International Journal of Heat and Mass Transfer最新文献

{"title":"Experimental investigation of external flow condensation heat transfer in horizontal tube-in-tube configuration","authors":"Jiayuan Li,&nbsp;Jayachandran K. Narayanan,&nbsp;Chirag R. Kharangate","doi":"10.1016/j.ijheatmasstransfer.2025.127044","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.127044","url":null,"abstract":"<div><div>Flow condensation is an important process used to achieve heat rejection across thermal power and energy systems. Studies on tube condensation have concentrated on the condensing fluid flowing in the inner tube. However, common heat exchanger configurations like the shell-and-tube types see the condensing fluid on the outer surface of the tubes. To address this gap, in this study, we investigate the local and channel-averaged heat transfer characteristics of flow condensation happening on the exterior of a horizontal tube in the tube-in-tube configuration. An external flow condensation module is developed and tested to obtain heat transfer and flow visualization data, with PF-5060 as the condensing fluid flowing outside the tube and de-ionized water as the cooling fluid flowing inside the tube in the counter-current direction. Densely arranged thermocouples are installed on the exterior surface of the 12.7-mm outer-diameter tube and embedded within the water flow to measure variations in wall and water temperatures respectively, which determines the local heat transfer characteristics along a 683.6-mm condensation path. Flow visualization is achieved using a transparent polycarbonate plate that serves as the PF-5060 flow channel. The test conditions cover PF-5060 inlet mass velocities of 26.66 – 58.67 kg/m²·s, water mass velocities of 330.9 – 463.26 kg/m²·s, PF-5060 inlet pressures of 124.76 – 155.24 kPa, and PF-5060 inlet superheats of 4.39 – 5.63 °C. The local condensation heat transfer coefficient is highest near the upstream region and decreases monotonically in the downstream direction due to the thickening of liquid film and transition of flow regimes along the condensation path. Further, the heat transfer coefficient increases with both PF-5060 and water flow rates, with the PF-5060 showing a more pronounced effect. Pressure effects are also examined, showing the heat transfer coefficient decreases with the increase in operating pressure. Further, common correlations for internal flow condensation show underprediction in measured heat transfer coefficient for external flow condensation. Finally, flow visualization of external flow condensation reveals continuous detachment of liquid film at tube's underside, highlighting a clear distinction from the internal flow condensation.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"245 ","pages":"Article 127044"},"PeriodicalIF":5.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143737974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of flow separation and its control over rotor blades in forward flight with plasma actuator","authors":"Haocheng Yu,&nbsp;Jianguo Zheng","doi":"10.1016/j.ijheatmasstransfer.2025.127023","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.127023","url":null,"abstract":"<div><div>Flow separation and its control over constantly rotating rotor blades operating at a large angle of attack in forward flight are comprehensively investigated through detailed numerical simulation possibly for the first time. An unsteady three-dimensional Reynolds-Averaged Navier-Stokes calculation with a Reynolds stress turbulence model is utilized to capture the dynamics of airflow. The resolved transient baseline flow pattern around the blade is observed to be heavily influenced by the azimuthal angle, exhibiting significant spatiotemporal characteristics. Two critical indicators, the high-order central moment of pressure (HCMP) and modulated location of peak pressure (MLPP), are generalized to identify the critical flow events involved in the flow evolution. As a result, one typical flow evolution cycle can be classified into three distinct stages: the initial flow separation stage, the flow reattachment stage, and the secondary separation stage. A vorticity transport framework is established within a non-inertial coordinate system attached to the blade, aimed at quantifying the sources and sinks of vorticities crucial for the flow evolution within a chordwise body-fitted control region. It is found that the vorticity transport process over the blade in different flow evolution stages or flow events is influenced by distinct vorticity generation mechanisms. The tip speed ratio (TSR) significantly influences the flow, with more pronounced flow separation occurring at higher TSR values. Moreover, active flow control is realized through the utilization of nanosecond dielectric barrier discharge (NS-DBD) pulsed plasma actuators. Thermal perturbations generated by NS-DBD plasma interact with the separated flow, inducing a series of spanwise vortices that effectively mitigate flow separation. The generation of the spanwise vortices introduces a significant amount of planar convective flux into the separation region and enhances vorticity production through the vortex tilting effect. As a result, the vorticity transport system is reshaped by these spanwise vortices. Under plasma actuation, the aerodynamic performance of the blade is notably enhanced. Across various TSRs, the torque coefficient of the rotor blade can be significantly reduced, with a maximum reduction of up to 21.58 %. Furthermore, thrust enhancement is more pronounced at higher TSRs, with the thrust coefficient of the blade increasing by 10.44 % at TSR = 0.5.