Pub Date : 2026-04-01Epub Date: 2026-02-28DOI: 10.1016/j.csite.2026.107877
Hisham M. Almongy , I. Elbatal , A.E. Kabeel , Wissam H. Alawee , Z.M. Omara , Fadl A. Essa , T.E.M. Atteya , Samah M. Elkholy
Solar distillation represents a sustainable solution for freshwater production in water-scarce regions. However, conventional solar stills (CSS) face significant limitations including low productivity rates, substantial heat losses through rear walls, and inefficient utilization of solar radiation. The study integrates three modifications: (1) a water unit (WU) for heat loss reduction, (2) a vertical wick solar still (VWSS) for hot water feeding, and (3) PCM enhanced with silver nanoparticles for thermal storage. The integrated system CSS + WU + VWSS + PCM-Ag was tested against conventional CSS. Results demonstrated that the fully integrated system (CWCSS + WU + VWSS with PCM-Ag) achieved cumulative daily productivity of 13,250 mL/m2, representing a 327% improvement over conventional solar stills producing 3100 mL/m2. The modified system also reduced the cost of distilled water from 0.024 $/L to 0.013 $/L. These findings confirm that integrated modifications combining heat loss reduction, hot water feeding, and thermal storage substantially enhance solar still performance while maintaining economic viability. The study recommends further optimization of nano-enhanced PCM configurations and extended testing under varying climatic conditions.
{"title":"Enhanced conventional solar still performance with water unit, vertical wick system, and PCM-Ag nano integration","authors":"Hisham M. Almongy , I. Elbatal , A.E. Kabeel , Wissam H. Alawee , Z.M. Omara , Fadl A. Essa , T.E.M. Atteya , Samah M. Elkholy","doi":"10.1016/j.csite.2026.107877","DOIUrl":"10.1016/j.csite.2026.107877","url":null,"abstract":"<div><div>Solar distillation represents a sustainable solution for freshwater production in water-scarce regions. However, conventional solar stills (CSS) face significant limitations including low productivity rates, substantial heat losses through rear walls, and inefficient utilization of solar radiation. The study integrates three modifications: (1) a water unit (WU) for heat loss reduction, (2) a vertical wick solar still (VWSS) for hot water feeding, and (3) PCM enhanced with silver nanoparticles for thermal storage. The integrated system CSS + WU + VWSS + PCM-Ag was tested against conventional CSS. Results demonstrated that the fully integrated system (CWCSS + WU + VWSS with PCM-Ag) achieved cumulative daily productivity of 13,250 mL/m<sup>2</sup>, representing a 327% improvement over conventional solar stills producing 3100 mL/m<sup>2</sup>. The modified system also reduced the cost of distilled water from 0.024 $/L to 0.013 $/L. These findings confirm that integrated modifications combining heat loss reduction, hot water feeding, and thermal storage substantially enhance solar still performance while maintaining economic viability. The study recommends further optimization of nano-enhanced PCM configurations and extended testing under varying climatic conditions.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"80 ","pages":"Article 107877"},"PeriodicalIF":6.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147330302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Stirling engines are significant for their high efficiency, low emissions, and capability to use various heat sources for renewable energy systems, waste heat recovery, and applications where low maintenance is crucial. Hydrogen-powered Stirling engines combine the high efficiency of Stirling engines with the clean-burning nature of hydrogen fuel. This study introduces a new approach by optimizing the air inlet angle in a hydrogen-fueled Stirling engine using CFD simulations. The effects of air inlet angle variation (60°, 90°, and 120°) on the performance of a hydrogen-fueled Stirling engine are studied. Unlike prior studies focusing on fuel type or scale, this work highlights the effects of inlet geometry on inducing combustion dynamics, thermal behavior, and engine performance. The parameters such as power output, thermal efficiency, hydrogen mass fraction, velocity, peak temperature, and flow organization are examined. Results show that the 90° air inlet angle offers the best performance, improving thermal efficiency and power output by 15% and 17.6%, respectively, compared to the 60° angle case, and by 12% and 11% compared to the 120° angle configuration. Enhanced performance is attributed to improved mixing, more complete hydrogen combustion, and a 28% increase in peak temperature. In contrast, the 60° case causes less efficient flow patterns and delayed combustion. These insights present a valuable framework for optimizing inlet angle design in hydrogen-fueled Stirling engines, advancing their potential for sustainable energy applications.
