International Communications in Heat and Mass Transfer最新文献

{"title":"Mixed convection and entropy generation in a lid-driven cavity with multiple porous elliptic heat sources using a local RBF-based meshfree scheme","authors":"Jiban Chowdhury,&nbsp;Sanyasiraju VSS Yedida","doi":"10.1016/j.icheatmasstransfer.2025.109633","DOIUrl":"10.1016/j.icheatmasstransfer.2025.109633","url":null,"abstract":"<div><div>This study investigates the numerical behavior of laminar, incompressible mixed convection flow of a Newtonian fluid in a square cavity with moving top and left walls containing multiple heat-generating porous elliptical cylinders. The flow within the porous medium is modeled using the Brinkman and Forchheimer-corrected Darcy equations to capture both viscous and inertial effects. The governing equations are discretized using a local radial basis function (RBF) based meshfree scheme, which efficiently handles irregular geometries and complex boundary conditions. The numerical model is validated against previously reported mixed convection results inside cavities obtained by conventional CFD methods. Then it is used to analyze the influence of key dimensionless parameters, including Richardson number <span><math><mrow><mo>(</mo><mn>0</mn><mo>.</mo><mn>01</mn><mo>≤</mo><mi>R</mi><mi>i</mi><mo>≤</mo><mn>100</mn><mo>)</mo></mrow></math></span>, Prandtl number <span><math><mrow><mo>(</mo><mi>P</mi><mi>r</mi><mo>=</mo><mn>0</mn><mo>.</mo><mn>71</mn><mo>,</mo><mn>6</mn><mo>.</mo><mn>946</mn><mo>)</mo></mrow></math></span>, Darcy number <span><math><mrow><mo>(</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>6</mn></mrow></msup><mo>≤</mo><mi>D</mi><mi>a</mi><mo>≤</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>2</mn></mrow></msup><mo>)</mo></mrow></math></span> along with cavity inclination angle <span><math><mrow><mo>(</mo><mo>−</mo><mn>4</mn><msup><mrow><mn>5</mn></mrow><mrow><mo>∘</mo></mrow></msup><mo>≤</mo><mi>γ</mi><mo>≤</mo><mn>4</mn><msup><mrow><mn>5</mn></mrow><mrow><mo>∘</mo></mrow></msup><mo>)</mo></mrow></math></span>, and heat source orientation angle <span><math><mrow><mo>(</mo><msup><mrow><mn>0</mn></mrow><mrow><mo>∘</mo></mrow></msup><mo>≤</mo><mi>δ</mi><mo>≤</mo><mn>9</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>∘</mo></mrow></msup><mo>)</mo></mrow></math></span> at fixed Reynolds number <span><math><mrow><mi>R</mi><mi>e</mi><mo>=</mo><mn>100</mn></mrow></math></span>. Results show that increasing <span><math><mrow><mi>R</mi><mi>i</mi></mrow></math></span> enhances convective heat transfer, with the average Nusselt number nearly doubling from <span><math><mrow><mi>R</mi><mi>i</mi><mo>=</mo><mn>10</mn></mrow></math></span> to <span><math><mrow><mi>R</mi><mi>i</mi><mo>=</mo><mn>100</mn></mrow></math></span>, while the Bejan number declines beyond <span><math><mrow><mi>R</mi><mi>i</mi><mo>=</mo><mn>10</mn></mrow></math></span> due to intensified viscous dissipation. Lower Darcy numbers reduce heat transfer and increase entropy generation, whereas higher Prandtl numbers improve thermal mixing.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"169 ","pages":"Article 109633"},"PeriodicalIF":6.4,"publicationDate":"2025-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145057103","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}

