International Journal of Heat and Mass Transfer最新文献_第10页

Entropy generation analysis of topology-optimized porous reactors under pulsating flow conditions 脉动流动条件下拓扑优化多孔反应器的熵生成分析

IF 5.8 2区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Heat and Mass Transfer

Pub Date : 2026-01-09 DOI: 10.1016/j.ijheatmasstransfer.2026.128332

Mengly Long , Patcharawat Charoen-amornkitt , Mehrzad Alizadeh , Takahiro Suzuki , Shohji Tsushima

Enhancing electrochemical energy storage and conversion devices through topology optimization enables advanced electrode design and improved performance. Previous research indicates that the performance of topologically optimized porous reactors improves with increasing design dimensionality; however, 2D optimization is often sufficient. This study employs density-based topology optimization to design porous reactors with distinct flow characteristics (FC): one-dimensional (1D) FC, two-dimensional (2D) FC, and three-dimensional (3D) FC. The 1D FC system shows significant performance improvement with 2D optimization, while the 2D FC system also benefits from higher-dimensional optimization, though the difference between 1D and 2D optimization is smaller compared to the improvement observed in the 1D FC system. However, in the 3D FC system, the impact of increasing design dimensionality diminishes, in contrast to the 1D and 2D FC systems, which clearly benefit from higher-dimensional optimization. To overcome this limitation, a fourth-dimensional parameter, namely the temporal variation in species supply (pulsating flow), is introduced to enhance the performance of the 3D FC system. Additionally, entropy generation analysis is derived and applied as a post-processing tool to assess system performance. The results reveal that pulsating flow significantly improves the 3D FC system, achieving the lowest scaled entropy generation compared to constant flow. Higher non-dimensional pressure amplitudes further reduce scaled entropy generation, enhancing system efficiency. Moreover, across all pressure amplitudes, increasing the Womersley number consistently leads to lower scaled entropy generation, demonstrating that systems operating at higher Womersley numbers achieve greater efficiency and adaptability under dynamic flow conditions.

通过拓扑优化增强电化学能量存储和转换装置，可以实现先进的电极设计和提高性能。以往的研究表明，拓扑优化多孔反应器的性能随着设计尺寸的增加而提高；然而，2D优化通常就足够了。本研究采用基于密度的拓扑优化设计了具有不同流动特性（FC）的多孔反应器：一维（1D） FC、二维（2D） FC和三维（3D） FC。一维FC系统在二维优化后表现出显著的性能提升，而二维FC系统也受益于高维优化，尽管与一维FC系统相比，一维和二维优化之间的差异较小。然而，在3D FC系统中，与一维和二维FC系统相比，增加设计维度的影响会减弱，而一维和二维FC系统显然受益于高维优化。为了克服这一限制，引入了一个四维参数，即物种供应的时间变化（脉动流量）来增强三维FC系统的性能。此外，导出了熵产生分析，并将其作为后处理工具来评估系统性能。结果表明，与恒流相比，脉动流显著改善了三维FC系统，实现了最小的尺度熵生成。更高的无量纲压力幅值进一步减少了尺度熵的产生，提高了系统效率。此外，在所有压力幅值中，增加沃默斯利数始终会导致更低的熵产，这表明在较高沃默斯利数下运行的系统在动态流动条件下具有更高的效率和适应性。

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引用次数: 0

Numerical investigation of mass transfer in thermally regenerated amino-based flow batteries with square-wave flow channels 具有方波通道的热再生氨基液流电池传质的数值研究

IF 5.8 2区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Heat and Mass Transfer

