International Journal of Heat and Fluid Flow最新文献

{"title":"Review of particle deposition on aeroengine turbine blades and its mitigation","authors":"Guangfu Bin ,&nbsp;Pingping Yang ,&nbsp;Jian Li ,&nbsp;Chao Li ,&nbsp;Weihao Zhang ,&nbsp;Haiyan Miao ,&nbsp;Fengshou Gu","doi":"10.1016/j.ijheatfluidflow.2025.110023","DOIUrl":"10.1016/j.ijheatfluidflow.2025.110023","url":null,"abstract":"<div><div>When aeroengines operate in harsh environments — such as deserts, dust storms, and marine regions— solid particles from the external environment are carried by the airflow into the turbine, where they are heated and deposit on the turbine blades. Additionally, solid particles produced during fuel combustion are also ingested into the turbine and accumulate on the blade surfaces. As these deposits build up over time on the blade surfaces, the turbine’s performance progressively deteriorates, consequently compromising the engine’s operational safety. In this review paper, we first examine the advantages and disadvantages of several typical deposition analysis models, including the critical velocity deposition model, critical viscosity deposition model, viscoelastic-plastic deposition model, and composite deposition model. Next, the effects of particle properties, inlet airflow conditions, blade characteristics, and cooling operation conditions on deposition patterns are summarized. Subsequently, the advantages and limitations of low-temperature, high-temperature, and actual deposition experiments are discussed, followed by analyzing the effects of particle deposition on turbine aerodynamic performance and cooling efficiency. Finally, the latest advancements in protective technologies, such as coatings and blade optimization, are explored. Based on the comprehensive review of the latest research progress, knowledge gaps are identified and potential future research directions are proposed. These findings provide practical references for the development of protection technologies and condition monitoring of turbine blades in aeroengines.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"117 ","pages":"Article 110023"},"PeriodicalIF":2.6,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144887467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 fin bendiness on heat transfer and flow dynamics in phase change material-based systems","authors":"Aman Kumar,&nbsp;Ambrish Maurya","doi":"10.1016/j.ijheatfluidflow.2025.110019","DOIUrl":"10.1016/j.ijheatfluidflow.2025.110019","url":null,"abstract":"<div><div>A phase change material-based system that can absorb and release energy is a crucial component in renewable energy applications. The performance of such a system can be improved by incorporating fins into the phase change material region of the system. Conventionally, the most common shape for these fins is straight and unbend. However, in this study, the impact of using wave-shaped bend fins has been explored instead of the unbend ones. Different cases have been analysed, with variations in their amplitude, which influences the degree of bendiness. For the considered cases, a transient analysis computer simulation model was developed and validated against published experimental data. Using this model, the charging and discharging processes of the PCM were analysed based on liquefied portion and temperature variation. The findings demonstrate that bend fins significantly enhance heat transfer and PCM flow dynamics. For the wave-shaped fin with the highest amplitude, the charging and discharging times were reduced by 35.55% and 37.82%, respectively, compared to straight unbend fins. The thermal-fluid behaviour of the material was further evaluated based on phase change time, as well as variations in temperature and velocity of the PCM at critical points (locations below the first and second peaks of the horizontally oriented wave-shaped bend fin). The results reveal that increased fin bendiness (higher amplitude of the wave-shaped fin) delays the initiation of phase change at these critical points. Additionally, PCM flow dynamics near critical points were significantly improved with bend fins.