International Journal of Heat and Mass Transfer最新文献

{"title":"Unveiling the weld pool dynamic mechanisms in ultrasonic pulse current-assisted underwater wet flux-cored arc welding via multiphysics simulations and experiments","authors":"Xuefei Cui,&nbsp;Ji Chen,&nbsp;Shengli Li,&nbsp;Hao Su,&nbsp;Dongsheng Wu,&nbsp;Chuansong Wu","doi":"10.1016/j.ijheatmasstransfer.2026.128487","DOIUrl":"10.1016/j.ijheatmasstransfer.2026.128487","url":null,"abstract":"<div><div>Weld pool behavior in underwater wet flux-cored arc welding (UWFCAW) plays a crucial role in determining the overall quality and efficiency of the welding process. In this study, a numerical analysis was conducted to investigate the effect of ultrasonic frequency pulse current (UFPC) on the dynamic behavior of the weld pool. A mathematical model of “water-droplet-weld pool” was established using the finite volume method, which considered the interaction between ultrasonic waves generated by UFPC and the molten metal. The study analyzed differences in energy, temperature, fluid flow, and pressure fields between conventional UWFCAW (C-UWFCAW) and UFPC-assisted UWFCAW (UFPC-UWFCAW). The results revealed that the application of UFPC significantly altered the weld pool behavior. Specifically, UFPC induced ultrasonic oscillations that generated a distinct counterclockwise vortex in the weld pool. This vortex promoted the downward flow of high-temperature molten metal from the surface to the bottom of the weld pool. The maximum temperature on the surface of the weld pool in UFPC-UWFCAW was higher than that of C-UWFCAW, and the temperature distribution became more uniform. Additionally, UFPC eliminated the small bulge at the front of the weld pool, which was beneficial in preventing undercut and improving welding quality. The simulated weld penetration, reinforcement, fusion line, and thermal cycle curve were in good agreement with the experimental results, demonstrating the accuracy of the computational model. These findings provide valuable insights into the underlying mechanism of UFPC-UWFCAW weld pool behavior and form a foundation for further optimizing welding processes in underwater environments.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"260 ","pages":"Article 128487"},"PeriodicalIF":5.8,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147385799","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":"Thermofluidic characterization of additively manufactured butterfly-shaped inserts for heat transfer enhancement in tubular heat exchangers","authors":"Luca Pagliarini ,&nbsp;Umberto Neviani ,&nbsp;Teresa Primo ,&nbsp;Antonio Del Prete ,&nbsp;Sara Rainieri","doi":"10.1016/j.ijheatmasstransfer.2026.128449","DOIUrl":"10.1016/j.ijheatmasstransfer.2026.128449","url":null,"abstract":"<div><div>Heat transfer enhancement in heat exchangers still represents a crucial target for industrial plants efficiency. Passive methods, such as turbulators, are usually preferred to active ones due to their intrinsic capability to operate on the fluid flow without any need for auxiliary power. Butterfly-shaped inserts stand as valuable solutions for tubular heat exchangers due to their high degree of induced turbulence. However, their potential for turbulent regimes has not been fully disclosed yet. In the present work, different geometries of swirled butterfly inserts, directly integrated into tubular samples via additive manufacturing, are investigated with the aim of providing a full characterization of their thermofluidic behavior in the range 4000 &lt; <em>Re</em> &lt; 14,000. Steady-state tests are carried out by circulating water through the test section, heated by Joule effect. Pressure drops are monitored via liquid column gauges; inlet/outlet water temperature is measured by means of thermocouples, while the outer wall temperature is acquired via infrared thermography. The local and global Nusselt numbers <span><math><mrow><mi>N</mi><mi>u</mi></mrow></math></span> and <span><math><mover><mrow><mi>N</mi><mi>u</mi></mrow><mo>‾</mo></mover></math></span> are estimated by analytically correcting the measured outer wall temperature distributions. The fitting loss coefficients <span><math><mi>K</mi></math></span> related to each butterfly insert geometry are additionally estimated by considering the introduced local pressure losses. Finally, the Nusselt number and friction factor deviations from the benchmark geometry (plain tube) are compared through performance evaluation plots, by also quantifying performance indexes <span><math><mi>η</mi></math></span>. The results highlighted that holes in the butterfly insert layout are highly beneficial in terms of augmented heat transfer and mitigated pressure drops. The provided pieces of data can be useful for the design of butterfly-shaped inserts operating in turbulent flows, as well as for the conceptualization of novel heat transfer augmentation approaches based on modular, 3D printed sections for tubular heat exchangers.