International Journal of Thermofluids最新文献

{"title":"Theoretical analysis of effect of MHD, couple stress and slip velocity on squeeze film lubrication of rough Triangular plates","authors":"","doi":"10.1016/j.ijft.2024.100882","DOIUrl":"10.1016/j.ijft.2024.100882","url":null,"abstract":"<div><div>In this study, Christensen's stochastic theory is utilized on rough surfaces' hydrodynamic lubricating effect to examine how surface roughness, couple stress fluid, slip velocity, magnetohydrodynamic (MHD), and the triangular surface interact. Modified Reynolds equation is derived analytically using combining theories of Stokes couple stresses, Lorentz forces, and Christensen's stochastic hypothesis about hydrodynamic lubrication. Pressure, load carrying capacity and squeeze film time expression is derived mathematically using Reynolds equation that accounts for surface roughness and coupling stress. For various parameters including rough parameter, slip velocity, Hartmann number, and couple stress, the lubricating characteristics are analysed graphically. Squeeze film time, load carrying capacity, and pressure are enhanced by an increase in slip velocity, couplestress and magnetic field. The lubrication characteristics decreases (increases) on squeeze film pressure, load carrying capacity and squeeze film time through increasing values of the longitudinal (transverse) roughness parameter.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142358466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Features of Soret and Dufour effects on an unsteady mixed convection nanofluid flow about a revolving Riga cone","authors":"","doi":"10.1016/j.ijft.2024.100883","DOIUrl":"10.1016/j.ijft.2024.100883","url":null,"abstract":"<div><div>Temperature, concentration, and composition gradients may all produce mass and energy fluxes when heat and mass transfer occur concurrently in a flowing fluid. This has ramifications for several industries, including aircraft and thermal engineering. The present study focuses on the numerical modelling of an Ag-kerosene oil nanofluid spinning in a rotating cone with time-dependent angular velocities affected by heat and mass diffusion. The cone Riga surface creates an external electric field that causes the wall to paralleled Lorentz force, which regulates the nanofluid flow. The effects on the heat and mass distributions of the diffusion-thermo (Dufour) and thermal-diffusion (Soret) are all considered. Similarity analysis yields a non-dimensional system of ODEs, and the shooting technique with the Runge-Kutta-Fehlberg scheme is then used to carry out the simulation. Graphs are used to illustrate the parametric analysis of the different flow profiles and the validation with the existing study is demonstrated with a strong connection in this specific scenario. It is observed that the flow dynamics were affected by the spinning Riga cone shape that generates centrifugal forces, which result in complicated thermal dispersion and flow pattern features.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142358467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comprehensive assessment and energetic-exergetic performance optimization of a new solar thermal electricity system based on Scheffler-type receivers combined with screw-type volumetric machines","authors":"","doi":"10.1016/j.ijft.2024.100881","DOIUrl":"10.1016/j.ijft.2024.100881","url":null,"abstract":"<div><div>This study explores the potential of a novel solar-powered cascade Rankine cycle system based on Scheffler-type receivers combined with screw expanders. Specifically, in this solar power system, steam is generated in the Scheffler-type receiver, which proves to be well performing compared with other technological solutions to exploit solar energy, due to satisfactory efficiency of the focal receiver that is able to curtail heat losses, even at high evaporation temperatures. Subsequently, steam expands in the screw machines which, unlike conventional steam turbines, are specially fitting in energy conversion with vapor-liquid mixes in the field from tens to hundreds of kW. In the present study, comprehensive assessment of this renewable energy power system is thoroughly conducted in a large range of operating states. For this purpose, specific numerical models and basic criteria fixed for the screw expanders and Scheffler receivers part-load behavior are combined with thermodynamic formulations established for energetic-exergetic performance optimization of the entire solar thermal electricity plant. Hence, parametric optimization of the major thermodynamic factors involved at part-load operating situations is conducted to enhance the energetic and exergetic efficiencies of the designed solar thermal power system.