaction chemistry of NSC pyrolysis, characterized by high reactivity, was evidenced by thermodynamic parameters (entropy, enthalpy and gibbs free energy), which indicated increasing endothermic behavior as rate of conversion (α) increased from 0.20 to 0.75. The positive change in enthalpy (230.92 kJ/mol) throughout the process indicates, when neem seedcake decomposes, energy is absorbed (endothermic behavior) to break the complex chemical bonds. The neem seedcake pyrolysis promotes sustainable waste management, reduces pollution, decreases reliance on fossil fuels, and supports climate change efforts. This study enhances knowledge of biomass pyrolysis, especially for less-explored non-edible oil seedcakes. Journal of Thermal Engineering Journal of Thermal Engineering 2026-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7512 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7512 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7512

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7469 2025-11-25T21:00:00Z 1

Numerical investigation of sulfur trioxide decomposition in microchannel heat exchangers Elham Omidbakhsh AMIRI, Behzad SAADATI Heat Exchanger; Microchannel; Numerical Simulation; Sulfur Trioxide. Due to global increasing in the energy demand and the need to reduce greenhouse gases, hydrogen is considered as an important energy carrier. In this work, numerical modeling of sulfur trioxide decomposition in the sulfur-iodine cycle in micro-channel heat exchangers has been considered. Different baffles shapes have been investigated. Results show by using these baffles in the flow path, the rate of decomposition increases. The highest decomposition percentage of 91.84% was obtained for the alternative design for the channel with asymmetric rectangular baffles. Also, the effect of the operating conditions such as the direction of inlet fluid flow, the inlet temperature of the helium channel and the type of reaction heat supply gas have been investigated. Results show that in the model with counter-current flow, the molar decomposition of sulfur trioxide is about 7% and the thermal performance coefficient is about 31% more than the parallel flow. Also, by increasing the inlet temperature of the helium flow, by about 18% compared to the base model, the molar sulfur trioxide decomposition increases by about 32%. But there is an about 21% reduction in the thermal performance coefficient. This study can provide a useful consideration of the effective parameters on the performance of a high temperature heat exchanger which worked as a sulfuric acid decomposer for hydrogen production within the sulfur-iodine thermochemical cycle. Journal of Thermal Engineering Journal of Thermal Engineering 2025-11-25T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7469 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7469 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7469

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7468 2025-11-25T21:00:00Z 1

Relative assessment of single-tube and multi-tube inverse diffusion flame for thermal and emission characteristics Mayur VADOLIYA, Rupesh SHAH, Nikhil BARAIYA CO and NOx Emission; Flame Length; Flame Shape and Appearance; Inverse Diffusion Flame; Multi-tube IDF. The thermal and emission characteristics of multi-tube inverse diffusion flame is investigated and compared with single-tube inverse diffusion flame. Liquefied petroleum gas is used as a fuel. The study focuses on flame length, CO and NOx emissions and temperature profiles under varying equivalence ratios and air velocities. Multi-tube configurations enhance air-fuel mixing by increasing the contact surface area. This results in shorter and more compact flames that results in low NOx emissions compared to single-tube inverse diffusion flames. The flame length of the multi-tube inverse diffusion flame reduces by an average of 12.7% compared to the single-tube configuration. The temperature profile of the multi-tube inverse diffusion flame reveals distinct flame zones at higher air velocities, while at lower air velocities, the flames merge into a homogeneous high-temperature region in the post-combustion zone. CO emissions reduce significantly with the multi-tube inverse diffusion flame, which emits 18 PPM less CO than the single-tube inverse diffusion flame at low equivalence ratios. Conversely, NOx emissions exhibit an opposite trend, with higher levels observed at elevated equivalence ratios and at reduced air velocities. The multi-tube inverse diffusion flame consistently shows lower NOx emissions, emitting 4 PPM less at higher equivalence ratios and 3 PPM less across all velocity variations compared to the single-tube configuration. A novel multi-tube inverse diffusion flame burner design, featuring air and fuel ports divided into multiple smaller, circumferentially arranged segments improves air-fuel mixing, stabilizes the flame, reduces emissions, and provides valuable insights for optimizing burner performance for optimum emissions and flame length. Journal of Thermal Engineering Journal of Thermal Engineering 2025-11-25T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7468 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7468 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7468

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7460 2025-11-25T21:00:00Z 1

Study the influence of thermophoretic effect buoyancy force in prandtl fluid flow on a stretching sheet in presence of joule heating and viscous dissipation Puspanjali MAHAPATRA, Tusar Kumar PARIDA, Kharabela SWAIN Brownian Motion; Buoyancy Force; Chemical Reaction; Joule Heating; Prandtl Fluid; Stretching Sheet; Thermophoresis; Viscous Dissipation. There are many natural phenomena and engineering usage susceptible to magneto fluid dynamics. The boundary layer theory is precisely such as asymptotic theory for the ease of very large Reynolds number. A numerical investigation was made to analyze the effects of Brownian motion, thermophoresis, and buoyancy force of non-Newtonian nanofluid relying on the Prandtl fluid model over a stretching sheet. The energy equation is empowered by the influence of Joule heating, viscous dissipation, and thermal radiation, whereas the concentration equation is determined by a chemical reaction. Similarity transformations are used to convert the governing partial differential equations (PDEs) into a system of nonlinear ordinary differential equations (ODEs). The resulting systems are effectively solved using the numerical scheme known as the Runge-Kutta-Fehlberg›s method with shooting technique and bvp4c solver in MATLAB code. The graphical results show the effect of pertinent parameters under buoyancy-assisting/opposing forces on velocity, temperature, and concentration profiles. Momentum transport gets accelerated for higher material/characteristic parameter of the non-Newtonian fluid model irrespective of presence or absence of porous matrix but thermal energy gets depleted for higher material parameter across the flow domain contributing to thermal stability. The elastic property of the Prandtl fluid and the effect of electromagnetic force increase slightly the solutal concentration but significantly to temperature. Thus, it is concluded that the generated Lorentz force (the additional body force) increases the thermal transport and solutal concentration of non-Newtonian nanofluid model. Journal of Thermal Engineering Journal of Thermal Engineering 2025-11-25T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7460 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7460 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7460

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7461 2025-11-25T21:00:00Z 1

Performance enhancement of box solar cooker with photovoltaic panel H. A. VAIDYA, Manish K. RATHOD, S. A. CHANNIWALA Figure of Merit; Hybrid; Photovoltaic Panel; Plate Temperature; Pot Temperature; Sidewall Inclination; Solar Cooker. In developing countries, the energy needed for cooking accounts for approximately 90 % of the total energy consumption in households. A solar cooker is a tool that utilizes the sun’s power to heat food and prepare it for consumption. Cooking with the aid of the sun, also known as solar cooking, is a method of preparing food that is typically practiced in settings that prioritize using as little fuel as possible and maintaining good health. The focus of the present study is the inability to perform during the low solar intensity. It is significant for the performance of the solar cooker as it can hamper the motive of using the renewable energy and to conserve the energy used by fossil fuels through solar cookers. It is highly significant for the acceptability of the solar cooker in the society as it is one of the major causes of non-popularization of solar cookers. In the current work, an experimental approach is used in which the construction of a hybrid solar cooker is accomplished by merging the photovoltaic panel and the heater following the design adjustments done in the constructed solar cooker with optimized sidewall inclination to increase the heat intake to the solar cooker. The developed cooker has inclined sidewalls giving the heat to the food vessels from the sides also, which increases the heat given to the food vessel and it is incorporated with the 50 W photovoltaic panels at cover lid and a DC heater placed beneath the absorber plate for giving the auxiliary heat. The use of sidewall inclination with the photovoltaic panel of only 50 watts is rarely observed in the literature. Hence this work of incorporating photovoltaic panel and heater with the inclined side-walled solar cooker is novel for that aspect. Extensive experimental research is carried out on the newly created hybrid cooker, and its performance is evaluated about that of the conventional solar cooker. The maximum temperature achieved in the hybrid cooker during no-load tests is found 25% higher than that of the conventional cooker. The figures of Merit F1 and F2 with values 0.11 and 0.63 respectively were also found higher in hybrid solar cooker as compared to conventional solar cooker having values of 0.09 and 0.375 respectively and with few researches found in literature. Even during the month of December, when the solar radiation is as low as 500 W/m2, cooking was possible within 120 minutes. The experimental results project new developed hybrid solar cooker to be more efficient than the conventional solar cooker. Performance parameters are also found better as compared to few researches found in literature. Cooking is also possible during low solar radiation which can be useful to make the solar cooker more popular. Journal of Thermal Engineering Journal of Thermal Engineering 2025-11-25T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7461 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7461 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7461

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7472 2025-11-25T21:00:00Z 1

Experimental investigation of methyl-ester soybean biodiesel: performance and emission characteristics as an alternative diesel fuel Bholu KUMAR, Digamber SINGH, Sanjay Singh RATHORE, Sudhir KUMAR, Piyush Kumar PATHAK, Nikhil SHARMA Compression Ignition Engine; Engine Efficiency; Performance Profile; Soybean Biodiesel. Due to the higher demand for renewable and sustainable energy sources, it is very important to investigate fuels such as soybean biodiesel. This study focuses on a compression ignition diesel engine’s performance characteristics and emissions when running on soybean biodiesel (B100 with 5% ethanol) in comparison to normal diesel fuel. The hypothesis is based on soybean being a biodiesel that can perform reasonably close to normal diesel engine with low emissions. Key performance variables such as indicated power, brake horse power, frictional power, thermal efficiencies, mechanical efficiency and specific fuel consumption were obtained during the experimental analysis as depicted in the research methodology. Emissions of CO, HC, CO₂, O₂, and NOx for the diesel fuel and for various biodiesel blends (B25, B50, B75) were also studied. Findings indicated that soybean biodiesel had comparative fuel economy and power generation as diesel, and CO emission was reduced by 40, while NOx emissions increased by 48 percent at full load condition. This studies clearly show that it is easy to use soybean oil based biodiesel as a renewable eco-friendly alternative biodiesel for compression ignition engines with much more improvement opportunities in terms of emissions performance. The originality of this work resides in the broader scope to evaluate the performance, emissions and trade-offs of soybean biodiesel blends and prospects that the literature on the sustainability of biodiesel is expanding by bringing in such new perspectives on it. Through the integration of experimental results, relevant performance as well as environmental assessments, this study extends previous endeavors and provides concrete recommendations for researchers, industry players and policy-makers willing to contribute to the advancement of alternative fuels. Journal of Thermal Engineering Journal of Thermal Engineering 2025-11-25T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7472 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7472 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7472

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7516 2026-01-30T21:00:00Z 1

Introducing an optimal pressure ratio for aircraft design and investigating the effect of nozzle efficiency on the jet engine’s performance Hadi SIYAHI, Mehdi SIYAHI, Mohsen FALLAH, Zahra MOHAMMADI Aircraft; Efficiency; Jet Engine; Nozzle Effect; Optimal Design Point; Propulsion The aviation sector contributes substantially to global transportation energy use, underscoring the critical need for improving energy efficiency in propulsion systems. Conventional energy-based evaluations can sometimes yield misleading results; therefore, exergy-based analysis provides a more realistic understanding of how energy is utilized and degraded within such systems. In this study, a jet engine is analyzed using exergy efficiency as a principal criterion, with specific attention to the effects of compressor pressure ratio and flight altitude. The investigation identifies an optimal operating point that corresponds to the most effective pressure ratio, which also governs engine sizing. The point where the thrust and exergy efficiency curves intersect is proposed as the optimal design condition. Moreover, the role of nozzle efficiency is examined under a range of flight scenarios. The results indicate that at the optimal design points, specific fuel consumption can be reduced by as much as 22.27% at sea level and 13.43% at cruise altitude when compared to maximum thrust conditions. These design points feature lower compressor pressure ratios than those at maximum exergy efficiency, thus improving practical feasibility for real-world applications. Enhancing nozzle efficiency further improves overall engine performance. For instance, at cruise altitude, increasing flight velocity from 100 to 200 m/s and raising nozzle efficiency from 60% to 100% increases thrust by approximately 33–39% and exergy efficiency by 68–71%. At sea level, these improvements reach up to 41% and 73%, respectively. The findings offer valuable insights into achieving concurrent optimization of thrust and exergy efficiency, providing a practical framework for future propulsion and advanced energy system designs. Journal of Thermal Engineering Journal of Thermal Engineering 2026-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7516 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7516 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7516

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7518 2026-01-30T21:00:00Z 1

Analysis of thermal, chemical and physical properties of paraffin and beeswax blended fuels for hybrid rocket applications Saravanan G, Avi THUMAR, Ayush DEVAK, Amritansh SINGH Blended Fuels; Beeswax; Chemical and Physical Characterization; Fourier Transform Infrared Spectroscopy (FTIR); Paraffin Wax; Scanning Electron Microscopy (SEM); Thermal; X-Ray Diffraction (XRD) Fuels made of paraffin and beeswax was created for hybrid rocket engines, and carbon, boron, and aluminium powders were added. Scientists used Scanning Electron Microscopy, X-ray Diffraction, and Fourier Transform Infrared Spectroscopy for study of these fuels’ thermal, chemical, and physical properties. The fuels were found to form homogeneous mixtures, and key chemical structures were identified. In tests, a beeswax-based fuel blend provided a 15% greater heat of fusion and 10% greater thermal stability than the pure paraffin-based fuels, and improved mechanical and combustion performance compared to the same properties of the paraffin fuels, providing an increase of specific impulse of up to 12%. The results indicate that paraffin / beeswax combinations show promise as a green, convenient and high performance fuel in a hybrid rocket. Journal of Thermal Engineering Journal of Thermal Engineering 2026-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7518 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7518 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7518

