Xi Chen , Wuqiang Long , Changhong Ma , Pengbo Dong , Zhenxian Zhang , Jiangping Tian , Keiya Nishida , Hua Tian
{"title":"Experimental and modeling study on liquid phase ammonia spray characteristics under high-pressure injection and engine-like ambient conditions","authors":"Xi Chen , Wuqiang Long , Changhong Ma , Pengbo Dong , Zhenxian Zhang , Jiangping Tian , Keiya Nishida , Hua Tian","doi":"10.1016/j.icheatmasstransfer.2025.108853","DOIUrl":"10.1016/j.icheatmasstransfer.2025.108853","url":null,"abstract":"<div><div>Ammonia, a renewable fuel with low-carbon emissions, is a promising alternative fuel for internal combustion engines. This study investigates the evaporation of liquid-ammonia spray using optical experiments and numerical simulation. Based on the experimental results, the computational model was established and validated, in addition to the optimization of the empirical formulas for spray tip penetration and spray angle. The results show that the model can accurately predict the development of liquid-ammonia spray under high-temperature and high-pressure environment conditions. The prediction error of the model for the spray tip penetration does not exceed 8 %. And the liquid phase ammonia spray is not sensitive to the changes in injection pressure with high temperature atmosphere. The temperature distribution along the spray's central axis exhibits three stages: constant, logarithmic growth, and linear growth, affecting vapor-phase mass fraction due to entrainment intensity. The logarithmic growth region serves as an ideal ignition zone for ammonia diffusion combustion. Additionally, increasing ambient temperature reduces the first stage distance and enhances the second stage's change rate. Even with a consistent temperature span (200<em>K</em>), the vapor-phase ratio and average turbulent dissipation show non-linear changes. These insights are crucial for enhancing liquid-ammonia spray mixture quality and controlling its combustion characteristics.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"164 ","pages":"Article 108853"},"PeriodicalIF":6.4,"publicationDate":"2025-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143629192","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}
Menglong He , Hui Wang , Qifan Ying , Shang Liu , Liejin Guo
{"title":"The effect of aspect ratios and inclination angles on the thermal energy storage of phase change materials in partially filled metal foam","authors":"Menglong He , Hui Wang , Qifan Ying , Shang Liu , Liejin Guo","doi":"10.1016/j.icheatmasstransfer.2025.108858","DOIUrl":"10.1016/j.icheatmasstransfer.2025.108858","url":null,"abstract":"<div><div>This paper conducted a numerical study on the thermal energy storage (TES) of partially filled metal foam composite phase change materials (PCM) in rectangular cavity devices. The melting mechanisms under different aspect ratios (AR) and inclination angle models were analyzed, and a predictive formula for the dimensionless TES rate density z' was established. The results indicate that the TES performance of PCM improves with the increase of AR. When AR = 2, the enhancement efficiency reaches 22.6 %, exhibiting the optimal improvement effect. When AR is greater than 8, heat conduction dominates the entire melting process. The natural convection effect is the best in the 60° inclination angle model. When AR = 1, the energy storage performance at θ = 60° is 5 % higher than that at θ = 90°, but for other ARs, θ = 60° leads to a decrease in performance. This is because the change in inclination angle triggers the Rayleigh - Bénard convection phenomenon, generating counter - rotating vortices that inhibit the energy storage efficiency, and as AR increases, the inhibition becomes more significant. The established predictive formula takes both AR and inclination angle into account, which is more comprehensive.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"164 ","pages":"Article 108858"},"PeriodicalIF":6.4,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143628867","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}
Jie Sun , Bo Yuan , Guanqun Ding , Junsen Fu , Zhenqin Xiong , Yao Xiao , Hanyang Gu
{"title":"Investigation of buoyancy and spacer effects on heat transfer in low-flow-rate upward flow of Lead-bismuth alloy","authors":"Jie Sun , Bo Yuan , Guanqun Ding , Junsen Fu , Zhenqin Xiong , Yao Xiao , Hanyang Gu","doi":"10.1016/j.icheatmasstransfer.2025.108836","DOIUrl":"10.1016/j.icheatmasstransfer.2025.108836","url":null,"abstract":"<div><div>The influence of buoyancy on convective heat transfer in liquid lead‑bismuth (LBE) flow inside a smooth round tube and the spacer effects are studied numerically. The analysis indicates that the effect of buoyancy on convective heat transfer depends on the <em>Bo</em> number. The mixed convection heat transfer performance in a smooth circular tube is analogous to water, namely, mixed convection heat transfer deterioration and free convection heat transfer enhancement. However, this effect is much weaker compared to water. Detailed analysis of radial velocity and turbulent kinetic energy inside the smooth round tube reveals that the distortion of velocity curves induced by buoyancy leads to both deterioration and enhancement of mixed convection. Furthermore, the influence of the spacer, its radial structure and the blockage ratio on the flow and heat transfer is investigated. Unlike water, no heat transfer oscillations are found downstream of the spacer in LBE and orifice-type spacer creates a stagnation region where heat transfer deteriorates as <em>Bo</em> increases. In contrast, there is no stagnation region downstream of the disk-type spacer, with the downstream heat transfer enhancing initially and then deteriorating as <em>Bo</em> increases.