International Journal of Heat and Mass Transfer最新文献

{"title":"Molten pool flow and microstructure evolution in laser cladding of SiC/Mo-based coating","authors":"Zhaoyuan Cai,&nbsp;Meiyan Feng,&nbsp;Wei Zhang,&nbsp;Rongxin Chen,&nbsp;Guofu Lian","doi":"10.1016/j.ijheatmasstransfer.2025.127482","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.127482","url":null,"abstract":"<div><div>The influence of melt pool flow and microstructure on coating morphology and performance is of significant research value. However, there is currently a lack of systematic research on the multi-scale coupling mechanism between heat transfer, flow behavior, and grain evolution during the laser cladding process, especially the insufficient understanding of the synergistic effect under non-isothermal conditions. In this study, a multiphase coupled numerical model combined with a cellular automaton (CA) model is employed to investigate the mechanisms underlying non-isothermal flow and microstructural evolution during the laser cladding process. Experimental results validate the effectiveness of the developed multiphase model that couples macroscopic heat transfer and flow in laser cladding. Based on the multiphase coupled model, the heat transfer and flow behavior within the melt pool were analyzed, revealing the interaction mechanisms between temperature and flow velocity. The evolution of cellular, columnar, and equiaxed crystals during the solidification of the molten pool was further investigated, and the solidification parameters (G, R), as well as the composite parameters (G*R, G/R) were quantitatively analyzed. Dendritic growth results indicate that during columnar crystal growth, the solute concentration between adjacent grains continuously increases, leading to microsegregation; whereas at the top of the melt pool, the overlapping solute accumulation zones associated with equiaxed crystal growth inhibit dendritic growth. The study identified that the primary cause of the undercooling nucleation phenomenon is the increased growth rate during solidification, which alters the temperature gradient at the solid-liquid interface. This change leads to the undercooling of the composition and ultimately results in the transformation from columnar to equiaxed crystals (CET). The SiC/Mo-based coating significantly enhances the microhardness and wear resistance of IN718 alloy. This study provides a theoretical foundation for predicting microstructural evolution in carbide-coated laser cladding processes.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"252 ","pages":"Article 127482"},"PeriodicalIF":5.0,"publicationDate":"2025-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144557272","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 fundamentals-based vaporization model for radiofrequency ablation of biological tissues: Comparison with the enthalpy method","authors":"Jose Bon ,&nbsp;Enrique Berjano ,&nbsp;Macarena Trujillo","doi":"10.1016/j.ijheatmasstransfer.2025.127478","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.127478","url":null,"abstract":"<div><div>Intratissue vaporization is a crucial phenomenon to be considered in the theoretical modeling of the radiofrequency ablation (RFA) of biological tissues. The enthalpy method (EM) is one of the most common methods to model it. However, this method does not consider either the vapor pressure or the water content in gas phase and consequently does not realistically consider vaporization. Our objective was to develop a new fully coupled model (FCM) for liver RFA including a multiphase porous media model as well as the vapor pressure and the fraction of water in form of liquid and gas. The results show that the FCM can efficiently calculate the vapor pressure and the water content in all the points and times during the RFA, what differences this model from other existing models. As compared to EM, the FCM presents a more uniform solution without unrealistic fluctuations in the temperature and electrical impedance progresses.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"252 ","pages":"Article 127478"},"PeriodicalIF":5.0,"publicationDate":"2025-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144557273","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":"Boiling heat transfer characteristics of multi-directional dynamic intelligent surfaces based on shape memory alloys","authors":"Weijia Zheng ,&nbsp;Yibo Yan ,&nbsp;Yanxin Hu ,&nbsp;Tingting Wu ,&nbsp;Rui Zhang ,&nbsp;Mengjie Song","doi":"10.1016/j.ijheatmasstransfer.2025.127503","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.127503","url":null,"abstract":"<div><div>Traditional single-modified surfaces lack geometric adaptability during heat transfer processes, relying exclusively on fixed surface properties to accommodate dynamic thermal conditions—a limitation that inherently compromises their boiling heat transfer capacity. Shape memory alloys (SMAs), with their exceptional shape memory effect, offer the potential to achieve enhanced boiling heat transfer across different heat transfer stages. In this study, dynamic surfaces with varying orientations were fabricated using NiTi alloy as the base material, and their boiling performance was investigated. The results indicate that the bent structure of the dynamic surface in the early stage promotes superheat buildup and enhances bubble nucleation, while the upright structure in the later stage facilitates bubble detachment. Additionally, dynamic surfaces with combinations of different bending directions effectively guide bubble detachment and enhance disturbances. These surfaces also provide extra liquid replenishment channels, further improving their heat transfer performance. Among the tested surfaces, the multi-directional dynamic surface (MDS) exhibited the highest critical heat flux (CHF) and heat transfer coefficient (HTC), representing improvements of 71.55 % and 92.85 %, respectively, compared to the plain surface.