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7471 2025-11-25T21:00:00Z 1

Examining the effect of temperature and thicknesss on polycrystalline semi-conductor CIGS solar cell M. Mert ERBEY, N. Filiz TUMEN OZDIL CIGS; Efficiencies; Numerical Simulation; SCAPS 1D. Solar panels can convert the sunlight into electricity, which can be used in industry and homes. Using sunlight which is solar energy is the most plenty renewable energy sources on Earth. We acknowledge the criticism regarding the lack of clarity about the innovation in our article. The main objective of this study is to provide a detailed analysis of the factors influencing the performance of CIGS solar cells, specifically focusing on the impact of temperature and thickness on efficiency of solar cell. SCAPS 1D which is a numerical simulation software that (simulating the electrical properties of thin film heterojunction solar cells, considering both DC and AC characteristics.) has been used in this study of copper indium gallium selenide (CIGS) solar cell. In this investigation, the effect of temperature and thickness on efficiency of the solar cells has been investigated. The measurements have been shown and discussed using SCAPS 1D version 3.3.11. The experiment result clearly observed that temperature and thickness diversity directly affect the efficiency of CIGS solar cell. These parameters have been used for CIGS solar cell by electrical properties of I-V measurements. These measurements provide a critical snapshot of the cell’s performance under varying operating conditions. By analyzing the I-V curves at different temperatures and thicknesses, the experiment gathered empirical evidence to corroborate our theoretical understanding. The efficiency value for indium gallium selenide (CIGS) solar cell at 300K (Working point of SCAPS 1D is 300 K and this temperature serves as a convenient reference point for calibrating and comparing models, establishing a consistent starting point for further simulations.) has been found optimum value 10.88%. This study showed that as temperature and thickness rises from 200 K to 350 K and from 1 μm to 5 μm, the efficiencies of solar cell decrease from 17.2% to 7.5% for CIGS respectively. Journal of Thermal Engineering Journal of Thermal Engineering 2025-11-25T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7471 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7471 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7471

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7527 2026-01-30T21:00:00Z 1

Magnetohydrodynamic mixed convection within a ventilated cavity crossed by a nanofluid: Effect of the obstacle position Mourad MODERRES, Seddik KHERROUBI, Abdelkader BOUTRA, Abdelhakim SETTAR, Chaouki Ghenai, Djelloul AZZOUZI, Hakan F. OZTOP Circular Obstacle; Magnetic Field; Mixed Convection; Nanofluids; Ventilated Cavity This study presents a numerical investigation into mixed convection heat transfer within a ventilated square cavity containing a circular obstacle, evaluated under various magnetic field inclination angles. Ventilation is ensured by two fixed openings on the vertical walls of the cavity. Cold Carbon Nanotubes-water nanofluid enters through the opening at the top of the left vertical wall and exits through the opening located at the bottom of the right vertical wall. All four walls of the cavity are maintained at the same temperature, which is higher than that of the incoming nanofluid. The finite volume method, combined with the SIMPLER algorithm for pressure-velocity coupling, was utilized to solve the governing differential equations of the system. The objective was to determine the optimal geometry that offers the best thermal performance with the lowest pressure drop. Key results indicate that increasing the nanoparticle volume fraction from 0% to 6% enhances the average Nusselt number by up to 20.3%, significantly improving heat transfer performance. Similarly, tilting the magnetic field at an angle of 45° minimizes the pressure drop by 12% compared to the baseline case. The optimal obstacle position was identified as the cavity center, balancing heat transfer enhancement with a manageable pressure drop. These findings can be applied to optimize the design of cooling systems in industrial applications such as electronic device cooling, energy storage systems, and heat exchangers, where efficient thermal management and minimal pressure loss are crucial. The research introduces a new application of Carbon Nanotubes-water nanofluid to enhance heat transfer performance, with the added complexity of a magnetic field influencing the flow dynamics. Journal of Thermal Engineering Journal of Thermal Engineering 2026-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7527 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7527 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7527

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7510 2026-01-30T21:00:00Z 1

Enhanced heat transfer with iron oxide nanofluids: SYNTHESIS and performance evaluation Mehdi AMIRI, Rasoul KARIMI, Iman ABBASPOUR Co-precipitation Method; Critical Heat Flux (CHF); Heat Exchangers; Heat Transfer Enhancement; Iron(II, III) Oxide; Magnetic Nanoparticles; Nanofluids The low thermal conductivity of conventional fluids like water poses a significant challenge in heat transfer applications. In this study, iron oxide (Fe₃O₄) nanoparticles were synthesized using the co-precipitation method with precise size control. Two samples were prepared by adjusting the pH with NH₄OH (Sample 1: 29.42 nm) and NaOH (Sample 2: 38.04 nm). Characterization using XRD, SEM, and TEM confirmed cubic-phase Fe₃O₄ with spherical morphology. Stable nanofluids were prepared using Arabic gum as a stabilizing agent, achieving zeta potential values of -31.7 and -35.2 mV. Critical Heat Flux (CHF) analysis revealed that Sample 1 showed a 2.7% increase in CHF at 620 kg/m²s, outperforming Sample 2 (1.6% improvement). The Nusselt number for Sample 1 increased by 4.5% at 920 kg/m²s. These results demonstrate that smaller nanoparticle size (29.42 nm) significantly enhances heat transfer efficiency. These findings highlight the potential of Fe₃O₄ nanofluids for industrial applications, including energy systems, automotive cooling, and electronic thermal management, where improved heat transfer efficiency is critical. Journal of Thermal Engineering Journal of Thermal Engineering 2026-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7510 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7510 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7510

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7475 2025-11-25T21:00:00Z 3

Comprehensive review of algae biodiesel: production, engine performance, and emission characteristics with additives Teku KALYANI, Aditya KOLAKOTI, Lankapalli Sathya Vara PRASAD, B VENU Biodiesel Feedstocks; Algae; Processing Methods; Additives; Compression Ignition Engine Combustion; Performance and Emissions. The combustion of petro-diesel fuels in internal combustion engines is one of the contributing factors to increased environmental air pollution.The combustion byproducts are toxic exhaust emissions, which are dangerous to human health and the environment. Therefore, the need for sustainable and renewable fuels, like biodiesels, is gaining significant attention to regulate the toxic exhaust emissions form compression ignition engines. Biodiesels are popular due to theirbiodegradable, renewable, eco–friendly, non-toxic factors and their ability tobe employed in diesel engines without major modifications. These features have attracted researchers to investigate different biodiesels and their performance and emissions compatibility with existing engines. In this systematic review,research findings from the year 2009 to 2024 on biodiesel production from second and third-generation feedstocks, their significant fuel properties, and fatty acid compositions are critically reviewed. In addition, combustion performance and exhaust emission characteristics of different diesel and biodiesel blends are discussed. Similarly, additives are gaining popularity for improving the significant biodiesel properties and enhancing combustion performance with regulated emissions. Therefore, the influence of additive blending in biodiesel is also highlighted.Further, a comprehensive review was conducted on the emergence of algae biodiesel processing methods of algae to meet the future energy requirements in engines.The findings from the literatureconfirmed that the presence of high saturated fatty acid composition in green algae biodiesel mitigated the upsurge in nitrogen oxide emissions and suggested that green microalgae biodieselis best suited as a potential source of biodiesel production. Finally, this review reported that compared to non-edible biodiesel,algae biodiesel resulted in enhanced combustion propensity, engine performance, and reduced nitrogen oxide emissions, a prominent source of green, sustainable fuel to replace fossil fuel. Journal of Thermal Engineering Journal of Thermal Engineering 2025-11-25T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7475 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7475 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7475

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7602 2026-03-31T21:00:00Z 1

The development and evaluation of a solar Stirling engine integrated with an annular Fresnel lens concentrator system Yasir MEHMOOD, Asnaf AZIZ, Abid HUSSAIN, Fasih Ur RAHMAN, Afzal KHAN, Muhammad ABUBAKKAR, Imad RASOOL Alpha Configuration; Clean Energy; Computational Modelling; Heat Exchanger Design; Solar Concentrator; Solar Energy; Stirling Cycle; Stirling Engine. The study addresses the critical energy and environmental crises by exploring renewable energy sources, with a focus on solar energy. Solar Stirling engines are particularly relevant due to their efficiency in converting solar energy into electricity. This research presents the development and evaluation of a solar Stirling engine integrated with an annular Fresnel lens concentrator system. Designed to operate within a temperature range of 370–450 °C with air as the working fluid, the engine’s performance was assessed by measuring pressure drops in the regenerator and energy losses in the cylinders. Experimental results revealed that the alpha configuration prototype produced 37 watts of power with an efficiency of 26.4%. These findings underscore the engine’s effectiveness in solar energy conversion and its potential for practical applications in generating electricity. The integration of the Fresnel lens concentrator represents a novel approach not extensively covered in existing literature. The study’s optimization of the engine’s design and detailed performance metrics contribute to improved efficiency and broader applicability of solar Stirling engines, offering a viable solution for reducing reliance on fossil fuels and addressing environmental challenges. Journal of Thermal Engineering Journal of Thermal Engineering 2026-03-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7602 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7602 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7602

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7511 2026-01-30T21:00:00Z 1

Numerical study of 3d thermal-flow in a scraped surface heat exchanger Fatima Zohra BAKHTI, Belqassim Elmahdi ZERGUINE CFD Modeling; Glycerin; Heat Exchanger; Heat Transfer Convection; Scraped Surfaces This study investigates the thermal and fluid dynamics performance of scraped surface heat exchangers, optimizing key operational parameters to enhance heat transfer efficiency in processing viscous fluids. Using a numerical approach, the effects of blade count, rotational speed, and mass flow rate were analyzed. Results indicate that increasing blade count improves convective heat transfer, with a four-blade configuration enhancing the Nusselt number by 44.74% over a two-blade setup at 240 rpm. Higher rotational speeds reduce outlet temperatures by intensifying fluid mixing, though diminishing returns occur at very high speeds due to shorter residence times. These findings provide valuable insights for optimizing scraped surface heat exchanger design to balance thermal performance and energy efficiency, addressing critical needs in food, pharmaceutical, and chemical industries. Journal of Thermal Engineering Journal of Thermal Engineering 2026-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7511 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7511 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7511

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7585 2026-03-31T21:00:00Z 1

Thermal regulation of an ev battery pack using mineral oil: jordan case study Heba ALZABEN, Tayseer FADDAH, Amir Al SAWAIR Electrical Vehicle Battery; Immersion Cooling; Mineral Oil Cooling; Thermal Management. Thermal management is vital for optimizing the performance, lifespan, and safety of electric vehicle (EV) battery packs. This paper experimentally explores the use of mineral oil as a thermal regulation medium for EV batteries under Jordanian climate conditions. The study includes analyses of the electrical and thermal behavior of battery cells at different temperatures, the compatibility and impact of mineral oil on battery materials, and the practical feasibility of integrating such a system within an EV module. Battery testing was conducted under three cooling conditions: no cooling, air cooling, and mineral oil cooling. The electrical behavior of the battery was studied across these three cooling cases under 0.5C and 1C discharge rates, as well as under a 0.5C charge rate. The results indicate that mineral oil significantly moderates the battery temperature, keeping it within optimal operational ranges compared to other cooling methods. Specifically, the temperature delta is reduced by 50% at a discharge rate of 0.5C, while temperature uniformity is maintained within 2°C. This study designs and utilizes a mineral oil cooling system to investigate the thermal behavior of an existing battery module from the HTU student Racing Formula Team under Jordanian climatic conditions. The ambient temperatures during the testing period ranged between 28°C and 34°C. The findings suggest that mineral oil cooling is a feasible solution for improving the thermal management of EV batteries under variable conditions. Journal of Thermal Engineering Journal of Thermal Engineering 2026-03-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7585 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7585 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7585

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7458 2025-11-25T21:00:00Z 1

Design and thermal analysis of light weight radiator for automobile applications K Sunil KUMAR, Raviteja SURAKASI, S SUDHA, M SURESH, S. Jebarose JULIYANA, Nitin GUDADHE Cosmos; Fin Effectiveness; Forced Convection; Heat Exchanger. This present study deals with the simulation of the radiator and its fin efficiency, where the coolant is used as air, and the working fluid is used as water and air to measure the thermal performance. Heat dissipation by conventional materials has enormous demerits. Hence, lightweight aluminium material has considerable benefits in better heat dissipation and energy transfer. The methods used in this analysis for design SolidWorks and analysis are done by cosmos software. The materials used here were copper for the fins and aluminium as the outer cover material. The properties such as thermal conductivities, heat capacity, and vapour absorption rates were calculated. From the experimental results, it was observed that the heat transfer rate was achieved in the range of 30 degrees Celsius with a change in temperature difference. An increase in fins from 10 to 20 number tends to increase the heat transfer rate by 10 to 15% as compared to other conventional materials. The results also concluded that there would be an increase in the overall efficiency of the radiator. The results also reveal that implementing copper tubes with the combination of aluminium fins has an extent decrease in heat transfer rate. Hence, a radiator for heat transfer applications can achieve a marginal temperature difference of 25 degrees Celsius to 30 degrees Celsius. Journal of Thermal Engineering Journal of Thermal Engineering 2025-11-25T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7458 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7458 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7458