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"164 ","pages":"Article 108836"},"PeriodicalIF":6.4,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143619394","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":"Submerged jet's profile-specific heat transfer: Stagnation zone and beyond","authors":"Barak Kashi, Herman D. Haustein","doi":"10.1016/j.icheatmasstransfer.2025.108815","DOIUrl":"10.1016/j.icheatmasstransfer.2025.108815","url":null,"abstract":"<div><div>A general analytical description for the heat transfer distribution (HTD) under an impinging submerged jet is derived, from the jet velocity profile arriving at the wall. First, the cause-and-effect chain is broken down: i) the streamline-bending projection of the arriving profile's dynamic pressure gives the wall pressure distribution; ii) the pressure gradient drives the radial acceleration; iii) the acceleration unlocks the entire flow field: boundary layer, wall-shear and vorticity distributions; iv) ultimately also the HTD is recovered from similarity; iv) this extends up to deceleration, approaching the known wall-jet solution.</div><div>This new theory is validated against simulations and experiments over a wide range of conditions: from uniform to fully developed issuing profiles, over a range of flights. Thus, confirming that the arriving profile contains everything needed for the subsequent wall-flow description, and demonstrating that the HTD diversity corresponds to that of the arrival profiles. This permits the prediction of the HTD in a universal way, from stagnation point to wall-jet. Specifically, relating the well-known off-center peak (boundary layer thinning) to an incoming profile shape with strong velocity gradients, as encountered in profiles with a potential core. Two different pathways for the generation of this off-center peak are studied and compared.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"164 ","pages":"Article 108815"},"PeriodicalIF":6.4,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143619396","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":"Thermophysical properties of SWCNT/molten carbonate composite phase change material: A molecular dynamics study","authors":"Jingtao Wang, Mingyuan Yang, Yuting Jia, Hongliang Chang","doi":"10.1016/j.icheatmasstransfer.2025.108857","DOIUrl":"10.1016/j.icheatmasstransfer.2025.108857","url":null,"abstract":"<div><div>Carbonate molten salts are considered the most competitive heat storage medium for the next-generation concentrated solar power (CSP) systems. This research presents a material composition design strategy aimed at improving the thermophysical properties of carbonate molten salts through the development of carbonate molten salt/single-walled carbon nanotubes (SWCNT) composite phase change material (CPCM). The mechanism of thermophysical property improvement was investigated using molecular dynamics (MD) simulations, focusing on aspects such as microstructural evolution, thermal diffusivity, and energy variation. The thermal properties including density, thermal conductivity, specific heat capacity, and viscosity of the CPCM with different mass fraction of SWCNT (1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%) were predicted in the high-temperature range of 1150 K to 1450 K. The results indicate that as the increasing mass fraction of SWCNT, leads to a substantial enhancement in both the thermal conductivity and specific heat capacity of the system. When the mass fraction of SWCMT is 5 wt%, the maximum increments are 16.41 % and 3.00 %, respectively. Simultaneously, it is observed that an increase in SWCNT mass fraction restricts the migration of molten salt ions, leading to a reduction in the self-diffusion coefficient of the system and an increase in shear viscosity. The research outcomes offer valuable insights for the design and implementation of molten salt-based elevated temperature thermal energy storage materials in next-generation CSP systems.