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142322941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cascaded lattice Boltzmann simulation of Newtonian and non-Newtonian mixture nanofluids with variable thermophysical properties in a cavity with vertical heat radiator","authors":"","doi":"10.1016/j.ijft.2024.100865","DOIUrl":"10.1016/j.ijft.2024.100865","url":null,"abstract":"&lt;div&gt;&lt;div&gt;The central moments-based cascaded lattice Boltzmann method (CLBM) for then Newtonian and non-Newtonian Buongiorno’s model mixture nanofluids (CuO, ZnO, Al&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;O&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;-water) has been implemented and applied in a square chamber with a vertical heat radiator using accelerated graphics processing unit (GPU) computing through compute unified device architecture (CUDA) C/C++ platform. Due to the higher numerical stability, the CLBM is a superior numerical tool to the raw moments-based MRT-LBM (multiple-relaxation-time lattice Boltzmann method). Three different models for the viscosity and thermal conductivity of the nanofluids: (i) the Binkmann model for the constant viscosity and the Maxwell model for the constant thermal conductivity (ii) Binkmann and Maxwell model with temperature dependent Brownian motion and (iii) Corcione model with non-Newtonian fluid where the temperature and strain rate determine the nanofluid effective thermal conductivity and viscosity, have been used. The enclosure’s upper and bottom walls are thermally adiabatic, but the left and right walls are uniformly cold. A vertical heater is immersed in the middle position of the cavity. The benchmark results for non-Newtonian, Newtonian, and nanofluids for the various computational domains are used to validate the current code adequately. The Bingham number (&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;B&lt;/mi&gt;&lt;mi&gt;n&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;), the Rayleigh number (&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;), and The volume fraction of the nanoparticles (&lt;span&gt;&lt;math&gt;&lt;mi&gt;ϕ&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt;) are the three key parameters that are varied in this investigation to demonstrate the effects of natural convection on the isotherms, streamlines, isolines of nanoparticle volume fractionation, yielded and unyeilded zone, and average Nusselt number (&lt;span&gt;&lt;math&gt;&lt;mover&gt;&lt;mrow&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;mi&gt;u&lt;/mi&gt;&lt;/mrow&gt;&lt;mo&gt;¯&lt;/mo&gt;&lt;/mover&gt;&lt;/math&gt;&lt;/span&gt;). The Brownian motion effects of the nanoparticles augmented the average rate of heat transfer and the use of the Bingham nanofluids reduced the heat transfer enhancement. For the CuO-water nanofluid, the augmentation of the rate of heat transfer is 15.42% from &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;ϕ&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; to 4% while &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;6&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; and the corresponding heat transfer enhancement for the ZnO-water nanofluid is 11.11%. For the Bingham fluid, the rate of heat transfer increases 7% from &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;5&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; to &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;6&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; while &lt;span&gt;&lt;math&gt;&lt;mro","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142322943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced distilled water productivity using an innovative semi-cylindrical tent-shaped solar still coupled with evacuated tubes","authors":"","doi":"10.1016/j.ijft.2024.100880","DOIUrl":"10.1016/j.ijft.2024.100880","url":null,"abstract":"<div><div>Despite advances in enhancing the output of conventional solar stills, the pursuit of the most efficient solar distillation technique remains ongoing. Evacuated tubes, known for their superior thermal capacity compared to traditional single-basin solar stills, offer a promising solution for high-yield distillation. This study evaluates the performance of a semi-cylindrical tent-shaped solar still coupled with evacuated tubes (SCTSCET) against a conventional single-basin, single-slope solar still, used as a benchmark. Experiments conducted in Amman, Jordan, in May 2023, demonstrate that the SCTSCET significantly outperforms the conventional solar still in distilled water production. The SCTSCET achieved a daily yield of up to 9.7 liters, which is approximately 288 % higher than the 2.5 liters produced by the conventional still. This increased productivity is due to a 45.7 % enhancement in heat capacity provided by the evacuated tubes, which raised the water basin temperature to 61.4 °C, compared to 41.2 °C in the conventional still. This higher temperature facilitated a faster evaporation rate and improved water output. Additionally, the SCTSCET exhibited a 10 % higher hourly thermal efficiency and a peak exergy efficiency of 5.7 %, compared to 3.4 % for the conventional still, highlighting its superior ability to harness and utilize solar energy for distillation.