Case Studies in Thermal Engineering最新文献

{"title":"Porous gallium-based nanoparticle-enhanced PCM heat sink for CubeSat thermal management","authors":"Zhang Haokun, Firas Jarrar, M.D. Didarul Islam, Yap Yit Fatt","doi":"10.1016/j.csite.2026.108474","DOIUrl":"https://doi.org/10.1016/j.csite.2026.108474","url":null,"abstract":"Thermal management of CubeSats is challenging because of their compact size, high-density electronics housed, and constrained heat rejection capability in space environment. This study investigates the thermal performance of a modular porous gallium-CNT nanoparticle-enhanced phase change material (NePCM) heat sink for CubeSat thermal management using a coupled numerical model. The heat sink effectively buffers abrupt transient heat loads by storing excess thermal energy as gallium latent heat and maintaining most of the system close to the gallium phase-change temperature. Increasing CNT loading enhances the effective thermal conductivity and thermal diffusivity, thereby accelerating heat transfer and gallium melting, but simultaneously reduces the available gallium mass and latent heat storage capacity. Multi-cycle simulations demonstrate that incomplete gallium solidification between successive high-load operations leads to progressive loss of thermal buffering capacity and eventual overheating, whereas sufficient low-load recovery cycles restore the latent heat storage capacity. Overall, the porous gallium-CNT NePCM heat sink shows strong potential for passive CubeSat thermal management, provided that CNT loading, gallium inventory, porosity, heat-flux distribution, and operational sequence are considered together.","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"30 1","pages":""},"PeriodicalIF":6.8,"publicationDate":"2026-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148884852","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":"Analysis on influencing factors for temperature control of concrete surrounding spiral case of hydropower station","authors":"Wenjie Xu, Gang Wang, Jinjian Zhang, Cheng Zhang, Zhenyue Ma","doi":"10.1016/j.csite.2026.108463","DOIUrl":"https://doi.org/10.1016/j.csite.2026.108463","url":null,"abstract":"The spiral case and its surrounding concrete (SCSC) are critical structural components and primary load-bearing elements for hydropower generation, necessitating stringent safety and reliability measures. The SCSC is a mass concrete structure, with temperature control typically achieved through water pipe cooling during construction period. This study employs grey relation analysis (GRA) to investigate the effects of ambient temperature, pouring temperature, cooling temperature, and cooling water pipe layout on the poured SCSC. The study demonstrates that using concrete with a low initial temperature, appropriate cooling water, and a specified cooling duration during construction period effectively mitigates the temperature rise caused by hydration heat, regulates the temperature gradient, and improves the temperature-control performance of the concrete during construction. Furthermore, the correlation degrees obtained through grey correlation analysis are used as weight coefficients in the objective function. The established objective function is solved using optimization algorithms, thereby transforming the cooling parameter inversion problem into a mathematical optimization problem. This approach enables the inverse determination of various cooling system parameters and facilitates intelligent cooling system design. This study addresses the problem of water pipe cooling in mass concrete from both qualitative and quantitative perspectives. The findings provide theoretical guidance and technical references for the cooling design and safety evaluation of concrete structures surrounding the spiral case.","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"40 1","pages":""},"PeriodicalIF":6.8,"publicationDate":"2026-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148884853","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 Network Analysis of a Hybrid Excitation Eddy Current Damper and Temperature-Dependent Electrical Conductivity of the Conductor","authors":"Wenbin Yang, Hongyi Zhang, Xixi Wen, Zhengqing Chen, Xugang Hua, Huawei Niu, Zhiwen Huang, Wenxi Wang","doi":"10.1016/j.csite.2026.108322","DOIUrl":"https://doi.org/10.1016/j.csite.2026.108322","url":null,"abstract":"This study investigates the thermal behavior of a segmented outer-rotor electromagnetic–permanent magnet hybrid excitation eddy current damper (EM–PM ECD). A thermal network model based on the equivalent thermal circuit method is developed to predict the temperature distribution within the device. To validate the model, a dedicated experimental setup capable of simultaneously measuring rotor and stator temperatures is designed and implemented. The predicted temperatures agree well with experimental measurements, with a maximum deviation of 1.9 °C. The results reveal that the coupled thermal effects of copper losses in the excitation coils and eddy current losses in the conductor dominate the temperature rise in the electromagnetic components and consequently influence the damping torque. The influence of forced-air cooling on the transient temperature rise and steady-state