International Journal of Heat and Mass Transfer最新文献

{"title":"Analysis on optimal angle for hot steam injection dehumidification in a twisted blade cascade using entropy-weighted TOPSIS method","authors":"Lihua Cao,&nbsp;Jie Li,&nbsp;Xifeng Liu","doi":"10.1016/j.ijheatmasstransfer.2026.128480","DOIUrl":"10.1016/j.ijheatmasstransfer.2026.128480","url":null,"abstract":"<div><div>The last stage(LS) of steam turbine operates in a wet steam environment, where the presence of the water droplets not only reduces the stage efficiency but also threatens the blade safety. Using the hot steam injection(HSI) into the hollow blades to reduce the wetness in the 3D twisted blades of the LS was proposed in this paper. Five steam injection cases with the angles ranging from -30° to 60° on the suction surface(SS) were designed. Based on the defined “KQJEI evaluation criteria”, the entropy-weighted TOPSIS multi-objective optimization method was introduced to determine the optimal injection angle. The results indicate that the efficiency ratio (E_R) holds the highest weight, while the condensation loss ratio (Q_R) has the lowest weight. An injection angle of 0° is identified as the optimal case, achieving the maximum relative closeness coefficient of 0.667. At 57% chord on the suction surface at 10% blade height under the optimal case, the peak nucleation rate and average droplet radius are 55.47% and 52.63% of the no hot steam injection(NHSI) case, respectively, with condensation loss reduced by 58.91%. At 50% blade height, the average droplet radius is only 0.005 μm. No condensation occurs above 75% blade height, and all liquid-phase parameters are zero. Steam injection at the 0° angle, which perpendicular to the blade surface, facilitates the manufacturing and processing. This study provides an important theoretical basis for dehumidification in the hollow twisted blades operating in the wet steam zone of steam turbines.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"260 ","pages":"Article 128480"},"PeriodicalIF":5.8,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147385805","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":"Dynamic modeling of mass and heat transfer in membrane humidifiers for proton exchange membrane fuel cells","authors":"Michael Kreitmeir,&nbsp;Ladislaus Schoenfeld,&nbsp;Philipp Schwab,&nbsp;Sebastian Rehfeldt,&nbsp;Harald Klein","doi":"10.1016/j.ijheatmasstransfer.2026.128470","DOIUrl":"10.1016/j.ijheatmasstransfer.2026.128470","url":null,"abstract":"<div><div>This paper features a dynamic model for gas-to-gas membrane humidifiers based on first principles. The key novelty is the consideration of membrane relaxation in the dynamics.</div><div>The model is validated under steady-state conditions against experimental data showing a deviation of less than 10<!--> <!-->% for 46<!--> <!-->% of the data points for Nafion® 211, for 77<!--> <!-->% of the data points for Nafion® 212, and for 77<!--> <!-->% of the data points for Nafion® 115.</div><div>Three step responses are investigated using characteristic time scales. In all cases considered in this paper, the fluid-dynamic residence time has the lowest value (approximately 0.01<!--> <!-->s) and the diffusive time constant (approximately 3<!--> <!-->s) is in the same order of magnitude or one magnitude lower than the relaxation time constant (approximately 3 to 50<!--> <!-->s).</div><div>Finally, a step test for varying membrane thickness between 25.4<!--> <!-->µm and 127<!--> <!-->µm is conducted, yielding response times between 155<!--> <!-->s and 211<!--> <!-->s being dominated by relaxation.</div><div>The findings highlight the importance of considering relaxation while modeling membrane humidifiers.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"260 ","pages":"Article 128470"},"PeriodicalIF":5.8,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147385879","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":"Thermoreflectance imaging to characterize Joule heating, current, and junction resistance in silver-nanowire networks","authors":"Yuta Sugihara ,&nbsp;Kanji Tamai ,&nbsp;Yuki Wakamatsu ,&nbsp;Reiko Kuriyama ,&nbsp;Kazuya Tatsumi","doi":"10.1016/j.ijheatmasstransfer.2026.128426","DOIUrl":"10.1016/j.ijheatmasstransfer.2026.128426","url":null,"abstract":"<div><div>Silver nanowire (Ag-NW) networks are promising transparent and flexible electrical conductors. Their performance and reliability are governed by nonuniform current paths and localized Joule heating, which are determined by the nanowire configuration and junction (contact) resistance between the nanowires. However, directly mapping temperature, current, and junction resistance remains