International Journal of Heat and Mass Transfer最新文献

{"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}

{"title":"Experimental investigations on the performance and bubble dynamics of two-phase immersion cooling system with multiple chips","authors":"V.B. Krishnadasan,&nbsp;Pratheek Suresh,&nbsp;C. Balaji","doi":"10.1016/j.ijheatmasstransfer.2025.126977","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.126977","url":null,"abstract":"<div><div>The continuous miniaturization of power electronics has led to increasingly compact devices, accompanied by a direct increase in the associated heat flux. Two-phase immersion cooling has established itself as a significant advancement for cooling high-power density systems; however, its performance in multi-chip configurations has not been extensively investigated. This study presents a fully experimental investigation to analyze the thermal performance and bubble dynamics in a two-phase immersion system with multiple chips. Experiments were conducted in an immersion tank with 10 mm thick aluminum walls, housing a printed circuit board with seven power resistor chips immersed in a dielectric liquid. The boiling process was recorded using a high-speed camera, and the images captured were analyzed to determine the bubble departure diameter (BDD) and bubble departure frequency (BDF). At a heat flux of 12.5 W/cm², the temperature of a specific chip increased by 15%, while the heat transfer coefficient (HTC) improved by 22.7% when all seven chips operated simultaneously, compared to when only that chip was powered. The BDD rose as heat flux increased while only the single chip was operating. However, when additional chips were activated, the BDD began to decrease beyond a critical Jakob number as the Jakob number increased with higher heat fluxes. At elevated Jakob numbers, the bulk liquid velocity increased, promoting the generation of a greater number of smaller bubbles instead of fewer, larger ones. The shrinking of bubbles and the enhancement of bulk liquid mixing contributed to the observed increase in the HTC as more chips were activated. A correlation for the average Nusselt number is developed as a function of the heat flux supplied to individual chips and the number of simultaneously operating chips. This correlation, expressed in terms of system control parameters, provides a framework for ensuring the thermal safety and reliable operation of multi-chip systems. The study concludes that under high computational workloads, distributing tasks across multiple processors is a more effective thermal management strategy compared to operating a single processor. This is largely because the activation of nearby chips enhances the HTC significantly due to reduced BDD and improved bulk liquid mixing.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"245 ","pages":"Article 126977"},"PeriodicalIF":5.0,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143746455","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":"Assessment of the spectral vanishing viscosity LES model for the simulation of coupled molecular radiation and Rayleigh–Bénard convection in a cubic cavity","authors":"M. Delort-Laval,&nbsp;L. Soucasse,&nbsp;Ph. Rivière,&nbsp;A. Soufiani","doi":"10.1016/j.ijheatmasstransfer.2025.126991","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.126991","url":null,"abstract":"<div><div>Large-eddy simulations (LES) of coupled turbulent convection and radiative transfer in a cubic Rayleigh–Bénard cell are performed up to a Rayleigh number of <span><math><mrow><mi>Ra</mi><mo>=</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>10</mn></mrow></msup></mrow></math></span>, for an air mixture containing small amounts of water vapor and carbon dioxide. The Spectral Vanishing Viscosity (SVV) model is used to account for the unresolved subgrid scales. The accuracy of the LES-SVV model with respect to the model parameters is assessed against Direct Numerical Simulations (DNS) at Rayleigh numbers <span><math><mrow><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>8</mn></mrow></msup></mrow></math></span> and <span><math><mrow><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>9</mn></mrow></msup></mrow></math></span>. Comparisons between LES-SVV and DNS calculations are given in terms of first order and second order statistics, spatial auto-correlation functions, and POD eigenmodes. Simulation results at <span><math><mrow><mi>Ra</mi><mo>=</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>10</mn></mrow></msup></mrow></math></span> show a significant increase of the kinetic energy of the mean flow and of the convective flux when radiative transfer is taken into account. On the other hand, radiation has little influence on the wall radiative and conductive fluxes, on the turbulent kinetic energy and on the variance of temperature fluctuations. In the Rayleigh number range <span><math><mrow><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>6</mn></mrow></msup><mo>≤</mo><mi>R</mi><mi>a</mi><mo>≤</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>10</mn></mrow></msup></mrow></math></span>, the simulations show that radiative transfer effects decrease when the Rayleigh number increases at fixed cavity size.