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"117 ","pages":"Article 110019"},"PeriodicalIF":2.6,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144887465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integral Conservation Physics-Informed Neural Networks with different network architectures for patient-specific aortic flow simulations","authors":"Youqiong Liu ,&nbsp;Li Cai ,&nbsp;Yaping Chen ,&nbsp;Jing Xue ,&nbsp;Wangwei He ,&nbsp;Wenxian Xie ,&nbsp;Jie Wei","doi":"10.1016/j.ijheatfluidflow.2025.110011","DOIUrl":"10.1016/j.ijheatfluidflow.2025.110011","url":null,"abstract":"<div><div>The numerical simulation of blood flow in the patient-specific thoracic aorta not only accurately reproduces personalized hemodynamic characteristics but also provides robust data support for the diagnosis and treatment of vascular diseases. This study advances the numerical simulation of blood flow in patient-specific thoracic aortas by extending our previously developed Integral Conservation Physics-Informed Neural Networks (ICPINNs) framework (Liu et al., 2025) from steady-state to transient flow problems. The ICPINNs method leverages the integral conservation form of the nonlinear Navier–Stokes equations, incorporating residual terms derived from both governing equations and training data, with Monte Carlo integration employed for integrals. We address two main classes of aortas: (1) unsupervised learning for anomalous branching of the aorta, and (2) integration of sparse velocity measurements for geometrically complex healthy and pathological full thoracic aortas. Furthermore, we conduct the first systematic comparison of different neural network architectures for real-world transient aortic flows, assessing their computational efficiency and accuracy against conventional numerical solutions. Numerical results demonstrate that fully-connected neural networks within the ICPINNs framework achieves optimal performance for healthy aortas, while more sophisticated architectures such as the Deep Galerkin Method prove superior for modeling complex pathologies like Marfan syndrome-associated aneurysms, despite increased computational costs. This work represents an important step toward personalized hemodynamic modeling, offering clinically relevant insights that could enhance diagnostic precision and therapeutic planning for cardiovascular diseases.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"117 ","pages":"Article 110011"},"PeriodicalIF":2.6,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144880189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-scale analyses of flow separation around rectangular prisms in uniform flow","authors":"Sedem Kumahor ,&nbsp;Xingjun Fang ,&nbsp;Robert J. Martinuzzi ,&nbsp;Mark F. Tachie","doi":"10.1016/j.ijheatfluidflow.2025.110012","DOIUrl":"10.1016/j.ijheatfluidflow.2025.110012","url":null,"abstract":"<div><div>Turbulent flows around infinitely spanned rectangular prisms in uniform flow with streamwise aspect ratios, AR = 1, 2, and 3 were studied using time-resolved particle image velocimetry (TR-PIV) at a Reynolds number of 16,200 based on free-stream velocity and prism height. These aspect ratios span regimes that transition from direct shear layer shedding in the wake (AR1) to intermittent reattachment (AR2) and mean reattachment on the prism surface (AR3). The mean flow topology, Reynolds shear stress, and turbulent transport were analyzed. Spatiotemporal characteristics were investigated using two-point correlation, integral time scales, reverse flow areas, and proper orthogonal decomposition (POD) of the vorticity field. The results reveal non-monotonic variations of statistical and structural characteristics with aspect ratio. The case of AR2 possesses the largest recirculation region as well as the largest spatial and temporal scales of coherent structures. The wake exhibits quasi-periodic fluctuations concentrated in a single frequency for AR1, and AR3 but dual frequencies for AR2. The POD of the vorticity effectively decomposed a wide range of scales. Depending on the aspect ratio, spectra of the POD coefficients revealed concentrated spectral energy at the dominant vortex shedding frequency, its harmonics and at Kelvin-Helmholtz instability frequencies associated with small-scale vortices near the leading edge.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"117 ","pages":"Article 110012"},"PeriodicalIF":2.6,"publicationDate":"2025-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144863281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Data-driven flow instability analysis methods for oblique T-S waves in supersonic boundary layers using CNNs and MLPs","authors":"Lei Qiao ,&nbsp;Xi Jiang ,&nbsp;Jiakun Fan ,&nbsp;Yutian Wang ,&nbsp;Lu Xie ,&nbsp;Ningjuan Dong ,&nbsp;Jiakuan Xu ,&nbsp;Junqiang Bai","doi":"10.1016/j.ijheatfluidflow.2025.110010","DOIUrl":"10.1016/j.ijheatfluidflow.2025.110010","url":null,"abstract":"<div><div>Oblique Tollmien-Schlichting (T-S) wave instability is one of the most critical flow instability types in supersonic boundary layers. However, traditional linear stability theory (LST) analysis requires calculating the second derivatives of velocity and temperature profiles along the wall-normal