Pub Date : 2026-01-08 DOI: 10.1016/j.ijheatmasstransfer.2025.128265

Xin Zhou , Wei Lu , Gang Cheng , Ping Lu , Xin Li

During the scale-up of the Triethylamine-Copper Redox Flow Battery (TRAFB), low diffusion coefficients and concentration boundary layers limit the current density of kilowatt-level cell stacks. Notably, TRAFB outperforms conventional vanadium redox flow batteries (VRFBs) in key commercialization metrics: its raw material cost is reduced by 40% (owing to abundant and low-cost copper and amine ligands), the voltage window is expanded to 0.38 V (vs. 0.33 V for VRFBs), and the recyclability rate of electrolytes exceeds 95%, addressing the core cost and sustainability bottlenecks of VRFBs. Square-wave flow channels, leveraging right-angle secondary vortices for passive mixing, offer a cost-effective solution. square-wave flow channel However, the quantitative relationship between the geometry and mass transfer of square-wave flow channels remains unexplored. This paper, for the first time, establishes a three-dimensional, isothermal, multi-species coupled CFD model to systematically evaluate the effects of the length and width of square-wave flow channels. In the model validation and mesh independence verification, the error is less than 5%, ensuring the accuracy and reliability of our numerical model in predicting the limiting current density and pressure drop. The results show that compared with straight flow channels, square-wave flow channels significantly reduce the diffusion layer thickness, enhance the uniformity of Cu²⁺ concentration and the upper limit of flux, and delay the occurrence of active material depletion zones at 300 A m⁻². Under constant volumetric flow rate, increasing the length (from 2.6 to 3.2 mm) or decreasing the width (from 4 to 1 mm) can both enhance local shear and normal flow velocity, with the maximum cross-scale transport efficiency increased by approximately 2.4 times. This work provides a low-cost, high-performance design basis for TRAFB commercialization and a transferable platform for other ligand-mediated flow systems.

在三乙胺-铜氧化还原液流电池（TRAFB）的放大过程中，低扩散系数和浓度边界层限制了千瓦级电池堆的电流密度。值得注意的是，TRAFB在关键的商业化指标上优于传统的钒氧化还原液流电池（vrfb）：其原材料成本降低了40%（由于丰富且低成本的铜和胺配体），电压窗口扩大到0.38 V (vrfb为0.33 V)，电解质的可回收利用率超过95%，解决了vrfb的核心成本和可持续性瓶颈。方波流道，利用直角二次涡流进行被动混合，提供了一种经济有效的解决方案。然而，方波流道的几何形状与传质之间的定量关系尚未得到充分的研究。本文首次建立了三维等温多物种耦合CFD模型，系统地评价了方波流道长度和宽度的影响。在模型验证和网格无关性验证中，误差小于5%，保证了数值模型预测极限电流密度和压降的准确性和可靠性。结果表明，与直流通道相比，方波流通道显著减小了扩散层厚度，增强了Cu 2 +浓度的均匀性和通量上限，延迟了300 A m⁻²处活性物质枯竭区的发生。在体积流量不变的情况下，增加长度（从2.6 mm增加到3.2 mm）或减小宽度（从4 mm减少到1 mm）均可提高局部剪切速度和法向流动速度，最大跨尺度输送效率提高约2.4倍。这项工作为TRAFB的商业化提供了低成本、高性能的设计基础，并为其他配体介导的流动系统提供了可转移的平台。

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引用次数: 0

Heat transfer dynamics in graphene-coated paraffin spheres for enhanced thermal transport 石墨烯包覆石蜡球增强热传递的传热动力学

IF 5.8 2区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Heat and Mass Transfer

