International Journal of Thermofluids最新文献

{"title":"Predictive modeling and optimization of noise emissions in a palm oil methyl ester-fueled diesel engine using response surface methodology and artificial neural network integrated with genetic algorithm","authors":"J.M. Zikri ,&nbsp;M.S.M. Sani ,&nbsp;M.F.F.A. Rashid ,&nbsp;J. Muriban ,&nbsp;G.S. Prayogo","doi":"10.1016/j.ijft.2025.101103","DOIUrl":"10.1016/j.ijft.2025.101103","url":null,"abstract":"<div><div>This research examines the predictive performance of two modeling techniques—Response Surface Methodology (RSM) and an Artificial Neural Network enhanced by a Genetic Algorithm (ANN-GA)—in relation to noise emission levels from a single-cylinder diesel engine running on palm oil methyl ester (POME). By employing different engine speeds and loads within the low to high range, noise emissions were recorded from multiple engine components to evaluate the performance of each predictive model. The outcomes of the experiments were contrasted with the forecasts produced by the RSM and ANN-GA models, emphasizing the goal of reducing error percentages. The analysis indicates that the ANN-GA model consistently yields predictions that align more closely with the experimental noise values compared to the RSM model. The average error for the ANN-GA model was 1.03%, significantly less than the 1.82% average error found with the RSM model. This demonstrates a significant enhancement in predictive accuracy using ANN-GA, highlighting its potential as a dependable tool for forecasting noise emissions in biodiesel-powered engines. Specific components, such as the radiator, crankshaft, and crankcase, exhibited minimal prediction errors under ANN-GA, suggesting that this model is particularly adept at capturing the complex noise emission patterns associated with POME-fueled engines. In summary, the results illustrate that the ANN-GA model outperforms the RSM model in predicting noise emissions under the conditions tested, providing a more accurate and effective method. These findings endorse the feasibility of applying ANN-GA in scenarios where precise noise prediction is crucial, particularly in relation to alternative fuels like POME.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"26 ","pages":"Article 101103"},"PeriodicalIF":0.0,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143167630","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 and mass diffusion in chemically reactive, radiative hybrid nanofluid (Cu and TiO2) flow over a rotating disk","authors":"Raja Ram Meena,&nbsp;Pooja Sharma","doi":"10.1016/j.ijft.2025.101104","DOIUrl":"10.1016/j.ijft.2025.101104","url":null,"abstract":"<div><div>The current research work is focused on thermal and mass transfer analysis on a hybrid nanofluid (water as a base fluid,) flow over a rotating disk with free convective, viscous dissipation, MHD, and radiation effects. The model was prepared in terms of the nonlinear PDEs and transformed into ODEs by using similarity analysis. Subsequently, it's solved numerically and graphically by ‘using the ‘bvp4c’ tool in MATLAB. The results depict that the fluid radial velocity can be enhanced by reducing the volume fraction of TiO₂, and the azimuthal velocity of the disc is improved, due to nanoparticle TiO₂ vol fraction and buoyancy force. Mass diffusion becomes low in the case of highly chemically reactive conditions. The flow characteristics are significantly influenced by variations in heat generation, thermal radiation, and MHD parameters. The calculated values of shear stress, Nusselt, and Sherwood numbers at the surface of the disk are also incorporated for complete verification. The deliberated model and graphical results have significant contributions in many fields like rotating machinery, lubricants, computer storage devices, viscometry, crystal growth process, etc.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"26 ","pages":"Article 101104"},"PeriodicalIF":0.0,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143167635","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":"Parametric study and optimization of thermal performance and pressure drop in heat sinks with double-layer porous microchannels","authors":"Fahimeh Aliyari,&nbsp;Keivan Fallah,&nbsp;Hossein Zolfaghary Azizi,&nbsp;Farhad Hosseinnejad","doi":"10.1016/j.ijft.2025.101085","DOIUrl":"10.1016/j.ijft.2025.101085","url":null,"abstract":"<div><div>In this study, the effective parameters in thermal performance and pressure drop of heat sinks with double-layer porous microchannels were investigated. Initially, a heat sink with porous fins was simulated in ANSYS Fluent 18, and the results were validated against reference data. Subsequently, 340 additional models were simulated with variations in parameters such as microchannel length and width, heat sink wall width and height, inter-channel distance, fluid velocity, and porosity levels (0, 20, 40, 60, and 80 percent). The results indicated that increasing porosity improved thermal performance in all samples, though it also led to higher pressure drops at higher porosity levels. Additionally, parallel flow demonstrated better thermal performance than counter flow across all samples. Reducing the microchannel length and width by 3 times