International Journal of Heat and Mass Transfer最新文献

{"title":"Effects of NaHCO3 thermal decomposition characteristics on variable-pressure methane/air flames","authors":"Zhuo Xu ,&nbsp;Ligang Zheng ,&nbsp;Jian Wang ,&nbsp;Rongkun Pan ,&nbsp;Xi Wang ,&nbsp;Hao Li ,&nbsp;Bingjie Zhang","doi":"10.1016/j.ijheatmasstransfer.2025.127826","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.127826","url":null,"abstract":"<div><div>NaHCO₃ is widely used for flame inhibition due to its efficient heat absorption ability. However, the coupling effect between the powder particle size and initial pressure on the decomposition efficiency of NaHCO₃ at the flame front remains unclear. To further investigate the interaction mechanism between variable-particle-size powders and variable-pressure flames, experiments were conducted using NaHCO₃ with four particle sizes (median diameters D₅₀ of 40.36, 18.36, 16.23, and 9.29 μm) and three initial pressures of premixed gas (0.8, 1.0, and 1.4 atm) in a 36 L spherical vessel. The thermal decomposition model of NaHCO₃ suggested that a higher initial pressure shortens the residence time of particles in the flame front, thereby hindering NaHCO₃ decomposition. Moreover, with increasing initial pressure, the flame temperature gradually decreases. Besides, we propose a dimensionless concentration parameter to characterize the coupling effect of the initial pressure and powder particle size quantitatively. The results revealed that the sensitivity of the explosion suppression efficiency to the particle size decreased with increasing initial pressure; the reduction in the explosion induction time and pressure peak arrival time caused by smaller NaHCO₃ particles was more significantly affected by the initial pressure. Finally, the LBVs obtained via the confined spherical flame method were compared for the inhibited and uninhibited flames, and the most recent kinetic mechanisms for inhibited flames were discussed. This study provides a theoretical basis for effectively preventing and reducing the risk of methane explosion accidents.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"255 ","pages":"Article 127826"},"PeriodicalIF":5.8,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145060046","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":"Full-scale modelling and thermal analysis of an air-cooled proton exchange membrane fuel cell stack with U-shape gas architecture and close cathode mode","authors":"Lixin Fan ,&nbsp;Bin Miao ,&nbsp;Yozo Okuyama ,&nbsp;Ovilian Ding ,&nbsp;Siewhwa Chan ,&nbsp;Zhengkai Tu","doi":"10.1016/j.ijheatmasstransfer.2025.127822","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.127822","url":null,"abstract":"<div><div>Air-cooled proton exchange membrane fuel cells (ACFCs) typically employ an open-cathode structure but suffer from heat accumulation and low oxidant partial pressure, limiting performance and durability. To address these challenges, a full-scale U-shaped intake ACFC stack model with close cathode was developed, incorporating electrochemical reactions, multicomponent mass transport, Darcy flow, and fluid-solid heat transfer. The model was used to evaluate thermal and output characteristics under varying coolant flow rates. Results indicate that thermal non-uniformity is most pronounced at the end of the flow path. Increasing coolant velocity enhances forced convection and reduces reactant-driven thermal gradients; however, this effect diminishes at higher velocities. A coolant velocity of 5 m/s was found to achieve optimal thermal management and stack performance with minimal auxiliary power consumption. Specifically, increasing coolant velocity from 3 m/s to 5 m/s reduced the stack temperature difference from 17.12 °C to 10.92 °C, while a further increase to 7 m/s only reduced it to 8.32 °C. In-plane temperature uniformity is primarily controlled by coolant flow, with minor influence from reactant distribution, whereas axial thermal gradients are largely independent of reactant flow. Thermal uniformity progressively declines along the flow direction, with upstream cells showing better heat dissipation due to proximity to reactant inlets/outlets. This contributes to localized thermal homogenization and reduced hot spots. These findings provide insights into improving ACFC thermal design for enhanced stability and efficiency.