Pub Date : 2026-01-08 DOI: 10.1016/j.ijheatmasstransfer.2026.128339

Kevin A. Redosado Leon , Alexey Lyulin , Bernard J. Geurts

<div><div>This paper investigates the transient thermal response of a graphene-coated paraffin sphere embedded in air, in the context of thermal energy storage (TES). The work introduces a passive enhancement strategy in which graphene coatings enable faster heat transfer in composite materials without external energy input. The main innovation lies in coupling high-fidelity transient simulations with effective property extraction to quantify how microstructural design governs energy storage and release dynamics. Using high-fidelity simulations in OpenFOAM, we resolve the time-dependent temperature field in a periodic domain subjected to a vertical temperature gradient. The focus is on extracting effective thermal properties, i.e., volumetric heat capacity (<span><math><msub><mrow><mi>C</mi></mrow><mrow><mtext>eff</mtext></mrow></msub></math></span>), thermal conductivity (<span><math><msub><mrow><mi>κ</mi></mrow><mrow><mtext>eff</mtext></mrow></msub></math></span>), and thermal diffusivity (<span><math><msub><mrow><mi>α</mi></mrow><mrow><mtext>eff</mtext></mrow></msub></math></span>), as a function of the volume fraction of the coated paraffin sphere. Results show that <span><math><msub><mrow><mi>C</mi></mrow><mrow><mtext>eff</mtext></mrow></msub></math></span> increases nearly linearly with paraffin content, while <span><math><msub><mrow><mi>κ</mi></mrow><mrow><mtext>eff</mtext></mrow></msub></math></span> grows nonlinearly due to improved conduction pathways provided by the graphene coating. In contrast, <span><math><mrow><msub><mrow><mi>α</mi></mrow><mrow><mtext>eff</mtext></mrow></msub><mo>=</mo><msub><mrow><mi>κ</mi></mrow><mrow><mtext>eff</mtext></mrow></msub><mo>/</mo><msub><mrow><mi>C</mi></mrow><mrow><mtext>eff</mtext></mrow></msub></mrow></math></span> decreases with increasing volume fraction, as the gain in heat capacity outweighs the enhancement in thermal conductivity. This explains why systems with more paraffin, although better at storing energy, respond more slowly to thermal stimuli than systems with lower filler content. The characteristic response time <span><math><mrow><mi>τ</mi><mo>=</mo><msup><mrow><mi>L</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>/</mo><msub><mrow><mi>α</mi></mrow><mrow><mtext>eff</mtext></mrow></msub></mrow></math></span>, with <span><math><mi>L</mi></math></span> characterizing the size of the cubical unit cell, quantifies this trade-off. Comparison with the lumped-capacitance model shows that <span><math><mi>τ</mi></math></span> is underestimated by about 25%–30% while preserving the correct order of magnitude. For the reference microscale case (<span><math><mrow><mi>L</mi><mo>=</mo><mn>7</mn><mo>.</mo><mn>22</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span>, <span><math><mrow><mi>ϕ</mi><mo>=</mo><mn>30</mn><mtext>%</mtext></mrow></math></span>), we obtain <span><math><mrow><msub><mrow><mi>α</mi></mrow><mrow><mtext>eff</mtext></mrow></msub><mo>=</mo><mn>4</mn><mo>.</mo><mn>46</mn><mo>×</m

本文研究了石墨烯包覆石蜡球在热储能（TES）环境下的瞬态热响应。这项工作介绍了一种被动增强策略，其中石墨烯涂层可以在没有外部能量输入的情况下加快复合材料的传热。主要的创新在于将高保真瞬态模拟与有效的性能提取相结合，以量化微结构设计如何控制能量存储和释放动力学。利用OpenFOAM中的高保真度模拟，我们解决了受垂直温度梯度影响的周期域中随时间变化的温度场。重点是提取有效热性能，即体积热容（Ceff），导热系数（κeff）和热扩散系数（αeff），作为包覆石蜡球体积分数的函数。结果表明，Ceff随着石蜡含量的增加几乎呈线性增长，而石墨烯涂层提供了改善的传导途径，使得nf eff呈非线性增长。相反，αeff=κeff/Ceff随体积分数的增加而减小，这是因为热容的增加大于导热系数的增加。这就解释了为什么石蜡含量高的体系，虽然能更好地储存能量，但对热刺激的反应却比填料含量低的体系慢。特征响应时间τ=L2/αeff，其中L表征立方体单元胞的大小，量化了这种权衡。与集总电容模型的比较表明，在保持正确数量级的情况下，τ被低估了约25%-30%。在参考微尺度下（L=7.22μm， ϕ=30%），我们得到αeff=4.46×10−8 m2 s−1和τ≈1.17×10−3 s，证明了复合材料的快速内在响应。τ随L2的缩放进一步表明，微尺度设计显著加快了响应性：即使对于高石蜡含量，τ也从毫米尺寸结构域的秒降至微尺度（L ~ 10μm）的毫秒。