temperature of different components is further analyzed. Electrical conductivity measurements show that the linear temperature-dependent conductivity model accurately describes the behavior of copper, copper–iron alloys, and aluminum alloys over the tested temperature range. In addition, an electromagnetic–thermal coupled finite element model incorporating temperature-dependent material properties is established. The model significantly improves the prediction accuracy of the damping force–speed characteristics, with a maximum deviation of 1.7% compared with experimental results.","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"228 1","pages":""},"PeriodicalIF":6.8,"publicationDate":"2026-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148402470","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":"Automated architecture design and performance optimization of thermal management systems for supersonic transport aircraft","authors":"Linxuan Yang, Liping Pang, Qinghui Ma, Yuandong Guo","doi":"10.1016/j.csite.2026.108268","DOIUrl":"https://doi.org/10.1016/j.csite.2026.108268","url":null,"abstract":"Due to aerodynamic heating and heat sink scarcity, Environmental Control Systems (ECS) and Thermal Management Systems (TMS) of Supersonic Transport (SST) aircraft face serious challenges. Current research on TMS for SST remains scarce, necessitating dedicated in-depth exploration. Integrating the heat sink characteristics of SST, this paper adopts an approach based on graph theory for automated architectural design and performance optimization of TMS. This research built a closed-loop framework encompassing automated topology generation, simulation model synchronization, parametric optimization, and comprehensive evaluation. Inspired by the Concorde's TMS architecture, two types of system architectures were established, utilizing fuel and ram-air as primary heat sinks, with cabin exhaust as an optional sink. In total, 520 candidate architectures were generated. Through systematic screening, optimization, and evaluation, 47 feasible solutions, each meeting all system constraints under supersonic cruise terminal phase conditions, were efficiently identified from the initial candidate architectures. Among these, 2 superior configurations with better performance metrics than the Concorde's TMS were selected to recommend optimal parameter configurations. This research broke through the limitations of traditional empirical design methods, offering a comprehensive approach that spans from architecture generation to performance verification for the engineering design of SST thermal management systems.","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"160 1","pages":"108268"},"PeriodicalIF":6.8,"publicationDate":"2026-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148287759","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":"The effects of heat rejection from split air conditioner on microclimate of residential areas by field measurements and CFD simulations","authors":"Kang Mu, Zhaolong Li, Wei Li, Xiaoqin Sun, Jing Ye, Qilin Cao","doi":"10.1016/j.csite.2026.108252","DOIUrl":"https://doi.org/10.1016/j.csite.2026.108252","url":null,"abstract":"To investigate the impact of split air-conditioning (AC) heat rejection on the thermal environment in residential areas, this study uses a comprehensive research method to study a real residential community in Changsha as a case study. Field measurement results indicate that air temperature in AC exhaust zones is approximately 5 °C higher than in non-exhaust areas, with the maximum nighttime difference reaching 8 °C, indicating stronger nocturnal heat accumulation. Relative humidity shows only minor and spatially limited variations. CFD simulation results show that increasing AC usage from 50% to 100% leads to an increase in average air temperature of approximately 0.7 °C during daytime and 0.9 °C at night, indicating that AC heat rejection significantly affects environmental temperature rise. The airflow field is also modified by the interaction between AC exhaust and urban morphology, leading to increased wind speeds (maximum 4.91 m/s) and downstream low-velocity zones. Surface thermal responses vary significantly among land cover types. Concrete surfaces exhibit temperature increases due to high heat storage and limited evaporative cooling, whereas vegetated and water surfaces show stronger thermal buffering effects. Overall, this study quantitatively reveals the significant influence of AC heat rejection on the thermal environment and airflow distribution in high-density residential areas of hot-summer regions, indicating that AC heat rejection must be explicitly considered in urban microclimate assessment. Furthermore, mitigation strategies through layout optimization and open ground floor design are explored, providing scientific support for heat mitigation, ventilation design, and energy management in urban residential communities.","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"18 1","pages":"108252"},"PeriodicalIF":6.8,"publicationDate":"2026-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148289925","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":"Experimental investigation on flow and boiling heat transfer of ammonia in