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142358464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal analysis in unsteady oscillatory Darcy blood flow through stenosed artery","authors":"","doi":"10.1016/j.ijft.2024.100864","DOIUrl":"10.1016/j.ijft.2024.100864","url":null,"abstract":"<div><div>This study aims to provide an extensive overview of the consequences of heat source and thermal radiation on blood flow in stenosed arteries through Casson fluid. We examine the behaviour of an unsteady non-Newtonian fluid under oscillatory Darcy flow. This analysis explores the impact of blood flow in the stenosed arteries on the momentum and energy profiles of the Casson fluid. In addition, this study examines a parametric analysis to illustrate the impact of the Nusselt number and Casson parameter. Higher values of the thermal radiation and Casson-Viscous parameters result in enhanced velocity fields. The Brinkman model accurately represents the resistance to flow caused by the porous material, known as Darcy resistance. The inner space of the coronary artery generates cholesterol-rich fatty plaques and blood clots that block the artery, simulating the diseased condition of blood circulation in this study. We employ a set of non-dimensional variables to convert the governing equations of the current flow into dimensionless partial differential equations. Analytical methods have derived a solution for the studied problem. The discovery is pertinent to the natural circulation of blood through coronary arteries, which are highly porous. A particular artery pathology creates a permeable structure within the arterial lumen. The current study demonstrates that blood flow may be manipulated by adjusting the intensity of the external magnetic field, while the temperature of the blood can be managed by either increasing or decreasing its thermal conductivity. The graphical representation demonstrates the impact of different physical parameters on velocity, temperature, and concentration profiles. The significant results of the current studies are that, the fluid velocity diminishes with rising magnetic and Biot numbers but exhibits an increase when considering the Darcy number and Hall parameter. There is a gentle increase in the wall shear stress as the Casson parameter (<span><math><mi>β</mi></math></span>) increases from <em>0.1</em> to <em>0.3</em>. For <span><math><mi>β</mi></math></span> <em>= 0.3</em>, the percentage change along the axial direction (<em>x</em>) is more pronounced. This is because the wall shear stress is proportional to the number of Casson parameters.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666202724003057/pdfft?md5=037e39a7191e18fd18e6d39a5fddfe9c&pid=1-s2.0-S2666202724003057-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142310270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal performance of nanofluid natural convection magneto-hydrodynamics within a chamber equipped with a hot block","authors":"","doi":"10.1016/j.ijft.2024.100873","DOIUrl":"10.1016/j.ijft.2024.100873","url":null,"abstract":"<div><div>In this study, flow and free convection thermal performance within a chamber in the presence of a permanent magnetic field are simulated. Boussinesq approximation and the Lorentz force equation are used for the density variation in free convection, and the magnetic field, respectively. The steady-state, two-dimensional, and incompressible governing equations are simulated using the Semi-Implicit Method for Pressure Linked Equations (SIMPLE). The present study is simulated for different Rayleigh numbers (Ra) corresponding to the situation where the conduction mechanism was predominant (<em>Ra</em>  =  100) and the convection heat transfer was predominant (<em>Ra</em>  =  10⁵). Also, different intensities of the magnetic field (0 ≤ <em>Ha</em>  ≤ 40) and different directions of the magnetic field along with the effects of three different nanoparticles Ag, Cu, and <em>Al</em>₂<em>O</em>₃ are given. The present study showed that in the case of the dominant convection mechanism, the presence of the magnetohydrodynamics (MHD) condition decreases the Nusselt number (Nu). However, if the conduction is predominant, the applied magnetic field improves the average Nu number. The optimum state for the magnetic field strength was found in the low Rayleigh number. The presence of nanoparticles also intensifies the magnetic field effects. In the high Rayleigh number, the heat transfer rate reduces by 13.5% with the increase of the Hartmann number.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142358457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Wire mesh-based heat transfer enhancement in absorber tube of solar collector-An experimental study","authors":"","doi":"10.1016/j.ijft.2024.100878","DOIUrl":"10.1016/j.ijft.2024.100878","url":null,"abstract":"<div><div>Urbanization and technological progress have intensified the demand for energy efficiency, prompting a shift towards renewable sources like solar energy. Among solar technologies, the parabolic trough collector stands out for capturing sunlight efficiently. Various methods, including optical concentration and improved fluid heat transfer, are employed to enhance the performance. This study investigates the thermal enhancement in the absorber tube of a parabolic trough solar collector using inserts like wire mesh twisted tape and circular ring wire mesh. Thermal oil Sigma therm K is taken as a working fluid at a constant mass flow rate of 0.18 kg/s. Parameters