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"260 ","pages":"Article 128449"},"PeriodicalIF":5.8,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147385886","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 of an open-source heat and mass transfer model for Floating Zone growth","authors":"Iason Tsiapkinis,&nbsp;Kaspars Dadzis","doi":"10.1016/j.ijheatmasstransfer.2026.128378","DOIUrl":"10.1016/j.ijheatmasstransfer.2026.128378","url":null,"abstract":"<div><div>The growth of crystals using the Floating Zone (FZ) method involves a complex interplay of heat and mass transfer phenomena, including electromagnetic heating, radiative heat transfer, melt convection, phase change, and complex shapes of phase boundaries. Numerical simulation is key to understanding these coupled phenomena and optimizing growth conditions. Open-source modeling tools provide a flexible foundation for simulating complex crystal growth processes. This work presents a general-purpose small-scale FZ model for the growth of small-diameter crystals, implemented entirely in the open-source software OpenFOAM. The transient, 2D axisymmetric model supports both inductive and optical heating configurations. The framework extends OpenFOAM with custom solvers, boundary conditions, and utilities for electromagnetic fields, heat transfer with internal sources, melt flow with external forces, phase change, and free surface tracking with growth angle enforcement. A simple stepwise coupling approach is followed to solve the multiphysical problem. The model is verified against analytical solutions and validated with literature data, demonstrating accurate prediction of temperature fields, flow patterns, and interface shapes. The new framework offers a flexible, extensible platform for future FZ crystal growth studies.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"260 ","pages":"Article 128378"},"PeriodicalIF":5.8,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147385891","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":"Fully diamond-based embedded manifold microchannel heat sink: Achieving ultra-high heat flux cooling","authors":"Jianyu Du ,&nbsp;Xinyi Wei ,&nbsp;Haoyang Sun ,&nbsp;Shangyang Shi ,&nbsp;Jiale Tu ,&nbsp;Feng Ji ,&nbsp;Junjun Wei ,&nbsp;Wei Wang ,&nbsp;Chi Zhang","doi":"10.1016/j.ijheatmasstransfer.2026.128420","DOIUrl":"10.1016/j.ijheatmasstransfer.2026.128420","url":null,"abstract":"<div><div>Silicon-based manifold microchannel heat sinks (MMHSs) have demonstrated strong heat dissipation capability but show clear performance limitations under extreme heat fluxes. Diamond, with its exceptional thermal conductivity, offers a promising pathway toward managing ultra-high heat fluxes. However, studies on diamond-based MMHSs that integrate manifold architectures for efficient fluid delivery remain relatively limited. Here, we present a fully diamond-based embedded manifold microchannel heat sink (FDMMHS) for ultra-high heat flux thermal management. Two configurations with channel widths of 100 μm and 50 μm were fabricated and tested using heat sources of 1 mm × 1 mm and 3.4 mm × 3.3 mm, respectively. The 1 mm × 1 mm hotspot sustained a record high heat flux of 10,000 W·cm⁻² with a temperature rise of 120 K, while the larger 3.4 mm × 3.3 mm heat source handled 1000 W·cm⁻² with only a 42 K temperature rise. The corresponding effective convective heat transfer coefficients reached 1.3 × 10⁵ W·m⁻²·K⁻¹ (50 μm channels, large heat source) and 3.5 × 10⁴ W·m⁻²·K⁻¹ (100 μm channels, small heat source), among the highest values reported for single-phase microfluidic cooling. These results highlight the synergistic advantages of diamond’s superior thermal conductivity and manifold-based flow routing architectures. The FDMMHS demonstrates good potential for compact electronic systems requiring reliable heat management. It also provides a foundation for further optimization through advanced diamond microfabrication.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"260 ","pages":"Article 128420"},"PeriodicalIF":5.8,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146026032","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":"Jet morphology and oscillations induced by direct contact condensation of steam discharges into a water pool","authors":"D. Blanco-Muelas ,&nbsp;C. Berna-Escriche ,&nbsp;J.L. Muñoz-Cobo ,&nbsp;I. Atindehou","doi":"10.1016/j.ijheatmasstransfer.2026.128443","DOIUrl":"10.1016/j.ijheatmasstransfer.2026.128443","url":null,"abstract":"<div><div>Steam discharges into subcooled water pools exhibit a behavior that depends strongly on the mass flux of the injected steam and the temperature of the liquid medium, influencing the morphology and dynamic evolution of the resulting jet. An experimental study was conducted using a dedicated experimental facility, where steam is injected under controlled conditions into a pool of stagnant subcooled water, at different condensation regimes. The jet behavior is recorded using a high-speed camera, and the discharge process is analyzed through direct visualization techniques combined with an image processing methodology. Sequences of 18,000 frames are processed to extract parameters such as the mean penetration length and the maximum expansion diameter of the jet. Furthermore, the Fast Fourier Transform is applied to the time series of instantaneous jet lengths to identify the dominant frequencies associated with oscillations driven by direct contact condensation. The results reveal a transition from conical to ellipsoidal shape jets with increasing temperature and mass flux, and an exponential increase in penetration length is observed when pool temperatures exceed 70 ⁰C. Finally, empirical correlations are proposed to estimate some jet geometrical parameters, such as penetration length, and to predict oscillation frequency as a function of dimensionless variables.