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引用次数: 0

Nonlinear evolution and coupling mechanism of molten metal flow behavior at high-speed current-carrying friction interfaces 高速载流摩擦界面下熔融金属流动行为的非线性演化及耦合机制

IF 5.8 2区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Heat and Mass Transfer

Pub Date : 2026-01-08 DOI: 10.1016/j.ijheatmasstransfer.2026.128336

Guiwen Liao , Wei Wang , Jimin Xu , Xiaojun Liu , Kun Liu

Delving into the operational stability of high-speed current-carrying friction interfaces under extreme temperature conditions, the research primarily focuses on elucidating the generation mechanisms and flow characteristics of molten metal fluids. By integrating theories of magnetic fields, energy conservation, Joule heating, and frictional heating generation, a finite element model using the modified heat capacity method was constructed to simulate interfacial phase transitions and the dynamics of molten metal. The research findings reveal that the interface temperature undergoes significant multi-stage variations, resulting in a continuous transition from solid-solid to solid-liquid contact. Quantified by the liquid phase volume fraction (LVF), the degree of interface melting provides further insight into the mechanisms underlying the dynamic evolution of the contact interface. Furthermore, the research uncovers intricate couplings between molten metal flow, temperature gradients, and magnetic field distributions, elucidating their combined influence on the distinct flow patterns observed at the interface. These discoveries provide crucial theoretical foundations and practical guidelines for optimizing the performance of the electromagnetic launcher (EML) and enhancing the stability and efficiency of current transmission.

研究了高速载流摩擦界面在极端温度条件下的运行稳定性，重点阐述了熔融金属流体的产生机理和流动特性。结合磁场理论、能量守恒理论、焦耳加热理论和摩擦发热理论，采用改进的热容法建立了模拟金属液界面相变和动力学的有限元模型。研究结果表明，界面温度经历了明显的多阶段变化，导致了从固-固接触到固-液接触的连续转变。通过液相体积分数（LVF）来量化界面熔化程度，可以进一步了解接触界面动态演变的机制。此外，研究揭示了熔融金属流动、温度梯度和磁场分布之间复杂的耦合关系，阐明了它们对界面上观察到的不同流动模式的综合影响。这些发现为优化电磁发射装置（EML）的性能，提高电流传输的稳定性和效率提供了重要的理论基础和实践指导。

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引用次数: 0

Numerical study on thermal management performance of liquid-based battery energy storage system with crenellated mini-channels 多孔小通道液体电池储能系统热管理性能的数值研究

IF 5.8 2区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Heat and Mass Transfer

Pub Date : 2026-01-07 DOI: 10.1016/j.ijheatmasstransfer.2025.128322

Xiaowei Qiu , Shuai Huo , Siyi Han , Yuanping Huo , Zhaoyi Zhang , Xu Wang , Qi Wang , Zhentao Wang , Junfeng Wang

Large-scale battery energy storage systems (BESS) with sodium-ion battery (SIB) are gaining prominence, yet they face unique thermal management challenges due to lower energy density of SIBs, which necessitates compact structure and excellent thermal performance. To address this, this study proposes a novel symmetrical dual-serpentine (SDS) liquid cooling plate (LCP) with crenellated mini-channels to meet these requirements. A CFD model is developed to evaluate the mechanism of heat transfer enhancement. Numerical results reveal that the SDS design achieves more uniform flow distribution and improved temperature uniformity across the battery surface under varying ambient conditions, increasing the cooling efficiency coefficient (j_w) by 330.2% and 661.2% compared to conventional U-shaped and single-serpentine layouts, respectively. Furthermore, to bridge the gap between numerical simulation and real-time application, an XGBoost-based surrogate model is constructed for the battery management system (BMS). Coupled with Shapley additive explanations (SHAP) analysis, the model uncovers the non-linear relationship between inlet flow rate and cooling performance, providing a scientific basis for formulating energy-efficient operational control strategies. This work validates the efficacy of flow-disrupting channel geometries for large-format SIBs and offers a data-driven framework for their intelligent thermal control, offering valuable insights for designing BTMS for future BESS.