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"252 ","pages":"Article 127503"},"PeriodicalIF":5.0,"publicationDate":"2025-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144557274","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 the Biot number on error in measuring enthalpy using the T-history method","authors":"Youngmun Lee ,&nbsp;Sanjiv Sinha","doi":"10.1016/j.ijheatmasstransfer.2025.127492","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.127492","url":null,"abstract":"<div><div>The T-history method measures the enthalpy and the phase transition temperatures in bulk scale samples. Despite its widespread use in characterizing phase change materials (PCMs), a systematic investigation of errors in T-history measurements is still lacking. While a lumped capacitance is often assumed in the data analysis, actual experimental conditions may not justify such use. To help identify when such analysis can be significantly erroneous, this paper investigates the quantitative relationship between the Biot number (<em>Bi</em>) and error using both experiments and computational modeling. We use two different sample tubes in combination with convection conditions to vary <em>Bi</em>. At <em>Bi</em>&lt;0.1, T-history shows excellent agreement with Differential Scanning Calorimetry (DSC) measurements. As <em>Bi</em> approaches 1, the error increases progressively due to the development of a vertical non-uniformity in temperature. At low <em>Bi</em>, the thermal time constant of the sample can still introduce significant uncertainty in data analysis that is often overlooked. Finally, the analysis is also sensitive to the specific heat of the reference material. By identifying experimental conditions that properly justify the use of the T-history data analysis, this work helps improve the overall accuracy and reliability of the method most commonly used in characterizing PCMs.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"252 ","pages":"Article 127492"},"PeriodicalIF":5.0,"publicationDate":"2025-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144557270","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 regimes and heat transfer for opposing flow mixed convection in the thermal entry region of a vertical tube","authors":"Kosuke Motegi ,&nbsp;Yasuteru Sibamoto ,&nbsp;Takashi Hibiki","doi":"10.1016/j.ijheatmasstransfer.2025.127451","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.127451","url":null,"abstract":"<div><div>This study focused on the thermal entry length problem for turbulent opposing flow mixed convection in a vertical tube. A Reynolds-averaged Navier–Stokes (RANS) simulation was performed using the <em>v²–f</em> turbulence model, and its results were compared with previous experimental data. The simulation results revealed several flow structures and heat transfer characteristics in the entry region, which varied depending on the competing strength of forced and natural convection. Flow regimes were classified based on their flow structures as follows: (a) Non-separating flow regime: When natural convection minimally influences the flow field, the Nusselt number in the entry region is higher than that in the fully developed region. As the influence of natural convection strengthens, the entry length decreases. (b) Separation bubble regime: As the influence of natural convection on the flow field increases, the velocity boundary layer along the heated wall in the entry region separates, leading to the formation of a recirculation region known as a separation bubble. Here, the depression in the Nusselt number distribution was observed owing to the thickening of the thermal boundary layer caused by the separation bubble. (c) Reverse flow regime: Further strengthening of the influence of natural convection leads to the formation of reverse flow along the entire heated wall. Here, the Nusselt number exhibits a nearly flat distribution in the entry region because the reverse flow thickens the thermal boundary layer. A flow regime map based on the results of the RANS simulation was created and proposed in this paper.