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"164 ","pages":"Article 108857"},"PeriodicalIF":6.4,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143619398","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 the thermal barrier coating set up and modeling in numerical analysis for prediction gas turbine blade temperature and film cooling effectiveness","authors":"Yong Hui Pi, Jun Su Park","doi":"10.1016/j.icheatmasstransfer.2025.108860","DOIUrl":"10.1016/j.icheatmasstransfer.2025.108860","url":null,"abstract":"<div><div>Gas turbine blades are protected from hot combustion gases by employing various cooling technologies such as film cooling and thermal barrier coating (TBC). Considering these methods, the accurate prediction of the turbine blade temperature and cooling performance is crucial to ensure the application of the appropriate cooling technology. This study investigated the effect of the TBC setup and modeling through numerical simulations to predict the turbine blade temperature and film cooling effectiveness. Conjugate heat transfer calculations were performed using two different TBC setups and modeling approaches: a thin-material interface model and actual three-dimensional (3D) modeling. Consequently, the calculation using the thin-material interface model yielded a maximum temperature that was 110 °C lower than that obtained using the actual 3D modeling for TBC. When performing calculations using the actual 3D model of the TBC, the film cooling hole angle on the TBC layer was found to change depending on the manufacturing method of the film cooling hole. Accordingly, the discharge pressure of the cooling fluid and the film cooling effectiveness changed owing to the variation in the angle of the film cooling holes on the TBC layer.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"164 ","pages":"Article 108860"},"PeriodicalIF":6.4,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143628826","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}
Feng Han , Zhuxuan Jiang , Honghua Chen , Junkui Mao , Xiaofeng Ding
{"title":"Numerical investigations on the heat transfer characteristics of pin-fin heat sink for power converters in more electric aircraft","authors":"Feng Han , Zhuxuan Jiang , Honghua Chen , Junkui Mao , Xiaofeng Ding","doi":"10.1016/j.icheatmasstransfer.2025.108866","DOIUrl":"10.1016/j.icheatmasstransfer.2025.108866","url":null,"abstract":"<div><div>Efficient cooling of high-power density converters is critical for the aerospace industry. This study investigates a 40-kW aviation power converter and examines the heat transfer (HT) characteristics of pin-fin heat sinks under specific operating conditions. The effects of the height-to-diameter ratio (<span><math><msub><mi>r</mi><mi>h</mi></msub></math></span>), relative spanwise spacing (<span><math><msub><mi>r</mi><mi>s</mi></msub></math></span>), relative streamwise spacing (<span><math><msub><mi>r</mi><mi>x</mi></msub></math></span>), and Reynolds number (<em>Re</em>) on HT performance are analyzed. When the pin-fin diameter is fixed, the average Nusselt number (<span><math><mover><mi>Nu</mi><mo>¯</mo></mover></math></span>) of the pin-fin surface (PFS) is consistently 40 %–70 % higher than that of the end wall. Both <span><math><mover><mi>Nu</mi><mo>¯</mo></mover></math></span> levels on the PFS and end wall increase as <em>Re</em> increases. The thermal performance index (TPI) and improved thermal performance index (TPI’) both initially increase and then decrease with increasing <span><math><msub><mi>r</mi><mi>h</mi></msub></math></span> when <span><math><mo>Re</mo></math></span> ≤ 10,000, while they consistently decrease with increasing <span><math><msub><mi>r</mi><mi>h</mi></msub></math></span> when 15,000 ≤ <span><math><mo>Re</mo></math></span>≤25,000. Additionally, the friction coefficient and resistance enhancement coefficient increase as <span><math><msub><mi>r</mi><mi>h</mi></msub></math></span> varies from 4 to 20. The optimal heat sink structure is identified as having a pin-fin diameter of <em>D</em> = 6 mm, a height-to-diameter ratio of <span><math><msub><mi>r</mi><mi>h</mi></msub></math></span> = 10, a relative spanwise spacing of r<sub>s</sub> = 3, and a relative streamwise spacing of <span><math><msub><mi>r</mi><mi>s</mi></msub></math></span> = 3 and <span><math><msub><mi>r</mi><mi>x</mi></msub></math></span> = 2.5, respectively.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"164 ","pages":"Article 108866"},"PeriodicalIF":6.4,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143628866","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":"Simplified thermal stability analysis of diffusion-reaction problems using surrogate modeling","authors":"Ankur Jain, Muhammad Mehdi Abbas, Arun Narasimhan","doi":"10.1016/j.icheatmasstransfer.2025.108793","DOIUrl":"10.1016/j.icheatmasstransfer.2025.108793","url":null,"abstract":"<div><div>Thermal stability analysis of problems involving temperature-dependent heat generation, for example, due to Joule heating or chemical reactions is of much practical interest for the safety of Li-ion cells, chemical reactors and similar systems. There remains an important need for thermal stability analysis of such diffusion-reaction heat transfer problems using simplified methods for practical use. This work presents surrogate modeling based thermal stability analysis of diffusion-reaction problems. Instead of deriving expressions for the transient temperature distribution, an approximate model for total energy of the body as a function of time is used for deriving conditions that cause divergence at large times. Results are shown to agree well with previously reported results based on eigenvalue analysis, and also with independent numerical simulations. Under special conditions, results are shown to reduce to past work on diffusion-reaction and pure-diffusion decay problems. A practical problem related to thermal management of an encapsulated Li-ion cell is analyzed, highlighting the role of intra-cell thermal conduction and convective heat removal at the boundary. Compared to past work, this work offers a mathematically simpler, yet accurate technique for thermal stability prediction. This work extends the state-of-the-art in thermal stability analysis and may benefit a number of engineering systems.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"164 ","pages":"Article 108793"},"PeriodicalIF":6.4,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143619395","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}