{"title":"Effect of air inlet angle variation on the efficiency of hydrogen-powered Stirling engines","authors":"Heba Alzaben , Ahmad Aljabr , S.A. Marzouk , Saad Alshammari , Dame Ayane","doi":"10.1016/j.csite.2026.107830","DOIUrl":"10.1016/j.csite.2026.107830","url":null,"abstract":"<div><div>Stirling engines are significant for their high efficiency, low emissions, and capability to use various heat sources for renewable energy systems, waste heat recovery, and applications where low maintenance is crucial. Hydrogen-powered Stirling engines combine the high efficiency of Stirling engines with the clean-burning nature of hydrogen fuel. This study introduces a new approach by optimizing the air inlet angle in a hydrogen-fueled Stirling engine using CFD simulations. The effects of air inlet angle variation (60°, 90°, and 120°) on the performance of a hydrogen-fueled Stirling engine are studied. Unlike prior studies focusing on fuel type or scale, this work highlights the effects of inlet geometry on inducing combustion dynamics, thermal behavior, and engine performance. The parameters such as power output, thermal efficiency, hydrogen mass fraction, velocity, peak temperature, and flow organization are examined. Results show that the 90° air inlet angle offers the best performance, improving thermal efficiency and power output by 15% and 17.6%, respectively, compared to the 60° angle case, and by 12% and 11% compared to the 120° angle configuration. Enhanced performance is attributed to improved mixing, more complete hydrogen combustion, and a 28% increase in peak temperature. In contrast, the 60° case causes less efficient flow patterns and delayed combustion. These insights present a valuable framework for optimizing inlet angle design in hydrogen-fueled Stirling engines, advancing their potential for sustainable energy applications.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"80 ","pages":"Article 107830"},"PeriodicalIF":6.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147330152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-04-01Epub Date: 2026-03-05DOI: 10.1016/j.csite.2026.107912
Mumtaz Khan , M.S. Anwar
The thermal management of microfluidic devices and renewable energy systems relies heavily on the efficient transport of non-Newtonian fluids. Specifically, these electro-kinetic and transport mechanisms are directly applied in the real-world design of electro-kinetic micropumps and biomedical lab-on-a-chip devices. Fractional calculus extends classical differentiation to non-integer orders, enabling realistic modeling of systems with memory and spatial nonlocality. This study examines the unsteady electro-osmotic flow of a Walter-B viscoelastic fluid past a semi-infinite vertical plate embedded in a Darcy porous medium under a transverse magnetic field. The model incorporates thermal radiation, internal heat generation, Soret-Dufour cross-diffusion, and a first-order chemical reaction, while Caputo fractional derivatives are used to represent memory-dependent heat and mass diffusion mechanism. The governing equations are non-dimensionalized and solved numerically using a fully implicit finite-difference scheme based on the second-order fractional backward-difference formula (FBDF2), ensuring stability and accuracy. To the best of the authors’ knowledge, this is the first study that combines fractional electro-osmotic Walter-B flow with simultaneous Soret–Dufour effects and chemical reaction within an FBDF2-based fully implicit finite-difference framework. The results reveal that smaller fractional orders intensify memory effects and delay thermal and solutal relaxation, reflecting the inherent nonlocality of fractional transport. Quantitatively, the Soret number enhances the heat transfer rate by approximately 5.38% while reducing the mass transfer rate by about 11.02%. The radiation parameter markedly improves thermal transport, producing nearly 33.36% enhancement in the Nusselt number. In contrast, the thermal Grashof number slightly reduces the skin-friction coefficient by 3.20%, whereas the electro-osmotic parameter decreases it by 7.95%. Moreover, the Dufour number yields a modest 2.10% increase in the Sherwood number.