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"252 ","pages":"Article 127451"},"PeriodicalIF":5.0,"publicationDate":"2025-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144549850","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":"Thermovelocimetric characterization of liquid metal convection in a rotating slender cylinder","authors":"Yufan Xu ,&nbsp;Jewel Abbate ,&nbsp;Cy David ,&nbsp;Tobias Vogt ,&nbsp;Jonathan Aurnou","doi":"10.1016/j.ijheatmasstransfer.2025.127325","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.127325","url":null,"abstract":"<div><div>Rotating turbulent convection occurs ubiquitously in natural convective systems encompassing planetary cores, oceans and atmospheres, as well as in many industrial applications. While the global heat and mass transfer of water-like rotating Rayleigh–Bénard convection is well-documented, the dynamics in low-Prandtl-number liquid metals remain less understood. In this study, we experimentally investigate rotating Rayleigh-Bénard convection in liquid gallium (Prandtl number <span><math><mrow><mo>Pr</mo><mo>≈</mo><mn>0</mn><mo>.</mo><mn>027</mn></mrow></math></span>) within a slender cylinder (diameter-to-height aspect ratio <span><math><mrow><mi>Γ</mi><mo>=</mo><mi>D</mi><mo>/</mo><mi>H</mi><mo>=</mo><mn>1</mn><mo>/</mo><mn>2</mn></mrow></math></span>) using novel thermovelocimetric diagnostic techniques that integrate simultaneous multi-point thermometry and ultrasonic Doppler velocity measurements. Our results reveal the formation of a stable, global-scale azimuthal wavenumber <span><math><mrow><mi>m</mi><mo>=</mo><mn>2</mn></mrow></math></span> quadrupolar vortex at low supercriticality. We propose that enhanced wall modes facilitated by the slender cylinder geometry interact with the bulk flow to create these large-scale axialized vortices. Furthermore, our findings imply a distinct scaling behavior for the wall-mode precession frequency in liquid metals, extending previous results obtained for moderate-<span><math><mo>Pr</mo></math></span> fluids. This provides new insights into wall-bulk coupling mechanisms of low-<span><math><mo>Pr</mo></math></span> rotating convective turbulence.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"252 ","pages":"Article 127325"},"PeriodicalIF":5.0,"publicationDate":"2025-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144557271","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 study on the thermal mixing and fluctuation characteristics of high-temperature mixing valves","authors":"Junyu Tao ,&nbsp;Ziqiang Du ,&nbsp;Xu Zheng ,&nbsp;Zhe Lin ,&nbsp;Guang Zhang","doi":"10.1016/j.ijheatmasstransfer.2025.127488","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.127488","url":null,"abstract":"<div><div>The high-temperature mixing valve is widely used in petrochemical flue gas treatment systems to precisely control the inlet temperature; however, its internal flow and thermal fluctuation characteristics have not been sufficiently studied. The Detached Eddy Simulation (DES) method is employed in this study to analyze systematically the mixing mechanism of cold and hot fluids, temperature profile, flow field distribution, and vorticity distribution within the mixing valve. It is found that as the valve opening rises, the throttling effect decreases, and the distribution of high-temperature gas varies from the valve body center region to the entire valve chamber. The direction of the high-temperature jet on the downstream side of the valve core is shifted toward the main flow direction. Furthermore, the extension, rupture, and merging of different types of turbulence vortices within the valve significantly improve heat exchange efficiency. The study also predicts thermal fatigue failure is likely to occur in the lower regions on both sides near <em>X</em> = 250 mm of the valve core at valve openings of 0.2<em>L</em> and 0.4<em>L</em> . This research provides new theoretical support for the design optimization of high-temperature mixing valves, which helps to improve the thermal efficiency of flue gas treatment systems, extend equipment lifespan, and increase overall reliability.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"252 ","pages":"Article 127488"},"PeriodicalIF":5.0,"publicationDate":"2025-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144557269","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":"Development and assessment of the data-informed continuous machine learning approach based on CHF prediction","authors":"Meiqi Song ,&nbsp;Fabian Wiltschko ,&nbsp;Xiaojing Liu ,&nbsp;Aurelian F. Badea ,&nbsp;Xu Cheng","doi":"10.1016/j.ijheatmasstransfer.2025.127474","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.127474","url":null,"abstract":"<div><div>Machine learning (ML) method has attracted more and more interests in engineering applications. Despite extensive efforts in the last decades in the application of the ML-method to thermal- and fluid mechanics, there exist in general some obvious shortcomings. Generally, neither sufficient information about the data base used by the previous researchers nor information about the uncertainty (or error) is included in the ML-model and is not available for the next researchers. This makes the continuous learning process difficult or even impossible.