基于钠离子电池（SIB）的大型电池储能系统（BESS）正日益受到重视，但由于SIB的能量密度较低，需要紧凑的结构和优异的热性能，因此面临着独特的热管理挑战。为了解决这一问题，本研究提出了一种新型对称双蛇形（SDS）液冷板（LCP），该液冷板具有细孔微通道，以满足这些要求。建立了一个CFD模型来评估传热强化的机理。数值计算结果表明，在不同的环境条件下，SDS设计使电池表面的流动分布更加均匀，温度均匀性得到改善，冷却效率系数（jw）比传统的u型布局和单蛇形布局分别提高了330.2%和661.2%。此外，为了弥合数值模拟与实时应用之间的差距，构建了基于xgboost的电池管理系统（BMS）代理模型。该模型结合Shapley加性解释（SHAP）分析，揭示了进口流量与冷却性能之间的非线性关系，为制定节能运行控制策略提供了科学依据。这项工作验证了大尺寸sib的流动干扰通道几何形状的有效性，并为其智能热控制提供了数据驱动的框架，为未来BESS的BTMS设计提供了有价值的见解。

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引用次数: 0

Effect of rotation control on thermal performance of phase change unit with annular fins 旋转控制对环形翅片相变机组热性能的影响

IF 5.8 2区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Heat and Mass Transfer

Pub Date : 2026-01-07 DOI: 10.1016/j.ijheatmasstransfer.2026.128337

Bo Yang , Junfei Guo , Muzhi Li , Wenjing Zhang , Xiaohu Yang , Bengt Sundén

Thermal energy storage(TES) devices are critical for efficient energy utilization and stable supply in building-integrated solar energy systems. Previous studies on rotation-driven TES devices have overlooked the trade-off between energy consumption and heat storage performance. Numerical simulations were conducted in this study to systematically explore finned paraffin-based thermal energy storage devices. Key thermal performance parameters, including thermal charging behavior, temperature distribution, flow field characteristics, heat storage capacity, heat storage efficiency, and energy consumption, were analyzed to evaluate the impact of rotation on/off switching moments. Results indicate that rotation-driven enhancement significantly shortens the charging time of vertical finned thermal energy storage tubes, with the benefits of this enhancement most pronounced in the late melting stage. The "first fixed then rotated" strategy (activating rotation at a liquid fraction of approximately 0.6) outperforms continuous rotation: compared with continuously rotating vertical finned thermal storage tubes, this strategy increases the benefits of reduced melting time, improved melting rate, and enhanced temperature response by 40.47%, 43.52%, and 36.98% per unit energy consumption, respectively. This study fills the existing research gap in dynamic rotation control for finned PCM storage devices. It provides a theoretical basis and technical support for optimizing finned thermal energy storage units in building solar systems, thereby promoting higher energy efficiency and operational stability of such systems.

在建筑一体化太阳能系统中，蓄热装置是实现能源高效利用和稳定供应的关键。之前关于旋转驱动TES设备的研究忽略了能量消耗和储热性能之间的权衡。本研究采用数值模拟的方法对鳍状石蜡基储热装置进行了系统的研究。分析了关键热性能参数，包括热充电行为、温度分布、流场特性、蓄热能力、蓄热效率和能耗，以评估旋转开关力矩的影响。结果表明，旋转驱动的强化显著缩短了垂直翅片式蓄热管的充能时间，且在熔化后期效果最为明显。“先固定后旋转”策略（在液体分数约为0.6时激活旋转）优于连续旋转：与连续旋转的垂直翅片式储热管相比，该策略在单位能耗方面分别提高了40.47%、43.52%和36.98%，分别缩短了熔化时间、提高了熔化速度和提高了温度响应。本研究填补了现有翅片PCM存储装置动态旋转控制的研究空白。为建筑太阳能系统中翅片式蓄热单元的优化提供理论依据和技术支持，从而提高太阳能系统的能效和运行稳定性。