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"260 ","pages":"Article 128443"},"PeriodicalIF":5.8,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146076285","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":"Fundamental understanding of flow distribution control in parallel multi-channel heat transfer devices with electrohydrodynamic conduction pumping","authors":"Mana Masrouri,&nbsp;Jamal Yagoobi","doi":"10.1016/j.ijheatmasstransfer.2026.128445","DOIUrl":"10.1016/j.ijheatmasstransfer.2026.128445","url":null,"abstract":"<div><div>Flow maldistribution in heat transfer devices such as parallel tube heat exchangers is an undesirable phenomenon that results from uneven pressure drops among the channels. Factors like non-uniform heating, geometric configuration, and system orientation can contribute to these imbalances in pressure drop, which can significantly diminish the overall energy performance of the system. In this study, Electrohydrodynamic (EHD) conduction pumping has been fundamentally studied as an active method to control the distribution of the flow in multi-channel heat exchangers. EHD conduction pumping is based on a net Coulomb force applied to a dielectric fluid. This force arises due to the formation of heterocharge layers, layers of opposite polarity, near asymmetric submerged electrodes, which are caused by enhanced dissociation of impurities in the fluid under a strong electric field. In this work, a two-dimensional domain representing a mesoscale heat exchanger using HFE-7100 as the working fluid was numerically investigated. The device comprises two parallel channels (each 7 cm long and 0.5 cm high), with electrohydrodynamic (EHD) conduction pumps embedded at the inlet. After establishing a foundational understanding of the influence of EHD conduction-driven flow distribution control on the system’s thermal performance under uneven heating loads at steady-state, an emphasis is placed on transient processes that govern the system’s response to sudden changes in operating conditions, as commonly encountered during flow distribution adjustment, going beyond the earlier work in this domain. Results show that transient charge accumulation takes 5.5 ms to reach a steady-state magnitude of (0.000826–0.000829) C/m, depending on the applied potential. This time is in the order of charge relaxation time. Additionally, the novel effect of pulsation on EHD-driven flow distribution control is investigated in detail to fundamentally understand its impact through the transient formation of the heterocharge layers. The contribution of pulsation is shown to depend strongly on the operating conditions and the applied frequency.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"260 ","pages":"Article 128445"},"PeriodicalIF":5.8,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146075863","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":"Diffusive circulation via spatiotemporal modulation","authors":"Jiaxin Li","doi":"10.1016/j.ijheatmasstransfer.2026.128474","DOIUrl":"10.1016/j.ijheatmasstransfer.2026.128474","url":null,"abstract":"<div><div>Controlling diffusive fluxes underpins efficient energy management, thermal regulation, and emerging information processing technologies. However, diffusion in conventional materials is inherently reciprocal and always drives flux along potential gradients, preventing directional routing and circulation. Realizing a circulator in diffusion, which traditionally relies on directional in-plane motion of the medium, is fundamentally challenging because physically moving material conflicts with the requirement of fixed boundary ports. Here we demonstrate diffusive circulation based on spatiotemporal modulation. Conductivity and capacity are modulated as traveling waves along a closed loop, generating an effective convective bias without material movement. We develop a rigorous analytical framework that exactly solves the modulated diffusion equation and introduce effective quantities that characterize intrinsic circulation. A rectification ratio is defined to quantify flux rectification under different port boundary conditions. This work not only clarifies the fundamental mechanisms underlying diffusive nonreciprocity but also provides a general strategy to control and route flux, establishing a versatile framework for diffusive circulation in mass, charge, and thermal systems.