minichannels","authors":"Hongyu Tian, Shiyu Qian, Tao Ding, Lingyun Hou, Xiao Yu, Jian Cheng, Xiaoxuan Chen","doi":"10.1016/j.csite.2026.108261","DOIUrl":"https://doi.org/10.1016/j.csite.2026.108261","url":null,"abstract":"Ammonia's high heat sink makes it suitable for highly efficient and compact thermal management systems in high thrust weight ratio aero-engines. This study experimentally investigated the flow boiling heat transfer of ammonia in a rectangular minichannel with a hydraulic diameter of 1 mm. Tests covered pressures from 1.22 to 2.31 MPa, mass fluxes of 152.62–394.19 kg/(m<ce:sup loc=\"post\">2</ce:sup>·s), and outlet vapor qualities of 0.027–0.98. Flow visualization identified typical flow regimes and their heat transfer mechanisms. It is indicated that heat transfer in the low vapor quality region is dominated by nucleate boiling (bubbly/slug flow). In the medium-to-high vapor quality region, heat transfer peaks due to conduction and evaporation within the liquid film of the annular flow regime. Heat transfer deteriorates in the dispersed flow regime due to the liquid film’s dryout. Increasing pressure promotes the generation and detachment of smaller bubbles by reducing the vapor-liquid density ratio and surface tension, while also facilitating the earlier onset and enhanced stability of the annular flow regime. The higher two-phase flow velocities at elevated pressures lead to heat transfer enhanced across the entire vapor quality range. Based on the experimental data, a piecewise composite heat transfer correlation for saturated flow boiling incorporating scaling effects was developed. The proposed correlation predicts the experimental data with a mean absolute deviation of 12.07%, and the majority of the predictions fall within a ±30% error band. This study provides a theoretical basis and a design tool for minichannel heat exchangers using ammonia as the working fluid.","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"34 1","pages":"108261"},"PeriodicalIF":6.8,"publicationDate":"2026-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148287760","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":"Quasi-steady load-following thermal management and power generation for hypersonic vehicle RBCC engines via a helium-xenon closed Brayton cycle","authors":"Xin Zhao, Zhaohui Yao, Xing He, Ziqi Zhou, Jiongrui Wang, Weimin Bao, Wen Bao","doi":"10.1016/j.csite.2026.108238","DOIUrl":"https://doi.org/10.1016/j.csite.2026.108238","url":null,"abstract":"Rocket-based combined cycle (RBCC) engines operating across a wide Mach-number range (Ma 4-8) face dual challenges of severe aerodynamic heating and high onboard power demand. Conventional hydrocarbon-fuel cooling is limited by the coking-temperature threshold, while near-critical supercritical CO2 cycles may encounter strong property variation and control difficulty near the pseudo-critical region. This paper numerically assesses an integrated third-fluid cooling and power-generation concept using a binary helium-xenon (He-Xe) mixture. A coupled system-level model, linking RBCC internal ballistics, temperature-dependent mixture properties, an Eckert reference-enthalpy heat-transfer model, and closed Brayton-cycle thermodynamics, is established to evaluate cooling and shaft-power trends. Submodel-level verification checks are added for mixture properties, cooling-channel heat transfer and pressure loss, and the Brayton-cycle power boundary.","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"29 1","pages":"108238"},"PeriodicalIF":6.8,"publicationDate":"2026-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148287101","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 coating of camouflage fabric using activated carbon and inorganic powder for protective effect","authors":"Kittiphop Promdee, Doungkamon Phihusut, Tharapong Vitidsant","doi":"10.1016/j.csite.2026.108207","DOIUrl":"https://doi.org/10.1016/j.csite.2026.108207","url":null,"abstract":"This research developed a multifunctional thermal camouflage coating for military textiles, utilizing activated carbon (AC) and inorganic powders to provide protection against chemical, biological, and radiological (CBR) hazards. Thermal suppression performance was evaluated by integrating conduction analysis via Fourier's Law and radiation analysis through the Stefan-Boltzmann Law. The results demonstrated that the low-emissivity coating (<ce:italic>ε</ce:italic> ≈ 0.55) synergistically reduced heat flux, achieving a 42.1% decrease in radiative heat transfer at 150 °C, thereby significantly enhancing infrared (IR) concealment. The coating's physical and chemical properties were characterized using Scanning Electron Microscopy (SEM), UV-Vis-NIR spectroscopy, and ATR-FTIR. SEM analysis across four treatments; (1) AC, (2) AC + Talc + TiO<ce:inf loc=\"post\">2</ce:inf>, (3) AC + TiO<ce:inf loc=\"post\">2</ce:inf> + Talc + Bentonite, and (4) the optimized AC + TiO<ce:inf loc=\"post\">2</ce:inf> + Talc + Bentonite composite—revealed an organized amorphous distribution of powders and binders within the fabric texture at magnifications up to 4,000×. UV-Vis-NIR spectra indicated that the optimized composite effectively suppressed noise, particularly within the UV-Vis region. While IR reflectivity decreased