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引用次数: 0

Coupling DSMC and AKMC to simulate graphite erosion due to hyperthermal oxidation at the nanoscale 耦合DSMC和AKMC在纳米尺度上模拟高温氧化引起的石墨侵蚀

IF 5.8 2区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Heat and Mass Transfer

Pub Date : 2026-01-07 DOI: 10.1016/j.ijheatmasstransfer.2025.128317

Sharon Edward , Moon-ki Choi , Harley T. Johnson

A one-way coupling is introduced between the particle-based gas flow method, direct simulation Monte Carlo (DSMC), and the material evolution method, atomistic-kinetic Monte Carlo (AKMC), at the nanoscale. The coupled DSMC

\to

AKMC method is used to simulate hyperthermal oxidative pitting in graphite exposed at various tilt angles, with relevance to ablative pitting in carbon fibers used for Thermal Protection System (TPS) materials during reentry. Simulated DSMC particles have a one-to-one mapping with real atoms or molecules, and the two methods are spatially coupled such that particles from DSMC can directly trigger adsorption events in AKMC. The coupled method more accurately captures gas behavior on pit geometries compared to pure uncoupled AKMC that typically uses simplified assumptions to approximate the adsorption behavior from the gas phase. Comparison between results from DSMC

\to

AKMC and pure uncoupled AKMC reveals a discrepancy between their predicted pit geometries, especially at lower angles of graphite tilt. That is, pure uncoupled AKMC falsely overpredicts the depth and narrowness of the evolving pits due to the simplified assumption of vertical oxygen incidence rather than a realistic oblique incidence as in DSMC

\to

AKMC. This discrepancy in pit geometry is essential to acknowledge when evaluating the influence of pit geometry on the structural stability of carbon fibers during reentry ablation. In addition, the physical insights on pit evolution under realistic gas behavior from the coupled DSMC

\to

AKMC simulations can be used to improve uncoupled AKMC simulations by applying appropriate boundary conditions. Lastly, an exploratory analysis is performed in DSMC to determine if CO molecules emitted from the oxidizing graphite affect the number density of oxygen local to the graphite, assessing the need for a two-way coupling between DSMC and AKMC.

在纳米尺度上，引入了基于粒子的气体流动方法，直接模拟蒙特卡罗（DSMC）和材料演化方法，原子动力学蒙特卡罗（AKMC）之间的单向耦合。采用耦合的DSMC→AKMC方法模拟了石墨在不同倾斜角度下的高温氧化点蚀，并与热保护系统（TPS）材料用碳纤维在再入过程中的烧蚀点蚀相关。模拟的DSMC粒子与真实的原子或分子具有一对一的映射关系，并且两种方法在空间上耦合，使得DSMC粒子可以直接触发AKMC中的吸附事件。与通常使用简化假设从气相近似吸附行为的纯非耦合AKMC相比，耦合方法更准确地捕获了坑几何上的气体行为。通过对DSMC→AKMC和纯不耦合AKMC结果的比较，揭示了它们预测的坑几何形状之间的差异，特别是在石墨倾斜角度较小的情况下。也就是说，单纯的不耦合AKMC由于简化了氧垂直入射的假设，而不是DSMC→AKMC中实际的斜入射假设，错误地高估了演化坑的深度和窄度。在评估再入烧蚀过程中凹坑几何形状对碳纤维结构稳定性的影响时，必须认识到凹坑几何形状的差异。此外，从耦合的DSMC→AKMC模拟中获得的真实气体行为下的坑演化的物理见解可以通过应用适当的边界条件来改进非耦合的AKMC模拟。最后，在DSMC中进行了探索性分析，以确定氧化石墨释放的CO分子是否会影响石墨局部氧的数量密度，评估DSMC和AKMC之间双向耦合的必要性。

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引用次数: 0

Thermal performance enhancement of blade battery packs via multi-branch-converging channel design 通过多分支汇聚通道设计提高叶片电池组的热性能

IF 5.8 2区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Heat and Mass Transfer