{"title":"A machine learning-based generative design approach for rapid topology optimization of microchannel heat sinks","authors":"Zhipeng Yang ,&nbsp;Shaopeng He ,&nbsp;Jiacheng Yu ,&nbsp;Qianglong Wang ,&nbsp;Hanrui Qiu ,&nbsp;Mingjun Wang ,&nbsp;Wenxi Tian ,&nbsp;G.H. Su","doi":"10.1016/j.icheatmasstransfer.2025.109655","DOIUrl":"10.1016/j.icheatmasstransfer.2025.109655","url":null,"abstract":"<div><div>Microchannel heat sinks are crucial for managing thermal loads in high-power systems, yet conventional topology optimization methods are computationally prohibitive for real-time applications. Furthermore, existing machine learning-based approaches lack adaptability to constraints and user-defined requirements. To address these issues, we propose a machine learning-assisted generative design framework that enables real-time, high-fidelity topology optimization, enhancing efficiency and practicality in engineering scenarios. Key findings include: (1) Multi-objective weighting governs the trade-off between topology and performance. Adjusting the weights for heat transfer, flow resistance, and temperature uniformity enables the tailoring of channel morphology; (2) The Reynolds number dictates adaptive structural evolution, with optimized designs transitioning from wide, low-resistance channels at <em>Re</em> = 60 to densely branched networks at <em>Re</em> = 160. This adaptation enhances heat transfer (increasing from <span><math><mn>15458</mn><mi>W</mi><mo>⋅</mo><msup><mi>m</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math></span>to<span><math><mn>35664</mn><mi>W</mi><mo>⋅</mo><msup><mi>m</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math></span>) and intensifies flow dissipation (increasing from <span><math><mn>2.59</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>5</mn></mrow></msup><mi>W</mi><mo>⋅</mo><msup><mi>m</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math></span> to <span><math><mn>19.23</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>5</mn></mrow></msup><mi>W</mi><mo>⋅</mo><msup><mi>m</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math></span>). (3) The machine learning-assisted framework achieves high-fidelity topology optimization predictions, with average errors below 2 % across multi-physics fields. Compared to conventional CFD calculation, the proposed approach accelerates computations by a factor exceeding 7200. Our results show that the proposed method enables real-time, high-fidelity optimization under varied constraints, enhancing computational efficiency and practical applicability for rapid microchannel heat sink design in dynamic engineering environments.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"169 ","pages":"Article 109655"},"PeriodicalIF":6.4,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045273","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}

{"title":"Data-driven modeling for fast and accurate transient thermal predictions in shell-and-tube latent thermal energy storage devices","authors":"Siyu Zheng ,&nbsp;Yihang Zhao ,&nbsp;Zeran Han ,&nbsp;Dan Dan ,&nbsp;Zengxin Qiao ,&nbsp;Rui Dai","doi":"10.1016/j.icheatmasstransfer.2025.109660","DOIUrl":"10.1016/j.icheatmasstransfer.2025.109660","url":null,"abstract":"<div><div>Traditional numerical simulation methods have long struggled with high computational costs when predicting the melting behavior of phase change materials in latent thermal energy storage (LTES) devices. This study presents a reduced-order prediction model that combines proper orthogonal decomposition (POD) with Bayesian neural networks (BNN) for efficient forecasting of melting behavior in a shell-and-tube LTES device. A three-dimensional unsteady numerical model was established and validated using experimental data, and spatiotemporal datasets were generated across various operational conditions. The POD approach was employed to reduce the dimensionality of flow field by extracting dominant modes, while operating parameters such as time, inlet temperature, and inlet flow rate were mapped to reduced-order coefficients through the BNN, enabling fast field reconstruction under different operating conditions. Results showed that the proposed data-driven model achieves high prediction accuracy. The mean absolute errors for temperature and liquid fraction were 0.29 K and 1.15 × 10⁻³ under a specific operating condition, respectively. As for varying operating conditions, temperature predictions exhibited mean absolute errors of 4.3–12.3 K at monitoring points, while liquid fraction predictions had mean absolute errors of 0.044–0.094, with melting time deviations of approximately 4.0 %. Furthermore, the model provides a computational speedup of approximately 10⁴ times compared to traditional CFD simulations. Overall, the data-driven approach proposed in this work exhibits potential for providing accurate and computationally feasible transient thermal predictions in LTES devices.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"169 ","pages":"Article 109660"},"PeriodicalIF":6.4,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045359","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}