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"245 ","pages":"Article 126991"},"PeriodicalIF":5.0,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143715725","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":"Multiphysics simulation of tumor ablation in magnetic hyperthermia treatment","authors":"Qian Jiang ,&nbsp;Feng Ren ,&nbsp;Chenglei Wang ,&nbsp;Zhaokun Wang ,&nbsp;Gholamreza Kefayati ,&nbsp;Sasa Kenjeres ,&nbsp;Kambiz Vafai ,&nbsp;Xinguang Cui ,&nbsp;Yang Liu ,&nbsp;Hui Tang","doi":"10.1016/j.ijheatmasstransfer.2025.126982","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.126982","url":null,"abstract":"<div><div>Magnetic hyperthermia is a promising cancer treatment method that involves complex multiphysics phenomena, including interstitial tissue fluid flow, magnetic nanoparticle (MNP) transport, and temperature evolution. However, these intricate processes have rarely been studied simultaneously, primarily due to the lack of a comprehensive simulation tool. To address this issue, we develop a comprehensive numerical framework in this study. Using this framework, we simulate a circular-shaped tumor embedded in healthy tissue. The treatment process is examined under two scenarios: one considering gravity and the other neglecting it. Without gravity, the interstitial tissue flow remains stationary, and hence MNP transport and temperature evolution are determined solely by diffusion. The optimal treatment time, when the tumor cells are completely ablated, decreases with both the Lewis number and the heat source number, following a power law. When gravity is considered, treatment efficacy deteriorates due to buoyancy-induced MNP movement, significantly extending the time required to completely ablate the tumor cells. This required time increases with both the buoyancy ratio and the Darcy ratio, also following a power law. The results from this study could provide valuable guidelines for practical magnetic hyperthermia treatment.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"245 ","pages":"Article 126982"},"PeriodicalIF":5.0,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143705086","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":"Experimental and numerical study of free convective heat transfer in air performed simultaneously from the upper and lower surfaces of a horizontal plate heated on both sides","authors":"Michał Ryms ,&nbsp;Krzysztof Tesch ,&nbsp;Witold s.M. Lewandowski","doi":"10.1016/j.ijheatmasstransfer.2025.126973","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.126973","url":null,"abstract":"<div><div>This paper presents an experimental study, supported by numerical analysis, on convective heat transfer in air from a newly designed, horizontal, double-sided heated Type II plate. Unlike the single-sided heated Type I plate, where the heating surface faces either upwards or downwards, the Type II plate heats both surfaces simultaneously.</div><div>The tested plate was constructed from three glued laminates, each 0.6 mm thick, resulting in a total thickness of 2.1 mm. Minimal lateral-surface heat loss (&lt;4.2%) ensured high measurement accuracy. Surface resistance thermometers (<em>T</em>_low/up) were etched into the copper layer on one side, while two resistance heaters (<em>N</em>_low/up) were embedded in the copper-coated middle laminate.</div><div>Numerical calculations (Num.II and Num.I) for Type II and I plates revealed discrepancies under the UWT (Uniform Wall Temperature) condition: <em>C</em>_Exp._II/<em>C</em>_Num.II = 33.8% (upper) and -8.4% (lower), and for UHF (Uniform Heat Flux): 17.8% (upper) and 6.1% (lower). Similar discrepancies in <em>C</em>_Num.II/ <em>C</em>_Num.I (-36.1% UWT_up, 0.5% UWT_low, -26.9% UHF_up, 0.7% UHF_low) confirmed different heat transfer mechanisms on the upper heating surfaces of Type II and I plates.</div><div>In the absence of the mean literature correlation (MLC.II) for Type II plates, numerical verification (<em>C</em>_Num.II) was conducted, yielding <em>C</em>_Exp./<em>C</em>_Num.II = 1.338 (upper) and 0.916 (lower) for UWT, and 1.178 (upper) and 1.061 (lower) for UHF. Indirect verification using Type I plate data (MLC.I) required numerical transformation, yielding <em>C</em>_Exp.II/<em>C</em>_MLC.I = 1.426 (upper) and 0.748 (lower) for UWT, and 1.017 (upper) and 0.896 (lower) for UHF. These results confirm the reliability of the Type II plate tests.