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7462 2025-11-25T21:00:00Z 1

Potential performance of diesel engine powered by mango seed blends + pyrolysis oil doped with zirconium catalyst K. Sunil KUMAR, Raviteja SURAKASI, Somasundaram B, Suresh G Emissions; Energy; Mango Seed Blends; Pyrolysis Blends; Zr2O3 Catalyst. The release of exhaust gases from compression ignition engines has gradually increased daily due to increased demand for automobiles. This causes a heavy depletion of diesel. The novelty in this work is testing the single-cylinder diesel engine followed by 50D25MO25PO+ 20 ppm zirconium oxide, 70D15MO15PO + 40 ppm zirconium oxide, 80D10MO10PO + 60 ppm zirconium oxide, 50MO50PO + 80 ppm zirconium oxide, and diesel. The zirconium oxide is a novel catalyst for boosting engine performance, improving combustion rates, and reducing emission formations. The method used for proportions is the ultra-sonification process. The results were good in terms of superior brake thermal efficiency for the blend 50D25MO- 25PO+ 20 ppm zirconium oxide is 34.2%, which is 11.67% greater than diesel, Brake specific fuel consumption is 0.20 kg/kWh for the blend 50D25MO25PO+ 20 ppm Zirconium oxide 31.43 % less than diesel, Maximum heat release rate is reached for the blend 80D10MO10PO + 60 ppm zirconium oxide followed by 89 KJ/CA with highest peak pressures of 69 bar for blend 70D15MO15PO + 40 ppm zirconium oxide. 70D15MO15PO + 40 ppm zirconium oxide blend offers very few Hydro carbon emissions, followed by 77.7% than diesel; the least Carbon monoxide formations are found for the same blend, followed by 40% less than diesel. 70D15MO15PO + 40 ppm zirconium oxide blend possesses very low carbon dioxide with a marginal difference of 5.6% than diesel, and lower nitrogen emissions are 50MO50PO + 80 ppm zirconium oxide found to be 700 ppm. Journal of Thermal Engineering Journal of Thermal Engineering 2025-11-25T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7462 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7462 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7462

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7464 2025-11-25T21:00:00Z 1

Design and parametric evaluation of proton exchange membrane fuel cell for enhanced performance Srinivas Prasad SANAKA, K RAMANAIAH, K Durga RAO, Naga Sai Pranay GUNDA COMSOL; Computational Fluid Dynamics; Fuel Cell; Gas Diffusion Layer; Hydrogen; Proton Exchange Membrane. The objective of the study is to explore the influence of various operating conditions on the performance of the Proton exchange membrane fuel cell (PEMFC) using COMSOL software. The effects of gas diffusion layer porosity, membrane conductivity, electrolyte thickness and operating temperature are studied. A structured hexahedral mesh was employed for the simulations. Essential geometric and operational factors are calculated analytically. The computational analysis of the PEMFC is conducted using a coupled approach that integrates free and subsurface flow, species transport and current distribution modules. The governing equations used in the simulation included conservation of energy, momentum, mass and species. The Joule heating, Butler-Volmer and the Nernst equation were incorporated to enable the modeling of reaction kinetics and cell performance. The uniqueness of this study lies in its comprehensive examination of the interactions between gas diffusion layer, gas diffusion electrode and membranes under various conditions, an area that has been less thoroughly investigated in the existing literature. Results reveal that higher gas diffusion layer porosity, increased electrolyte conductivity and reduced membrane thickness enhance fuel cell performance. A 26.54% increase in power density is observed when electrolyte conductivity is raised from 5.05 to 10.6, and a 21.19% improvement is achieved by decreasing electrolyte thickness from 254 μm to 127 μm. This data is vital for applications requiring high power output, such as in transportation or portable devices. Higher conductivity permits for better ion transport within the electrolyte, which can lead to more efficient reactions at the electrodes. This characteristic makes such fuel cells suitable for applications that demand rapid response times and high energy outputs. This study presents a novel approach to optimizing the performance of PEMFCs by systematically investigating the effects of critical operating conditions. Journal of Thermal Engineering Journal of Thermal Engineering 2025-11-25T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7464 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7464 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7464

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7363 2025-07-30T21:00:00Z 1

Machine learning enhanced hybrid energy storage management system for renewable integration and grid stability optimization in smart microgrids Ali PAŞAOĞLU, Ashkan HABIBNEZHAD Energy Storage Systems; Grid Stability Optimization; Machine Learning Control; Renewable Integration; Smart Microgrid Management. The increasing share of variable renewable energy sources in the power grid has brought about tremendous challenges in the context of stability and reliability. An active energy storage management system is designed and presented in this paper to cater to the intermittency of renewable resources while keeping the grid stable. The study develops and validates a novel hybrid energy storage management system that combines battery and supercapacitor technologies with machine learning optimization algorithms. The research methodology employs a dual-layer control architecture integrating reinforcement learning for strategic energy dispatch and model predictive control for real-time operation. System performance was evaluated using a comprehensive testbed comprising a 500kW solar installation, 250kWh battery storage, and 50kW supercapacitor array across varying weather and load conditions over six months. The system proposed, yielded results that were 27% better in overall energy performance than traditional storage management approaches while reducing voltage fluctuations by 43%. The machine learning algorithm successfully predicted renewable generation patterns with 92% accuracy, enabling proactive storage management strategies that reduced peak demand charges by 31%. The system maintained consistent performance across seasonal variations, with high availability (99.97%) and significant reductions in maintenance requirements (62.5% fewer events). The successful integration of hybrid storage technologies with advanced machine learning algorithms establishes a viable framework for enhancing grid stability and economic performance in renewable-rich microgrids. The results reveal meaningful aspects for developing next-gen smart grid storage solutions for applications, particularly where comparatively high reliability is needed to integrate renewables efficiently Journal of Thermal Engineering Journal of Thermal Engineering 2025-07-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7363 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7363 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:4 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7363

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7465 2025-11-25T21:00:00Z 1

Experimental evaluation of hybrid electric-heat operation for reliable residential water heating technology using photo-thermal system Ahmad Ilzam Anshori HASIBUAN, Ridwan NURDIN, Ismail ISMAIL, Reza Abdu RAHMAN Amperage; Coolant; Flowrate; PVT; Sand; Thermal. Photovoltaic (PV) is equipped with additional cooling system to reduce the cell temperature and enhance its efficiency. Numerous studies have addressed the issue using various methods such as thermoelectric, passive, and active cooling. In this work, the excess heat is taken as additional energy input considering the trend of PV direct heating system. The present study introduces PV and thermal collector as one compact system for heating application. PV output is connected to heating element while thermal collector harvests the waste heat from PV module. It allows the system to accumulate higher effective heat energy, which is useful for residential water heating applications. Experimental work is performed using 50 Wp monocrystalline PV by varying the filler material (sand and grease) inside the thermal collector and flowrate of the working fluid. The effect of filler material is observed as rapid heat dissipation, which is obtained by sand. Also, coolant flowrate affects the maximum temperature output and the accumulated heat energy from PV module. Despite the variation, the cooling effect from thermal collector reduces the PV temperature up to 30.1% and enhances the electric generation by 15.1%. The collected heat energy reaches a maximum value of 129.3 Watts, while peak electricity output only 46.4 Watts. The heated water from PV output reaches maximum temperature of 75 °C with maximum coolant temperature of 48.7 °C. It shows that the system is highly reliable for residential heating, offering a compact PV-thermal collector with higher power output. Journal of Thermal Engineering Journal of Thermal Engineering 2025-11-25T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7465 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7465 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7465

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7474 2025-11-25T21:00:00Z 3

Operational, design, and economic factors impacting gravitational water vortex hydropower systems Hussein M. ZAINAL, Omer K. AHMED Design, Economic Impact; Gravitational Water Vortex; Hydropower; Operational Factors; Vortex Power. This work investigates and assesses the main operational, design, and economic factors that influence the performance of Gravitational Water Vortex Hydropower Systems and their overall contribution to energy sustainability. The thesis highlights improving performance through turbine blade angle, basin design, and material selection -an essential aspect to overcome worldwide energy problems. The system’s power output is evaluated based on experimental, numerical, and theoretical approaches for varying the flow rate, vortex height, and turbine configuration. The findings reveal that five blades with a 44° angle provide an efficiency of only 82%, and an advanced material-based turbine shows an improvement in torque of 1.23% concerning conventional components. Moreover, combining conical basins with optimized nozzles can gain power (60%) and reduce energy losses. The result helps develop renewable energy creative methods in regions with limited energy access. This study extends previous works in the scientific literature by proposing a complete analysis and optimization framework for turbine design and performance under the need for sustainable energy production. These findings lay the groundwork for future studies designed to enhance the efficiency of small hydropower plants and further the world’s move to low-carbon energy. Journal of Thermal Engineering Journal of Thermal Engineering 2025-11-25T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7474 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7474 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7474

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7529 2026-01-30T21:00:00Z 3

Optimizing biomass fuel utilization for GHG emission reduction: An action plan for efficient fuel blending and sustainable practices K RAVI, M. MATHESWARAN Biomass Fuel; Coal-Fired Boilers; Greenhouse Gas Emissions; Net Zero Emissions JSW Steel’s Salem plant has committed to achieving Net Zero emissions by 2050, with a specific focus on reducing greenhouse gas emissions from its coal-based steam generation systems. Biomass, including briquettes, spent coffee grounds, wood chips, rice husk, and cattle dung logs, has been identified as a key component in reducing these emissions, particularly through its incorporation as a supplementary fuel in coal-fired boilers. This paper presents a comprehensive analysis of the challenges and solutions related to biomass fuel preparation, including briquette sizing, feed optimization, and contamination control. We propose an innovative action plan aimed at enhancing biomass fuel efficiency through optimized fuel size control, expanding biomass supply, and fostering deeper collaboration with suppliers. This action plan has resulted in a significant reduction in CO₂ emissions, with approximately 8,000 tons of CO₂ reduced annually a 5-10% improvement in boiler efficiency, and substantial cost savings due to reduced coal consumption through biomass blending. The novelty of this work lies in its comprehensive approach to biomass utilization, addressing challenges across the entire process from fuel preparation to combustion, and its focus on a real-world industrial setting using an AFBC boiler. In addition, we assess the plant’s current biomass fuel mix and compare it to India’s national strategies for sustainable energy utilization. The technical measures discussed herein for improving biomass feed systems contribute to improved boiler efficiency, higher fuel blending ratios, and substantial reductions in greenhouse gas emissions. these findings support broader sustainability goals and offer valuable insights for industries in India aiming to reduce their carbon footprints. Journal of Thermal Engineering Journal of Thermal Engineering 2026-01-30T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7529 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7529 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7529

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7593 2026-03-31T21:00:00Z 1

Influence of viscous dissipation, chemical reaction, thermophoresis and heat absorption on the flow via an exponentially stretching sheet Sunmoni MUDOI, Dipak SARMA Heat Absorption, Chemical Reaction, Thermophoresis, Viscous Dissipation, Eckert Number, Schmidt Number. The effects of convective boundary conditions on the flow of a viscous fluid through a porous sheet that is expanding exponentially are studied in this study, along with additional factors such as heat absorption, viscous dissipation, thermophoresis, chemical reactions, and others. The numerical solutions to the governing equations are evaluated using the bvp4c technique in conjunction with similarity requirements. The effect of different parameters on different physical variables are depicted using graphs. The fluid›s velocity increases with the increase in thermophoretic parameter. The temperature profile decreases with the rise in Grashof number and Schmidt number. While the concentration profile escalates with the rise in Schmidt number. Many real-world situations involve the co-existence of thermophoresis, viscous dissipation, chemical processes, heat absorption etc. Journal of Thermal Engineering Journal of Thermal Engineering 2026-03-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7593 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7593 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7593