challenging, and numerical models often assume a uniform junction resistance, obscuring hotspot formation. In this study, we measured the temperature of an Ag-NW network using thermoreflectance imaging and combined it with numerical computation. An inverse analysis was applied to infer the current distribution and estimate the junction resistances. By matching the computed temperature distribution with the measurement obtained through iterative adjustment of the current and junction resistance, these parameters were obtained. The results indicate that the junction resistance varies over a wide range, significantly restricting the available current paths, concentrating the current into fewer routes, and increasing the incidence and intensity of hotspots. This conclusion was supported by the probability density functions of current and temperature, which exhibited heavier high-value tails when junction resistance variability was considered. We developed two models for sheet resistance that account for current flow along nanowire segments with an effective distance between junctions. The models agreed well with the experimental and computational results under high Ag-NW density conditions, whereas discrepancies appeared when the Ag-NW density decreased and approached the critical percolation threshold. Comparison among the measurements, computations, and models elucidated the sources of these discrepancies and highlighted the effects of junction resistance variation on the sheet resistance.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"260 ","pages":"Article 128426"},"PeriodicalIF":5.8,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147385889","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-hydraulic performance of flat-tube air-to-fluid heat exchangers for vehicle applications using TPMS-based fins in varying altitudes","authors":"Xinyue Zhang ,&nbsp;Ziwen Zou ,&nbsp;Jie Liu ,&nbsp;Yiming Zhang ,&nbsp;Yong Liang ,&nbsp;Yiwei Sun ,&nbsp;Menglong Hao ,&nbsp;Wenqi Zhong","doi":"10.1016/j.ijheatmasstransfer.2026.128469","DOIUrl":"10.1016/j.ijheatmasstransfer.2026.128469","url":null,"abstract":"<div><div>Increasing altitude deteriorates heat transfer performance of heat exchangers (HXs), underscoring the need for more compact and efficient HX designs for the vehicle to maintain its system efficiency and longevity. Triply periodic minimal surfaces (TPMS), known for their compact structure and high heat exchange intensity, are ideal candidates for cooling fins in flat-tube air-to-fluid HXs used in vehicles. Nevertheless, their thermal-hydraulic performance as extended surfaces in HXs, especially under high-altitude conditions, remains to be explored. In this study, three HXs are designed using Diamond, Gyroid, and IWP TPMS structures, all with the same porosity, and fabricated via additive manufacturing. Their thermal-hydraulic performances are experimentally evaluated across altitudes from sea level to 4,800 m. The convective heat transfer coefficient of the TPMS structures shows a slower growth trend with the airflow rate when the altitude rises. Additionally, the <em>Nu</em> of different TPMS structures exhibits 93.8%–307.4% higher than that of the louvered-fin structure, alleviating the issue of poor heat transfer performance of traditional HXs at high altitudes. At the same porosity, the Gyroid-based HX shows the best Coefficient of Performance (<em>COP</em>), a metric used to evaluate the ratio of heat transfer performance to fan power input. However, according to the Performance Evaluation Criteria (<em>PEC</em>) that simultaneously considers heat transfer and flow resistance, the Diamond structure demonstrates superior overall performance at <em>Re</em>&gt;160. This work offers insights into the thermal-hydraulic performance of TPMS-based flat-tube HXs under different altitudes and contributes to the advancement of vehicle HX designs for varying altitude applications.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"260 ","pages":"Article 128469"},"PeriodicalIF":5.8,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147385890","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":"Physics-guided neural networks for microwave heating temperature field prediction","authors":"Xincheng Yang ,&nbsp;Kuangrong Hao ,&nbsp;Chenyang Meng ,&nbsp;Xian Qi ,&nbsp;Lei Chen ,&nbsp;Yan Cheng","doi":"10.1016/j.ijheatmasstransfer.2026.128428","DOIUrl":"10.1016/j.ijheatmasstransfer.2026.128428","url":null,"abstract":"<div><div>Microwave heating often exhibits nonuniform temperature distributions due to standing wave patterns and material property variations, limiting its industrial applicability. Existing models rely on idealized