International Journal of Thermal Sciences最新文献

{"title":"Manufacturing-constrained multi-objective optimization of diamond microchannel heat sinks via interpretable machine learning","authors":"Song Yang,&nbsp;Liang Du,&nbsp;Jin Yuan,&nbsp;Xinlong Zhao,&nbsp;Wenbo Hu,&nbsp;Zhaoyang Zhang,&nbsp;Hongxing Wang","doi":"10.1016/j.ijthermalsci.2026.110729","DOIUrl":"10.1016/j.ijthermalsci.2026.110729","url":null,"abstract":"<div><div>Modern electronics are continually evolving toward miniaturization and high performance, posing significant challenges for chip-level thermal management under ultra-high heat flux (&gt;1000 W/cm²). Conventional heat sinks are inadequate for these demands. Diamond microchannel heat sinks, leveraging diamond's exceptional thermal conductivity, offer a promising solution. However, the high hardness and cost of diamond lead to elevated manufacturing costs for such heat sinks. Consequently, the co-optimization of thermal-hydraulic performance and manufacturing costs presents a critical challenge. This study employed a machine-learning-based multi-objective optimization approach to design diamond microchannel heat sinks, simultaneously considering thermal-hydraulic performance and manufacturing objectives. An artificial neural network predicted the thermal-hydraulic performance, and a genetic algorithm then identified Pareto-optimal solutions. First, a thermal-hydraulic dual-objective optimization was conducted to analyze the trade-off between the maximum temperature and pressure drop. Subsequently, two manufacturing objectives (aspect ratio and cross-sectional area) were introduced, thereby formulating a manufacturing-constrained multi-objective optimization problem. The results demonstrated clear trade-offs among these four objectives on the Pareto front. One notable optimal solution achieves a 61.6 % reduction in material cost and an estimated 58 % decrease in fabrication difficulty with only a 20 % compromise in thermal-hydraulic performance. Thus, this work provides a systematic design methodology that successfully balances performance with manufacturability, paving the way for the scalable industrial adoption of diamond microchannel heat sinks.</div></div>","PeriodicalId":341,"journal":{"name":"International Journal of Thermal Sciences","volume":"224 ","pages":"Article 110729"},"PeriodicalIF":5.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146074473","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 HFE-7100 flow boiling in aluminum open microchannels heat sink","authors":"Liaofei Yin ,&nbsp;Tianjun Qin ,&nbsp;Wenhao Ma ,&nbsp;Yi Ding ,&nbsp;Yawei Xu","doi":"10.1016/j.ijthermalsci.2026.110672","DOIUrl":"10.1016/j.ijthermalsci.2026.110672","url":null,"abstract":"<div><div>For thermal management of large heat-generating devices, aluminum heat sinks exhibit promising application prospects owing to their lightweight and corrosion-resistant properties. This research presents an experimental study of HFE-7100 flow boiling within an aluminum heat sink with large heating area featuring open microchannels. By incorporating visualizations of bubble dynamics and flow regime transitions, the heat transfer mechanisms in large-area open microchannels heat sink were elucidated. The study revealed that increasing the mass flux simultaneously enhanced both the average heat transfer coefficient (HTC) and the critical heat flux (CHF), while elevated inlet temperatures significantly improved heat removal capability under moderate to high heat flux conditions. Notably, a previously unreported two-phase flow regime was identified, characterized by wave-like periodic features, and was termed “surge flow”. The flow boiling regime underwent longitudinally a sequential evolution from bubbly flow to plug flow and finally to surge flow along the flow direction. Examining the localized thermal performance across various regions of the heat sink revealed that the HTC of the surge flow regime exceeded those of bubbly and plug flow patterns by as much as 117.1 % and 58.7 %, respectively. Furthermore, the CHF was observed when the surge flow occupied approximately 65.0 %–70.0 % of the flow passage in the heat sink.</div></div>","PeriodicalId":341,"journal":{"name":"International Journal of Thermal Sciences","volume":"224 ","pages":"Article 110672"},"PeriodicalIF":5.