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"260 ","pages":"Article 128474"},"PeriodicalIF":5.8,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147385803","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":"Asymmetric wave flow field for enhanced mass transfer in high-power-density PEM fuel cells with metal bipolar plates","authors":"Ruolin Li ,&nbsp;Jintao Wu ,&nbsp;Ruiming Zhang ,&nbsp;Biao Xiao ,&nbsp;Shanshan Cai ,&nbsp;Zhengkai Tu","doi":"10.1016/j.ijheatmasstransfer.2026.128454","DOIUrl":"10.1016/j.ijheatmasstransfer.2026.128454","url":null,"abstract":"<div><div>The development of proton exchange membrane fuel cell (PEMFC) technology has led to increased attention being paid to high-power-density stacks based on metal bipolar plates. In the present study, a novel asymmetric wave flow channel was proposed and investigated through a multiphysics simulation, with the aim of improving output performance and mass transfer behavior. The electrochemical, mass-transfer, and distribution properties of the gas channels in several configurations were compared and quantitatively evaluated. The results showed that the PEMFC with an asymmetric wave channel demonstrated superior performance, and the maximum net output power and temperature distribution uniformity were improved by 11.90% and 16.61%, respectively, compared to the basic straight channel. Subsequently, the curve phase, number of wave cycles, blockage occupancy ratio, and amplitudes of the blockages and grooves were individually analyzed. The performance of PEMFCs with asymmetric wave channels can be enhanced by adjusting the curve phase, increasing the number of cycles, increasing the blockage occupancy ratio, and arranging the amplitudes of the blockages and grooves within a reasonable range. Through structural optimization, the oxygen convection flux, and temperature uniformity of the PEMFC increased by 29.74%, and 10.95%, respectively. These findings provide theoretical support for the structural optimization and formation of metal bipolar plates.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"260 ","pages":"Article 128454"},"PeriodicalIF":5.8,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147385804","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":"Corrigendum to ‘Local convection characteristics of inline arrangement of Kagome-shaped unit cells in a square duct’ [International Journal of Heat and Mass Transfer, 2026, Vol. 258, 128308]","authors":"Youssef Aider ,&nbsp;Kai Li ,&nbsp;Kashif Nawaz ,&nbsp;Prashant Singh","doi":"10.1016/j.ijheatmasstransfer.2026.128450","DOIUrl":"10.1016/j.ijheatmasstransfer.2026.128450","url":null,"abstract":"","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"260 ","pages":"Article 128450"},"PeriodicalIF":5.8,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147384973","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":"Natural- and mixed-convection heat transfer coefficients for upward flows of heated supercritical carbon dioxide","authors":"Kwun Ting LAU,&nbsp;Takashi HIBIKI","doi":"10.1016/j.ijheatmasstransfer.2026.128453","DOIUrl":"10.1016/j.ijheatmasstransfer.2026.128453","url":null,"abstract":"<div><div>Heat transfer in upward flows of supercritical carbon dioxide is of central relevance to advanced energy systems, particularly under reactor-relevant conditions where natural convection (NC) and mixed convection (MC) become significant. In this study, the experimental database of Zahlan et al. is re-examined [1], comprising several hundred data points corresponding to buoyancy-dominated conditions in upward heated carbon dioxide in tubes with pressures of 7.44–8.67 MPa and diameters of 8–22 mm. A NC correlation, <span><math><mrow><mover><mrow><mi>N</mi><mi>u</mi></mrow><mo>‾</mo></mover><mo>=</mo><mn>0.0030</mn><msup><mrow><mover><mrow><mi>G</mi><msub><mi>r</mi><mi>b</mi></msub></mrow><mo>‾</mo></mover></mrow><mrow><mn>0.53</mn></mrow></msup></mrow></math></span>, is developed for the NC regime defined by <span><math><mrow><mi>B</mi><mi>u</mi><mo>≥</mo><mn>5</mn><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>4</mn></mrow></msup></mrow></math></span>, preserving structural consistency with the forced convection (FC) formulation of Nusselt number definition, and predicting the NC dataset with maximum percentage errors of approximately 30 %. The MC regime is then investigated using a p-norm blending correlation and a modified Jackson-type model incorporating FC and NC asymptotes; both approaches exhibit significant limitations and do not deliver a sufficiently reliable MC correlation. These findings indicate that mixed-convection correlations should presently be regarded as diagnostic rather than design-ready for engineering applications. To facilitate future developments, a general sigmoid-based framework is finally proposed for coupling FC, MC, and NC correlations.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"260 ","pages":"Article 128453"},"PeriodicalIF":5.8,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147385057","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}