{"title":"Numerical simulation of fractional electro-osmotic Walter-B flow in a magnetized porous medium with Soret–Dufour and chemical reaction effects","authors":"Mumtaz Khan , M.S. Anwar","doi":"10.1016/j.csite.2026.107912","DOIUrl":"10.1016/j.csite.2026.107912","url":null,"abstract":"<div><div>The thermal management of microfluidic devices and renewable energy systems relies heavily on the efficient transport of non-Newtonian fluids. Specifically, these electro-kinetic and transport mechanisms are directly applied in the real-world design of electro-kinetic micropumps and biomedical lab-on-a-chip devices. Fractional calculus extends classical differentiation to non-integer orders, enabling realistic modeling of systems with memory and spatial nonlocality. This study examines the unsteady electro-osmotic flow of a Walter-B viscoelastic fluid past a semi-infinite vertical plate embedded in a Darcy porous medium under a transverse magnetic field. The model incorporates thermal radiation, internal heat generation, Soret-Dufour cross-diffusion, and a first-order chemical reaction, while Caputo fractional derivatives are used to represent memory-dependent heat and mass diffusion mechanism. The governing equations are non-dimensionalized and solved numerically using a fully implicit finite-difference scheme based on the second-order fractional backward-difference formula (FBDF2), ensuring stability and accuracy. To the best of the authors’ knowledge, this is the first study that combines fractional electro-osmotic Walter-B flow with simultaneous Soret–Dufour effects and chemical reaction within an FBDF2-based fully implicit finite-difference framework. The results reveal that smaller fractional orders intensify memory effects and delay thermal and solutal relaxation, reflecting the inherent nonlocality of fractional transport. Quantitatively, the Soret number enhances the heat transfer rate by approximately 5.38% while reducing the mass transfer rate by about 11.02%. The radiation parameter markedly improves thermal transport, producing nearly 33.36% enhancement in the Nusselt number. In contrast, the thermal Grashof number slightly reduces the skin-friction coefficient by 3.20%, whereas the electro-osmotic parameter decreases it by 7.95%. Moreover, the Dufour number yields a modest 2.10% increase in the Sherwood number.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"80 ","pages":"Article 107912"},"PeriodicalIF":6.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147387309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-04-01Epub Date: 2026-03-10DOI: 10.1016/j.csite.2026.107932
Zhi Zhu , Hao He , Tosin Famakinwa , Y.X. Zhang , Helen Wu , David Fox , Richard (Chunhui) Yang
Numerical simulation-based digital twins are emerging as a transformative technology capable of significantly enhancing operational efficiency and minimising costly maintenance and human intervention for smart products and services. However, the inherent limitations of physical monitoring and the uncertainties associated with product or service performance can be effectively addressed through the strategic application of parameterised numerical models combined with advanced machine learning (ML) algorithms. To address the research gap, this research investigates how a novel and systematic digital-twin-based design and analysis approach can facilitate the transformation of a conventional Shell-and-Tube Heat Exchanger (STHE) into a smart machine within the evolving framework of Industry 4.0. The methodology involves devising a data-driven digital twin (DT) for the STHE, utilising coupled Computational Fluid Dynamics (CFD) and Finite Element Analysis (FEA) simulations to numerically investigate key performance parameters. This process enables the integration of virtual sensors, the fusion of physical measurements, and the deployment of advanced machine learning algorithms to precisely identify critical points for sensor and actuator placement in an Internet of Things (IoT)-based machine condition monitoring (MCM) system. The developed STHE digital twin successfully demonstrates its capability to extract data of key performance parameters, which enables seamless integration with sensors and actuators. This digital twinning further empowers a digital design and prototyping process for visualiszed, real-time IoT based machine condition monitoring. Advanced ML algorithms are employed to identify the locations of the critical points in the STHE, where sensors are installed for IoT-based MCM. The developed STHE DT demonstrates its capability of extracting crucial data based on fundamental principles of mass, energy, and momentum, facilitating seamless integration with sensors. The underpinning concept, comprehensive methodological framework, and practical implementation process of the STHE digital twin presented herein provide a robust foundation. This work represents a significant scientific contribution towards enabling the transformation of conventional mechanical systems into intelligent, data-driven smart products, aligning with the objectives of Industry 4.0.