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7605 2026-03-31T21:00:00Z 3

A comprhensive review on aircooled battery thermal mangement system of electric vehicles Prem Kumar S, Krishnappa BG, Madhu DEVEGOWDA Electric Vehicles; Battery Thermal Management; Air Based Battery Cooling; Material Recovery; Hydrometallurgy; Pyrometallurgy; Plug-in EVs; Li-ion Battery; Battery Material Recovery. Battery-operated modern mobility systems are commonly referred to as Electric Vehicles. The transition from conventional internal combustion engines to modern electric mobility is progressing rapidly. Incorporating Electric Vehicles is a practical solution to addressing environmental pollution caused by the combustion of petroleum-based fuels. Among the various energy storage options, Lithium-ion batteries are the preferred choice due to their superior features, including high energy density, longevity, and efficiency. However, the performance, safety, and lifespan of Lithium-ion batteries are highly sensitive to operating temperature. Therefore, an effective battery thermal management system is essential. This review paper focuses on air-based thermal management systems. Compared to other cooling methods, airbased systems offer notable advantages, such as simplicity, lower cost, and ease of implementation. Despite these benefits, air-based systems often face challenges in efficiently managing higher thermal loads. Various techniques related to air-based cooling systems are discussed in detail. Additionally, the paper provides an overview of alternative cooling methods for comparison and context. Journal of Thermal Engineering Journal of Thermal Engineering 2026-03-31T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7605 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7605 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7605

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7586 2026-03-31T21:00:00Z 1

Thermal performance evaluation of an Underground U-Bend tube heat exchanger integrated with phase change material Md. Nur ALAM, Dipayan MONDAL, Mohammad Rafat ISLAM Double U-shape Pipe; Ground Heat Exchanger; Numerical Simulation; Phase Change Material; Thermal Performance. This study presents a numerical investigation of the thermal performance of a U-bend tube ground heat exchanger (GHE) with paraffin wax as the phase change material (PCM) using ANSYS Fluent R1 2020. Using a U-tube instead of the straight tube results in the same or increased surface area at the reduced pipe length which further lowers the initial cost associated with GHE construction. Though there is a handful of studies regarding the performance enhancement of GHE, studies related to GHE with PCM, particularly fitted with a U-tube are inadequate, The GHE was constructed with a double U-shaped pipe, buried 45 meters underground, and the borehole was filled with paraffin wax as PCM due to its availability, steadiness, corrosion resistance, non-toxicity, and high latent heat capacity. The governing equations in this study are solved by the Realizable k-ε turbulence model. Air was circulated at velocities ranging from 0.5 ms-1 to 5 ms-1 in increments of 0.5 ms-1 for 12 hours to explore the system’s performance, with an inlet temperature of 309 K in all cases. Upon increasing the velocity from 0.5 ms-1 to 5 ms-1, it was found that at 12 hours of operation, the mean rate of heat transfer per meter increased from 76.27 Wm-1 to 116.45 Wm-1, thus the highest velocity exhibiting a 65.5% increase over the lowest, while the temperature drop decreased as velocity increased, ranging from 9.09 °C at 0.5 ms-1 to 7.2 °C at 5 ms-1. When it comes to effectiveness, initially for all air velocities the system’s maximum effectiveness was found to be between 64% and 61%. After 12 hours, effectiveness dropped to 47% at 0.5 ms-1 and to 37% at 5 ms-1 demonstrating that effectiveness reduces over time and at lower velocities the system is more effective. Moreover, it was also found that after 40 meters of GHE, there was a minimal temperature change, thus using GHE beyond this length gives insignificant thermal benefits. This necessitates future research on finding the optimal length for GHE, focus should also be given to improving performance under various environmental conditions, design optimization, and thermal performance improvement, using phase change materials to reduce initial costs. Journal of Thermal Engineering Journal of Thermal Engineering 2026-03-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7586 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7586 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7586

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7604 2026-03-31T21:00:00Z 1

Experimental analysis and optimization of the air-cooled solar panel Vineet SINGH, Vinod Singh YADAV, Niraj KUMAR, Anurag MAHESWARI, Javed Khan BHUTTO, Sultan ALSHEHERY, Mohammed Azam ALI, Manoj KUMAR Exergy; Fins; MINITAB; Optimization; RSM; Solar Panel The efficiency and sustainability of solar panels throughout the day remain significant challenges, primarily due to the temperature rise in solar cell materials during peak sunlight hours, which reduces their efficiency. This study aims to enhance the efficiency of solar panels using an air-cooling mechanism. Based on prior insights, an indoor experimental setup was developed, featuring a cooling system with 196 circular pin fins, each with a diameter of 3 mm and a length of 16 mm, mounted on the rear surface of the solar panel. An aluminum heat sink of 3 mm thickness was integrated to support the fins, while a variable-speed fan supplied airflow across the fins. The solar flux and airflow rate were identified as critical parameters influencing solar panel efficiency. These parameters were optimized using Response Surface Methodology, with ranges of 400–800 W/m² for solar flux and 0.01–0.02 m³/s for airflow rate. Optimization was performed using MINITAB 17 and Design Expert 18 software. The optimized input conditions, solar flux of 403.33 W/m² and airflow rate of 0.0221 m³/s, yielded the following outcomes: exergy efficiency of 15.79%, power output of 4.12 Wp, module temperature of 22.43°C, and solar panel efficiency of 14.48%, with a composite desirability score of 0.5737. This work is novel and new in its simple and light weight arrangement as compared to heavy vibrating pumps required in liquid and nano-fluid cooling. Additionally, the optimization approach and economic analysis of the solar panel cooling system are relatively new and have received little attention in previous literature. Perturbation plots revealed that solar flux had a more pronounced effect on panel performance compared to airflow rate. This study highlights the potential of air-cooling systems to mitigate midday efficiency losses and improve the operational sustainability of solar panels. The findings contribute to advancing cooling technologies for solar energy systems, promoting greater energy efficiency and reliability Journal of Thermal Engineering Journal of Thermal Engineering 2026-03-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7604 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7604 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7604

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7270 2025-03-23T21:00:00Z 1

Influence of curved trapezoidal winglet vortex generators on thermalhydraulic performance in fin-and-tube heat exchangers Alisan GONUL Curved Trapezoidal Winglet Vortex Generators; Heat Transfer Enhancement; Response Surface Methodology. Fin-tube heat exchangers play a crucial role in various industrial and HVAC applications due to their high heat transfer efficiency. This study focuses on the numerical analysis of fin-tube heat exchangers integrated with curved trapezoidal winglet vortex generators. In the current work, the impact of three key factors on heat transfer and flow characteristics: inlet velocity (2–5 m/s), vortex generator position angle (45°–120°), and arc length (3.80–6.33 mm) is analyzed. To enhance the accuracy of output predictions, this research extends beyond conventional parametric studies by utilizing a structured design of experiments approach. The study determines the optimal configurations through Kriging response surface methodology analysis. Results indicate a potential 48.5% improvement in heat transfer and up to an 18.3% enhancement in thermo-hydraulic performance. Moreover, the study reveals that improper sizing and positioning of vortex generators may lead to a 5% decrease in thermo-hydraulic performance compared to the heat exchanger without vortex generators. This work aims to explore strategies for enhancing the thermal performance of fin-and-tube heat exchangers through novel vortex generator designs by considering their geometric dimensions and positioning. Journal of Thermal Engineering Journal of Thermal Engineering 2025-03-23T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7270 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7270 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7270

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7457 2025-11-25T21:00:00Z 1

Mathematical simulation of magnetohydrodynamic slip transportation phenomena towards non-linear stretching cylinder induced with free stream velocity utilizing buongiorno’s model Saloni GUPTA, Chinta Mani TIWARI Brownian Motion; Heat Radiation; MHD; Non-linear Stretching Cylinder; Partial Slip; Thermophoresis. The manuscript’s goal is to examine how magneto-hydrodynamic slip flow affects a non-linear stretching cylinder while producing heat and radiation in presence of free stream velocity. Non-linear behavior produces a flow along with Brownian motion and thermophoresis. The shooting technique model was employed to solve moulded equations numerically following the advent of the Runga Kutta Fehlberg approach in MATLAB programming. The attractive pattern combined thermophoresis with a study of the effects of Brownian motion are also discussed. The effects of important fluid characteristics, such as outer velocity, heat radiation, and velocity of slip, thermophoresis, and Brownian motion are studied and represented via graphs and tables. It is revealed that, heat transfer rate falls down by 71.31% with increment in free stream velocity whereas heat transfer rate rises up by 34.43% with rise in Brownian motion parameter. Moreover, skin friction coefficient intensifies with increment in free stream velocity parameter. Current research has major applications in the production of glass fibers, biotechnological field, encompassing power plants, manufacturing of tetra packs, refrigeration systems, medical science, micro-electro-mechanical Systems and in wide variety of industries. Journal of Thermal Engineering Journal of Thermal Engineering 2025-11-25T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7457 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7457 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7457

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7594 2026-03-31T21:00:00Z 1

Thermodynamic performance analysis of an air conditioning system integrated with a solid desiccant dehumidifier wheel using solar reactivation Shriramshastri CHAVALI, Ravikant NANWATKAR, Sachin MUTALIKDESAI, Tarang SHINDE, Aparna BAGDE, Pravin NITNAWARE, Shruti DIKSHIT, Sourabh KULKARNI Air-conditioning System, Solid Desiccant Dehumidifier Wheel, Dehumidification Effectiveness, Regeneration Effectiveness, Adsorption Rate, Coefficient of Performance. The present study investigates the thermodynamic performance of an air-conditioning system integrated with a solid desiccant dehumidifier wheel (SDDW) using a combined heating mode of electrical and solar heaters. The obtained results were compared with standard results. During the experimentation, the solid desiccant wheel with silica gel as an adsorption material was used along with a conventional vapour compression cycle. The effect of inlet air temperature in the range of 23.6 °C to 37.2 °C and air inlet velocity in the range of 1.5 m/s to 4.1 m/s on the thermodynamic performance of an air-conditioning system integrated with a solid desiccant dehumidifier wheel was experimentally investigated. A combined electrical and solar heater mode was used to supply regeneration air for the solid desiccant dehumidifier at a constant velocity of 4.5 m/s. Experimentation was performed in all three seasons, namely summer, rainy and winter, to find the effect of seasonal variation on the performance of the air-conditioning system. The dehumidification effectiveness and adsorption rate in all three seasons increased with a decrease in the air inlet temperature. A maximum experimental value of dehumidification effectiveness was obtained in the summer season. At 23.6 °C and 1.5 m/s air inlet velocity, the maximum value of dehumidification effectiveness was 0.19. While at the same temperature, the maximum value of the adsorption rate at 4.1 m/s air inlet velocity was 0.4 kg/hr. In all three seasons, regeneration effectiveness increased with an increase in the inlet air temperature. While the regeneration effectiveness was reduced due to an increase in air let velocity. A maximum value of dehumidification effectiveness obtained in the summer season at 37.2 °C inlet air temperature and 1.5 m/s velocity was 0.298. The coefficient of Performance in all three seasons for the vapour compression cycle decreased with an increase in the inlet air temperature and velocity. A maximum experimentation value of the Coefficient of Performance obtained in the winter season for the vapour compression cycle at 23.6 °C inlet air temperature and 1.5 m/s air inlet velocity was 0.51. The combined use of these heating methods resulted in a 33% increase in effectiveness compared to the use of the electric heater alone. Journal of Thermal Engineering Journal of Thermal Engineering 2026-03-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7594 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7594 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7594

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7591 2026-03-31T21:00:00Z 1

Water heater employing granular coal photothermal absorber and solar thermal collector combination Alfan SARIFUDIN, Indri YANINGSIH, Budi KRISTIAWAN, Aditya WIBAWA, Ahmad FUDHOLI, Muhammad AZIZ Differential Scanning Calorimetry (DSC); Renewable Energy; Solar Energy; Spectrophotometry; Thermogravimetric Analysis (TGA); Thermodynamic. Coal’s conventional use causes environmental problems and threatens future energy security. This research presents a photothermal method for coal use, integrating a granular coal photothermal absorber into a solar thermal collector for solar water heater. This method offers a novelty in utilizing heat energy from coal, which is usually burned coal, but this photothermal method converts light into heat. Therefore, the photothermal method will not produce emissions and can be used repeatedly. The solar thermal collector combines a Fresnel lens and a parabolic reflector. Scanning electron microscope and energy dispersive spectroscopy analysis shows the granular coal photothermal absorber’s light-trapping carbon structure, with optimal sizes of 10-20 mesh generating temperatures of 378.15 K and an absorbance of 1.04. Thermogravimetric analysis and differential scanning calorimetry reveal a working temperature range of 336.31–684.31 K, with an optimal light-to-heat conversion temperature of 399.25 K, achieving 86.64% energy efficiency and 21.29% exergy efficiency. Performance tests show optimal solar water heater storage temperatures of 317.88 K and 316.75 K. The water temperature in the storage corresponds to the application of warm water bathing. The solar thermal collector’s maximum energy and exergy efficiencies are 33.06% and 5.51%, respectively, with average efficiencies of 22.90% and 3.44%. The solar water heater system peaks at 27.85% energy and 5.90% exergy efficiency, with average efficiencies of 20% and 3.09%. This approach highlights potential sustainable energy use and reduced environmental impacts of coal utilization. Journal of Thermal Engineering Journal of Thermal Engineering 2026-03-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7591 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7591 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7591