assumptions and static boundaries, which prevents them from accurately predicting temperature evolution under dynamic conditions. To address this, we propose a novel neural network framework featuring a Heat Source Estimator (HSE) and a Thermal Diffusion Operator (TDO). Unlike conventional Physics-Informed Neural Networks (PINNs) that impose governing equations as soft constraints in the loss function, our approach embeds the heat conduction law as a structural inductive bias, achieving greater flexibility and efficiency while preserving physical interpretability. Furthermore, we build the Microwave Heating Spatiotemporal Dataset (MHSTD) via infrared thermography to document thermal dynamics across varying materials. Compared to the state-of-the-art TAU model, our method reduces the RMSE by 5.3% in standard benchmarks and by 43.5% in cross-domain generalization tests. This work establishes a new paradigm for spatiotemporal prediction in microwave heating, providing a high-performance predictive foundation for the optimization of heating processes.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"260 ","pages":"Article 128428"},"PeriodicalIF":5.8,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146026031","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":"General synthetic iterative scheme for fast solving coupled electron–phonon Boltzmann equations","authors":"Jia Liu ,&nbsp;Xing Xiang ,&nbsp;Yanguang Zhou ,&nbsp;Wei Su","doi":"10.1016/j.ijheatmasstransfer.2026.128510","DOIUrl":"10.1016/j.ijheatmasstransfer.2026.128510","url":null,"abstract":"<div><div>Understanding and controlling electron–phonon interactions is essential for optimizing thermal performance in microelectronic and thermoelectric devices, where strong non-equilibrium effects span multiple length and time scales. The coupled electron–phonon Boltzmann equations offer an insightful framework for modeling such transport, but their high dimensionality and stiffness pose significant computational challenges. Conventional iterative solvers typically suffer from excessive numerical dissipation and slow convergence in diffusive regimes. In this work, we develop a general synthetic iterative scheme (GSIS) that significantly accelerates the solution of coupled electron–phonon Boltzmann equations. The key innovation is the formulation of macroscopic synthetic equations that effectively capture diffusion-limit behavior, while precisely incorporating non-equilibrium corrections extracted from the kinetic level. During iterations, the kinetic solver provides high-order moment closures, while the macroscopic equations update the driving fields, ensuring rapid convergence. This strategic coupling across scales facilitates efficient global information exchange and robust multiscale resolution. Fourier analysis and numerical benchmarks show that GSIS can reduce computational time by up to three orders of magnitude compared to the conventional iterative scheme. Implemented with a high-order discontinuous Galerkin method, the GSIS is applicable to complex geometries and extendable to nonlinear and non-gray transport models.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"260 ","pages":"Article 128510"},"PeriodicalIF":5.8,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147384692","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":"Bio-inspired alula-based winglet design for enhanced heat transfer in high temperature fin-and-tube heat exchangers","authors":"Prashant Saini ,&nbsp;Julian D. Osorio ,&nbsp;Ruhanii Avula","doi":"10.1016/j.ijheatmasstransfer.2026.128396","DOIUrl":"10.1016/j.ijheatmasstransfer.2026.128396","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Fin-and-tube heat exchangers (FTHEs) are widely used for high-temperature flue-gas heat recovery, but their performance is often limited by wake regions and non-uniform fin-surface temperatures. This study proposes and numerically evaluates four bio-inspired longitudinal vortex generator (VG) configurations in a high-temperature FTHE with flue-gas inlet temperature ∼1230 K: double-delta, curved double-delta, alula, and a new curved-alula geometry. The reference fin is not hydraulically plain; it already incorporates leading-edge separation columns and convex protrusions, so the alula-type winglets are assessed as downstream add-ons acting on a strongly disturbed flow. In a second step, perforations (one, two and three circular holes) are introduced into the curved-alula VGs to further tailor the flow field. Three-dimensional simulations with the Shear Stress Transpor (SST) &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;k&lt;/mi&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mi&gt;ω&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; model, temperature-dependent