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145908879","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":"Resolving inverse heat conduction problems based on space marching method with Gauss filter - An experimental validation","authors":"Ruiqin Cheng ,&nbsp;Hongchu Chen ,&nbsp;Zitao Yu ,&nbsp;Changnian Pu","doi":"10.1016/j.ijthermalsci.2026.110693","DOIUrl":"10.1016/j.ijthermalsci.2026.110693","url":null,"abstract":"<div><div>The space marching method (SMM) is an effective approach for solving inverse heat conduction problems (IHCPs). It enables efficient prediction of surface heat flux and temperature using embedded temperature sensors, offering advantages such as computational speed, high effectiveness, and accuracy. However, the in-depth temperature measurements often contain noise, which can be amplified during the prediction process, leading to unstable results due to the ill-posed nature of IHCPs. To stabilize the problem, it is necessary to filter the noisy in-depth temperature data. The Gauss filter has been demonstrated through numerical simulations as a valid method for stabilizing noisy data when using SMM to solve IHCPs. However, the application of the space marching technique with the Gauss filter for solving IHCPs has not been experimentally validated. In this paper, an experimental setup based on electric heating is designed and implemented to validate the effectiveness of the method. Compared with the prediction results with other regularization parameters, the SMM prediction with the optimal regularization parameter significantly reduces the relative root mean square error (RRMSE), demonstrating that SMM with the Gauss filter can be effectively applied in engineering practice.</div></div>","PeriodicalId":341,"journal":{"name":"International Journal of Thermal Sciences","volume":"224 ","pages":"Article 110693"},"PeriodicalIF":5.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146023750","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 non-invasive microwave hyperthermia for breast cancer treatment: FEA-based multiphysics approach for optimizing thermal dosage","authors":"Anudev J. ,&nbsp;Balakrishnan Shankar ,&nbsp;Massimo Donelli ,&nbsp;Sreedevi K. Menon","doi":"10.1016/j.ijthermalsci.2026.110688","DOIUrl":"10.1016/j.ijthermalsci.2026.110688","url":null,"abstract":"<div><div>Microwave hyperthermia has emerged as a potential supplement therapy for cancer treatment. The treatment modality elevates the temperature of cancer cells within the therapeutic limit (40 °C–45 °C). This will help to enhance their receptiveness to conventional treatments such as chemotherapy and radiation therapy. Numerical simulation strategies are adopted in this paper to simulate the effects of electromagnetic radiation on cancer cells. Combining electromagnetics and transient thermal analyses through a multiphysics approach, the thermal effects of electromagnetic (EM) radiation on the target cells are studied. A pentagonal patch antenna resonating at 2.45 GHz has been specially designed for this purpose and analysed experimentally. To mimic the breast tissues, a multi-layered simulation model has been designed with various sections such as skin, fat, fibroglandular tissue and tumor, positioned at different depths from the skin. The thickness of each layer is provided based on the average physiological measurements. To assure proper energy concentration at the tumor region, the electric field intensity and specific absorption rate are quantified through electromagnetic simulations. Subsequently, thermal simulations are performed in ANSYS Icepak by varying the input power levels of the antenna from 3 W to 10 W, to examine the therapeutic temperature developed at the tumor region. The effectiveness of thermal dosage is quantified with cumulative equivalent minutes at 43 °C (CEM43). Multiple simulations are performed by assuming varied positions of the tumor from the skin level, providing varied power levels accordingly. The proposed system acquires a rise in temperature to hyperthermia levels from the base temperature at a maximum rate less than 0.32 °C/s. Across the tested power levels, system attains CEM43 = 60 minutes for various tumor depths with tumor SAR≤ 40 W/kg and skin SAR&lt;4 W/kg, falls under exposure limits. The proposed pentagonal patch antenna achieves faster therapeutic heating (&lt;60 s) than prior antenna designs at 2.45 GHz with optimized power for varying tumor depths, keeping the skin temperature within the permissible limits.</div></div>","PeriodicalId":341,"journal":{"name":"International Journal of Thermal Sciences","volume":"224 ","pages":"Article 110688"},"PeriodicalIF":5.