{"title":"Digital transformation of conventional shell-tube heat exchanger using digital twinning and machine learning","authors":"Zhi Zhu , Hao He , Tosin Famakinwa , Y.X. Zhang , Helen Wu , David Fox , Richard (Chunhui) Yang","doi":"10.1016/j.csite.2026.107932","DOIUrl":"10.1016/j.csite.2026.107932","url":null,"abstract":"<div><div>Numerical simulation-based digital twins are emerging as a transformative technology capable of significantly enhancing operational efficiency and minimising costly maintenance and human intervention for smart products and services. However, the inherent limitations of physical monitoring and the uncertainties associated with product or service performance can be effectively addressed through the strategic application of parameterised numerical models combined with advanced machine learning (ML) algorithms. To address the research gap, this research investigates how a novel and systematic digital-twin-based design and analysis approach can facilitate the transformation of a conventional Shell-and-Tube Heat Exchanger (STHE) into a smart machine within the evolving framework of Industry 4.0. The methodology involves devising a data-driven digital twin (DT) for the STHE, utilising coupled Computational Fluid Dynamics (CFD) and Finite Element Analysis (FEA) simulations to numerically investigate key performance parameters. This process enables the integration of virtual sensors, the fusion of physical measurements, and the deployment of advanced machine learning algorithms to precisely identify critical points for sensor and actuator placement in an Internet of Things (IoT)-based machine condition monitoring (MCM) system. The developed STHE digital twin successfully demonstrates its capability to extract data of key performance parameters, which enables seamless integration with sensors and actuators. This digital twinning further empowers a digital design and prototyping process for visualiszed, real-time IoT based machine condition monitoring. Advanced ML algorithms are employed to identify the locations of the critical points in the STHE, where sensors are installed for IoT-based MCM. The developed STHE DT demonstrates its capability of extracting crucial data based on fundamental principles of mass, energy, and momentum, facilitating seamless integration with sensors. The underpinning concept, comprehensive methodological framework, and practical implementation process of the STHE digital twin presented herein provide a robust foundation. This work represents a significant scientific contribution towards enabling the transformation of conventional mechanical systems into intelligent, data-driven smart products, aligning with the objectives of Industry 4.0.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"80 ","pages":"Article 107932"},"PeriodicalIF":6.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147387371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-04-01Epub Date: 2026-03-09DOI: 10.1016/j.csite.2026.107923
Wenhao Li , Yinxiang Wu , Min Huang , Zhenyong Liu
To improve the thermal management and temperature uniformity of lithium-ion batteries, this study proposes and evaluates a novel liquid cooling plate structure featuring gradient porous metal foam (GPFM). A fully integrated three-dimensional electrochemical-thermal coupled model was developed to accurately capture the battery's internal thermal behavior and assess the cooling plate's performance. The numerical simulations for this model were conducted using COMSOL Multiphysics. The study systematically investigated the influence of key input parameters—specifically, four distinct porosity gradient variations (defined by the gradient index n) and discharge rates (e.g., 2C, 5C, 7C)—on the primary output parameters: the battery's peak temperature and maximum temperature difference (). The results indicate that the designed GPFM cooling plate effectively lowers the peak temperature while markedly improving thermal uniformity. The enhancement was most evident when the gradient variation index n = 2. The impact of the gradient design varied with the discharge rate. The maximum temperature reduction peaked at 13.5% under a 7C discharge rate. Conversely, the temperature difference achieved its highest percentage reduction of 58.1% at a 2C discharge rate. This study demonstrates that optimizing the porosity gradient design is an effective approach to enhancing temperature uniformity in lithium-ion batteries, particularly offering significant benefits under high-discharge-rate conditions.