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7601 2026-03-31T21:00:00Z 1

Numerical analysis of two-phase flow in u-bend pipes: effects of curvature, and pipe orientation on pressure drop and liquid hold-up Md. Zahid HASAN, Dipayan MONDAL, Mihir Ranjan HALDER Two-phase Flow; U-bend Pipe; Pressure Drop; Phase Distribution; Liquid hold-up; VOF Model. This work investigates the effects of bend curvature, pipe orientation, and bend angle on twophase flow dynamics in U-bend tubes using a numerical approach. Two-phase flow in U-bend tubes introduces secondary flows, significantly impacting pressure drops and phase distributions. This study employs numerical simulations using ANSYS Fluent 2020 R1® to analyze the effects of bend curvature and pipe orientation (horizontal and vertical) on flow behavior, with water and air as the working fluids at an inlet velocity of 3 m/s. The volume of fluid model was employed to capture phase interactions and this is the novelty of this present work as in the previous works, the use of this model was absent. Results reveal a wavy stratified flow with secondary vortices caused by centrifugal forces in the bend. Pressure losses of 1186 Pa and 1415 Pa were observed for 50% and 70% water volume fractions in the vertical orientation, while horizontal orientation exhibited negligible losses for 50% and 80 Pa for 70%. Consequently, the pressure losses were found higher in vertical orientations, with 50% and 70% water volume fractions, respectively. The pressure drop is observed more with a higher bend angle along the bend. This Increased liquid hold-up and water accumulation at the bend were observed with higher water fractions, contributing to greater pressure drops. These findings are critical for applications in oil and gas, chemical processing, and refrigeration, highlighting the need for further studies on flow patterns and alternative geometries. The flow pattern as well as can significantly affect the overall flow behavior. Journal of Thermal Engineering Journal of Thermal Engineering 2026-03-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7601 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7601 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7601

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7600 2026-03-31T21:00:00Z 1

Energy and financial efficiency of a single family house in Algeria, the best way to get rid of state subsidies Rabea KAOULAL, Sifia BELGHERRAS, Sidi Mohammed El Amine BEKKOUCHE Building's Energy Balance, Thermal Rehabilitation, Energy Efficiency, Subsidies, Return on Investment. Financial aid and subsidies for electricity are intended to mitigate the impact of energy bills on low-income households. Unfortunately, these subsidies can represent a significant financial burden for governments. By eliminating them, states can reduce their budget deficit and reallocate those funds to other priorities, such as education or health. Several methods and alternative solutions to avoid or reduce dependence on electricity subsidies can be considered, but they will need to be adapted to the specific context of each country or region. Promoting energy efficiency will help consumers to reduce their electricity consumption and offset price rises. The integration and investment in renewable energy are essential to diversify energy sources and reduce dependence on fossil fuels. These two actions can effectively reduce the need and dependence on subsidies by decreasing demand. Moreover, by implementing more rational aid programs instead of subsidizing fossil electricity for low-income households, it will be highly possible to encourage states to stabilize their budgets acceptably by reallocating funds to other priorities. This study aims to evaluate the energy and economic performance of the Algerian buildings. This paper quantitatively analyzes the financial and energy efficiency of buildings and, rehabilitation projects of single-family houses in all of Algeria’s climatic regions. An assessment of the building’s overall energy balance was the basis of the investigation method. According to the obtained results, the current state subsidy system will not have to be fully maintained. Eliminating or reducing electricity subsidies is a complex process that requires a thoughtful and gradual approach. It must be carried out gradually and accompanied by protective measures for vulnerable households. To avoid negative impacts on the purchasing power and well-being of citizens, these measures must be based, firstly, on specific and limited investments and financial aid according to climatic regions, unlike what they were at the beginning (unlimited); secondly, on the judicious integration of renewable energies; and thirdly, on strengthening energy efficiency. From a financial point of view, subsidies are significantly lower for lower cooling energy needs. By adopting rehabilitation measures, unsubsidized energy bills are lower than those corresponding to a conventional home without thermal rehabilitation and with subsidized bills. Subsidizing the thermal rehabilitation procedure, or subsidizing thermal rehabilitation, a suitable solar water heater and, a stand-alone, optimized and well-sized photovoltaic system at the same time, can be a good alternative for effectively reducing the need for and dependence on subsidies by reducing demand or getting rid of these subsidies altogether. The most suitable regions for financial assistance, ranked according to merit, are M’sila, Naâma, Biskra, Bechar and, lastly, the Drabla climatic region. Journal of Thermal Engineering Journal of Thermal Engineering 2026-03-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7600 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7600 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7600

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7603 2026-03-31T21:00:00Z 3

Simulation of the thermal marangoni effect in a free surface cavity: Heatline and entropy visualizations Nagham Yass KHUDAIR, Qusay Rasheed AL-AMIR, Hayder K. RASHID Marangoni Convection; Cavity; FVM; Heat Function; Entropy Generation. There are many modern engineering applications of natural convection with free surface square cavity. In this paper analyzes numerically convection that is both natural and Marangoni. Together adiabatic cooling and convective cooling are subject to the upper free surface boundary, whereas a portion of the bottom wall boundary is exposed to constant heat flux and the remaining portions are maintained adiabatically. The unique of this research is the possibility of using its numerical analysis to enhance the applications related to solar energy, which is considered one of the most important applications in the field of renewable energy, in addition to food storage. The boundaries of the vertical walls of square cavity are kept cold. Under the influence of constant heat flux, two physical phenomena thermocapillary and buoyancy forces are considered and statistically depicted. A finite volume method is used to solve the governing equations based on the heat line approach. The current research is supported by other studies that are published in the literature. For different values of the Marangoni number (-103 to +104), Grashof number (104 to 105), Prandtl number (0.054, 0.16, 0.71, 6.2, 100), and Biot number (0 to 80) are produced to investigate the impacts on streamlines, isothermal lines, heat lines, and local entropy generation. The solving of the government equations is depending on numerical solution for the control volume system with assumed that the situation of heat transfer and fluid flow is steady with generating entropy over the all-control volume under investigation and density differences are ignored. It has been noted that the maximum stream function increases as Marangoni numbers increase from 0 to 104. This trend results from the fact that the flow velocity increases with the increasing Marangoni number. However, the Marangoni It has a reciprocal effect with convective heat transfer. The solution and its improvement are within the conditions of this research. The flow pattern is not considerably affected when the Biot number is changed from 40 to 80 as the surface tension is minimal. Journal of Thermal Engineering Journal of Thermal Engineering 2026-03-31T21:00:00Z Review Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7603 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7603 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7603

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7530 2026-01-31T21:00:00Z 1

Kinetics of UV degradation of hydrogen sulfide without oxidization by Homotopy Perturbation Method Sreelatha DEVI, K. SARANYA, D. VIJAYABALAN, Jayanthi RAJENDRAN, Muthumari G, Banu PRIYA V H2S; Homotopy Perturbation Method; Mathematical Modeling; Nonlinear Equations The promotion of biogas energy has been constrained by the presence of H2S. Classical H2S photodegradation is typically carried out with oxygen present, but this is inappropriate for biogas desulfurization and must be prevented. Thus, the current study was to examine the UV degradation of H2S without O2 from a mathematical perspective. This paper was performing a theoretical investigation of UV degradation of H2S without oxygen. First, the Homotopy perturbation approach was used to construct a theoretical computer model on H2S photodegradation. This model included models for the distribution of gas flows, radiation kinetics in the photoreactor, mass balance, and degradation rate. Then, to verify the mathematical model, the effects of the initial H2S concentration and gas retention duration on the photodegradation rate were examined. To validate the mathematical model, the effects of factors on the initiative H2S mass and gas retention time toward the photo-degradation rate were investigated. The primary photodegradation products were identified as elemental S and H2. Journal of Thermal Engineering Journal of Thermal Engineering 2026-01-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7530 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7530 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7530

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7507 2026-01-30T21:00:00Z 1

Performance investigation of high-powered light emitting diodes using copper and silicon-oxide based nanofluid filled heat pipe Ashish KHUDAIWALA , Rupesh PATEL Cooling System; Heat Pipe; LEDs; Nanofluid. Thermal management of light-emitting diodes (LEDs) significantly reduces the chances of failure due to overheating and provides a better lifespan. The most efficient, compact, and lowcost cooling system must be developed for better heat dissipation. Researchers have conducted major investigations on LED performance for low-wattage applications. The current work focuses on the high-wattage real-life application of LEDs. Researchers have considered investigations for 100 W, 200 W, and 400 W capacity high-wattage LEDs in street, stadium, and high-mast tower applications. Copper-made, cylindrical, two-layered heat pipe with screen mesh wick has been designed and fabricated to cool LEDs. Dispersed copper and silicon oxide nanoparticles in distilled water are used as a working medium in a heat pipe. Types of working medium, filling ratio, and LED capacities were considered input variables during the experiment. The resultant variables are the evaporator and condenser temperature difference, thermal resistance, energy consumption, effective thermal conductivity, and overall heat transfer coefficient. Researchers have developed a dedicated experimental setup for testing, with all required measuring and controlling devices. A superior performance was observed with the Cu/DI water-filled heat pipe, considering a 60% filling ratio in the tested LEDs. Cu/DI water with a 60% filling ratio has a 15.2% and 3.5% lower temperature difference, contrasting with DI water and SiO2/DI water for 100 W LED. Journal of Thermal Engineering Journal of Thermal Engineering 2026-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7507 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7507 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7507

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7595 2026-03-31T21:00:00Z 1

3D mathematical investigation of MHD flow imposed with bioconvective conditions over casson nanofluid induced by permeable surface utilizing lie symmetry transformation Saloni GUPTA, Chinta Mani TIWARI 3D MHD flow; Bioconvection; Buongiorno’s Model; Casson Fluid; Chemical reaction; Lie symmetry analysis; Nanofluid; Shooting Method. In the current framework, consequence of three dimensional Magnetohydrodynamics bioconvective Casson nanofluid flow by permeable extending surface in the existence of gyrotactic micro-organisms and chemical reaction has been scrutinized. Lie group analysis has been performed along with Runge Kutta Fehlberg algorithm by utilizing shooting technique in MATLAB programming. This model has been solved to calculate the impact of Peclet number Pe (0.1 ≤ Pe ≤10.0), micro-organism concentration difference parameter κ (0.1 ≤ κ ≤ 5.0), Bioconvective Lewis number Lb (0.1 ≤ Lb ≤ 0.9), Gyrotactic microorganism Biot number Bi3 (1 ≤ Bi3 ≤ 10), thermal Biot number Bi1 (0.1 ≤ Bi1 ≤ 2.0, Concentration Biot number Bi2 (1 ≤ Bi2 ≤ 5), Permeability parameter K (0.1 ≤ K ≤ 0.5), Chemical reaction parameter Cr (0 ≤ Cr ≤ 4), Lewis number Le (1 ≤ Le ≤ 20), thermophoresis Nt (0.5 ≤ Nt ≤ 2.5), Brownian motion Nb (0.1 ≤ Nb ≤ 5.0), Prandtl number Pr (0.732 ≤ Pr ≤ 20.0), Magnetic parameter M (1.5 ≤ M ≤ 3.5) and Casson fluid parameter β (0.1 ≤ β ≤ 0.9). Flow features are exemplified quantitatively for above mentioned fluid parameters via graphs and tables. Additionally, graphs are plotted for physical quantities of interest for non-Newtonian nanofluid parameters. Motile density declines with augmentation in Bio-convective Lewis number Lb and Bio-convective constant κ. It is found that, with augmentation in thermal Biot number from 0.1-2.0, heat transfer rate falls down by 85.45% whereas mass transfer rate falls down by 51.95% for higher concentration Biot number from 1.0-5.0. Moreover, motile concentration de-escalates for higher Pe and κ. Ultimately, the results show that the output outcomes can be accurately predicted by the applied model. Journal of Thermal Engineering Journal of Thermal Engineering 2026-03-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7595 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7595 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7595

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7597 2026-03-31T21:00:00Z 1

Numerical investigation of radiative hybrid nanofluid flow containing sodium alginate and aluminium alloys over a power-law stretching/ shrinking sheet with suction Pawan Kumar JANGIR, Ruchika MEHTA, Anurika MEHTA, Tripti MEHTA Sodium Alginate; AA7072- AA7075 Hybrid Nanofluid; BVP4C; Dual Solutions; Magnetic Field Effect; Power- Law Stretching/Shrinking Sheet; Radiative Heat Transfer; Suction Effect; Thermal Distribution The present work considers dual-solution behaviour of radiative hybrid nanofluid flow of sodium alginate containing aluminium alloys (AA7072 and AA7075) past a power-law stretching/shrinking sheet with suction. This understanding of such flow is important because of applications in thermal energy systems, biomedical devices, and aerospace cooling technology. The governing nonlinear boundary layer equations have been transformed using similarity variables and then solved numerically using the MATLAB bvp4c solver. The influence of the magnetic field, thermal radiation, suction, volume fractions of the nanoparticles, thermal slip, and chemical reactions on the velocity, temperature, and concentration profiles has been discussed in the analysis. It is found that the temperature profile increased by 15.6% due to the increase of the radiation parameter and heat source term. In comparison, the velocity approached the wall decreased by 12.3% due to the increase of the modifier parameter. The suction leads to better stability for the boundary layer, while increasing the values of the Prandtl and Schmidt numbers enhances the thermal and concentration boundary layer thickness. In certain ranges of both the suction rate and the stretching/shrinking rates, there exist dual solutions that indicate a bifurcation of the flow and a sensitivity of the stability. The new addition to existing models presented in this work is the mixture of sodium alginate with dual aluminium alloy nanoparticles under the influence of both radiative and MHD effects, allowing for new perspectives in hybrid nanofluid control mechanisms. These findings can be applied to increase the efficiency of heat and mass transfer in new, high-tech industrial and biomedical systems. Journal of Thermal Engineering Journal of Thermal Engineering 2026-03-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7597 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7597 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7597