</div><div>This paper proposes the new data-informed continuous machine learning (DI-CML) approach, to overcome the above shortcomings. The main feature of the DI-CML approach is to generate a machine learning package, which, in addition to the ML-model, contains the distribution functions of the input variables and the distribution function of the uncertainty (error). With this ML-package, an artificial data base can be produced, which should be as similar as possible to the original data base used for the development of the ML-model. This would make the continuous learning process possible and efficient.</div><div>The main idea and the procedure of the DI-CML approach is described. The feasibility of the DI-CML approach is assessed by means of CHF prediction. The large CHF data base provided by the OECD-NEA benchmark working group is used. The accuracy of the CHF prediction by the DI-CML approach is analysed by using different features of data base sets, different methods to derive the distribution functions of the input variables as well as different methods for the generation of the artificial data base. The results confirm the good feasibility of the proposed DI-CML approach. Furthermore, challenges and future research needs are also identified.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"252 ","pages":"Article 127474"},"PeriodicalIF":5.0,"publicationDate":"2025-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144549849","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":"Study on characteristics of CO2 seepage within natural gas hydrate reservoirs","authors":"Mingjun Yang ,&nbsp;Ziming Yang ,&nbsp;Mingyu Wu ,&nbsp;Huiru Sun ,&nbsp;Tao Yu ,&nbsp;Bingbing Chen ,&nbsp;Yongchen Song","doi":"10.1016/j.ijheatmasstransfer.2025.127452","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.127452","url":null,"abstract":"<div><div>Carbon dioxide (CO₂) storage in natural gas hydrate (NGH) reservoirs through hydrate-based methods has emerged as a promising carbon sequestration technology. The dynamic permeability evolution of the reservoirs plays a crucial role in determining both the storage capacity and stability of CO₂ sequestration, particularly due to hydrate phase transitions during the injection process. However, the evolution of dynamic permeability and its influence mechanism are yet to be elucidated. In this paper, we investigated the dynamic permeability characteristics of NGH reservoirs with different hydrate saturations during CO₂ injection. The results show that the reservoir permeability can be influenced significantly by the water-CO₂ flow rate ratio (<em>r</em>). When <em>r</em> is 5:1 (mL/min), the relative permeability (<em>K_r</em>) of the water phase demonstrates instability, with values consistently exceeding 0.4, significantly reducing the likelihood of flow blockage formation. Moreover, <em>r</em> directly affects the fluid seepage dynamics. The variation in <em>r</em> (from 5:1 to 2:1 mL/min) promotes the blockage formation in mid-to-rear sections of the reservoir, thereby facilitating the expansion of the storage extent. Meanwhile, a method was developed for detecting blockage locations within reservoirs under non-visualized conditions, suitable for applications in CO₂ sub-seabed storage. Notably, a threshold effect of initial NGH saturation (<em>S_h0</em>) on ultimate storage capacity was observed. At S_h0 below 21 %, the storage capacity increases with <em>S_h0</em>.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"252 ","pages":"Article 127452"},"PeriodicalIF":5.0,"publicationDate":"2025-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144549909","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":"Single Re-entrant micropillar arrays for enhanced pool boiling performance","authors":"Saumyadwip Bandyopadhyay ,&nbsp;Qi-Jun Chen ,&nbsp;Ming-Chang Lu","doi":"10.1016/j.ijheatmasstransfer.2025.127473","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.127473","url":null,"abstract":"<div><div><em>Re</em>-entrant cavities are well-known for enhancing pool boiling by stabilizing vapor bubbles; however, the potential of <em>Re</em>-entrant pillar structures remains underexplored. This study investigates, for the first time, the effects of single <em>Re</em>-entrant micropillar (SR) structures on pool boiling heat transfer. We fabricated and tested four types of silicon surfaces: flat SiO₂, micropillar (MP), single <em>Re</em>-entrant micropillar (SR), and single <em>Re</em>-entrant micropillar with PTFE-coated top surfaces (SRT). Experimental results show that the SRT surface achieves a 219 % enhancement in heat transfer coefficient (HTC) and a 61.5 % increase in critical heat flux (CHF) compared to the flat surface. The HTC correlates positively with nucleation site density (NSD), which was quantified through thermal imaging. Force analysis further reveals that the <em>Re</em>-entrant geometry imposes significant resistance to bubble growth, anchoring liquid within the microstructures and delaying CHF onset. These findings demonstrate that <em>Re</em>-entrant pillar structures substantially enhance both HTC and CHF, offering a promising design strategy for next-generation thermal management surfaces.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"252 ","pages":"Article 127473"},"PeriodicalIF":5.0,"publicationDate":"2025-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144534605","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}