{"title":"Study on the temperature uniformity of lithium batteries based on gradient porous metal foam saturated liquid cooling plate","authors":"Wenhao Li , Yinxiang Wu , Min Huang , Zhenyong Liu","doi":"10.1016/j.csite.2026.107923","DOIUrl":"10.1016/j.csite.2026.107923","url":null,"abstract":"<div><div>To improve the thermal management and temperature uniformity of lithium-ion batteries, this study proposes and evaluates a novel liquid cooling plate structure featuring gradient porous metal foam (GPFM). A fully integrated three-dimensional electrochemical-thermal coupled model was developed to accurately capture the battery's internal thermal behavior and assess the cooling plate's performance. The numerical simulations for this model were conducted using COMSOL Multiphysics. The study systematically investigated the influence of key input parameters—specifically, four distinct porosity gradient variations (defined by the gradient index n) and discharge rates (e.g., 2C, 5C, 7C)—on the primary output parameters: the battery's peak temperature and maximum temperature difference (<span><math><mrow><mo>Δ</mo><msub><mi>T</mi><mi>max</mi></msub></mrow></math></span>). The results indicate that the designed GPFM cooling plate effectively lowers the peak temperature while markedly improving thermal uniformity. The enhancement was most evident when the gradient variation index n = 2. The impact of the gradient design varied with the discharge rate. The maximum temperature reduction peaked at 13.5% under a 7C discharge rate. Conversely, the temperature difference achieved its highest percentage reduction of 58.1% at a 2C discharge rate. This study demonstrates that optimizing the porosity gradient design is an effective approach to enhancing temperature uniformity in lithium-ion batteries, particularly offering significant benefits under high-discharge-rate conditions.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"80 ","pages":"Article 107923"},"PeriodicalIF":6.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147387427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-04-01Epub Date: 2026-03-09DOI: 10.1016/j.csite.2026.107925
Yabin Jing , Xialun Yun , Gedong Jiang , Hanbo Yang , Hu Shi , Haitao Wang , Xuesong Mei
The feed system (FS), a critical component in machine tools, significantly impacts machining accuracy through its thermal characteristics. Accurate modeling of its contact mechanism and coupled physical fields is essential for determining precise boundary conditions (BCs), which are fundamental to thermal characteristic modeling. To address this, this study proposes a fluid-solid-thermal coupling strategy to calculate the BCs integrating film-structure-temperature, convection-structure-temperature, and thermo-mechanical coupling. This strategy is built on a contact mechanism model (RCCD-CF-GM-ARCT) incorporating raceway curvature center displacement, centrifugal force, gyroscopic moment effects, and adaptive raceway control theory. Subsequently, the thermal characteristic model (TC-MPFC-HM) is developed using the finite element method, based on the multi-physical field coupling strategy and the moving heat of the FS. Additionally, a closed-loop iteration algorithm is proposed to dynamically update BCs, ensuring accuracy and responsiveness. The results show significant improvements over traditional models, reducing RMSE by 77.54%, 82.81%, and 85.17%, and MAE by 78.4%, 82.06%, and 86.41% under various working conditions. These results validate that the model has enhanced precision and robustness, offering a comprehensive approach for thermal error modeling of FS.
{"title":"Modeling and thermal characteristic analysis of feed system considering multi-physical field coupling","authors":"Yabin Jing , Xialun Yun , Gedong Jiang , Hanbo Yang , Hu Shi , Haitao Wang , Xuesong Mei","doi":"10.1016/j.csite.2026.107925","DOIUrl":"10.1016/j.csite.2026.107925","url":null,"abstract":"<div><div>The feed system (FS), a critical component in machine tools, significantly impacts machining accuracy through its thermal characteristics. Accurate modeling of its contact mechanism and coupled physical fields is essential for determining precise boundary conditions (BCs), which are fundamental to thermal characteristic modeling. To address this, this study proposes a fluid-solid-thermal coupling strategy to calculate the BCs integrating film-structure-temperature, convection-structure-temperature, and thermo-mechanical coupling. This strategy is built on a contact mechanism model (RCCD-CF-GM-ARCT) incorporating raceway curvature center displacement, centrifugal force, gyroscopic moment effects, and adaptive raceway control theory. Subsequently, the thermal characteristic model (TC-MPFC-HM) is developed using the finite element method, based on the multi-physical field coupling strategy and the moving heat of the FS. Additionally, a closed-loop iteration algorithm is proposed to dynamically update BCs, ensuring accuracy and responsiveness. The results show significant improvements over traditional models, reducing RMSE by 77.54%, 82.81%, and 85.17%, and MAE by 78.4%, 82.06%, and 86.41% under various working conditions. These results validate that the model has enhanced precision and robustness, offering a comprehensive approach for thermal error modeling of FS.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"80 ","pages":"Article 107925"},"PeriodicalIF":6.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147387429","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-04-01Epub Date: 2026-02-21DOI: 10.1016/j.csite.2026.107848
Huan-Yi Ren , Si-Liang Sun , Dong Liu , Muhammad Bilal Riaz , Y.S. Hamed , Afraz Hussain Majeed
Taylor-Couette (T-C) flow commonly occurs in the annular gaps of rotating machinery, and improving its heat transfer performance is essential for effective thermal management. However, existing empirical correlations often have limitations in both efficiency and accuracy. To address this, this study integrates machine learning with optimization algorithms to refine T-C flow configurations that incorporate elliptical slits, aiming to develop a more efficient and precise optimization approach. Four machine learning methods are compared against a predictive correlation to assess their prediction accuracy for T-C flow. The particle swarm optimization (PSO) algorithm is subsequently applied to determine the optimal slit parameters. The results indicate that the Genetic Algorithm-Back Propagation Neural Network (GA-BPNN) model is the most suitable model, showing the highest agreement between predicted and simulated values. By incorporating the PSO algorithm, the optimal slit width of 11.33 mm, slit depth of 12.48 mm, and slit number of 12 are obtained. The predicted results agree well with experimental data, exhibiting a relative error of only 2.99%. Compared to the rectangular slit model, the optimized elliptical slit enhances the Nusselt number by 17%. The methodology and findings presented in this study provide a methodological and technical reference for optimizing and enhancing T-C flow systems.