Mizanur Rahman , Mohammad Mokaddes Ali , Rehena Nasrin , Shaikh Mahmuda , Rajeeb Hossain
{"title":"Compartive statistical analysis with buoyancy effects on partitioned cavity","authors":"Mizanur Rahman , Mohammad Mokaddes Ali , Rehena Nasrin , Shaikh Mahmuda , Rajeeb Hossain","doi":"10.1016/j.icheatmasstransfer.2025.108843","DOIUrl":"10.1016/j.icheatmasstransfer.2025.108843","url":null,"abstract":"<div><div>The study of buoyancy effects in partitioned cavities has gained significant attention due to its relevance in numerous engineering and industrial applications, such as energy storage systems, electronic cooling devices, and thermal management solutions. Investigating the influence of key parameters such as Grashof number, Reynolds number, Hartmann number, and Prandtl number on heat transfer and fluid flow and bridging the knowledge gap by systematically examining computational results and statistical interpretations. Few works provide a detailed comparative analysis of buoyancy effects across various geometrical and physical parameters. Existing studies primarily focus on qualitative and computational results without integrating statistical methodologies to analyze trends and correlations. The governing equations are rendered dimensionless and numerically solved using the finite element method (FEM). The grid test and code validation criteria are established to ensure accurate solution convergence. The numerical results, presented visually for various dimensionless parameters, encompass heat transfer distributions, temperature, and velocity. At <em>Re</em> = 200, the heat transfer rate is 28.16 % greater than at <em>Re</em> = 50. At <em>Ha</em> = 50, it is 2.34 % lower than at <em>Ha</em> = 0. Furthermore, this study yields novel linear regression equations, ANOVA analysis, and predicted and residual values that are represented numerically and graphically. Based on R-squared values of 0.9523 for each, the heat transfer rates the Statistic linear regression algorithm achieves are extraordinarily high. This analysis is crucial for optimizing design parameters, improving energy efficiency, and enhancing thermal performance in real-world applications such as energy storage systems, electronics cooling, HVAC systems, renewable energy, and industrial processes.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"164 ","pages":"Article 108843"},"PeriodicalIF":6.4,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143619397","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}
Liang Liu , Le Liu , Ying Xu , Yan Li , Hui Han , Yuxing Li , Jianlu Zhu
{"title":"Theoretical and experimental study of the heterogeneous bubble nucleation in boiling of pure liquids and binary mixtures based on Gibbs free energy analysis and heated surface characteristics","authors":"Liang Liu , Le Liu , Ying Xu , Yan Li , Hui Han , Yuxing Li , Jianlu Zhu","doi":"10.1016/j.icheatmasstransfer.2025.108844","DOIUrl":"10.1016/j.icheatmasstransfer.2025.108844","url":null,"abstract":"<div><div>The onset of nucleate boiling (ONB) conditions significantly impact the performance of boiling heat transfer. Predicting and optimizing these conditions is crucial in various industrial applications. In this paper, the nucleation critical conditions for the heterogeneous boiling nucleation of both pure liquids and mixed liquids are established based on the stricter critical nucleation criterion of dΔ<em>G</em><sup>hetero</sup>/d<em>r</em> = 0. Additionally, a computation approach for predicting the ONB conditions of heterogeneous boiling in non-visible situations is developed by considering the characteristics of heated surface morphology and heat transfer. An experimental setup is constructed to validate the computational method by measuring the ONB superheat and heat flux of pure liquid and binary mixtures. The results demonstrate that the error between the model calculations and experimental values is within the range of ±20 %. Moreover, insights into the control mechanism of regular cavity surfaces on ONB conditions and nucleation sites are obtained, leading to the development of techniques for manipulating surface conditions to optimize the ONB. The findings reveal that as the wall superheat increases, the surface with regular micro-cavities shows a significantly lower transient change in nucleation density.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"164 ","pages":"Article 108844"},"PeriodicalIF":6.4,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143611017","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}