direction in body-fitted orthogonal coordinate systems, guessing initial eigenvalues, and solving eigenvalue problems, which is cumbersome and hinders its engineering applications. To address these issues, this paper introduces convolutional neural networks (CNNs) and multilayer perceptrons (MLPs) to replace the traditional eigenvalue-solving process through different technical routes. The former constructs training samples for CNNs using similarity solutions of laminar boundary layers in LST analysis to predict eigenvalues of different oblique T-S waves, while the latter uses artificially constructed non-similarity solutions of laminar boundary layers in LST analysis to generate training data for MLPs to predict the envelope of the most unstable amplification factors. Validated through numerous cases with varying Reynolds numbers, Mach numbers, and airfoils (i.e., altering pressure gradients), both models achieve satisfactory predictions of perturbation amplification factors. Notably, the proposed neural network models require only one-time training and can be reused infinitely without retraining. The study also reveals that using similarity solutions of laminar boundary layers as training samples leads to significant deviations in predicting amplification factor envelopes and results in limited generality. These findings provide efficient data-driven alternatives for supersonic boundary layer transition prediction, promoting the engineering application of linear stability theory in complex flow scenarios while clarifying the applicability boundaries of different technical approaches.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"117 ","pages":"Article 110010"},"PeriodicalIF":2.6,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144860508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Upstream history quantification and scale-decomposed energy analysis for weak-to-strong adverse-pressure-gradient turbulent boundary layers","authors":"Atharva Mahajan ,&nbsp;Rahul Deshpande ,&nbsp;Taygun R. Gungor ,&nbsp;Yvan Maciel ,&nbsp;Ricardo Vinuesa","doi":"10.1016/j.ijheatfluidflow.2025.110004","DOIUrl":"10.1016/j.ijheatfluidflow.2025.110004","url":null,"abstract":"&lt;div&gt;&lt;div&gt;The present study delineates the effects of pressure gradient history and local disequilibration on the small and large-scale energy in turbulent boundary layers (TBLs) imposed with a broad range of adverse-pressure-gradients (APG). This is made possible by analyzing four published high-fidelity APG TBL databases, which span weak to strong APGs and cover dynamic conditions ranging from near-equilibrium to strong disequilibrium. These databases enable the development of a methodology to understand the effects of PG history and local disequilibration, the latter defined here as the local streamwise rate of change of the pressure force contribution in the force balance. The influence of PG history on TBL statistics is quantified by the accumulated PG parameter (&lt;span&gt;&lt;math&gt;&lt;mover&gt;&lt;mrow&gt;&lt;mi&gt;β&lt;/mi&gt;&lt;/mrow&gt;&lt;mo&gt;¯&lt;/mo&gt;&lt;/mover&gt;&lt;/math&gt;&lt;/span&gt;), proposed previously by Vinuesa et al. (2017) to study integral quantities, which is compared here between cases at matched local PG strength (&lt;span&gt;&lt;math&gt;&lt;mi&gt;β&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt;), Reynolds number (&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;) and &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;d&lt;/mi&gt;&lt;mi&gt;β&lt;/mi&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mi&gt;d&lt;/mi&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; at nominally similar orders of magnitude. Here, &lt;span&gt;&lt;math&gt;&lt;mi&gt;β&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt; denotes a general umbrella term used for pressure gradient parameters that is estimated using different scaling parameters in this study. While the effects of local disequilibration (&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;d&lt;/mi&gt;&lt;mi&gt;β&lt;/mi&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mi&gt;d&lt;/mi&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;) are investigated by considering TBL cases at matched &lt;span&gt;&lt;math&gt;&lt;mi&gt;β&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt;, &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, and fairly matched &lt;span&gt;&lt;math&gt;&lt;mover&gt;&lt;mrow&gt;&lt;mi&gt;β&lt;/mi&gt;&lt;/mrow&gt;&lt;mo&gt;¯&lt;/mo&gt;&lt;/mover&gt;&lt;/math&gt;&lt;/span&gt;. This enables analysis of accumulated PG history and local disequilibration effects separately, where applicable, to highlight qualitative