{"title":"Enhancement of convective heat transfer in Taylor-Couette flow with elliptical slits using machine learning and particle swarm optimization","authors":"Huan-Yi Ren , Si-Liang Sun , Dong Liu , Muhammad Bilal Riaz , Y.S. Hamed , Afraz Hussain Majeed","doi":"10.1016/j.csite.2026.107848","DOIUrl":"10.1016/j.csite.2026.107848","url":null,"abstract":"<div><div>Taylor-Couette (T-C) flow commonly occurs in the annular gaps of rotating machinery, and improving its heat transfer performance is essential for effective thermal management. However, existing empirical correlations often have limitations in both efficiency and accuracy. To address this, this study integrates machine learning with optimization algorithms to refine T-C flow configurations that incorporate elliptical slits, aiming to develop a more efficient and precise optimization approach. Four machine learning methods are compared against a predictive correlation to assess their prediction accuracy for T-C flow. The particle swarm optimization (PSO) algorithm is subsequently applied to determine the optimal slit parameters. The results indicate that the Genetic Algorithm-Back Propagation Neural Network (GA-BPNN) model is the most suitable model, showing the highest agreement between predicted and simulated values. By incorporating the PSO algorithm, the optimal slit width of 11.33 mm, slit depth of 12.48 mm, and slit number of 12 are obtained. The predicted results agree well with experimental data, exhibiting a relative error of only 2.99%. Compared to the rectangular slit model, the optimized elliptical slit enhances the Nusselt number by 17%. The methodology and findings presented in this study provide a methodological and technical reference for optimizing and enhancing T<strong>-</strong>C flow systems.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"80 ","pages":"Article 107848"},"PeriodicalIF":6.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146777426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-04-01Epub Date: 2026-02-18DOI: 10.1016/j.csite.2026.107838
C.X. Lu , S.B. Xue , H. Li , S.J. Deng
During the freezing period in the artificial ground freezing (AGF) method under seepage conditions, frozen curtain development confronts the coupling effect of phase change and seepage pathways. Traditional models often treat the phase change as static phenomena and set the permeability as a constant value. To capture the dynamic evolution of phase change and their impact on permeability, a temperature-dependent smooth step function is introduced as the phase change function, dynamically linked to water saturation. In this study, a 2D double-pipe model is established to validate the accuracy of the model. Considering phase change, the frozen curtain alters the seepage pathways, preventing forming excessively large and impractical freezing curtain. The results demonstrated that the phase change process under this model can be explicitly embedded within the hydro-thermal coupling framework, dynamically altering permeability and seepage pathways. Subsequently, a case study on Freeze-Sealing Pipe-Roof (FSPR) method was conducted using COMSOL Multiphysics. It was found that seepage induces asymmetric frozen curtain thickness at both upstream and downstream, the thickness of the upstream frozen curtain is generally less than that downstream, with the difference becoming more pronounced as seepage velocity increases. At seepage velocities of 0.2, 0.4 and 0.8 m/d, the required freezing time for the frozen curtain thickness achieving 1.5 m are 45 days, 53 days and 80 days respectively. The critical seepage velocity threshold for achieving 1.5 m within 60 days is 0.7 m/d. These findings highlight the necessity of considering coupled phase-change and seepage effects in simulations to ensure safety.