in certain shades post-coating, the black and brown camouflage components remained within standard military specifications. ATR-FTIR analysis identified key absorbance peaks associated with <ce:italic>v</ce:italic>(C = O), v(CH<ce:inf loc=\"post\">2</ce:inf>), v(CN). All treatments exhibited stable spectral intensities within the 500–1500 cm<ce:sup loc=\"post\">−1</ce:sup> range, specifically between 1018.18 and 1023.52 cm<ce:sup loc=\"post\">−1</ce:sup>. Beyond its camouflage capabilities, the composite coating demonstrated superior environmental utility, achieving a 15.5% Lead (Pb(II)) removal efficiency facilitated by the functional sites of the activated carbon and inorganic constituents. This study presents a robust solution for next-generation military personal protective equipment (PPE), strategically balancing high-temperature thermal shielding with multifunctional hazardous material sequestration.","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"25 1","pages":"108207"},"PeriodicalIF":6.8,"publicationDate":"2026-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148287195","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":"An integrated electromagnetic induction system for rapid and uniform rewarming in multi-well plate cryopreservation","authors":"Hengxin Han, Yuhan Zhang, Ning Guo, Xinyue Wang, Hangyu Dang, Yi Xu","doi":"10.1016/j.csite.2026.108229","DOIUrl":"https://doi.org/10.1016/j.csite.2026.108229","url":null,"abstract":"In situ cryopreservation within multi-well plates is a promising strategy for parallel biospecimen storage, yet it is critically limited by the lack of rapid and uniform rewarming techniques. This study presents an integrated electromagnetic induction heating system designed to address this bottleneck. A novel multi-well plate was developed, featuring integrated heaters that serve as internal heating elements upon immersion in the sample solution. Through systematic investigation and optimization of key parameters—including heater position, coil geometry and size, plate architecture, and the implementation of a field shaper—the system achieved a maximum rewarming rate of 762.4 °C/min while maintaining a maximum temperature difference below 6 °C across the optimized multi-well configuration. This performance represents a 25-fold increase in rewarming rate compared to conventional hotplate methods. The findings provide a scientific basis for parameter selection in induction-based rewarming and establish an efficient and reliable plate-scale rewarming strategy. This technology provides a critical thermal engineering framework and hardware foundation for future in situ preservation studies.","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"33 1","pages":"108229"},"PeriodicalIF":6.8,"publicationDate":"2026-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148287194","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 contact resistance on thermal behavior of pouch-cell battery modules under partial direct liquid cooling: A numerical study","authors":"P.F. Arroiabe, J. Berasategi, M. Larrañaga-Ezeiza, G. Vertiz, I. Galarza, M. Martinez-Agirre","doi":"10.1016/j.csite.2026.108098","DOIUrl":"https://doi.org/10.1016/j.csite.2026.108098","url":null,"abstract":"Direct liquid cooling (DLC) using dielectric fluids is emerging as a highly effective strategy for thermal management in high-performance lithium-ion battery systems, particularly under demanding operating conditions. However, most existing thermal models neglect heat generation from passive components and electrical contact resistances, which can significantly affect prediction accuracy during fast charging and discharging. This work presents a validated 3D multi-scale numerical model of a pouch-cell battery module cooled via a partial immersion DLC approach. The module, composed of four 60 Ah cells in a 2s2p electrical configuration and in a 1s4p hydraulic arrangement, is modeled using a multi-domain framework that integrates electrochemical and thermal phenomena. All model input parameters were experimentally measured in our laboratory, ensuring high physical fidelity. Importantly, the model incorporates ohmic heating in passive components and heat generated by contact resistance, factors often overlooked in existing literature. Validation against experimental measurements demonstrates high accuracy in predicting both transient and steady-state temperature profiles, including spatial temperature distributions within and between cells. Results reveal that passive component heating can momentarily account for up to 46 % of total heat generation under high C-rate charge-discharge cycles, while contact resistance contributes up to 12 % during semi-fast charging. These findings highlight the critical need to include these sources in thermal models to ensure accurate predictions and support design improvements. The proposed approach offers valuable insights for enhancing thermal performance, reliability, and safety of pouch-cell battery modules in electric vehicle applications.","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"3 1","pages":""},"PeriodicalIF":6.8,"publicationDate":"2026-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147752848","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}