and 4.3 times, respectively, and reducing the microchannel height by up to 4.5 times enhanced thermal performance; however, these changes significantly increased the pressure drop. The effect of flow velocity showed that decreasing the velocity led to a 12-times improvement in thermal performance, yet pressure drop increased by up to 70 times. These findings underscore the importance of optimizing geometric and operational parameters to achieve a balance between high thermal efficiency and acceptable pressure drop in the design of porous heat sinks. In the continuation of the research, the extracted parameters were used as inputs for optimization with a multi-objective genetic algorithm aimed at enhancing thermal performance and reducing pressure drop. Accordingly, the optimization process was pursued using the multi-objective genetic algorithm to find the optimal parameters that achieve the best thermal performance along with the lowest pressure drop, ensuring a desirable balance between improved thermal performance and reduced pressure drop. The convergence results obtained for two parameters in the optimization process demonstrated the success of the optimization method used and confirmed that the optimized parameters can effectively contribute to the enhancement of cooling system performance in industrial applications.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"26 ","pages":"Article 101085"},"PeriodicalIF":0.0,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143167644","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":"Computational and experimental representation of simplified gas turbine bearing chamber geometries","authors":"Ahmad H. Attia,&nbsp;Budi Chandra,&nbsp;C.A. Toomer","doi":"10.1016/j.ijft.2025.101097","DOIUrl":"10.1016/j.ijft.2025.101097","url":null,"abstract":"<div><div>Gas turbine engines depend on bearing chambers to support and lubricate moving parts, facilitating movement and heat dissipation. However, achieving a uniform oil coating on bearings remains a challenge, often leading to excessive oil consumption and in-flight oil loss. This research aims to establish accurate experimental and CFD methods to measure the residence time distribution (RTD) in a simplified linear geometry, progressing towards investigations in a cylindrical bearing chamber rig.</div><div>The first test case uses an inclined rectangular acrylic channel (140 cm length, 3 cm height, 5 cm width) with a 39° slope and flow rates ranging from 0.9 l/min to 2.7 l/min. This simplified geometry allows the study of fundamental oil film dynamics. The experimental setup is complemented by CFD modelling using the Volume of Fluid (VOF) approach with Large Eddy Simulations (LES) to model turbulence.</div><div>Validation demonstrates high level of accuracy, with film thickness measurements showing an error margin of 0.22 % at lower flow rates and up to 1.7 % at higher velocities. These results confirm the experimental setup and CFD model's reliability, offering a solid foundation for studying multiphase flows in bearing chambers. Future phases will incorporate oil for further validation and refinement.</div><div>The research question we are asking is: <strong><em>Can the proposed method accurately measure the residence time in an experimental setup?</em></strong></div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"26 ","pages":"Article 101097"},"PeriodicalIF":0.0,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143169681","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":"Implementation of the methodology for calculation of the three-phase equilibrium of hydrocarbons and the aqueous phase","authors":"Oleg Aksenov ,&nbsp;Mikhail Kozlov ,&nbsp;Eduard Usov ,&nbsp;Dmitry Taylakov ,&nbsp;Nikita Kayurov ,&nbsp;Alexander Cheremisin","doi":"10.1016/j.ijft.2025.101093","DOIUrl":"10.1016/j.ijft.2025.101093","url":null,"abstract":"<div><div>The paper discusses the development and implementation of the algorithm for calculation of the three-phase equilibrium in the hydrocarbon/aqueous system. The work is done as a part of PVT module improvement for the “d-Flow” hydraulic simulator which is under development at Novosibirsk R&amp;D Center LLC. The numerical methods used in the presented three-phase algorithm are simple and available in the literature, however these methods are often need to be improved and tuned before an actual application. In order to increase phase composition calculation stability, a modification for stationary point selection algorithm is proposed. Moreover, unexpected behavior of the algorithm may be revealed during implementation, which is not described in the original articles. This work attempts to present the three-phase equilibrium calculation algorithm ready for direct use in the designed hydraulic simulator and provide the detailed description for different aspects and difficulties of the implementation. The numerical schemes for the phase stability test and the calculation of equilibrium compositions are described, and the general equilibrium search algorithm is given. To test the algorithm, simulations of different mixtures are done and phase diagrams are presented for several mixtures. The solubility of hydrocarbons in water for binary mixtures is also calculated and compared with experimental data from the literature.