Pub Date : 2026-01-06 DOI: 10.1016/j.ijheatmasstransfer.2026.128330

Xiaoqing Yang , Xin Zhong , Chuyan Su , Kai Chen , Jiekai Xie

Blade batteries have occupied a considerable share in the field of electric vehicles, because they possess a larger heat dissipation area and serve as structural components for power battery packs. However, their liquid cooling (LC) systems still face challenges of non-uniform heat dissipation and large energy loss along the narrow, elongated and tortuous flow channels. This work rationally designs a LC plate (LCP) with multi-branch-converging channels to solve the heat accumulation in the central area of the battery packs. The coolant is split at the inlet area to intentionally moderate local heat transfer and alleviate edge overcooling, whereas in the central area, the converging structure enhances turbulence intensity while extending the coolant residence time to enhance heat transfer. Through a series of optimizations, when the number of diversion channels, inlet flow rate and channel width are 3, 0.10 m⋅s⁻¹ and 3 mm, respectively, LCPs exhibit excellent temperature control performance with low energy consumption for blade battery packs. Even under the harshest working condition with an ambient temperature of 35.0 °C and a discharge rate of 3 C, the maximum temperature and temperature difference of the battery packs can be controlled at 29.9 and 3.14 °C, respectively, which are both lower than that using LCPs with conventional serpentine channels. Additionally, its energy consumption is greatly reduced from 113.4 to 15.7 J.

叶片电池在电动汽车领域占有相当大的份额，因为叶片电池具有较大的散热面积，并且是动力电池组的结构部件。然而，它们的液体冷却系统仍然面临着沿着狭窄、细长和弯曲的流道散热不均匀和能量损失大的挑战。本文合理设计了具有多支路收敛通道的LC板，解决了电池组中心区域的热积聚问题。在入口区域，冷却剂被分开，以有意地缓和局部传热和缓解边缘过冷，而在中心区域，收敛结构增强湍流强度，同时延长冷却剂停留时间，以增强传热。通过一系列优化，当导流通道数为3、进口流量为0.10 m·s−1、通道宽度为3 mm时，lcp对叶片电池包具有优异的温控性能和较低的能耗。即使在环境温度为35.0℃、放电速率为3℃的最恶劣工况下，电池组的最高温度控制在29.9℃，温差控制在3.14℃，均低于传统蛇形通道lcp。能耗由113.4 J大幅降低至15.7 J。

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引用次数: 0

Round robin study on thermophysical properties of thin films using four measurement techniques 利用四种测量技术对薄膜热物理性质进行了循环研究

IF 5.8 2区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Heat and Mass Transfer

Pub Date : 2026-01-06 DOI: 10.1016/j.ijheatmasstransfer.2026.128328

Yanhui Zhang , Jiahao Lu , Hao Zhan , Jingchao Li , Dazhi Hou , Qinyi Li , Gang Li , Yingjun Liu , Jianli Wang

Accurate measurement of the thermophysical properties of micrometer-scale films is essential for advancing the thermal science of materials. However, current techniques often struggle to rapidly and reliably characterize their thermal conductivity and diffusivity. To address this challenge, a round robin test was conducted using several widely adopted photothermal and thermoelectric methods, including micro-thermocouple (micro-TC)– and lock-in thermography (LIT)–based laser-spot-periodic-heating methods, laser flash analyzer (LFA), and the Hot Disk technique. Five representative films were evaluated, including isotropic 304 stainless steel (SUS304) and copper (Cu) films, as well as anisotropic materials such as polyimide (PI), graphene (GPE), and highly oriented bamboo fiber (BF) composites. Comparative analysis highlighted key differences in measurement outcomes, reflecting the fundamental limitations and strengths of each technique. For the LIT technique, limited spatial resolution and the accuracy constraints of infrared cameras led to significant deviations in cross-plane thermal diffusivity measurements for Cu and PI films. The LFA method proved suitable for measuring in-plane thermal diffusivity in high-conductivity films and cross-plane diffusivity in low-conductivity films. Nonetheless, its circular heat flow geometry prevented reliable resolution of in-plane anisotropy in BF composites. The slab mode of the Hot Disk technique enabled effective in-plane thermal diffusivity measurements for SUS304, but the values obtained for Cu films and GPE composites showed significant deviations. When applied in thin film mode to PI films, the Hot Disk technique enabled measurement of the cross-plane thermal conductivity. In the bulk mode, the technique was limited to determining only the effective bulk thermal diffusivity of BF composites. These findings underscore the importance of selecting appropriate techniques tailored to film material properties and geometry, providing valuable insights for improving thermophysical characterization of emerging thin-film materials.