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7599 2026-03-31T21:00:00Z 1

Insights of physico-chemical and thermal conductivity enhancement of polyvinylidene fluoride (PVDF) mixed znonanoparticles for heat transfer applications Mohammed MUQTASID, S. SRINIVASAN, R. PADMANABAN, M. SIVAKUMAR, A.P. LINGASWAMY Nanofluids; Polyvinylidene Fluoride; Thermal Conductivity; Ultrasonic Velocity; ZnO Nanoparticles. The conventional heat transfer liquids such as water, oil, etc., having lesser thermal properties cannot be fulfill the requirements of some of the heat exchangers system. To enhance the thermal properties of the liquid, nanoparticles are dispersed. Nanofluids (NF) have potential application in thermal transfer systems. The motto of the present work is devoted to studying thermo-physical studies on ZnO with different weight percentages of Polyvinylidene Fluoride (PVDF)-added nanocomposite-based nanofluids at various concentrations in water for heat transfer applications. The prepared nanocomposites were dispersed into the distilled water to prepare nanofluids and were characterized by ultrasonic velocity measurements to figure out the molecular interaction and thermal behavior of the nanofluids. Various physicochemical Characteristics, such as adiabatic compressibility, intermolecular free length, free volume, internal pressure, specific acoustic impedance, relaxation time, and surface tension, were determined. The mechanical properties of the PVDF ZnO NFs were analyzed based on the findings of the bulk modulus. Moreover, the thermal conductivity of the PVDF ZnO nanofluids was theoretically analyzed based on density and ultrasonic velocity measurements. The PVDF mixed with ZnO nanoparticle shows better thermal properties compared with conventional liquid say water. Journal of Thermal Engineering Journal of Thermal Engineering 2026-03-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7599 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7599 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7599

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7587 2026-03-31T21:00:00Z 1

Experimental investigation of a low-cost evacuated tube in a parabolic trough collector with and without porous insert Pooja RAVAL, Bharat RAMANI, Karan MOTWANI, Nikhilkumar CHOTAI Circular Ring Wire Mesh Insert; Evacuated Tube; Nusselt Number; Parabolic Trough Collector; Thermal Efficiency This research paper addresses the challenges of high upfront cost, maintaining vacuum, limited configurations and manufacturers, and fluid thermal retention in the evacuated receiver tube used in parabolic trough collector. These challenges affect the collectors cost and efficiency, which lowers its acceptance for the industrial market. Two attempts have been made to overcome this issue: developing an in-house evacuated tube of the specific configuration with locally available materials to reduce the cost. Furthermore, a novel porous insert is designed and examined inside the tube to improve fluid thermal retention, which will enhance the overall efficiency of the collector. An in-house developed evacuated tube with a notched circular ring porous insert is examined experimentally. The experimental tests were conducted using a manually tracked mechanism with a 2.36 m² aperture area and a 0.50 m focal length, utilizing water as the heat transfer fluid. Performance was evaluated with and without inserts at varying mass discharge rates (0.04, 0.06, and 0.08 kg/s), considering parameters such as Nusselt number, outlet fluid temperature, heat gain and thermal efficiency. The results demonstrate that the receiver tube with inserts significantly outperforms the plain tube (without insert). At higher mass flow rates, the insert-enhanced thermal efficiency is 31.2% and 20.46% in the Nusselt number. Also, a higher outlet fluid temperature is obtained in a tube with an insert, indicating improved thermal retention. This study establishes that incorporating novel inserts and developing in-house evacuated tube can be a viable solution for optimizing the cost and performance of the collector. Journal of Thermal Engineering Journal of Thermal Engineering 2026-03-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7587 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7587 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7587

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7592 2026-03-31T21:00:00Z 1

Performance evaluation of solar nozzle plant useful for electricity generation: A numerical analysis Anand GONDCHAWAR, Bhavesh KANABAR, Ramesh BHORANIYA Electricity Generation; Natural Convection; Solar Nozzle Plant; Updraft Tower Passive solar electricity generation relies on natural heat transfer, avoiding the use of fans or pumps. To decrease overall cost, it is essential to discover some new techniques for optimizing the solar chimney plant’s overall efficiency and capacity. The smoke jack devised by Leonardo da Vinci (1452-1519) has been quoted by many reviewers as the initial illustration of the principles of the solar chimney. The fundamental reason why it works is that it contains a venturi or nozzle. Thus, it is important to evaluate the performance of solar chimney plant using solar nozzles. Hence, this study numerically investigates the different configurations of solar chimney power plants (SCPP) with and without the use of solar nozzle design. The numerical analysis of the system has been done in ANSYS software with its latest available version (2022 R1). The three different model configurations of SCPP were studied and found that using solar nozzle design; one can achieve increased air release velocity at the outlet, thus, enhancing overall system performance. This SCPP design offers a sustainable electricity generation solution for both urban and rural environments. The solar nozzle plant is primarily depending on three governing equations i.e. mass, momentum and energy conservation laws. The natural convection heat transfer phenomenon related to SCPP is the useful fundamental law of heat transfer. The solar chimney equation plays a pivotal role in deciding different design parameters such as chimney dimensions, and the air released velocities at various parts. With the help of appropriate formulae; the efficiency of the overall design can be calculated. Results show that with the help of solar nozzle design, one can improve air release velocity at the outlet by a significant amount to the conventional basic design of SCPP with no nozzle. This increase in air updraft velocity will have a considerable impact on the power output of the electricity generation plant when the turbine is fixed at the nozzle outlet region. The solar nozzle model 6 with 3 m of nozzle height shows an optimum increment of nearly 29 % than solar chimney model of 3 m height and with no nozzle used. Journal of Thermal Engineering Journal of Thermal Engineering 2026-03-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7592 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7592 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7592

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7588 2026-03-31T21:00:00Z 1

Techno-economic analysis of a residential solar thermal-biodiesel heating and cooling system under the mediterranean climate Nyasha Netsai BEMA, Kemal MASERA Biodiesel as an Auxiliary Fuel; Biodiesel for Space Conditioning; Energy Demand in Residential Buildings; Solar Thermal Cooling; Solar- Biodiesel Hybrid This case study focused on the design of an economic and sustainable solar-biodiesel thermal system to meet the growing heating and cooling energy demand in Cypriot residential buildings. While the application of solar thermal systems in the residential sector has been one of the most efficient solutions to energy shortage issues experienced globally, auxiliary systems are often neglected. Therefore, this study addresses intermittency issues of solar and wind energy by exploring biodiesel as an auxiliary energy source. Biodiesel as an auxiliary fuel eliminates the use of expensive energy storage systems such as solar PV batteries and PCMs in solar thermal applications The proposed system which integrates evacuated tube solar collectors, thermal energy storage tank, Lithium-Bromide absorption chiller and a biodiesel boiler is modelled using TRNSYS. Different from most studies this study implements a user-centered method in determining residential space conditioning energy demand through a survey. TMY data is used to represent the available solar energy resources in Cyprus. The 10.5kW proposed system demonstrated a performance capability by satisfying 37800kJ/h of space conditioning energy demand. Thermal energy from solar managed to meet 100% and 87.7% of the cooling and heating energy demand respectively. The cost analysis reflected a payback period of 7.3 years and total savings of $37,200 over 20 years, highlighting the energy and cost effectiveness of renewable energy thermal systems in residential buildings. Journal of Thermal Engineering Journal of Thermal Engineering 2026-03-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7588 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7588 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7588

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7463 2025-11-25T21:00:00Z 1

Energy and exergy analysis of a novel solar-biomass tri-evaporator multigeneration plant integrated with fuel cell and electrolyzer Obiora Emeka ANISIJI, Ikuobase EMOVON, Olusegun David SAMUEL, Fidelis ABAM Biomass; Exergy; Hydrogen Production; Multigeneration; Solar Energy. This study presents the development and thermodynamic assessment of an environmentally benign multigeneration system utilizing solar and biomass resources. The system integrates parabolic trough collectors (PTC), biomass gasification, Organic Rankine Cycle (ORC), Kalina Cycle (KC), vapor absorption system (VAS), electrolyzer, and fuel cell to produce hydrogen, electricity, heating, cooling, and hot water. Thermodynamic analysis is conducted using the first and second laws, focusing on energy and exergy performance. The system is simulated using engineering equation solver (EES), with R245fa and an ammonia–water mixture as working fluids in the ORC and KC, respectively. The proposed system consists of PTC and biomass capacities of 1295 kW and 553.6 kW, respectively, and generates a total power output of 964 kW, including 276.03 kW from the ORC and 145.28 kW from the KC. Post-expansion cooling from the KC provides 129.6 kW at –33.5 °C with 12.15 kW of exergy, while the VAS yields 18.4 kW at 5 °C with 0.24 kW of exergy. The PTC supplies 311.4 kW and 683.8 kW of thermal input to the ORC and KC, respectively. Overall, the system attains energy and exergy efficiencies of 52.2% and 16.14%. The study demonstrates the feasibility and sustainability of integrating solar energy into biomass gasification, supporting its potential for clean energy generation. Journal of Thermal Engineering Journal of Thermal Engineering 2025-11-25T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7463 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7463 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7463

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7407 2025-09-29T21:00:00Z 1

Harnessing response surface methodology for diesel engine optimization using titanium dioxide-enhanced rice bran biodiesel to improve emissions and efficiency Manoj Kumar GUPTA, Ashok Kumar SRIVASTAVA CI Engine; Optimization; Response Surface Methodology; Rice Bran Biodiesel; Titanium Dioxide Nanoparticles. The present work is associated with synergistic optimization and the effect of three operational variables, namely Load on the engine, rice bran biodiesel Blend, and TiO2 Nanoparticle for emission attenuation of HC, CO2, NOx, O2, and CO, along with BTE amelioration of diesel engine sustainability. Under the category of Empirical Research work, Central Composite Design- based Response Surface Modeling and analysis of variance were done to find out the best suitable mathematical relationship with the most and least significant operational variable for all responses at a 95% level of confidence and 5% significance factor. Experimental data were obtained using a diesel engine test rig with biodiesel blends up to 30% and TiO₂ nanoparticles up to 200 ppm, under low, medium, and high load conditions. The responses were optimized using MINITAB with contour and surface plots. The optimum combination of three operation parameters reported as 2.64094 kW engine Load, 30 ppm rice bran Biodiesel, and 141.742 ppm TiO2 nanoparticles. Additionally, the optimal combination included CO 0.050% of the total sample, CO2 3.30% of the total sample, HC 13.29 ppm, NOX 385.78 ppm, and BTE 32.50%, resulting in a desirability effect of 73.74%; Improves BTE by 31.4% compared to pure diesel at low load and 22.9% at high load. A confirmation test run validates the result with a forecast error of less than 4%, with remarkable emissions reduction and performance gain of regular diesel engines without major changes, making it an eco-friendly option for the future. Journal of Thermal Engineering Journal of Thermal Engineering 2025-09-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7407 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7407 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7407

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7520 2026-01-30T21:00:00Z 1

Design of optimized exhaust system for two stroke unmanned aerial vehicle engine Faiq SAID, Zeeshan KHAN, Majid BASEER, Muhammad Nouman RASHID, Muhammad BILAL, Riaz HUSSAIN Backpressure; CFD Analysis; Exhaust System; Two-Stroke Engine; UAV This study investigated the optimization of exhaust system parameters for two-stroke engines in unmanned aerial vehicles, with a focus on improving performance at varying altitudes (sea level, 10,000 ft, and 21,000 ft). The research examined the impact of baffle plate hole diameter, header pipe length, and header pipe diameter on backpressure and exhaust flow dynamics. Two-stroke engines, while valued for their high power-to-weight ratio, suffer efficiency losses due to fresh air-fuel mixture leakage, particularly under reduced atmospheric pressure at high altitudes. The objective was to reduce backpressure-related inefficiencies by modifying three key exhaust parameters: baffle plate hole diameter, header pipe length, and header pipe diameter. Computational Fluid Dynamics simulations were performed in ANSYS Fluent using steady-state compressible flow assumptions, with boundary conditions replicating atmospheric pressures at sea level (1.013 bar), 10,000 ft (0.696 bar), and 21,000 ft (0.445 bar). Mesh independence validation was achieved with a final error margin of 0.01%, ensuring numerical accuracy. Important results show that decreasing the baffle plate hole diameter from 6 mm to 3 mm increases backpressure, enhancing scavenging efficiency but potentially raising exhaust temperature. At 21,000 ft, the optimal backpressure of 0.23 bar was achieved with a 4.6 mm baffle hole. Similarly, reducing header pipe length increased backpressure (0.105 bar at 122.5 mm vs. 0.09985 bar at 162.5 mm), while increasing header pipe diameter raised backpressure (0.104 bar at 36 mm vs. 0.097 bar at 24 mm). The optimal combination 4.6 mm hole, 122.5 mm length, and 36 mm diameter provides a favorable balance of flow resistance and scavenging, improving engine efficiency at high altitudes. These findings demonstrate that passive exhaust geometry tuning can effectively enhance UAV engine performance under altitude-induced pressure changes, offering a practical and scalable design approach. Unlike prior studies that focus on powertrain enhancements via turbocharging or fuel system control, this work offers a novel, passive exhaust geometry optimization strategy tailored to UAV engines. The study fills a critical research gap by systematically quantifying the relationship between exhaust configuration and altitude-dependent backpressure. Specific results include achieving a 0.23 bar backpressure at 21,000 ft using the optimized configuration, which allows for efficient engine operation without hardware modifications. This work contributes to lightweight, cost-effective unmanned aerial vehicle design by enabling high-efficiency performance without additional propulsion components, and the findings are presented in a manner accessible to a broad engineering audience. Journal of Thermal Engineering Journal of Thermal Engineering 2026-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7520 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7520 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7520