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"26 ","pages":"Article 101093"},"PeriodicalIF":0.0,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143168151","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":"Performance evaluation of interrupted and hybrid channel heat sinks for a triple junction high concentrator photovoltaic cell","authors":"Muhammad Usman Sajid,&nbsp;Omer Abedrabboh,&nbsp;Yusuf Bicer","doi":"10.1016/j.ijft.2025.101102","DOIUrl":"10.1016/j.ijft.2025.101102","url":null,"abstract":"<div><div>High concentrator photovoltaic (HCPV) systems are designed to minimize the use of semiconductor materials by concentrating sunlight onto a smaller cell area. However, managing the excess heat generated during this concentration is a significant challenge, as it can affect the efficiency and lifespan of the HCPV cells. Effective thermal management solutions are essential to ensure reliable and cost-effective operation. The objective of this study is to propose interrupted and hybrid channel heat sinks designed to effectively maintain the temperature of HCPV systems within safe operating limits. The present work explores the impact of heat sink channel configuration, concentration ratio, and Reynolds number on the performance of a high concentration triple-junction solar cell. A comprehensive thermal model was developed in COMSOL Multiphysics, and numerical results were validated against multiple sets of available experimental and computational data, ensuring both accuracy and reliability. The results reveal that the hybrid channel design (Geometry F) significantly reduces the maximum solar cell temperature from 82 °C to 78 °C at CR = 1500 and <em>Re</em> = 400, achieving up to a 39.5 % increase in the Nusselt number compared to the conventional straight channel design (Geometry A). Additionally, Geometry (F) maintains a high performance evaluation criterion (PEC) value of 1.22 at <em>Re</em> = 200, reflecting effective thermal-hydraulic performance. Furthermore, Geometry (F) reduces the heat sink weight by 3.7 %, which is particularly advantageous for sun-tracking applications, where minimizing weight is essential.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"26 ","pages":"Article 101102"},"PeriodicalIF":0.0,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143167657","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":"CFD analysis of the main operating parameters for a complete braking friction system under transient working conditions","authors":"F. Orlandi ,&nbsp;C. De Marco ,&nbsp;S. Meleti ,&nbsp;A. Manian ,&nbsp;M. Milani ,&nbsp;L. Montorsi","doi":"10.1016/j.ijft.2025.101100","DOIUrl":"10.1016/j.ijft.2025.101100","url":null,"abstract":"<div><div>A braking system represents a very complex physical system to be properly modelled since it involves the solution of multiphase flow and thermal distribution and multi-body motions under dynamic operating conditions. Most approaches focus on a single braking element coupling, generally between a steel and a friction material element, which demonstrated to be insufficient to predict the effective behaviour of these systems. The present work extends the approach adopted for a single braking couple, to include a full braking system including the disks and braking piston motions and the thermal dissipated energy along the braking event. The comprehensive numerical model allows to deeply analyse the thermal dissipation of the solid elements and the oil of the systems and thus the cooling efficiency of the lubricant oil can be calculated. Furthermore, a sensitivity analysis with respect of the main braking system operating parameters is carried out to investigate the influence of heat dissipation rate of the oil and the cooling efficiency of the full braking system. In particular, the lubricant oil flow rate, the thermal energy to be dissipated and the characteristic braking time are analysed. The most critical operating conditions are highlighted as well as the optimal configuration is defined.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"26 ","pages":"Article 101100"},"PeriodicalIF":0.0,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143169680","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":"Experimental investigation of thermal characteristics of a 12S1P Li-ion NMC-21700 battery module under different environments for EV applications","authors":"Jay Patel,&nbsp;Rajesh Patel,&nbsp;Rajat Saxena,&nbsp;Abhishek Nair","doi":"10.1016/j.ijft.2025.101084","DOIUrl":"10.1016/j.ijft.2025.101084","url":null,"abstract":"<div><div>The rapid growth of electric vehicles (EVs) has placed significant emphasis on the performance and safety of lithium-ion (Li-ion) batteries, which serve as the primary energy storage solution. Effective thermal management is crucial to ensure battery safety, longevity, and efficiency, particularly under high discharge rates where excessive heat generation can compromise performance. This study examines the thermal behaviour of a 4 × 3 Li-ion nickel-cobalt-manganese (NCM)-21,700 battery module with a 12S1P configuration. The focus of this study is to mitigate the challenges associated with heat generation at high discharge