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"245 ","pages":"Article 127023"},"PeriodicalIF":5.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143737975","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 detailed comparison of heat transfer and fluid dynamics in Voronoi foam and triply periodic minimal surfaces (TPMS) via pore-scale investigation","authors":"Hamed Barokh ,&nbsp;Seyed Pooya Zoiee ,&nbsp;Hamidreza Najafi ,&nbsp;Majid Siavashi ,&nbsp;Mohammad Amin Sobati","doi":"10.1016/j.ijheatmasstransfer.2025.127007","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.127007","url":null,"abstract":"<div><div>In this study, the OpenFOAM library is employed to perform pore-scale simulations (PSS) to compare the flow and heat transfer characteristics of triply periodic minimal surfaces (TPMS) samples including Diamond, Gyroid, Lidinoid, and Split-P with those of a Voronoi foam (VF) sample. Conjugate heat transfer is simulated to ensure a comprehensive comparison. The samples are heated by a constant temperature heat source of 350 K at the bottom of the solid region. Numerical simulations are conducted in the non-Darcy regime for samples with identical thickness and the same porosity of 0.7. The outcomes revealed that the Voronoi sample had a lower pressure drop compared to the TPMS samples, while the Diamond sample, which had the lowest pressure drop among the TPMS samples, led to a 33 % higher pressure loss compared to VF at an inlet velocity of 0.1 m/s. Thermal analysis revealed that all TPMS samples except for Lidinoid outperformed Voronoi in heat transfer performance. For simultaneous thermal and flow evaluation, the performance evaluation criterion (PEC), defined as the ratio of improved heat transfer to enhanced power consumption, indicated the superior overall performance of VF among all studied cases. Diamond exhibited the closest performance to Voronoi among the four TPMS structures.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"245 ","pages":"Article 127007"},"PeriodicalIF":5.0,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143737972","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":"Falling film thickness distribution around a horizontal tube under countercurrent air flow","authors":"Jia-Wei Zheng ,&nbsp;Kai-Shing Yang ,&nbsp;Yu-Lieh Wu","doi":"10.1016/j.ijheatmasstransfer.2025.127011","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.127011","url":null,"abstract":"<div><div>Falling film heat exchangers are commonly used in various industrial applications. Although air stream–liquid interactions often occur in these exchangers, film thickness prediction models typically ignore their effects. In this study, a horizontal tube falling film experiment was performed with countercurrent airflow, and the behavior of the film was observed and analyzed. The film flow rate, nozzle height, countercurrent air velocity, heat flux, and drip temperature were varied. In the absence of forced convection, the minimum film thickness primarily occurs between 90° and 120° around the tube circumference. The film flow rate had the strongest effect on the film thickness. Countercurrent air greatly reduced the film thickness in the strong air stream–liquid interaction zone, further reducing the thickness of the thinnest sections. Boundary layer separation occurred and caused the location of minimum film thickness to move upwards on the tube to approximately 60°–80° These results highlight the need for practitioners to ensure that film ruptures and dry spots, which negatively affect heat transfer performance, do not occur in this region. A revised correlation equation for determining the film thickness and applicable in scenarios with or without counterflow air was developed and found to result in errors smaller than ±15 % for most experimental results.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"245 ","pages":"Article 127011"},"PeriodicalIF":5.0,"publicationDate":"2025-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143735053","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 simplified multi-mode wall condensation model for pure substances","authors":"Chidambaram Narayanan","doi":"10.1016/j.ijheatmasstransfer.2025.126993","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.126993","url":null,"abstract":"<div><div>Condensation is an important phenomenon in industries such as the nuclear and refrigeration sectors. The motivation for the development of a pure-component wall condensation model was the estimation of the amplitude of a condensation-induced hydraulic shock (CIHS) during the hot gas defrost in industrial ammonia refrigeration systems. In such a scenario, condensation occurs both homogeneously in the bulk of the fluid via interfacial and dispersed-phase condensation and heterogeneously on wall surfaces. Within the heterogeneous wall condensation, several modes of condensation have been identified, such as the dropwise and film condensation modes. A mathematical wall