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"255 ","pages":"Article 127822"},"PeriodicalIF":5.8,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045206","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":"Repercussions of maldistribution on subcooled fluid boiling in microchannel heat sink","authors":"Gurjeet Singh ,&nbsp;Ritunesh Kumar ,&nbsp;Paweł Dąbrowski ,&nbsp;Dariusz Mikielewicz","doi":"10.1016/j.ijheatmasstransfer.2025.127821","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.127821","url":null,"abstract":"<div><div>Flow boiling in microchannels still attracts enormous interest among the heat transfer community worldwide due to its exceptionally brilliant heat dissipation capability and the unfolded mysteries revolving around the flow reversal phenomenon. Finding ways of delaying/disrupting the flow reversal phenomenon acts as a counteractive strategy against the flow boiling instabilities in microchannel heat sink (MCHS). The presence of uneven fluid flow distribution leads to the early occurrence of flow reversal and associated flow boiling instabilities. In that context, this work addresses flow maldistribution and its intrinsic connection with flow boiling instabilities at the microscale level. Two configurations of MCHS, conventional design MCHS (CD-MCHS) and a design evolved by flow maldistribution mitigation: variable height design MCHS (VH-MCHS), are tested experimentally. It is noticed that under the strong flow maldistribution, boiling inception occurs in the side microchannels, while the flow remains single-phase in the central microchannels in the CD-MCHS design. On the other hand, uniform fluid flow distribution in the VH-MCHS design helped in removing the flow boiling phenomenon lag between the side and central microchannels, as observed in the CD-MCHS design. Flow uniformity across the parallel channels uplifts the supplied heat flux corresponding to the inception of the boiling process; a 7.7 - 17.3 % improvement is observed for the studied mass flow range of at <span><math><msub><mover><mi>m</mi><mo>˙</mo></mover><mrow><mi>i</mi><mi>n</mi></mrow></msub></math></span> = 0.0008 - 0.0032 kg/s. The proposed design also brings down wall superheat at the onset of nucleate boiling from 107.5°C for CD-MHCS to 106.3°C for VH-MCHS design at <span><math><msub><mover><mi>m</mi><mo>˙</mo></mover><mrow><mi>i</mi><mi>n</mi></mrow></msub></math></span> = 0.0024 kg/s and T_in = 30°C. Furthermore, the VH-MCHS design provided better surface temperature uniformity and lower vapor backflow intensity and low fluctuations in the pressure signals than the CD-MCHS design. A correlation is also proposed to predict a two-phase pressure drop ratio during subcooled flow boiling.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"255 ","pages":"Article 127821"},"PeriodicalIF":5.8,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045123","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":"Electroosmotic blood flow containing gold and silver nanoparticles through a microchannel: Effect of driving microorganisms","authors":"Debabrata Das,&nbsp;Firoj Ahmed,&nbsp;Rishi Raj Kairi","doi":"10.1016/j.ijheatmasstransfer.2025.127767","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.127767","url":null,"abstract":"<div><div>This study examines the impact of bioconvective transport of microorganisms in blood with suspended nanoparticles through a microchannel, relevant to biomedical and microfluidic applications. The Jeffrey non-Newtonian fluid model is utilized to characterize the blood and gold–silver (<span><math><mi>Au − Ag</mi></math></span>) nanoparticles are suspended in it. The aim is to assess how electroosmotic forces, nanoparticles, and fluid rheology affect velocity, temperature, concentration, and microorganism distributions. The model assumes a laminar, incompressible flow of a Jeffrey fluid, influenced by pressure gradient, electroosmosis, and a transverse magnetic field. The electric potential is computed using the Poisson–Boltzmann equation with the Debye–Hückel linearization, valid for low surface potentials. Analytical solutions are obtained for velocity, temperature, concentration fields, and important characteristics such as Nusselt &amp; Sherwood numbers. Due to the nonlinear nature of microorganism distribution, the Matlab bvp4c solver is employed to find the numerical solutions. Results show that higher volume fractions of <span><math><mi>Au − Ag</mi></math></span> nanoparticles enhance temperature, concentration, and microorganism distributions. The ratio of retardation to relaxation time parameter suppresses microorganism distribution. For purely electroosmotic-driven flow, microorganism distribution is profound compared to the presence of pressure. Also, the thermo-diffusion effect shows a clear correlation with the electroosmotic effect. We have observed that increasing the Soret number helps with concentration distribution and makes mass transfer more efficient, and its influence on microorganism transport varies with the electric double layer (EDL) thickness. We have also discovered that boosting the Hartmann number results in more microorganism buildup, all because it alters the flow structure. Even more importantly, a thinner electric double layer and a longer relaxation time greatly increase the volumetric flow rate while keeping the transfer efficiencies high. These outcomes have significant potential across various fields like chemical processing, the development of biochips for drug delivery, and biomedical engineering.