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146023855","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":"Gas transport modeling in confined graphitic nanopores under high pressure","authors":"Deng Yang ,&nbsp;Chongwen Jiang ,&nbsp;Kaidi Wan ,&nbsp;Chun-Hian Lee","doi":"10.1016/j.ijthermalsci.2026.110671","DOIUrl":"10.1016/j.ijthermalsci.2026.110671","url":null,"abstract":"<div><div>Gas transport through nanochannels is widespread in both natural and industrial systems and is critical for the design of advanced porous materials. While Knudsen theory is traditionally used to describe this regime, its assumption of fully diffuse reflections fails for graphite-based nanopores, where atomically smooth surfaces promote specular scattering. High-pressure adsorption layers further alter scattering and flow behavior, yet quantitative models that incorporate both effects remain limited. In this study, molecular dynamics simulations are employed to investigate gas transport in graphitic slit nanopores. Gas-solid collisions follow the Cercignani-Lampis-Lord (CLL) model on smooth surfaces, whereas adsorption layers introduce partial diffuse reflection. To quantify the resulting deviations from ideal CLL behavior, we propose a linear-combination scattering framework and develop a semi-empirical tangential momentum accommodation coefficient (TMAC) model. Building upon this framework, new permeability and mass flow rate models are established that incorporate dense gas behavior and confinement effects. Simulation results reveal that the velocity profile within slit nanopores tends toward a plug-like shape, with flow rates enhanced by one to three orders of magnitude compared to no-slip Poiseuille flow. The presence of adsorption layers impedes molecular motion, and the ability of gas molecules to overcome this resistance is directly related to temperature. Compared with conventional models developed for inorganic porous media, the proposed model accurately captures the distinct gas transport behavior along graphitic surfaces. These findings offer valuable guidance for the development and utilization of carbon aerogels and, more broadly, for understanding mass transport in carbon-based nanoporous materials.</div></div>","PeriodicalId":341,"journal":{"name":"International Journal of Thermal Sciences","volume":"224 ","pages":"Article 110671"},"PeriodicalIF":5.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145975203","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 heat transfer using CuO+ZnO-water hybrid nanofluid with helical coil inserts in double pipe heat exchanger: Performance analysis and correlation development","authors":"Brajesh Kumar Ahirwar ,&nbsp;Arvind Kumar","doi":"10.1016/j.ijthermalsci.2025.110650","DOIUrl":"10.1016/j.ijthermalsci.2025.110650","url":null,"abstract":"<div><div>The growing need for efficient thermal management has spurred extensive research into enhancing heat exchanger performance. Among emerging methods, nanofluids—especially hybrid variants—have shown significant potential due to their superior thermal properties. This study explores the thermal performance of CuO + ZnO-water hybrid nanofluids in a double-pipe heat exchanger (DPHE) equipped with wire coil inserts as a passive enhancement technique. Hybrid nanofluids were prepared using CuO and ZnO nanoparticles at three volume concentrations: 1.0 % (80:20), 0.5 % (60:40), and 0.1 % (40:60). These fluids were tested over a Reynolds number range of 5500–15000 with wire coil inserts of varying diameters (1.0 mm, 1.5 mm, 2.0 mm) and pitch ratios (0.625–3.125). Results demonstrated that the highest heat transfer performance was achieved using 1.0 % CuO: ZnO (80:20) with a 2.0 mm wire diameter and tightest pitch ratio (0.625), yielding a Nusselt number increase of up to 281.87 % over water. While the friction factor also rose—leading to a maximum pressure drop penalty of 600.72 %—the thermal performance factor (TPF) remained favourable, ranging from 1.61 to 1.74. Lower concentrations and alternate compositions showed moderate performance improvements. Empirical correlations for Nusselt number and friction factor were developed, with predictive deviations within ±10 % of experimental values, confirming their reliability. This comprehensive analysis highlights the synergistic benefits of hybrid nanofluids and optimized wire coil geometries, offering valuable insights for the design of high-efficiency, compact heat exchangers in advanced thermal systems.</div></div>","PeriodicalId":341,"journal":{"name":"International Journal of Thermal Sciences","volume":"224 ","pages":"Article 110650"},"PeriodicalIF":5.