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7589 2026-03-31T21:00:00Z 1

Thermal and nanoscale relations of particles in mineral oil: An analysis of metallic and non-metallic particles A. T. AKINSHILO, M. G. SOBAMOWO, L.. KOLSI Heat Transfer; MHD; Micro Channel; Nanolayer; Particle Size. The mineral oil, a viscous liquid which is a derivative product from petroleum processing, having wide range of engineering applications, is studied in this paper. Thermal analysis of mineral oil in a microchannel incorporating nanoscale relations of metallic and non-metallic nanoparticles is investigated. The thermal effect on the nano layer is considered, which shows the relationship between the base fluid and nanoparticle. Also, the effect of nanoparticle size on the thermal layer is examined to understand the fluid performance under thermal load. The mechanics of the heat transfer and fluid transport are developed using coupled nonlinear system of higher partial differentials. They are analyzed using the Homotopy perturbation method upon transformation from partial to ordinary equations utilizing suitable similarity transforms. Results obtained from analysis show that optimum nanolayer thickness increases the surface layer of the nanoparticle, consequently increasing fluid temperature. Also, it is observed that the volume of the nanoparticle concentration from 1 to 8 % improves heat transfer and enhances shear stress at the wall boundary. The heat transfer rate using the graphite particles is higher compared to the copper particles, about 23 times more. Nanolayer thickness of 1nm and particle radius size within 5 to 20 nm studied shows good agreement with literature. Study may provide useful insight to tribologist and scientist interested in lubricant designs and process cooling. Journal of Thermal Engineering Journal of Thermal Engineering 2026-03-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7589 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7589 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7589

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7523 2026-01-30T21:00:00Z 1

Analysis of a 5.0 kWp solar rooftop system: Techno-economic, design, and simulation using pvsyst Anand KUSHWAH, Supriya RAJ, Nikhil PATEL, Ashish GAURAV, Om Prakash SAHANI, Kapil GUPTA Payback; PV Module; PVsyst; Return on Investment; Solar Energy The paper focuses on performance of a 5.0 kWp PV solar system, a second-generation PV technology. The experimental PV solar system was installed on the rooftop of G.P. Convent School, located in Sankat Mochan Nagar Morar, Gwalior, M.P, India (78.21°E, 26.22°N). The observed data indicates that daily average energy yields for experimental solar system were 5 kWh/kWp (array yield), 6.25 kWh/kWp (reference yield), and 4.91 kWh/kWp (final yield). While PVsyst simulation estimates the slightly higher values of 5.46, 6.39, and 5.32 kWh/ kWp, respectively. The total yearly power generated was 6910.2 kWh for the experimental PV solar system and 7485 kWh according to PVsyst software. The payback period for the PV solar rooftop system ranges from between 4.57 years and 11.41 years, depending on the initial cost. The ROI ranges from 119% to 447.5%, with the system providing substantial long-term savings. Based on these outcomes, PV solar system will perform well under the meteorological conditions. Journal of Thermal Engineering Journal of Thermal Engineering 2026-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7523 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7523 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7523

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7598 2026-03-31T21:00:00Z 1

Thermal gradients and ferrite formation in weld joints: A detailed study of temperature effects on microstructure and mechanical properties Loay M. MUBARAK, Hussein M, Ahmed Hashim KAREEM, Bassam Ali AHMED, Hasan Shakir MAJDI AISI 304 Stainless Steel TIG Welding; Ferrite Content; Phase Transformation; Weld Microstructure; Welding Heat Input. This study investigates TIG welding current variations effects on 4 mm thickness AISI 304 stainless steel joint welded using Argon gas, and this process impacts on ferrite composition, structural properties and joint strength. Ferrite content control must be managed properly to prevent hot cracking while ensuring both material strength and corrosion resistance because improper management leads to deficits during welding operations. A set of welding currents starting at 100 A progressed to 150 A and ending at 190 A created welds which delivered heat inputs of 6 J/mm, 9 J/mm and 11.4 J/mm. Welds under each condition received full inspection using metal structure analysis, scanning electron microscopy (SEM) along with Ferritoscope ferrite measurement, Vickers hardness analysis and mechanical strength testing. Data showed that a rise in heat intensity led to more ferrite formation starting from 4% at 100 A up to 9% at 190 A. The welds with 150 A heat application produced the optimal combination of mechanical properties since they contained 6% ferrite and displayed peak tensile strength at 689 MPa and mid-range hardness from 160–170 HV along with increased resistance to hot cracking. The welding current at 100 A produced a high hardness level of 170–181 HV in the weld but lost strength because of excessive ferrite content. Meanwhile the weld at 190 A exhibited lower strength and reduced hardness (150–157 HV) due to its excessive ferrite formation. Because of its ability to achieve superior microstructure with desirable austenite-to-ferrite ratio the weld using 150A heat input delivers optimal weld quality. The current investigation establishes quantitative assessments about heat treatment effects on AISI 304 TIG welds which distinguishes itself from previous research. The integration of Schaeffler diagram modeling with direct ferrite evaluations paired with SEM verification leads to a superior method for welding process prediction and enhancement. Journal of Thermal Engineering Journal of Thermal Engineering 2026-03-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7598 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7598 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7598

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7582 2026-03-31T21:00:00Z 1

Numerical and experimental study on the impact of insulation in centrifugal casting R. Allwin YESUVADIAN, K S KEERTHIPRASAD ANSYS; Horizontal Centrifugal Casting; Mould Insulation; Numerical Heat Transfer Analysis; Solidification rate. There is significant increase in use of metals across various engineering, household and industrial applications along with continuous evolving process of manufacturing to produce precise shape and finish of components. Previous studies have mainly focused on mould pre heating to manage thermal gradients while the present work examines an alternate approach by the use of thermal insulation to reduce the heat loss during casting. Transient thermal investigation of the centrifugal casting mold was done in this work. In order to assess the heat transmission properties for both insulated and non-insulated mold surfaces and comprehend how different solidification rates affect the end quality of castings produced, ANSYS simulation software was utilized for analysis. Different insulation conditions were tested mechanically, and scanning electron microscopy (SEM) was used to look into microstructural differences. According to the findings, applying mold insulation along with preheating and rotating at an optimal speed improved heat retention and decreased heat loss by 27%. This results in better solidification, fewer casting flaws, and higher-quality cast products, accompanied by a 12.67% decrease in the outer mold surface temperature. Journal of Thermal Engineering Journal of Thermal Engineering 2026-03-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7582 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7582 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7582

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7524 2026-01-30T21:00:00Z 1

Energy-efficient refrigeration: The role of TiO2 nanoparticles in R600a/ R290 refrigerant blends M. Ravi KUMAR, R. Satya MEHER, A. Swarna KUMARI Coefficient of Performance (COP); Energy Efficiency; R600a/R290 Blend; Titanium Dioxide (TiO₂) Nanoparticles; Vapour Compression Refrigeration (VCR) System; Capillary Tube Length Analysis on the need for sustainable and energy-efficient cooling mechanisms has fuelled a drive towards developing sustainable vapor compression refrigeration (VCR) systems. Experimental advancement of VCR systems is accomplished using Titanium dioxide (TiO₂) nanoparticles, which are widely known for their high coefficient of performance (COP) and operational efficiency. This research studied the influence of TiO₂ nanoparticles poised in mineral oil on a VCR system utilizing a refrigerant mixture of R600a and R290 (60:40 mass ratio). The COP of the cooling system whenever nanoparticles were implemented and when they were not measured with the capillary tube lengths being 8, 10, 12, and 14 feet through pull-down and performance test, respectively. The outcomes show that the adding of nanoparticles can raise the heat transfer rates in the evaporator and condenser, resulting in a macrophenomenon with a maximum COP enhancement of 8% at 10 foot for the capillary length. More to the point, the nano refrigerant at this optimum length proved superior over the conventional R600a/R290 in system performance (7.1% increase) and compressor power consumption (7.14% decrease). Longer capillary tubes (12 and 14 feet) were not as effective, which led to increased power consumption and less refrigeration effect. The work identified challenges as well with nanoparticle dispersion and compressor lubricant compatibility. This paper presents a pathway to sustainable refrigeration by enhancing energy efficiency and operational performance through the optimization of the length of capillaries, which play a important role in the operation of nanoparticle-augmented VCR systems. Journal of Thermal Engineering Journal of Thermal Engineering 2026-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7524 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7524 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7524

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7425 2025-09-29T21:00:00Z 1

Enhancing carbon neutrality through renewable energy and demand-side management Yeqing ZHU, Yu WANG, Shen HOU, Yanjun CHEN, Luzheng ZHANG Carbon Reduction; Integrated Renewable Energy Systems; Carbon Dioxide Flux; Research and Office Parks. In the context of China’s dual carbon goals—carbon peaking and carbon neutrality—the implementation of high-efficiency carbon reduction and control technologies is of paramount importance. This study evaluates the impact of renewable energy integration and energy management strategies on carbon emissions in a research and office institute park located in Nanjing, China. A 1.162 MW photovoltaic system was deployed to supply on-site electricity demand. The system exhibited substantial performance, achieving electricity self-sufficiency rates exceeding 100% on 50 days and surpassing 50% on 58.8% of the monitored days over the study period. To enhance energy efficiency on the demand side, the air conditioning temperature set point was raised from 25 °C to 27 °C. This adjustment led to a 15.1% reduction in air conditioning energy consumption and increased the average summer photovoltaic self-sufficiency rate from 51.27% to 56.85%. In addition, a carbon flux tower was installed to facilitate continuous monitoring of carbon flux and atmospheric CO₂ concentrations. The measured data indicated consistently low carbon dioxide concentrations and negative carbon flux values, with average concentrations of 464.87 ppm and mean CO₂ flux of –0.0087 mg/m²·s, respectively. These results underscore the effectiveness of integrated renewable energy systems and active demand-side management in reducing operational carbon emissions in urban building clusters. Journal of Thermal Engineering Journal of Thermal Engineering 2025-09-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7425 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7425 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7425

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7581 2026-03-31T21:00:00Z 1

Improving insulation and energy efficiency in arid climate buildings with palm fiber-reinforced adobe: Impact on thermal and mechanical properties Abdelkader BASSOUD, Abdelmalek BADA, Hamid KHELAFI, Abderahemane Mejedoub MOKHTARI, Abdelrrahmane MOULAY-ALI, Abdelghani IDDER Adobe; Arid zone; Clay; Flexural Strength; Palm Fiber; Sand; Thermal Insulation. Improving the thermal insulation of contemporary cement buildings is a significant challenge, particularly in desert environments subject to high temperatures. Adobe, a raw earth-based material, represents a practical solution due to its natural thermal properties. However, its low mechanical strength, particularly in bending, limits its integration into modern construction. This study demonstrates that a 13 cm layer of adobe reinforced with palm fibers, used as ceiling insulation, improves the thermal insulation of the building by approximately 133%, while reducing annual energy consumption by up to 53%. Furthermore, the impact of the length and dosage of palm fibers on the mechanical and thermal properties of adobe was examined through a series of tests. Four dosages (0.25%, 0.50%, 0.75% and 1% by weight) and four fiber lengths (25 mm, 50 mm, 75 mm and 100 mm) were tested. The results reveal that concentrations between 0.5% and 1% offer the best performance. In particular, the 50 mm fibers at 0.5% increased the compressive strength by about 20%, while the 75 mm fibers at 1% improved the flexural strength by up to 45%, reaching 1.70 MPa. Journal of Thermal Engineering Journal of Thermal Engineering 2026-03-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7581 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7581 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7581