condensation model that blends the dropwise and film condensation modes was successfully developed and calibrated to a validated theoretical model for water. Through demonstrative CFD simulations, the dropwise condensation mode was shown to be a high heat transfer mode with the potential to completely condense an inlet stream of vapor. The area fraction covered by droplets was found to be between 7–11<span><math><mtext>%</mtext></math></span>, whereas heat flux through the droplet, was three orders of magnitude greater than the convective heat transfer. The current study presents the first closed-form wall condensation model for pure substances available for CFD codes that accounts for the high heat-flux dropwise condensation mode. This model can be implemented into both CFD and reduced-order codes and applied to a variety of transient multiphase flow problems in several industry sectors including safety-relevant cases.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"245 ","pages":"Article 126993"},"PeriodicalIF":5.0,"publicationDate":"2025-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical investigation on the molten pool and keyhole dynamic behaviors and weld microstructure in laser-induction hybrid welding of stainless steel","authors":"Yuewei Ai ,&nbsp;Yang Zhang ,&nbsp;Shibo Han ,&nbsp;Xin Liu","doi":"10.1016/j.ijheatmasstransfer.2025.126988","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.126988","url":null,"abstract":"<div><div>The laser-induction hybrid welding (LIHW) can inhibit the formation of welding defects and enhance the mechanical properties of welded joints, which improves the applicability of laser welding in different industries. In this paper, a macro-micro numerical model consisting of macroscopic heat transfer and fluid flow model coupled with magnetic field, transient solidification conditions (SCs) model and microscopic phase field model (PFM) is developed to investigate the LIHW of 304 stainless steel. The validity of the developed model is confirmed by comparing the simulation results with the experimental results. The effects of electromagnetic induction heating on the molten pool and keyhole dynamic behaviors and weld microstructure during LIHW are analyzed and discussed in detail. Compared with the single-laser welding (SLW), the depth and half width of the molten pool are increased and the stability of the keyhole has been improved during LIHW. Additionally, the primary dendrite arm spacing during SLW is smaller than that during LIHW. The results show that the proposed model is beneficial for understanding the molten pool and keyhole dynamic behaviors and microstructure evolution process during LIHW and hence improving the welding quality.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"245 ","pages":"Article 126988"},"PeriodicalIF":5.0,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143725149","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":"Topology optimization of compatible thermal microstructures","authors":"Tianjie Chen,&nbsp;Xiaoya Zhai,&nbsp;Ligang Liu,&nbsp;Xiao-Ming Fu","doi":"10.1016/j.ijheatmasstransfer.2025.126984","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.126984","url":null,"abstract":"<div><div>Thermal microstructures are arranged periodically or in gradients to create thermal management systems. Ensuring connectivity is a critical challenge in designing multiple thermal microstructures for multiscale applications. This is an important issue that has not yet been systematically studied in a quantitative manner. In this work, we introduce the concept of <strong><em>thermal compatibility</em></strong>. It refers to the ability of different microstructures to work together effectively in thermal systems. Thermal compatibility ensures efficient heat transfer while minimizing <strong><em>thermal resistance</em></strong>. To address this, we propose a novel framework incorporating thermal resistance into the topology optimization model with the constraint of predefined thermal conductivity tensors to generate compatible thermal microstructures. Our optimization model considers the compatibility of adjacent microstructures and extends to mutual compatibility. Moreover, it accounts for both isotropic and orthogonal anisotropic thermal microstructures. When the thermal microstructures exhibit good compatibility, the results from both full-scale and homogenization analyses are consistent. We further demonstrate the applicability of our method through two thermal-related multiscale design examples: thermal dissipation and thermal cloak design.