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"245 ","pages":"Article 126973"},"PeriodicalIF":5.0,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143715715","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 two-phase theoretical model incorporating liquid film dynamics for pulsating heat pipes","authors":"Ying Liu ,&nbsp;Yuhao Yan ,&nbsp;Xilei Wu ,&nbsp;Kangli Bao ,&nbsp;Jialiang Yang ,&nbsp;Maojin Zeng ,&nbsp;Xiaohong Han","doi":"10.1016/j.ijheatmasstransfer.2025.126997","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.126997","url":null,"abstract":"<div><div>Pulsating Heat Pipes (PHPs) hold significant potential for efficient thermal management of electronic devices due to their superior heat transfer capabilities, flexible design, and cost-effective manufacturing. However, in view of the fact that there may be different heat transfer distances between heat sources and heat sinks, the widespread application of PHPs has been limited by the lack of accurate models and experimental data to predict and understand their flow and heat transfer performance at varying heat transfer distances. To address these limitations, a two-phase heat and mass transfer model incorporating liquid film dynamics was developed and partial visualization experiments were conducted to validate the reliability of the theoretical model. Based on these, the flow and heat transfer performance of R1336mzz(Z)-PHPs under various heat transfer distances were numerically simulated and experimentally investigated. The flow and heat transfer characteristics of R1336mzz(Z)-PHPs were compared with those of water-PHPs and ethanol-PHPs to investigate the influence of working fluids on the operating performance of PHPs through numerical simulation. The results revealed that the two-phase heat and mass transfer model could capture the local dry-out phenomenon and accurately simulate the heat and mass transfer process in PHPs through the comparison of experimental results with simulation results. According to simulation results, increasing heat input enhanced both flow and heat transfer performance for R1336mzz(Z)-PHPs, especially at shorter heat transfer distances. There was an optimal heat transfer distance at which the flow and heat transfer performance of the PHP were best. Compared to water and ethanol, R1336mzz(Z) generated a greater driving force while experiencing lower flow resistance, resulting in a higher average flow velocity of the working fluid. This enabled the transition from oscillatory flow to one-way circulation flow at various heat transfer distances and avoided the occurrence of local dry-out, leading to superior flow performance. Besides, the performance of the R1336mzz(Z)-PHP was relatively less affected by heat transfer distance. Even at a large heat transfer distance, R1336mzz(Z) maintained superior flow and heat transfer performance.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"245 ","pages":"Article 126997"},"PeriodicalIF":5.0,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143705090","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 comprehensive study on heat transfer mechanism and thermal runaway suppression of the lithium‐ion battery","authors":"Tao Sun ,&nbsp;Yulong Yan ,&nbsp;Xinhua Wang ,&nbsp;Ghulam Rasool ,&nbsp;Kai Zhang ,&nbsp;Tie Li","doi":"10.1016/j.ijheatmasstransfer.2025.127027","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.127027","url":null,"abstract":"<div><div>Lithium-ion batteries are widely used for energy conversion and storage, but they suffer from significant performance and safety problems due to overheating and thermal runaway. High power charging and discharging puts forward higher requirements on the thermal control capability of lithium-ion batteries. Understanding the heat transfer mechanism inside lithium-ion batteries and suppressing thermal runaway are core issues related to the thermal safety of lithium-ion batteries. This work summarizes the heat transfer process between batteries and the multi-scale heat transfer mechanisms inside a single battery. Moreover, this article analyzes the thermal management and corresponding heat transfer methods of lithium-ion batteries. Finally, improving battery materials and structures, optimizing system design can suppress the propagation of thermal runaway and improve battery safety, which is a key issue in the design, manufacturing, and service of lithium-ion batteries. This article emphasizes the key role of heat transfer mechanism and thermal runaway suppression in maintaining safe, efficient, and stable operation of lithium-ion batteries. Which provide new ideas and directions for improving the thermal safety of lithium-ion batteries and large-sized lithium-ion battery packs.