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"255 ","pages":"Article 127767"},"PeriodicalIF":5.8,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045124","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":"Research on phase change of vertical annular falling film heat transfer in tube at high liquid film Reynolds number","authors":"Liang Wang","doi":"10.1016/j.ijheatmasstransfer.2025.127820","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.127820","url":null,"abstract":"<div><div>The turbulent gas–liquid heat transfer process in inlet section of falling film heat transfer in tube is very severe. To research the effect of high Reynolds number (<em>Re_l</em>=1.81 × 10⁴∼4.23 × 10⁴) phase change heat transfer characteristics and mechanism of falling liquid film in the scrubbing cooling tube. Vertical falling film flow model of the scrubbing cooling tube is established. The influence of liquid film temperature, <em>Re_l</em> and gas phase temperature on gas–liquid two-phase phase change heat transfer effect is studied using User Defined Function (UDF) in FLUENT. The results show that outlet temperature of gas–liquid mixed fluid rises with the increase of the initial gas temperature, and the gas–liquid heat transfer effect is most intense at 0–0.1 m. When gas temperature is 673 K, the maximum heat transfer coefficient (HTC)is about 899 W/(m²·K).When liquid film inlet temperature rises, HTC decreases, and the maximum deviation between calculated data and experimental correlations is about 12.43 %. When the gas temperature is between 1173 K and 1573 K, the cross-sectional temperature and water vapor content inside the tube increase. The HTC between gas and liquid phases is directly proportional to the liquid film <em>Re_l</em> and the dimensionless temperature. The maximum deviation between the fitted curve value and the calculated value is 11 %, fitting degree <em>R</em>² = 0.98.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"255 ","pages":"Article 127820"},"PeriodicalIF":5.8,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045121","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":"Investigation of solidification parameters and microstructure evolution in directed energy deposition with laser beam oscillation","authors":"Bo Chen ,&nbsp;Binxin Dong ,&nbsp;Yanhua Bian ,&nbsp;Shaoxia Li ,&nbsp;Chongxin Tian ,&nbsp;Xiuli He ,&nbsp;Gang Yu","doi":"10.1016/j.ijheatmasstransfer.2025.127774","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.127774","url":null,"abstract":"<div><div>Laser beam oscillation offers significant potential to enhance process stability, control solidification parameters, and tailor microstructure in directed energy deposition. A coupled mesoscopic-microcosmic numerical model is utilized in this work to investigate the effect of oscillating laser beam on the solidification parameters and microstructure evolution during the directed energy deposition with laser beam oscillation (DED-LBO) process. The dynamics solidification conditions induced by the oscillating laser beam are considered in the mesoscopic thermal-fluid model. Based on the solidification parameters, the columnar-to-equiaxed transition of the microstructure is discussed, and microstructure evolution is analyzed using the microcosmic phase-field model. The results show that temperature gradient (G) and cooling rate (GR) vary transiently with the position along the laser oscillation trajectory. The microstructure is predominantly characterized by columnar grain growth, with a relative probability exceeding 85.37 %. An increase in oscillation amplitude and frequency effectively reduces both G and GR, resulting in a coarser microstructure. Good agreement is achieved between the simulated and experimental dimensions and microstructural morphologies of the deposited layers, demonstrating the validity of the developed model. The findings of this work provide valuable insight into revealing the dynamic solidification parameters under the oscillating laser beam and elucidating the physical mechanisms governing microstructure evolution under varying oscillation conditions.