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"245 ","pages":"Article 126984"},"PeriodicalIF":5.0,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143735044","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical study of breakup and solidification of a liquid column","authors":"Nang X. Ho,&nbsp;Vinh T. Nguyen,&nbsp;Truong V. Vu","doi":"10.1016/j.ijheatmasstransfer.2025.127008","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.127008","url":null,"abstract":"<div><div>Liquid columns appear in many engineering problems. Such a liquid column held vertically between two rods and undergoing the solidification process is the focus of the present study. The investigation is conducted using an axisymmetric front-tracking method. Starting with an initial cylindrical shape, gravity causes the liquid to accumulate in the bottom of the column, leading to a thinner upper part and a wider lower part with the formation of a neck near the mid-plane of the column. As solidification initiates from the rod ends, this behavior of the column is imprinted. The neck size can further decrease and reach zero, leading to the breakup of the column during solidification. After breakup, the upper part quickly reaches the final solidified state while the solidification of the lower part takes longer. To prevent breakup, we can increase the solidification rate by raising the Stefan number. Additionally, increasing the Ohnesorge number, decreasing the Bond number, or reducing the length of the column also prevents the column from breaking up. The regime diagrams, showing the transition between breakup and non-breakup in the solidification of the column, are also proposed.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"245 ","pages":"Article 127008"},"PeriodicalIF":5.0,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143725150","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 physics-informed neural network method for thermal analysis in laser-irradiated 3D skin tissues with embedded vasculature, tumor and gold nanorods","authors":"Farnaz Rezaei ,&nbsp;Weizhong Dai ,&nbsp;Shayan Davani ,&nbsp;Aniruddha Bora","doi":"10.1016/j.ijheatmasstransfer.2025.126980","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.126980","url":null,"abstract":"<div><div>Obtaining an accurate temperature field of the entire treatment region and controlling the laser intensity is vital for successful clinical outcomes in hyperthermia skin cancer treatment. This article presents a Physics-Informed Neural Network (PINN) method to accurately predict transient temperature distributions and thermal damage in 3D triple-layered skin tissues with an embedded tumor, gold nanorods, and a vascular network that is designed based on the constructal theory of multi-scale tree-shaped heat exchangers. Fourier and non-Fourier Pennes bioheat transfer equations in triple-layered tissues and the convective energy balance equations in blood vessels are employed in the loss function, where the Gaussian-shaped laser beam with the laser power as a parametric variable is modeled. The convergence of the neural network solution is analyzed theoretically. The new algorithm with time sequence is tested for a duration of at least 400 seconds over three different case studies. Results show that the PINN-predicted temperatures agree well with those predicted temperatures based on the finite element/finite difference methods. In particular, for the case study with a tumor, the thermal damage analysis reveals that with an optimal power of 0.9 W/cm, the skin tissues remain undamaged over 600 seconds, while the tumor cells’ death begins after 330 seconds, with the tumor's average temperature reaching about 43.7 °C. The advantage of the PINN method is that it can be easily applied to determine the optimal laser power when dealing with the irregulate tumor shape without mesh constructions that are used in the common numerical methods.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"245 ","pages":"Article 126980"},"PeriodicalIF":5.0,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143715716","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":"Performance improvement technique of natural draft dry cooling tower under ambient wind based on minimum mechanical energy dissipation","authors":"Jinygyao Wang ,&nbsp;Wenjie Zhang ,&nbsp;Huimin Wei ,&nbsp;Xiaoze Du ,&nbsp;Xinming Xi","doi":"10.1016/j.ijheatmasstransfer.2025.127022","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.127022","url":null,"abstract":"<div><div>The Natural draft dry cooling tower (NDDCT) performance decreases sharply under ambient winds. The drag reduction equation is introduced in paper to solve the flow field distribution inside NDDCT, which complies with the minimum mechanical energy dissipation and provides theoretical guidance for the baffle installation inside the NDDCT. Depending on the streamline distribution inside tower, the pressure drop between tower inlet and outlet can be reduced by 12.9 % to 76.9 % by installing the appropriate shape and size of deflectors inside the tower. The thermal behavior of NDDCT model, the two improved NDDCT model in reference, and the improved NDDCT model proposed in paper were compared under wind conditions. At a wind speed of 12m/s, the drag reduction model's drag coefficient was reduced by 10.9 %, and heat dissipation increased by 6.94 % compared to the NDDCT. Under high wind speed conditions, the improved model can greatly reduce the back pressure and coal consumption. At a wind speed of 16 m/s, the back pressure of unit is reduced by 3.29 kPa and the coal consumption is reduced by 1.71 g/(kW-h). Compared to the models mentioned in two references, it was determined that the improved NDDCT model reduces the negative impact of ambient wind on NDDCT mainly by reducing the resistance inside tower.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"245 ","pages":"Article 127022"},"PeriodicalIF":5.0,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143725148","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}