rates. Experiments are performed on a single NCM-21,700 cell to estimate the heat generation during charge and discharge. Based on this heat generation data, several experiments are performed on the 4 × 3 battery module under different thermal environments. These environments include natural convection, battery case, and phase change material (PCM) inside the battery case. The objectives of this study are to mitigate heat generation and ensure effective thermal management. The findings of these experiments demonstrate that despite being simple and economical, natural convection is insufficient as the temperature of the battery module rises significantly at high discharge rates. Although standard EV applications do not exceed the range of 0.3–0.6 C-rate, our study is focussed on extreme conditions of 1C and 2C rates. The maximum battery cell temperature in the battery module was found to be 48 °C and 53 °C for 1C and 2C discharge rates, respectively. The maximum temperature difference in the battery module was found to be 6 °Cand 13 °C for 1C and 2C discharge rates, respectively. The maximum temperature and maximum temperature difference of the battery module for PCM were reduced to 20 % and 45.45 % compared to conventional natural convection, respectively for a 1C discharge rate. PCM-based cooling provides better thermal uniformity across the battery module, helps to avoid thermal hotspots, and provides even performance across the battery module. The maximum temperature in any battery module is observed at the central cell due to the lesser space for heat dissipation. The results underscore the need for specialized cooling techniques for enhanced battery life, safety, and performance of high-energy Li-ion batteries in EV applications. This study also offers insights into efficient thermal management techniques for EV battery modules.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"26 ","pages":"Article 101084"},"PeriodicalIF":0.0,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143169682","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":"Entropy formation in the radiative flow of bioconvective Oldroyd-B nanofluid across an electromagnetic actuator with second-order slip: Active and passive control approach","authors":"K. Loganathan ,&nbsp;N. Thamaraikannan ,&nbsp;S. Eswaramoorthi ,&nbsp;Sanju Jangid ,&nbsp;Reema Jain","doi":"10.1016/j.ijft.2025.101099","DOIUrl":"10.1016/j.ijft.2025.101099","url":null,"abstract":"<div><div>This research communication provides the impact of heat-mass transmission of Oldroyd-B nanofluid flow having gyrotactic microorganisms past a heated Riga plate. A non-Fourier model is thought to be the one that describes heat and mass fluxes. Second-order slip conditions are introduced into the flow velocity. To develop governing models, a partial differential system is initially built. This system is translated into an ordinary differential model by applying the relevant transformations. Solutions based on convergent series are used to solve the ordinary differential system. Detailed illustrations are presented for the effects of numerous physical factors on nanofluid velocity, thermal, nanofluid concentration, motile microbe density, skin friction coefficient, local Nusselt number, local Sherwood number, motile density microorganism, entropy, and Bejan number profiles. The relaxation and retardation time parameters lead to downturns in the fluid velocity profile. The thermal profile intensifies when enlarging the values of Eckert number and radiation parameter. The chemical reaction parameter and Lewis number play an opposite roles in the nanofluid concentration profile. The bioconvection Lewis number downturns the microorganism profile. Modified Hartmann number causes a reduction in both entropy and Bejan number profiles.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"26 ","pages":"Article 101099"},"PeriodicalIF":0.0,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143167645","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":"Nonlinear normalized fractional electroosmotic spacelike fluid model","authors":"Talat Körpinar ,&nbsp;Zeliha Körpinar ,&nbsp;Ali Akgül ,&nbsp;Qasem Al-Mdallal","doi":"10.1016/j.ijft.2025.101057","DOIUrl":"10.1016/j.ijft.2025.101057","url":null,"abstract":"<div><div>In this paper, we present optical recursively fractional <span><math><mrow><mi>SK</mi><mi>μ</mi><mo>−</mo></mrow></math></span>electroosmotic fractional recursively<span><math><mrow><mi>SK</mi><mi>μ</mi><mo>−</mo></mrow></math></span>energy. Also, we have spacelike microfluidicsfractional <span><math><mrow><mi>SK</mi><mi>μ</mi><mo>−</mo></mrow></math></span> electroosmotic recursively tension energy. Moreover, we construct main Katugampola recursive-normal hyperbolic fractional <span><math><mrow><mi>KF</mi><mi>α</mi><mo>−</mo></mrow></math></span>tension field in hyperbolic space. Finally, we characterize spacelike radiative recursively fractional <span><math><mrow><mi>SK</mi><mi>μ</mi><mo>−</mo></mrow></math></span> phase in hyperbolic space.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"26 ","pages":"Article 101057"},"PeriodicalIF":0.0,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143168164","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}