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"255 ","pages":"Article 127774"},"PeriodicalIF":5.8,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045122","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":"High-efficiency design of self-assembled monolayers for enhanced thermal conductance at solid-water interfaces via parallel screening with simple physical metrics","authors":"Shengluo Ma ,&nbsp;Dezhao Huang ,&nbsp;Dengke Ma ,&nbsp;Yunwen Wu ,&nbsp;Yuriy A. Kosevich ,&nbsp;Tapio Ala-Nissila ,&nbsp;Shenghong Ju","doi":"10.1016/j.ijheatmasstransfer.2025.127815","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.127815","url":null,"abstract":"<div><div>Solid-water interfacial thermal transport is crucial at the micro-nano scale and has important applications in thermal devices and nanofluids. Functionalizing material surfaces with self-assembled monolayers (SAMs) can bridge the solid-water interfaces, reduce vibrational mismatches, and thereby enhancing interfacial thermal conductance (ITC). However, existing research on SAM thermal transport regulation only involves simple structures with scarce data, and high-throughput (HTP) discovery for complex SAM end group structures have not been reported. This work proposes a high-efficiency design framework for SAM end groups through parallel screening using simple physical indicators associated with ITC. Compared to obtain ITC through full simulations of all the relevant materials, here we calculate the interfacial interaction energy and vibrational spectral coupling strength of 250 complex end group structures in SAMs at gold-water interface and integrate ML models to perform multi-objective screening on another 750 complex candidates. Ultimately, through complete nonequilibrium molecular dynamics (NEMD) simulations, 9 SAM end group structures with ITC higher than 150 MW/(m²K) and the synthetic accessibility scores below 3 were discovered, which the ML models screening success rate exceeding 85%. Through thermal transport decomposition analysis of Coulombic and van der Waals interactions, the SAM with extremely high ITC can be attributed to strong Coulombic interactions with water molecules due to highly polar end groups. This HTP framework fills the gap in research on HTP screening of SAM end groups for ITC regulation. Additionally, the related computational data will contribute to future data-driven research on SAMs.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"255 ","pages":"Article 127815"},"PeriodicalIF":5.8,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045125","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 improved four-equation transition-turbulence model for high-speed flows: Transition prediction and physical insight","authors":"Lei Wu ,&nbsp;Zuoli Xiao","doi":"10.1016/j.ijheatmasstransfer.2025.127798","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.127798","url":null,"abstract":"<div><div>In this paper, two major improvements are first proposed to break the bottleneck of conventional <span><math><mi>k</mi></math></span>-<span><math><mi>ω</mi></math></span>-<span><math><mi>γ</mi></math></span>-<span><math><msub><mrow><mover><mrow><mi>R</mi><mi>e</mi></mrow><mrow><mo>˜</mo></mrow></mover></mrow><mrow><mi>θ</mi><mi>t</mi></mrow></msub></math></span> transition-turbulence model for simulation of high-speed flows. One is reformulation of the correlation for maximum ratio between vorticity Reynolds number and momentum thickness Reynolds number derived from the self-similar solutions of compressible boundary layer. The other is modification of the empirical correlation for critical momentum thickness Reynolds number in consideration of the compressibility and nose bluntness effects. Then, these improvements are applied to the original <span><math><mi>k</mi></math></span>-<span><math><mi>ω</mi></math></span>-<span><math><mi>γ</mi></math></span>-<span><math><msub><mrow><mover><mrow><mi>R</mi><mi>e</mi></mrow><mrow><mo>˜</mo></mrow></mover></mrow><mrow><mi>θ</mi><mi>t</mi></mrow></msub></math></span> model for prediction of high-speed flow transition and investigation of underlying physics. Three configurations, including flat plate, sharp straight cones at different Reynolds numbers, and blunt straight cones with several nose bluntness, are adopted to fully validate the new developed model. Numerical results manifest that the transition trend given by the improved <span><math><mi>k</mi></math></span>-<span><math><mi>ω</mi></math></span>-<span><math><mi>γ</mi></math></span>-<span><math><msub><mrow><mover><mrow><mi>R</mi><mi>e</mi></mrow><mrow><mo>˜</mo></mrow></mover></mrow><mrow><mi>θ</mi><mi>t</mi></mrow></msub></math></span> model is basically consistent with that observed in experiments, considerably overcoming the disability of its original counterpart. In addition, several physical mechanisms are highlighted, such as the compressibility signatures, effects of Reynolds number/nose bluntness on transition, and applicability of generalized Reynolds analogy.