{"title":"Thermal performance, cost-effectiveness, and environmental assessment of a conical solar still enhanced with boule-shaped scrubber inox wire coils as a heat storage medium","authors":"Mohammed El Hadi Attia ,&nbsp;Mahmoud Bady","doi":"10.1016/j.icheatmasstransfer.2025.109661","DOIUrl":"10.1016/j.icheatmasstransfer.2025.109661","url":null,"abstract":"<div><div>Solar stills are promising devices for solar-driven water desalination, but their efficiency needs to be optimized to meet practical demands. This study investigates the enhancement of conical solar stills (CSSs) using boule-shaped stainless steel (inox) scrubber wire coils as a heat storage medium to improve thermal performance, cost-effectiveness, and environmental sustainability. Five CSS configurations—traditional (TCSS) and modified with 3, 5, 7, and 9 coils (CSS-SIW3, CSS-SIW5, CSS-SIW7, CSS-SIW9)—were experimentally evaluated under identical weather conditions in El Oued, Algeria, during June 2025. The coils' acceptable thermal conductivity (15–20 W/m·K) and corrosion-resistant properties, combined with their porous geometry and microscale turbulence, significantly enhanced heat transfer, capillary action, and evaporation rates, making them a practical material for long-term use. The CSS-SIW9 produced 5.93 L/m²/day of freshwater—55.2 % more than TCSS—achieving 67 % thermal and 8 % exergy efficiency. Its cost of $0.042/L, 27-day payback, and annual CO₂ mitigation of 0.327 tons (equivalent to $47.4 in credits) demonstrate its cost-effectiveness and sustainability, confirming boule-shaped inox scrubber coils as a promising solution for scalable solar desalination.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"169 ","pages":"Article 109661"},"PeriodicalIF":6.4,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045275","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}

{"title":"Neuro-computational dynamics of an electromagnetically reactive copper-titania -water mixture within a quadratically accelerated Riga channel with graduated thermo-solutal conditions","authors":"Asgar Ali ,&nbsp;Y.M. Mahrous ,&nbsp;Hela Elmannai ,&nbsp;Dilsora Abduvalieva ,&nbsp;Poly Karmakar ,&nbsp;Sanatan Das","doi":"10.1016/j.icheatmasstransfer.2025.109666","DOIUrl":"10.1016/j.icheatmasstransfer.2025.109666","url":null,"abstract":"<div><div>This study mathematically simulates the coupled thermo-solutal transport behavior of a copper- titania- water hybrid nanofluid in a quadratically accelerated Riga channel. The flow is influenced by ramped and uniform wall temperature and concentration conditions, electromagnetic forces, thermal radiation, chemical reactions, and porous medium resistance. The governing unsteady partial differential equations are solved in closed-form solutions using the Laplace transform method. A closed-form solutions-based dataset is used to train a Levenberg- Marquardt neural network, yielding high accuracy with <span><math><mi>R</mi><mo>=</mo><mn>0.99743</mn></math></span> for shear stress, <span><math><mi>R</mi><mo>=</mo><mn>0.99968</mn></math></span> for heat transfer, and <span><math><mi>R</mi><mo>=</mo><mn>0.99981</mn></math></span> for mass transfer. Results indicate that a higher modified Hartmann number enhances fluid acceleration, while longer magnetic-electrode configurations reduce velocity. Radiation intensifies cooling, and chemical reactions elevate mass transport. Ramped boundary conditions are more effective than uniform ones in enhancing flow and thermal behavior. Additionally, hybrid nanofluids show slightly lower thermal efficiency than conventional nanofluids. This hybrid analytical-machine learning approach advances understanding of electromagnetic hybrid nanofluid transport and enables efficient predictive modeling for thermal, energy, and bio-microfluidic applications.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"169 ","pages":"Article 109666"},"PeriodicalIF":6.4,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045263","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}

{"title":"Parametric optimization study of a novel throttling vortex tube","authors":"Weiwei Xu,&nbsp;Kai Chen,&nbsp;Zhihong Yu,&nbsp;Fuhao Wang,&nbsp;Qiang Li","doi":"10.1016/j.icheatmasstransfer.2025.109656","DOIUrl":"10.1016/j.icheatmasstransfer.2025.109656","url":null,"abstract":"<div><div>To address the safety risks associated with throttling-induced temperature rise during high-pressure hydrogen refueling, presents a throttling-type vortex tube structure with dual functions of temperature rise suppression and pressure drop control functionalities. The thermodynamic characteristics and parameter optimization of the vortex tube were systematically investigated by analyzing the internal temperature and velocity fields, and the throttling performance, quantified by the temperature difference between the inlet and the mixed outlet, was evaluated under various operating and structural parameters. The results indicate that the optimal structural combination—low aspect ratio (<em>L</em>_<em>h</em><em>/D</em>_<em>h</em> = 6), large vortex chamber diameter (<em>D</em>_<em>v</em> = 13.4 mm), and moderate cold end length (<em>L</em>_<em>c</em> = 16 mm)—achieves superior throttling performance. Regarding operational parameters, low inlet temperature (<em>T</em>_<em>in</em> = 225 K), low inlet pressure (<em>P</em>_<em>in</em> = 20 MPa), and high cold flow fraction (<em>μ</em> = 0.7) enhance throttling efficiency by over 40 % compared to conventional throttle valves. In addition, the tandem hydrogenation system composed of a throttling vortex tube and a basic single tube outperforms the integrated vortex tube system in terms of energy consumption and <em>COP</em>. This work provides a viable throttling optimization solution for high-pressure hydrogenation systems and support the design of compact energy-separation devices.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"169 ","pages":"Article 109656"},"PeriodicalIF":6.4,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145057102","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}