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145975206","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":"Numerical investigation on heat transfer and flow characteristics of triply periodic minimal surface in transpiration cooling","authors":"Zeyu Zhang ,&nbsp;Yong Song ,&nbsp;Zhi Tao ,&nbsp;Liming Song ,&nbsp;Jun Li","doi":"10.1016/j.ijthermalsci.2026.110666","DOIUrl":"10.1016/j.ijthermalsci.2026.110666","url":null,"abstract":"<div><div>Transpiration cooling has been proved to act as the next generation cooling technology. The Triply Periodic Minimal Surface (TPMS) structures are the newly developed porous medium with superior mechanical and thermal properties. However, an in-depth understanding of the TPMS applied in the transpiration cooling remains insufficient. In this work, a numerical investigation is established to extract the detailed information of the aerodynamic and thermal mechanisms. Four commonly used TPMS structures, P, W, G and D are compared comprehensively in terms of cooling efficiency, temperature uniformity and pressure cost. The effect of blowing ratios ranging from 0.45 % to 3.3 % and solid porosities from 0.3 to 0.5 on different structures is also investigated. The result turns out that the average cooling efficiency increases monotonously from around 0.43 to 0.96 with blowing ratio with a gradually slowing rate. The cooling behavior usually improves with decreased porosity because of better protection of coolant film. The integrated cooling performance combined with pressure cost is also discussed and found to get good grades with high blowing ratio and porosity. The structure G and D achieves superior cooling performance because of the continuous protective film attachment and highly distorted inner surface. The P structure ensures excellent temperature uniformity attributes to the minimum heat conduction resistance and velocity uniformity. But the intense vortex derived from fluid expansion and contraction causes high pressure cost and dissipation. By integrating these results, this study reveals the underlying thermofluidic mechanisms and establishes performance trends that can inform the preliminary selection of different structures.</div></div>","PeriodicalId":341,"journal":{"name":"International Journal of Thermal Sciences","volume":"224 ","pages":"Article 110666"},"PeriodicalIF":5.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145923843","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":"Strategic partial silver nanoparticles coating in enhancement of heat Sink's thermal performance","authors":"Xing Qi Lim ,&nbsp;Mohd Sharizal Abdul Aziz ,&nbsp;C.Y. Khor","doi":"10.1016/j.ijthermalsci.2026.110679","DOIUrl":"10.1016/j.ijthermalsci.2026.110679","url":null,"abstract":"<div><div>This study investigates the potential of a partially applied silver nanoparticle (AgNP) coating to enhance the thermal dissipation performance of the heat sink. Since the fully coated heat sink only showed marginal enhancement in the previous study, the heat sink is now partially coated on different surfaces. The simulation is completed using the ANSYS FLUENT software, and the accuracy of the setup is verified with an error percentage of less than 4 %. The heat sink with a front face coated (C3-AgNP) records the highest average overall heat transfer coefficient of 6.15379 W m⁻² K⁻¹, which is 1.141 % higher than the uncoated heat sink and 0.944 % better than the fully-coated (C1234-AgNP) heat sink. The C3-AgNP heat sink requires only a 5.4 mm³ AgNP coating, which is 96.655 % less than the 161.44 mm³ coating used by the C1234-AgNP heat sink. Although the presence of AgNP coating has adverse effects on the radiation heat loss of the heat sink, it enhances the heat dissipation process by facilitating heat flow from hotter regions to cooler regions. The AgNP coating promotes temperature uniformity in the heat sink, enabling greater heat loss through convection. This study reveals the possibility of unleashing the full potential of a coated heat sink through partial coating. It also contributes a solution for combining two or more different coatings, thereby optimizing heat sink performance in thermal management applications.</div></div>","PeriodicalId":341,"journal":{"name":"International Journal of Thermal Sciences","volume":"224 ","pages":"Article 110679"},"PeriodicalIF":5.