considered include Nusselt number, friction factor, and performance evaluation criteria for assessing the performance of inserts. Absorber tube made of copper with an internal diameter of 22 mm and 1300 mm length were taken. Wire mesh twisted tape of pitch 80 mm and circular ring wire mesh of diameter 18 mm have been tested. Experiments were conducted inside the laboratory with three different configurations, i.e., plain tube, wire mesh twisted tape, and circular ring wire mesh, for a duration of 50 min. The result reveals that circular ring wire mesh exhibits the highest thermal enhancement compared to wire mesh twisted tape and plain tube. The PEC of wire mesh twisted tape is 1.17, and the PEC of circular ring wire mesh is 1.34, proving the wire mesh inserts' efficacy. These findings validate the effectiveness of augmentation techniques that can be implemented to improve the performance of the solar collector.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142319155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical investigation of different transverse Rib shapes on thermal convection in a channel filled with nanofluid","authors":"","doi":"10.1016/j.ijft.2024.100872","DOIUrl":"10.1016/j.ijft.2024.100872","url":null,"abstract":"<div><div>With the growing interest in energy optimization, corrugated surfaces are arguably an excellent choice, finding applications in areas as diverse as heat exchangers, automobiles, building energy efficiency, and chemical reactors. However, due to the poor thermal properties of conventional fluids, heat transfer is limited. The introduction of nanoparticles into fluids is a promising solution to improve their thermal performance. This paper does a detailed numerical analysis of how different factors affect the forced convection heat transfer in a two-dimensional ribed channel. The shape of the ribs is one of the factors that are looked at, along with some new parameters like e/H, which is the ratio of rib height to channel height, and L₂/P, which is the test section to the pitch between the ribs. The aim is to determine the optimum geometry that maximizes the Nusselt number while minimizing the pressure drop. The study also examines the effects of nanoparticle type and concentration on heat transfer and fluid flow characteristics. To this end, the continuity, momentum, and energy equations were solved with the finite volume method using the SIMPLE scheme with the k-ε turbulence model at different Reynolds numbers ranging from 4000 – 14,000. The results indicate that triangular ribs with ratios e/H = 0.15 and L₂/P = 4 increase the Nusselt number by 63.3 % while reducing the pressure drop by 22 % compared with the other cases. The improvement in heat transfer in the water-SiO₂ case was the greatest compared with the other nanofluids tested. Particle size fraction and Reynolds number increased the Nusselt number in ribbed channels by 20.7 % compared with water.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666202724003136/pdfft?md5=faca4deda03292927c26a0d6dcb24290&pid=1-s2.0-S2666202724003136-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142310271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing the melting rate of RT42 paraffin wax in a square cell with varied copper fin lengths and orientations: A numerical simulation","authors":"","doi":"10.1016/j.ijft.2024.100877","DOIUrl":"10.1016/j.ijft.2024.100877","url":null,"abstract":"<div><div>Latent thermal energy storage units are especially preferred in renewable thermal energy systems for their significant capacity to store heat. Nevertheless, the phase change materials in these units have low thermal conductivity, prompting researchers to tackle this problem using several methods, such as incorporating fins. This numerical study contributes to improving the charging rate of a square cell (50 × 50 mm) used paraffin wax RT42 as phase change material by adding 4 copper fins inside, 1 mm thick and of different lengths. The fins were positioned on the left wall, where a constant-temperature heat flux was applied, while the other walls were thermally insulated. Four configurations of the cell were examined: without fins, with 10 mm length fins, with 20 mm length fins, and with 30 mm length fins, respectively. The results demonstrated that the presence of fins significantly improved the charging rate of the square cell. Compared to the baseline configuration without fins, the time required for the paraffin wax RT42 to completely melt was reduced by 22.22 %, 33.33 %, and 55.56 % with fins of 10 mm, 20 mm, and 30 mm lengths, respectively. Configuration four was also compared with a setup where similar fins were positioned on the bottom wall while maintaining the heat flux on the left wall. It was observed that the total melting time doubled compared to configuration four, suggesting that the optimal placement for the heat flux is on the wall where the fins are located. The study contributes to enhancing and developing the charge rates of square and rectangular PCM cells such as these used for cooling PV panels.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142322938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}