flue-gas properties and conjugate conduction are carried out for gas-side Reynolds numbers &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;msub&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;mi&gt;g&lt;/mi&gt;&lt;/msub&gt;&lt;mo&gt;≈&lt;/mo&gt;&lt;mn&gt;8.0&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mo&gt;×&lt;/mo&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;/mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; – &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mn&gt;3.6&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mo&gt;×&lt;/mo&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;/mrow&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; (mass flow rates 0.5 – 2.5 g/s), and the designs are compared in terms of surface heat flux, Nusselt number, friction factor and hydrothermal performance factor (HTPF). For this already-promoted fin, the additional downstream winglets provide moderate, incremental hydrothermal gains. At the highest Reynolds number, the best non-perforated design (curved-alula) increases surface heat flux from 1630.9 to 1794.7 kW/m² (∼ 10 % gain) and the Nusselt number from 227.6 to 242.6 (∼ 7 % gain), while the friction factor rises from 0.26 to about 0.30, yielding HTPF values close to unity (∼ 0.9 – 1.0). Introducing circular perforations into the curved-alula winglets acts mainly as a wake-bleeding refinement: the three-hole configuration provides a heat flux of 1824.7 kW/m² and a pressure drop of 127.9 Pa, with HTPF in the range ∼ 1.03 – 1.14 and a small (∼ 1 – 3 %) improvement over the solid curved-alula design. Flow-field analysis shows that the perforated curved-alula VGs shrink tube-wake regions, thin the thermal boundary layer and homogenize the fin-surface temperature (outlet-gas temperature ∼ 510 – 520 K and fin-surface temperature ∼ 420 – 421 K for the three-hole case). An optimal flue-gas mass flow rate of ∼ 1 g/s (&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;msub&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;mi&gt;g&lt;/mi&gt;&lt;/msub&gt;&lt;mo&gt;≈&lt;/mo&gt;&lt;mn&gt;1.5&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mo&gt;×&lt;/mo&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;/mrow&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;) is identified, beyond which additional heat-transfer gains are offset by rapidly increasing pressure losses. Overall, the results highlight that initial fin geometry and VG placement are as import","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"260 ","pages":"Article 128396"},"PeriodicalIF":5.8,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146026034","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":"Comprehensive performance evaluation and advanced design optimization of triply periodic minimal surface (TPMS) heat sinks","authors":"Jiaxuan Wang ,&nbsp;Fengrui Zhang ,&nbsp;Zhenyu Hou ,&nbsp;Chenyi Qian ,&nbsp;Junye Shi ,&nbsp;Jiangping Chen ,&nbsp;Binbin Yu","doi":"10.1016/j.ijheatmasstransfer.2026.128452","DOIUrl":"10.1016/j.ijheatmasstransfer.2026.128452","url":null,"abstract":"<div><div>This study focuses on optimizing heat sink performance through innovative Triply Periodic Minimal Surface (TPMS) structures. We analyze five heat sink structures: Fischer-Koch, Gyroid, Diamond, Split-P, and Fin. Fischer-Koch shows the highest heat transfer capacity (40 W/K), while Diamond has the best overall performance. Split-P has the highest flow resistance, making it unsuitable for high-flow applications. Based on flow and heat transfer mechanisms, we identify superior regions in each structure and integrate them into a novel mixed Diamond-Fischer-Koch-Gyroid design, which has been less explored in prior literature to exploit their complementary advantages. This mixed design reduces pressure drop by 15% and achieves a maximum heat transfer capacity of 37.6 W/K under a 15 kPa flow resistance constraint. Additionally, we originally apply particle swarm optimization (PSO) to optimize the wall thickness gradient fields of Gyroid and Diamond structures. The optimized designs achieve average wall temperature reductions of 2.8 K and 3.6 K, with performance improvements of 4.52% and 4.74%, respectively. These results demonstrate the promising potential of mixed TPMS designs and PSO gradient optimization to overcome the limitations of conventional structures, providing guidance for advanced heat sink design.