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"245 ","pages":"Article 127027"},"PeriodicalIF":5.0,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143715760","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":"Critical Heat Flux of Cryogenic Flow Boiling under Terrestrial, Partial, and Reduced Gravity Conditions","authors":"Sunjae Kim ,&nbsp;Nishad Damle ,&nbsp;Dylan Foster ,&nbsp;Steven Darges ,&nbsp;Jason Hartwig ,&nbsp;Issam Mudawar","doi":"10.1016/j.ijheatmasstransfer.2025.126957","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.126957","url":null,"abstract":"<div><div>Cryogenic fluid management (CFM) technology has been recognized as a critical area requiring substantial research to ensure the safe and reliable development of in-space cryogenic architectures, such as Nuclear Thermal Propulsion (NTP) systems. The urgency of this research is underscored by the lack of Critical Heat Flux (CHF) data for cryogenic fluids under reduced gravity conditions, which significantly hampers the development of accurate design tools. This study aims to elucidate the gravitational effects on cryogenic two-phase fluid physics and CHF by conducting the first-ever experimental measurements of cryogenic flow boiling using a steady-state heating method in a reduced gravity environment. Using liquid nitrogen (LN₂) as the working fluid, parabolic flight experiments were conducted to obtain both CHF measurements and high-speed video recordings of interfacial behavior under varying gravity levels, including microgravity and both Lunar and Martian gravities. Additionally, terrestrial ground experiments were performed across five distinct flow orientations: vertical upflow, vertical downflow, horizontal flow, 45° inclined upwards, and 45° inclined downwards. The study employed a circular heated tube featuring an inner diameter of 8.5 mm and a heated length of 680 mm. Vertical upflow exhibited the most enhanced CHF performance, while vertical downflow showed the poorest performance. Increasing gravitational acceleration—from microgravity to Lunar to Martian—reduced CHF due to intensified flow stratification caused by the strengthening buoyancy force. The gravitational effect was mitigated by increasing the mass velocity above a threshold of 700 kg/m²s. Finally, existing CHF correlations were evaluated, revealing a need for a new correlation specific to cryogenic fluids under reduced gravity conditions. Consequently, a new CHF correlation was developed and tested using datasets from microgravity as well as both Lunar and Martian gravities. The new correlation shows excellent predictive accuracy, evidenced by a mean absolute error (MAE) of 7.54%, against eleven newly acquired microgravity, Lunar and Martian CHF datapoints.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"245 ","pages":"Article 126957"},"PeriodicalIF":5.0,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143715763","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 & stabilisation to transcritical hydrocarbon fuels within additively manufactured turbulated microtubes","authors":"B.J. McMahon ,&nbsp;M.J. Patel ,&nbsp;R. Hubesch ,&nbsp;X. Li ,&nbsp;S. Periasamy ,&nbsp;A. Pudsey","doi":"10.1016/j.ijheatmasstransfer.2025.126979","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.126979","url":null,"abstract":"<div><div>Heat exchangers (HEXs) using supercritical hydrocarbon fuel as a regenerative coolant have been proposed to manage the extreme aerothermal heating experienced by the external surfaces of scramjet aircraft. Addit. Manuf. (AM) can improve scramjet HEX efficiency by easing both the fabrication of conformal HEX designs and the inclusion of internal heat transfer enhancement (HTE) features. To determine the potential of AM to improve HEX efficiency for hydrocarbon scramjet which become supercritical during heating, a heat transfer dataset using liquid decane as the fuel/coolant proxy was measured for three AMd microtube designs and compared to that obtained for a conventionally manufactured (CMd) tube. Two of the AMd designs included HTE features (helical ribs &amp; ring ribs) that are characterised here for HTE performance the first time, with the third design omitting turbulators but featuring increased wall roughness (relative to the CMd microtube). The influence of wall roughness &amp; HTE features on steady state Nusselt number, friction factor, and overall thermal performance factor (TPF) under two heat loads are characterised alongside the inhibition of transcritical oscillatory behaviour commonly experienced for smooth tube designs. HTE turbulator features significantly increased heat transfer (Nu increased by 66x relative to CMd tube leading to peak TPF of 12) and pressure &amp; temperature oscillations reduced from 580 % &amp; 12 % of the CMd tube's mean to 16 % &amp; 1 %, respectively. The datasets presented here can thus underpin the design of high-performance scramjet HEXs, leading to significantly reduced skin &amp; structural temperatures and thus reduced cost &amp; complexity.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"245 ","pages":"Article 126979"},"PeriodicalIF":5.0,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143715762","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}