{"title":"Thermally induced cilia mixture flow of phan-Thien-Tanner fluid with electro osmotic effects: Thermal transport in biological systems","authors":"Mubbashar Nazeer ,&nbsp;Ali B.M. Ali ,&nbsp;Nadia Batool ,&nbsp;Mohamed Kallel ,&nbsp;Meznah M. Alanazi ,&nbsp;Mohammed Jameel","doi":"10.1016/j.icheatmasstransfer.2025.109671","DOIUrl":"10.1016/j.icheatmasstransfer.2025.109671","url":null,"abstract":"<div><h3>Aim of the study</h3><div>The objective of the study is to discuss the mixture flow of Phan–Thien–Tanner (PTT) fluid through the wavy channel with metachronal waves.</div></div><div><h3>Methodology</h3><div>The linear Phan–Thien–Tanner fluid is considered to conduct the present research. The impact of electro-kinetic force is also taken into consideration. The Poisson equation is estimated through the Debye-Hückel approximation. The complexity in the governing equations is reduced through the lubrication approximation and produce the exact solution through computer simulations.</div></div><div><h3>Computational results</h3><div>The findings show that the electro-osmotic parameter improves the velocity distribution by 5 % and 3 % in the cilia and non-cilia-driven flow. The electro-kinetic force upgrades 3 % and 2 % of the shear stress of clear-phase and two-phase flow of PTT fluid, respectively.</div></div><div><h3>Significance of the study</h3><div>The current study can be useful in understanding the basic idea of solid-liquid suspension flow of electro-osmotic viscoelastic fluid through the wavy channel with ciliated and non-ciliated walls. Further, this study will also help in industries to handle the viscoelastic fluid suspended by tiny particles when an external electric field is applied.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"169 ","pages":"Article 109671"},"PeriodicalIF":6.4,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045360","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}

{"title":"Flow pattern and mechanism of the transformation of upward gas-liquid two-phase flow in vertical tubes under heaving vibration","authors":"Yunlong Zhou ,&nbsp;Yuqing Li ,&nbsp;Qichao Liu ,&nbsp;He Chang ,&nbsp;Shibo Zhang ,&nbsp;Cong Chen","doi":"10.1016/j.icheatmasstransfer.2025.109669","DOIUrl":"10.1016/j.icheatmasstransfer.2025.109669","url":null,"abstract":"<div><div>Gas-liquid two-phase flow in vertical tubes is critical to the operation safety of steam generators in floating nuclear power plants, which are subject to heaving vibration induced by ocean waves. However, the flow patterns and transition mechanisms under such dynamic conditions remain insufficiently understood, limiting accurate prediction of flow and heat transfer characteristics. This study experimentally investigated the gas-liquid two-phase flow pattern and mechanism of the transformation of vertical tube under heaving vibration. Five flow patterns were identified, including bubble flow, slug flow, churn flow, annular flow, and a newly discovered stagnant flow. Flow pattern maps were constructed to reveal how tube diameter, vibration frequency, and amplitude affect transition boundaries. Existing transition models for static and rolling conditions were found to be inapplicable. New models incorporating vibration parameters were developed, yielding average errors of 13.24 % for bubble to slug flow, 9.96 % for slug to churn flow, and 15.25 % for churn to annular flow transitions. These findings advance the understanding of oscillating gas-liquid two-phase flows by identifying a novel flow pattern and establishing validated transition models specific to heaving vibration, providing essential theoretical support for flow pattern prediction and parameter design in floating nuclear power systems.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"169 ","pages":"Article 109669"},"PeriodicalIF":6.4,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045264","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}