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145923777","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 and transport characteristics in the entrance region of Poiseuille-Rayleigh-Bénard double diffusive convection of binary fluid in a horizontal channel","authors":"Heng Lin ,&nbsp;Li Zhang ,&nbsp;Chun-Mei Wu ,&nbsp;You-Rong Li","doi":"10.1016/j.ijthermalsci.2026.110675","DOIUrl":"10.1016/j.ijthermalsci.2026.110675","url":null,"abstract":"<div><div>To understand the flow and transport characteristics in the entrance region of Poiseuille-Rayleigh-Bénard (P-R-B) double diffusive convection within horizontal channel, a series of three-dimensional numerical simulations are conducted to assess the impact of aspect ratio (<em>B</em>), Reynolds number (<em>Re</em>), buoyancy ratio (<em>N</em>), and Rayleigh number (<em>Ra</em>), with the following ranges: 1≤<em>B</em> ≤ 10, 0≤<em>Re</em> ≤ 25, −0.3≤<em>N</em> ≤ 0.3, and 40≤<em>Ra</em>≤1.2 × 10⁵. The results indicate that the vertical velocity exhibits periodic sinusoidal fluctuations in both space and time as transverse rolls (TRs) develop. The amplitude of these fluctuations increases with <em>Ra</em> and <em>N</em>, while the fundamental frequency decreases as <em>N</em> rises. In the presence of longitudinal rolls (LRs), the vertical velocity is symmetrically distributed in the spanwise direction. If LRs do not fully develop in the entrance region, the vertical velocity will not form regular periodic fluctuations. When stable TRs occupy the entrance region, both temperature and concentration fields fluctuate sinusoidally over time with identical fundamental frequency. Correspondingly, Nusselt (<em>Nu</em>) and Sherwood (<em>Sh</em>) numbers show sinusoidal variations in the streamwise direction, and their amplitudes increase with <em>Ra</em> and <em>N</em>. Moreover, for LRs, the entrance lengths for the onset of secondary flow (<em>L</em>₁) and for its full development (<em>L</em>₂) decrease with <em>Ra</em> and <em>N</em>, but increase with <em>Re</em> and <em>B</em>. Meanwhile, at high <em>Ra</em> or large positive <em>N</em>, the reductions of <em>L</em>₁ and <em>L</em>₂ become less pronounced. In addition, the overall transport performance is not improved monotonically with increasing <em>B</em>. Based on simulation data, correlations for <em>L</em>₁ and <em>L</em>₂ were proposed. Ultimately, the thermal and solute transport correlations including the entrance region were also derived. These findings provide a theoretical foundation for the dimensional design of chemical reactors, heat and mass transfer equipment, and other systems involving P-R-B double diffusive convection.</div></div>","PeriodicalId":341,"journal":{"name":"International Journal of Thermal Sciences","volume":"224 ","pages":"Article 110675"},"PeriodicalIF":5.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145923775","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 transport of GaN/substrate heterostructures under non-uniform heat source","authors":"Ershuai Yin,&nbsp;Wenzhu Luo,&nbsp;Lei Wang,&nbsp;Enjian Sun,&nbsp;Qiang Li","doi":"10.1016/j.ijthermalsci.2026.110669","DOIUrl":"10.1016/j.ijthermalsci.2026.110669","url":null,"abstract":"<div><div>Heat in gallium nitride (GaN) high-electron-mobility transistors (HEMTs) is typically generated as highly localized nanoscale hot spots and dissipates through GaN/substrate heterostructures, yet the impact of non-uniform heating on heterostructure thermal transport remains unclear. This work aims to elucidate the thermal transport mechanisms of GaN/substrate heterostructures under non-uniform heat sources. A heterostructure thermal transport model is developed by combining first-principles calculations with Monte Carlo simulations. The effects of heterostructure height, heat source width, and heat source height on thermal transport characteristics are analyzed for four typical GaN/substrate heterostructures: GaN/AlN, GaN/Diamond, GaN/Si, and GaN/SiC. The results show that non-uniform heating has only a minor effect on the average interfacial thermal conductance. However, it induces pronounced spatial non-uniformity when the heterostructure height is small, with substantially higher conductance near the hot-spot region. Increasing heat-source non-uniformity substantially elevates the total thermal resistance, reaching several times the value obtained under uniform heating. In contrast, conventional finite-element method significantly underestimates the total thermal resistance because it cannot capture the coupled effects of localized heating and size-dependent thermal transport. The findings can provide theoretical guidance for the thermal design and reliability assessment of GaN semiconductor devices.</div></div>","PeriodicalId":341,"journal":{"name":"International Journal of Thermal Sciences","volume":"224 ","pages":"Article 110669"},"PeriodicalIF":5.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145975207","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}