{"title":"A hydro-thermal coupling model for artificial ground freezing considering dynamic phase-change and seepage effects: A case study of the freeze-sealing pipe-roof method","authors":"C.X. Lu , S.B. Xue , H. Li , S.J. Deng","doi":"10.1016/j.csite.2026.107838","DOIUrl":"10.1016/j.csite.2026.107838","url":null,"abstract":"<div><div>During the freezing period in the artificial ground freezing (AGF) method under seepage conditions, frozen curtain development confronts the coupling effect of phase change and seepage pathways. Traditional models often treat the phase change as static phenomena and set the permeability as a constant value. To capture the dynamic evolution of phase change and their impact on permeability, a temperature-dependent smooth step function is introduced as the phase change function, dynamically linked to water saturation. In this study, a 2D double-pipe model is established to validate the accuracy of the model. Considering phase change, the frozen curtain alters the seepage pathways, preventing forming excessively large and impractical freezing curtain. The results demonstrated that the phase change process under this model can be explicitly embedded within the hydro-thermal coupling framework, dynamically altering permeability and seepage pathways. Subsequently, a case study on Freeze-Sealing Pipe-Roof (FSPR) method was conducted using COMSOL Multiphysics. It was found that seepage induces asymmetric frozen curtain thickness at both upstream and downstream, the thickness of the upstream frozen curtain is generally less than that downstream, with the difference becoming more pronounced as seepage velocity increases. At seepage velocities of 0.2, 0.4 and 0.8 m/d, the required freezing time for the frozen curtain thickness achieving 1.5 m are 45 days, 53 days and 80 days respectively. The critical seepage velocity threshold for achieving 1.5 m within 60 days is 0.7 m/d. These findings highlight the necessity of considering coupled phase-change and seepage effects in simulations to ensure safety.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"80 ","pages":"Article 107838"},"PeriodicalIF":6.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146778095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-04-01Epub Date: 2026-02-24DOI: 10.1016/j.csite.2026.107858
Yuan Wang , Guangjie Gong , Yanmei Zhang , Weijie Zhao , Jianing Xue , Ranyue Yang , Chengbin Zhang , Zilong Deng
Thermal stratification and localized overheating limit the charging rate and capacity of single-tank molten salt thermal storage systems driven by single source heaters. To address these challenges, this study is the first to systematically optimize annular fin geometry for single source molten salt heaters under natural convection, aiming to elucidate the coupling mechanism of fin geometry on natural convection heat transfer. A transient three-dimensional computational fluid dynamics (CFD) model based on the fundamental conservation laws was developed and experimentally validated to simulate the single-phase transient heating process. In this work, the effects of fin radial width and fin number on natural convection intensity, plume evolution, and temperature uniformity are investigated. The simulation results reveal that the annular fins effectively disrupt the thermal boundary layer and suppress the rapid ascent of thermal plumes, thereby intensifying fluid mixing at the tank bottom. Parametric analysis demonstrates that, in terms of extending thermal storage duration, increasing the fin number is more effective than increasing the fin radial width. Specifically, the optimal fin configuration (hring = 0.055m, Nring = 9) extended the thermal storage duration by 54.52% compared to the single source heating system, effectively mitigating localized overheating and achieving a significantly more uniform temperature distribution.