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"255 ","pages":"Article 127798"},"PeriodicalIF":5.8,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045126","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":"Multi-objective optimization and performance analysis of a CPV/T system based on NSGA-II and entropy weight TOPSIS method","authors":"Qingfan Liu ,&nbsp;Zilong Zeng ,&nbsp;Dong Yang ,&nbsp;Wenchuan Liu ,&nbsp;Xinlong Lu ,&nbsp;Liwu Zhou ,&nbsp;Dengwei Jing","doi":"10.1016/j.ijheatmasstransfer.2025.127810","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.127810","url":null,"abstract":"<div><div>This study presents a novel concentrating photovoltaic/thermal (CPV/T) system integrated with coaxial cross Kenics mixers to enhance performance. The solar concentration process was modeled using the Monte Carlo Ray Tracing method, while Computational Fluid Dynamics simulations and Response Surface Methodology were applied to analyze the effects of four key design variables: inlet velocity, gap between the receiver tube and the mixer, mixer pitch, and receiver tube diameter. Electrical efficiency, thermal efficiency, and performance evaluation criterion were defined as response indicators, and predictive models for each were developed. A thermodynamic optimization framework combining the NSGA-II algorithm with the entropy weighted TOPSIS method was used to identify the optimal system configuration. Optical simulation results show a uniform energy flux distribution on the solar cell surface. The system's optical efficiency decreases from 99.98 % to 47.31 % as the solar tracking error angle increases from 0.0° to 2.0°. The Response Surface Methodology based predictive models demonstrated high accuracy in capturing system behavior. Among the design variables, the receiver tube diameter had the most significant impact on electrical and thermal efficiencies, while the mixer pitch most strongly affected the performance evaluation criterion. Under an inlet velocity of 0.136 m s⁻¹, a gap between the receiver tube and the mixer of 0.75 mm, a mixer pitch of 15.01 mm, and a receiver tube diameter of 12.00 mm, the system achieves its highest overall performance. Compared to a system without the optimized mixers, electrical efficiency improved from 13.37 % to 14.55 %, and thermal efficiency increased from 58.03 % to 61.14 %.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"255 ","pages":"Article 127810"},"PeriodicalIF":5.8,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045128","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":"Stable implementation of a Chen-based enhancement to the Lee phase-change model for CFD simulation of film boiling under energetic melt-coolant interaction conditions","authors":"Mihael Boštjan Končar ,&nbsp;Matej Tekavčič ,&nbsp;Mitja Uršič ,&nbsp;Mihael Sekavčnik","doi":"10.1016/j.ijheatmasstransfer.2025.127813","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.127813","url":null,"abstract":"<div><div>This study investigates heat and mass transfer during energetic melt-coolant interactions, focusing on film boiling around a hot melt particle in subcooled convective flow. The considered conditions, free-flow velocities of a few m/s, melt particle temperatures of several thousand K, particle diameters of several tens of a μm, and liquid subcooling of several tens of a K, align with TREPAM experiments (CEA, France).</div><div>A two-phase computational fluid dynamics framework, based on the Volume of Fluid method, is used. An improved phase-change model is implemented, combining Chen’s explicit formulation of the phase-change intensity factor with the robustness of the conventional Lee model. The approach reduces sensitivity to empirical parameters and enhances phase-change localisation. Additional constraints on the intensity factor ensure numerical stability under extreme thermal conditions relevant to vapour energetic melt-coolant interactions.</div><div>Simulations of TREPAM experiments demonstrate improved heat flux predictions and enhanced flow dynamics capture. Analysis of the simulated velocity fields reveal secondary flows in the vapour wake, impacting heat and mass transfer and emphasizing the need to resolve vapor-phase flow conditions. To fully validate proposed modifications to phase-change model further numerical and experimental investigation is required, focusing on vapour film morphology and localized heat transfer intensity.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"255 ","pages":"Article 127813"},"PeriodicalIF":5.8,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045202","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}