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"260 ","pages":"Article 128452"},"PeriodicalIF":5.8,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146075851","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":"Effect of vent spacing on flow structure and heat transfer of transversely superimposed jets in crossflow at low velocity ratio","authors":"Jue Wang ,&nbsp;Jiayu Kang ,&nbsp;Cheng Jiang ,&nbsp;Shixuan Yu ,&nbsp;Gang Bai","doi":"10.1016/j.ijheatmasstransfer.2026.128436","DOIUrl":"10.1016/j.ijheatmasstransfer.2026.128436","url":null,"abstract":"<div><div>This study investigates the flow structure and heat transfer characteristics of transversely superimposed multi-jet-in-crossflow (JICF) systems at a low velocity ratio (<em>R</em> = 0.5, defined as the ratio of jet velocity to crossflow velocity) with varying jet-to-jet spacings (<em>d</em>_s<em>/d</em>_j = 2–18). The method of combining experiment and simulation was employed to resolve vortex dynamics, thermal fields, and field synergy distributions. A vortex-zone classification framework was developed, dividing the downstream region into strong attachment, weak attachment, fragmentation, and dissipation zones based on normalized vorticity. Results show that positioning the rear-stage jet within the strong attachment zone of the upstream jet enhances convective heat transfer through intensified field synergy, but shortens the downstream cooling persistence due to accelerated thermal diffusion. Conversely, placing it in the fragmentation zone improves cold fluid retention, yielding up to 50% higher cooling effectiveness at 20 <em>d</em>_j compared with single-stage configurations. The findings provide a quantitative basis for optimizing vent spacing to balance near-wall heat transfer and far-field thermal insulation, with implications for turbine blade cooling, electronic thermal management, and mine ventilation.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"260 ","pages":"Article 128436"},"PeriodicalIF":5.8,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146075866","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":"Heat-transfer enhancement and evaporation mechanisms on roughness-controlled wettability-contrast surfaces","authors":"D.V. Feoktistov ,&nbsp;E.G. Orlova ,&nbsp;E.Yu. Laga ,&nbsp;D.M. Klepikov ,&nbsp;K.K. Paushkina ,&nbsp;A.O. Pleshko ,&nbsp;D.O. Glushkov","doi":"10.1016/j.ijheatmasstransfer.2026.128413","DOIUrl":"10.1016/j.ijheatmasstransfer.2026.128413","url":null,"abstract":"<div><div>The problem of efficiently removing high heat fluxes (&gt;100 W/cm²) from integrated circuits is particularly relevant. Its solution requires beyond heat-transfer surfaces with specified functional properties. In this study, the mechanisms of water droplet evaporation on biphilic aluminum heat-transfer surfaces with spatially controlled wetting regions were investigated. For this purpose, a novel approach for creating heat-transfer surfaces was developed based on a combination of laser processing of metal surfaces and hydrophobization by grafting alkyl groups (-CH₂- and -CH₃-) from oil thermolysis products to the textured surface. Experimental data on the influence of wettability, as an independent factor, on the droplet evaporation characteristics in the surface heating temperature range of 80–300 °C were obtained. Heat transfer mechanisms were studied using high-speed optical visualization, particle image velocimetry (PIV), and planar laser-induced fluorescence (PLIF). Direct temperature measurements were also conducted in the near-surface layer of the sample at a depth of 500 μm from the heat transfer surface using microscale thermocouples. The results show that slower evaporation on biphilic surfaces promotes enhanced local cooling. Wettability contrast induces complex internal thermocapillary (Marangoni) flows and significantly increases the length of the three-phase contact line due to the formation of air pockets under the droplet on superhydrophobic regions of the heat-transfer surface. At a temperature of 80 °C, biphilic surfaces with a superhydrophobic region fraction of 30–45 % provide a 79–81 % greater temperature reduction in the near-surface layer of the sample than a polished surface, despite a lower evaporation rate (29–74 % lower). Moreover, optimal wetting contrast shifts the maximum cooling efficiency to higher temperatures (160 °C versus 140 °C for a polished surface), thereby delaying the onset of the Leidenfrost effect. For surfaces combining high roughness (<em>Sdr</em> ≈ 700 %) with hydrophilic/superhydrophilic regions, the cooling efficiency at moderate temperatures increases up to 20 times.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"260 ","pages":"Article 128413"},"PeriodicalIF":5.8,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147384697","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}