{"title":"Influence of upstream rim seal structures on mainstream hot gas ingress and unsteady flow characteristics in 1.5-stage turbine disk cavity","authors":"Min Wang,&nbsp;Zhao Liu,&nbsp;Zhenping Feng","doi":"10.1016/j.icheatmasstransfer.2025.109673","DOIUrl":"10.1016/j.icheatmasstransfer.2025.109673","url":null,"abstract":"<div><div>As gas turbine technologies evolve to meet increasing demands for higher operating effectiveness and performance, a continuous increase in turbine inlet temperatures has become essential. Mainstream hot gas ingress (MGI) in the stator-rotor cavity is a significant research subject for engine designers. Computational fluid dynamics simulations were employed to analyze the mechanism of MGI in a 1.5-stage turbine cavity. The differences and connections of MGI mechanisms in the upstream and downstream disk cavities were discussed comprehensively. Results show that the presence of non-axisymmetric pressure and circumferential velocity differences at the upstream rim clearance induces MGI. The upstream MGI is fundamentally caused by circumferential pressure or velocity non-uniformity. Downstream MGI mainly results from radial pressure gradients between the mainstream and rim clearance, displaying circumferential uniformity. Further study shows that the downstream mainstream ingress and egress are affected by the upstream cavity ingress and egress. The upstream egress characteristics are affected by the upstream rim seal (RS) configuration and sealing flow rates. Interaction between the egress and mainstream disrupts downstream main channel stability, alters hub passage vortex migration patterns, and reduces flow uniformity, influencing downstream MGI. The result reveals that the sealing effectiveness of the downstream cavity (<em>ε</em>_{c, <em>d</em>}) decreases with an increase in <em>Ф</em>_{0, <em>u</em>/}<em>Ф</em>_{min, <em>u</em>} (the ratio of the nondimensional sealing parameter (<em>Ф</em>_{0, <em>u</em>}) and the minimum value of the nondimensional sealing parameter to the seal cavity (<em>Ф</em>_{min, <em>u</em>})). Specifically, when the upstream rim seal is used as an axial seal, compared to when <em>Ф</em>_{0, <em>u</em>/}<em>Ф</em>_{min, <em>u</em>} = 0.5,<em>ε</em>_{c, <em>d</em>} decreases by 23.6 % when <em>Ф</em>_{0, <em>u</em>/}<em>Ф</em>_{min, <em>u</em>} = 1.5. Moreover, when the upstream rim seal is employed as the double radial seal, the <em>ε</em>_{c, <em>d</em>} is less affected by the <em>Ф</em>_{0, <em>u</em>/}<em>Ф</em>_{min, <em>u</em>}. Therefore, enhancing upstream sealing efficiency and reducing the minimum sealing flow rate mitigate MGI in the downstream disk cavity, thereby improving turbine efficiency.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"169 ","pages":"Article 109673"},"PeriodicalIF":6.4,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045272","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}

{"title":"Enhanced oxygen transport and distribution in a metal foam flow channel in PEMFC at various conditions","authors":"Jiacheng Li,&nbsp;Fangzhou Wang","doi":"10.1016/j.icheatmasstransfer.2025.109662","DOIUrl":"10.1016/j.icheatmasstransfer.2025.109662","url":null,"abstract":"<div><div>The performance of proton exchange membrane fuel cells (PEMFCs) is influenced by the flow channel design of bipolar plates. While conventional metal foam flow channels enhance gas flow, their disordered flow patterns often lead to uneven oxygen distribution at the catalytic layer, thereby limiting cell performance. This study innovatively proposes a metal foam flow channel featuring a horizontal pores-per-inch (PPI) gradient structure. This design guides oxygen transport through controlled pressure differentials. Three distinct gradient configurations were developed and evaluated under varying temperature (60–90 °C) and humidity (70–90 % RH) conditions by a three-dimensional two-phase non-isothermal model. Simulations show that compared to the homogeneous PPI foam (Case 1), the gradient-structured metal foam flow channel (Case 2) increases the average oxygen molar concentration at the cathode catalytic layer interface by 1.77 % and improves current density by 4.35 %. Among the three gradient configurations, the optimal design (Case 4) achieves a 14.04 % enhancement in peak current density and an 8.68 % increase in oxygen molar concentration at the gas diffusion layer-catalytic layer interface under 60 °C and 90 % RH conditions. The optimal operating condition is confirmed at 70 % RH and 90 °C. This work validates the advantages of gradient PPI metal foam flow channels by effectively regulating oxygen transport. This design improves oxygen concentration and distribution uniformity at the cathode catalytic layer and mitigates oxygen starvation in the catalyst region. In general, it provides an optimized design strategy for high-performance PEMFCs. Future research will focus on the dynamic condition adaptability and large-scale manufacturing feasibility of this innovative flow field design.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"169 ","pages":"Article 109662"},"PeriodicalIF":6.4,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045274","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}