{"title":"Enhancing thermal storage in a single-tank molten salt system using fins","authors":"Yuan Wang , Guangjie Gong , Yanmei Zhang , Weijie Zhao , Jianing Xue , Ranyue Yang , Chengbin Zhang , Zilong Deng","doi":"10.1016/j.csite.2026.107858","DOIUrl":"10.1016/j.csite.2026.107858","url":null,"abstract":"<div><div>Thermal stratification and localized overheating limit the charging rate and capacity of single-tank molten salt thermal storage systems driven by single source heaters. To address these challenges, this study is the first to systematically optimize annular fin geometry for single source molten salt heaters under natural convection, aiming to elucidate the coupling mechanism of fin geometry on natural convection heat transfer. A transient three-dimensional computational fluid dynamics (CFD) model based on the fundamental conservation laws was developed and experimentally validated to simulate the single-phase transient heating process. In this work, the effects of fin radial width and fin number on natural convection intensity, plume evolution, and temperature uniformity are investigated. The simulation results reveal that the annular fins effectively disrupt the thermal boundary layer and suppress the rapid ascent of thermal plumes, thereby intensifying fluid mixing at the tank bottom. Parametric analysis demonstrates that, in terms of extending thermal storage duration, increasing the fin number is more effective than increasing the fin radial width. Specifically, the optimal fin configuration (h<sub>ring</sub> = 0.055m, N<sub>ring</sub> = 9) extended the thermal storage duration by 54.52% compared to the single source heating system, effectively mitigating localized overheating and achieving a significantly more uniform temperature distribution.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"80 ","pages":"Article 107858"},"PeriodicalIF":6.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147278942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Efficient thermal management is essential for ensuring the safety, reliability, and longevity of Li-ion batteries, yet liquid-cooled plate (LCP) designs face persistent challenges in balancing cooling efficiency with hydraulic performance. This study presents an AI-based integrated workflow for the design and optimization of LCPs featuring leaf-inspired bifurcation geometries. The framework consists of four sequential stages: data analysis, predictive modeling using GMDH-type ANN, Pareto-based optimization via multi-objective arithmetic optimization algorithm (MOAOA) and multi-objective particle swarm optimization (MOPSO), and final design ranking with the WASPAS decision-making method. The GMDH models demonstrated high predictive accuracy, achieving R2 > 0.99 for thermal resistance and pressure drop. Both MOAOA and MOPSO produced nearly identical Pareto fronts, confirming robustness in capturing trade-offs between thermal and hydraulic performance. Optimized inputs revealed balanced designs at mass flow rates of 0.8–1.5 g/s, channel widths of ∼3.7–3.9 mm, and heights of 2.4–2.5 mm, achieving thermal resistance of 0.25–0.35 K/W with pressure drops of 10–25 Pa, ensuring efficient cooling without excessive hydraulic penalties. Decision analysis revealed context-specific optimal designs, ranging from ultra-low thermal resistance (0.1793 K/W) at the cost of high pressure drop (106.81 Pa) to energy-efficient solutions with minimal pumping penalties (ΔP = 2.14 Pa).
{"title":"Pareto-based multi-objective design of battery cold plates with leaf-inspired bifurcations using arithmetic optimization algorithm and WASPAS technique","authors":"Hatem Gasmi , Borhen Louhichi , Ali Basem , As'ad Alizadeh , Mohamed Shaban , Mujtaba A. Flayyih , Wajdi Rajhi , Khalil Hajlaoui","doi":"10.1016/j.csite.2026.107869","DOIUrl":"10.1016/j.csite.2026.107869","url":null,"abstract":"<div><div>Efficient thermal management is essential for ensuring the safety, reliability, and longevity of Li-ion batteries, yet liquid-cooled plate (LCP) designs face persistent challenges in balancing cooling efficiency with hydraulic performance. This study presents an AI-based integrated workflow for the design and optimization of LCPs featuring leaf-inspired bifurcation geometries. The framework consists of four sequential stages: data analysis, predictive modeling using GMDH-type ANN, Pareto-based optimization via multi-objective arithmetic optimization algorithm (MOAOA) and multi-objective particle swarm optimization (MOPSO), and final design ranking with the WASPAS decision-making method. The GMDH models demonstrated high predictive accuracy, achieving R<sup>2</sup> > 0.99 for thermal resistance and pressure drop. Both MOAOA and MOPSO produced nearly identical Pareto fronts, confirming robustness in capturing trade-offs between thermal and hydraulic performance. Optimized inputs revealed balanced designs at mass flow rates of 0.8–1.5 g/s, channel widths of ∼3.7–3.9 mm, and heights of 2.4–2.5 mm, achieving thermal resistance of 0.25–0.35 K/W with pressure drops of 10–25 Pa, ensuring efficient cooling without excessive hydraulic penalties. Decision analysis revealed context-specific optimal designs, ranging from ultra-low thermal resistance (0.1793 K/W) at the cost of high pressure drop (106.81 Pa) to energy-efficient solutions with minimal pumping penalties (ΔP = 2.14 Pa).</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"80 ","pages":"Article 107869"},"PeriodicalIF":6.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147330305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}