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7421 2025-09-29T21:00:00Z 1

Technical and economic feasibility analysis of 1kW Rooftop Solar Photovoltaic System for Mysuru, Karnataka, India Raghavendra Deva Das RAO, Bommegowda Sadashive GOWDA Carbon Dioxide Output; Economic Analysis; Financial Feasibility; Return on Investment; Rooftop Solar Photovoltaic (PV) Systems; Solar Irradiation Rooftop solar photovoltaic (PV) systems have emerged as a key decentralized energy solution in response to rising electricity demand, climate change concerns, and the global shift toward low-carbon power generation. Despite favourable policies and falling technology costs, adoption in many regions remains suboptimal. This study investigates the techno-economic feasibility of 1 kW rooftop solar PV systems in Mysuru, Karnataka, India, an urban area with high solar potential, receiving an average Global Horizontal Irradiance (GHI) of approximately 5.5 kWh/m²/day across over 300 sunny days annually. A system configuration comprising monocrystalline or polycrystalline PV modules, a 1 kW inverter. The system is projected to generate 1,500–1,800 kWh annually, resulting in savings of up to ₹8,850 per year at the current residential tariff of ₹5.90/kWh. Installation costs range between ₹45,000 and ₹50,000, with government subsidies such as those under the PM Surya Ghar: Muft Bijli Yojana, potentially covering up to ₹78,000. The financial analysis indicates a payback period of 4–6 years and a return on investment of 15–20% over a 25-year operational lifespan, alongside annual carbon dioxide emission reductions of approximately 1 ton. While the system proves technically and economically viable, challenges persist, including upfront capital costs, limited public awareness, and spatial constraints. The study underscores the importance of policy support, public engagement, and community solar initiatives in scaling rooftop PV adoption and advancing India’s renewable energy transition Journal of Thermal Engineering Journal of Thermal Engineering 2025-09-29T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7421 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7421 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:5 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7421

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7584 2026-03-31T21:00:00Z 1

Performance analysis of solar still with separate evaporatively cooled condenser Niladri SARKAR, Aneesh SOMWANSHI, Anil Kr. TIWARI Air Cooler; Distillate Output; Economic Analysis; Separate Condenser; Solar Still. Potable water scarcity is a serious global issue, and solar stills provide an eco-friendly way to produce clean water using sunlight. Their efficiency mainly depends on the temperature difference between the basin water and the glass cover. Adding an external condenser helps to boost this difference by keeping the condensation surface cooler, leading to more water output. Actively cooling the condenser can enhance this effect even further, significantly improving the distillate yield. In this study, the performance of a single-slope solar still with a separate condenser integrated into an air cooler system was investigated. A low-power exhaust fan directs the moist air towards the condenser. The condenser plate is cooled by water from the air cooler’s tank, which flows over it. This evaporatively cooled condenser enhances the condensation process, leading to increased overall productivity of the solar still. Mathematical model of the design was created and validated through experiments. Effect of parameters like water depth, mass flow rate of water over condenser, relative humidity and wind velocity of air on stills performance has been investigated. The depth of water in the solar still’s basin has very little impact on the distillate produced. When the depth of water in basin increased from 1cm to 5cm the total daily distillate output is decreased only by 4.9%. The mass flow rate of water flowing over condenser has very negligible effect on still’s performance. Unlike conventional still with increase in wind velocity from 1m/s to 4m/s the hourly distillate output decreases by 2.7%. With increase in humidity of air the output decreases. In Raipur, Chhattisgarh (India) for months of May (summer), January (winter), and October (autumn) the system produced 7.83 kg, 3.45 kg and 5.30 kg of distilled water daily. The water is produced at a reasonable cost of Rs. 1.30/kg (US$ 0.0151/kg). Due to continuous cooling of condenser, the system is able to generate some amount of water even in night time. Journal of Thermal Engineering Journal of Thermal Engineering 2026-03-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7584 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7584 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7584

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7456 2025-11-25T21:00:00Z 1

Thermal performance optimization of wickless heat pipes using flash evaporation for distillation Samah E. AL-SA'DI, Dhamyaa S. KHUDHUR, Akram W. EZZAT, Eric HU Flash Vaporization; Jet Nozzle; Saturation Temperature; Superheat; Thermosyphon; Wickless Heat Pipes. This study presents a numerical and experimental investigation of the effect of flash evaporation on the thermal performance of a wickless heat pipe used in desalination applications. Moreover, this study examines the factors that affect flashing efficiency, such as the feed water mass flow rate, inlet temperature, and cooling water flow rate. High-temperature liquid in the range of 373K-393K becomes superheated when injected through a jet nozzle into a wickless heat pipe. This study focuses on using a jet nozzle type with a small diameter (0.4 mm). The steady value of the mass flow rate of the water is 0.00138 kg/s. Computational Fluid Dynamics (CFD) was used to simulate the two-phase flow and heat transfer processes in a heat pipe, which involves evaporation, condensation, and phase change. This study is unique in that it employs a non-homogeneous multiphase model to capture these processes. The results indicate that increasing the inlet temperature of liquid water leads to a rise in flashing vapor to a certain extent, thereby increasing the condensate flow rate. The maximum condensate flow rate was observed at 388K. The findings suggest that flashing efficiency improves as the condensate flow rate and inlet temperature increase. The optimum flash efficiency was found to be 80% at 393K. A strong agreement was observed between the experimental data, numerical temperature profiles, and the heat pipe’s thermal performance. Journal of Thermal Engineering Journal of Thermal Engineering 2025-11-25T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7456 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7456 Journal of Thermal Engineering, Year:2025, Vol:11, Issue:6 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7456

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7509 2026-01-30T21:00:00Z 1

Evaluation of infrared radiations from top of the atmosphere through artificial neural network modeling Usama Ayub YOUSUFZAI, Muhammad Jawed IQBAL, Faisal Khan AFRIDI ANN Modeling; Infrared Radiations; IR Evaluation; Top of the atmosphere; Upper Atmosphere This study helps to forecast the Infrared Radiations from the top of the atmosphere over six cities in Pakistan using data gathered over a ten-year period from the Synoptic Top of the Atmosphere (TOA) and surface fluxes and clouds Edition 4A, a data product of clouds and the Earth’s Radiant Energy System which gathers daily ten-year local weather data. This work aims to use exploratory data analysis to examine infrared radiation quantification. The assessment of infrared radiations from the upper atmosphere, a crucial part of the Earth’s radiation budget with consequences for climate modeling and satellite based atmospheric research, is the main emphasis of this work. In order to accomplish this, atmospheric datasets taken from the NASA Earth observation gateway used in artificial neural network (ANN) modeling. By combining machine learning with NASA’s atmospheric datasets for Top of the Atmosphere (TOA) infrared radiation evaluation, this work is new in that it offers efficiency and accuracy gains over traditional methods. Artificial neural network (ANN) utilized in the Pakistani cities of Karachi, Thatta, Mirpurkhas, Gilgit, Kalam, and Astore to predict average daily infrared variation. Over the course of seven years, the network trained, validated, and tested using infrared flux data from 2011 to 2018. With the aid of the hidden layer’s training and validation settings, the average daily infrared flux estimated. We will be able to investigate the changes in Earth’s climate throughout time, which impact by various factors, thanks to research of this kind. Mean Squared Error (MSE), Mean Absolute Percentage Error (MAPE), correlation coefficient, Root Mean Square Error (RMSE), and Mean Bias Error (MBE) calculated for the purposes of validating the statistical errors. The statistical errors demonstrate that the neural network model predicts infrared radiations for Thatta city well, while average predictions generated for Astore, Gilgit, and Kalam, and Mirpurkhas city, respectively. Astore exhibits the best correlation, followed by Thatta, Karachi, Kalam, Gilgit, and Mirpurkhas. Journal of Thermal Engineering Journal of Thermal Engineering 2026-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7509 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7509 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7509

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7508 2026-01-30T21:00:00Z 1

Experimental evaluation of a dual-use solar cooker for indoor and outdoor applications Faiq SAID, Qazi Muhammad YASEEN, Sahibzada Naveed Inayat ULLAH, Muneeb AHMAD, Farhan AHMAD, Zakir ULLAH, Mir Muhammad Mehran KHAN, Ibrar HUSSAIN Domestic Cooking; Parabolic Solar Cooker; Renewable Energy; Solar Cooker. The design, construction, and experimental assessment of a portable parabolic solar cooker intended for both indoor and outdoor use in Peshawar, Pakistan, are presented in this study. The cooker boiled one liter of water in 12 minutes (from 34 to 94 degrees Celsius), boiled an egg in 12 minutes, and fried an egg in just one minute. It also reached a maximum temperature of 200.6 degrees Celsius. An optical efficiency of 48.69% ± 2.5% and a thermal efficiency of 46.72% ± 2.8% were obtained from performance testing under average solar irradiance of 937.75 W/m² (787.49 W/m² at 60° tilt). In sunny conditions, it was shown to operate continuously for up to eight hours. This cooker exhibit better thermal concentration, portability (8.5 kg), and user-friendliness than previous parabolic designs (usually < 140 °C peak temperature and longer boiling times). These findings demonstrate its potential as an affordable, sustainable, and clean cooking option for both urban and rural populations. Journal of Thermal Engineering Journal of Thermal Engineering 2026-01-30T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7508 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7508 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:1 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7508

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7596 2026-03-31T21:00:00Z 1

Enhancement of exhaust manifolds using hybrid Graphene-TiO2 nano fluids in multi-cylinder diesel engines: A CFD study on TiO2 advantages Ramesh Kumar R, Channa Keshava Naik N, Ali B. M. ALI, Bharath L, Ahmed Kateb Jumaah AL-NUSSAIRI, Vijaykumar B P, Amir KHAN, Aseel SMERAT, Anwar KHAN Ansys 2024 R2; CFD; Graphene and TiO2; Nano Fluid; Performance This work is about graphene-TiO₂ hybrid nanofluid used for cooling a diesel engine exhaust manifold via coupled CFD simulations and experimental validation. The authors of this paper confirmed grid independence at more than 800 mesh elements with the pressure converging within -6 to 4 Pa. At 4.102 m/s velocity, the hybrid nanofluid caused a 7.016 Pa pressure drop, whereas the same for the conventional coolants was only 4.620 Pa thereby, the 52% rise in the pressure differential that correlates with the convective mixing enhancement. Streamline visualization depicted flow regularity improvement with the use of nanofluids, whereas turbulent kinetic energy increased steadily from 0.05 to 0.25 m²/s² over the 0-4 m/s velocity range, thereby promoting heat transfer directly. The enhancements in thermal conductivity of 5% and the heat transfer coefficients of 6% (with respect to the baseline fluid) have made it possible to reduce the peak manifold temperature by 340°C. The pressure gradient or the change in pressure remained very stable (within ±6 Pa) all over the domain, which is a clear indication that the hydrodynamic behavior was under control. The experimental data corroborated the CFD predictions with temperature and pressure drop accuracy percentages of 30% and 20%, respectively. These results confirm that graphene-TiO₂ nanofluids are capable of resulting in specific improvement metric of "15% faster heat dissipation" or "20°C lower operating temperatures" in automotive exhaust systems and establish a validated computational framework for nanofluid-based thermal management design in internal combustion engines. Journal of Thermal Engineering Journal of Thermal Engineering 2026-03-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7596 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7596 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7596

oai:https://eds.yildiz.edu.tr/journal-of-thermal-engineering/ajaxtool/oai:article/7583 2026-03-31T21:00:00Z 1

Experimental study of the heat transfer coefficient of an automobile radiator using alumina & titania based nanofluids as coolants Salman Basha SHEIK, Praveena Devi NAGIREDDY, Kiran Kumar KUPIREDDI Alumina; Ethylene Glycol; Heat Transfer; Nanofluids; Titania. Better engine cooling capability remains a desperate challenge in automotive heat management, as traditional water–ethylene glycol coolants regularly manifest limited heat transfer potential. This work investigates the improvement of radiator operation using alumina and titania-based nanofluids as a progressive heat-transfer approach. Nanofluids were produced by ultrasonic dispersion of nanoparticles (0.02–0.08 vol%) in water–ethylene glycol mixtures, followed by experimental testing in a customized automobile radiator test rig at an inlet temperature of 65°C and flow rates of 7–14 L min−1. The specific-heat equation was employed to determine the rate of heat transfer, and differential surface-fluid temperature analyses were used to obtain convective heat-transfer coefficients. The results show that adding alumina and titania nanoparticles notably enhances heat transfer. The hybrid nanofluid (0.06 vol% alumina + 0.02 vol% titania) achieved a highest heat transfer coefficient of nearly 6400 W m−2 K−1, depicting a 155.6% increase over distilled water and about 60% advancement compared to the base water–ethylene glycol mixture. Radiator efficacy improved by 25–47%, while specific heat capacity was reduced by up to 73%, specifying a faster heating–cooling reaction. The results proposed that nanoparticle-induced micro-convection and improved thermal conduction govern the observed enhancements. The novelty of this work lies in experimentally quantifying the integrated thermal impact of alumina–titania nanofluids under practical automotive conditions, extending existing literature focused primarily on single nanoparticles. These results provide design insights for developing high-efficiency cooling systems in electronic thermal management, automobiles, and renewable-energy heat exchangers. Journal of Thermal Engineering Journal of Thermal Engineering 2026-03-31T21:00:00Z Research Article application/pdf https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7583 ISSN: 2148-7847 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7583 Journal of Thermal Engineering, Year:2026, Vol:12, Issue:2 https://eds.yildiz.edu.tr/ajaxtool/GetArticleByPublishedArticleId?PublishedArticleId=7583