精确测量微米尺度薄膜的热物理性质对于推进材料热科学至关重要。然而，目前的技术往往难以快速、可靠地表征它们的导热性和扩散率。为了解决这一挑战，采用了几种广泛采用的光热和热电方法进行了一轮循环测试，包括基于微热电偶（micro-TC）和锁定热成像（LIT）的激光点周期性加热方法、激光闪光分析仪（LFA）和热盘技术。评估了五种具有代表性的薄膜，包括各向同性304不锈钢（SUS304）和铜（Cu）薄膜，以及聚酰亚胺（PI）、石墨烯（GPE）和高取向竹纤维（BF）复合材料等各向异性材料。比较分析强调了测量结果的关键差异，反映了每种技术的基本局限性和优势。对于LIT技术，有限的空间分辨率和红外相机的精度限制导致Cu和PI薄膜的跨平面热扩散率测量存在显着偏差。实验证明，LFA方法适用于测量高导电性薄膜的面内热扩散系数和低导电性薄膜的面间热扩散系数。然而，其圆形热流几何形状阻碍了BF复合材料平面内各向异性的可靠分辨。热盘技术的平板模式可以有效地测量SUS304的平面内热扩散系数，但Cu薄膜和GPE复合材料的数值存在显着偏差。当在薄膜模式下应用于PI薄膜时，热盘技术可以测量平面间的导热系数。在体积模式下，该技术仅限于确定BF复合材料的有效体积热扩散系数。这些发现强调了选择适合薄膜材料性质和几何形状的合适技术的重要性，为改善新兴薄膜材料的热物理特性提供了有价值的见解。

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引用次数: 0

Fluid-resonant oscillations in a cavity flow with a honeycomb stack 蜂窝堆腔流中的流体共振振荡

IF 5.8 2区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Heat and Mass Transfer

Pub Date : 2026-01-05 DOI: 10.1016/j.ijheatmasstransfer.2025.128323

Hiroshi Yokoyama, Ryotaro Fukumoto, Takashi Kuraishi

To control and utilize aerodynamic sound energy through thermoacoustic effects, this study investigates the effects of a multi-channel stack on fluid-resonant oscillations in a cavity flow. Compressible flow simulations were conducted for a cavity containing a honeycomb stack with an incoming turbulent boundary layer, and the results were validated through wind tunnel experiments. The effects of the vertical position of the stack relative to the cavity depth on the self-sustained oscillations and heat-pumping effects were examined. The placement of the stack significantly affected the acoustic resonance within the cavity, with mode shifts observed in shear layer oscillations at specific stack positions. When the stack was positioned near the cavity bottom, an effective heat flow was induced through the stack due to thermoacoustic heat pumping, resulting in a temperature gradient between the stack ends. These findings demonstrate the possibility for controlling self-sustained oscillations in cavity flows using a honeycomb stack, highlighting energy conversion mechanisms between sound and heat.

为了通过热声效应控制和利用气动声能，本文研究了多通道叠加对空腔流动中流体共振振荡的影响。对具有来流边界层的蜂窝堆空腔进行了可压缩流动模拟，并通过风洞实验对模拟结果进行了验证。研究了烟囱垂直位置相对于空腔深度对自持续振荡和吸热效应的影响。叠层的位置显著影响腔内的声学共振，在特定叠层位置的剪切层振荡中观察到模移。当烟囱靠近空腔底部时，由于热声热泵的作用，烟囱内部产生了有效的热流，导致烟囱两端之间存在温度梯度。这些发现证明了使用蜂窝堆控制腔流中自我持续振荡的可能性，突出了声音和热量之间的能量转换机制。

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引用次数: 0