differences in statistical trends. It is found that &lt;span&gt;&lt;math&gt;&lt;mover&gt;&lt;mrow&gt;&lt;mi&gt;β&lt;/mi&gt;&lt;/mrow&gt;&lt;mo&gt;¯&lt;/mo&gt;&lt;/mover&gt;&lt;/math&gt;&lt;/span&gt; cannot unambiguously capture history effects when &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;d&lt;/mi&gt;&lt;mi&gt;β&lt;/mi&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mi&gt;d&lt;/mi&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; levels are significantly high, as it does not account for the delayed response of the mean flow and turbulence, nor the attenuation of the pressure gradient effect with distance. In two comparisons of APG TBLs under strong non-equilibrium, the values of &lt;span&gt;&lt;math&gt;&lt;mover&gt;&lt;mrow&gt;&lt;mi&gt;β&lt;/mi&gt;&lt;/mrow&gt;&lt;mo&gt;¯&lt;/mo&gt;&lt;/mover&gt;&lt;/math&gt;&lt;/span&gt; and &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;d&lt;/mi&gt;&lt;mi&gt;β&lt;/mi&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mi&gt;d&lt;/mi&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; expressed using Zagarola–Smits scaling were found to be consistent with the trends in mean velocity defect and Reynolds stresses noted previously for weak APG TBLs. While an increase in &lt;span&gt;&lt;math&gt;&lt;mover&gt;&lt;mrow&gt;&lt;mi&gt;β&lt;/mi&gt;&lt;/mrow&gt;&lt;mo&gt;¯&lt;/mo&gt;&lt;/mover&gt;&lt;/math&gt;&lt;/span&gt; is associated with energization of both the small and la","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"117 ","pages":"Article 110004"},"PeriodicalIF":2.6,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144860509","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 study on flow and heat transfer characteristics of supercritical carbon dioxide in 3D printed channels","authors":"Haohao Zhao,&nbsp;Xinyang Guo,&nbsp;Wencang Guo,&nbsp;Yuanao Yang,&nbsp;Xianliang Lei","doi":"10.1016/j.ijheatfluidflow.2025.110014","DOIUrl":"10.1016/j.ijheatfluidflow.2025.110014","url":null,"abstract":"<div><div>In the pursuit of higher heat transfer efficiency of microchannel heat exchangers in Supercritical carbon dioxide (sCO₂) Brayton cycle power generation system, the structure of microchannels is becoming increasingly complex. However, limited by the applicability of existing techniques such as chemical etching and diffusion bonding, these structures are difficult to manufacture. 3D printing manufacturing technology offers a significant promise for fabricating micro-scale and complex-structured channels. Unfortunately, the overall performance in 3D printed channels is still not quantitatively evaluated. In this study, straight circular channels fabricated using 3D printed SLM technology with an outer diameter of 6 mm and an inner diameter of 2 mm were fabricated. A systematic experimental study was conducted with a supercritical carbon dioxide flow and heat transfer test platform. Another straight channel made by conventional machining was tested and compared. It was found that the frictional and heat transfer coefficients in 3D printed is much higher than that in conventional machining channel, which is mainly effect by its large roughness height. In the liquid-like region, the Performance Evaluation Criterion (<em>PEC</em>) for 3D printed channel ranged from 1.67 to 2.52; in the pseudocritical region, the <em>PEC</em> ranged from 2.39 to 2.53; and in the gas-like region, the <em>PEC</em> ranged from 1.60 to 2.18. Based on the experimental data obtained, a new heat transfer predictive correlation for 3D printed channels on supercritical carbon dioxide was established. The deviation between predicted value and experiment data is within ± 20 % band.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"117 ","pages":"Article 110014"},"PeriodicalIF":2.6,"publicationDate":"2025-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144852278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 simulation of powder fuel mixing characteristics in supersonic circular combustion chamber","authors":"Wenxue Han ,&nbsp;Chunbo Hu ,&nbsp;Junjie Li ,&nbsp;Jiaxin Dong ,&nbsp;Rong Lei ,&nbsp;Chao Li","doi":"10.1016/j.ijheatfluidflow.2025.110002","DOIUrl":"10.1016/j.ijheatfluidflow.2025.110002","url":null,"abstract":"<div><div>To explore the combustion organization of a powder-fueled scramjets, a numerical investigation was conducted to analyze powder fuel mixing characteristics in supersonic combustors. This study systematically investigates particle-air mixing dynamics in a supersonic circular cavity-based combustor through parametric variations of injection positions and swirl angles. Subsequently, an innovative partially-covered cavity configuration is proposed, and its mixing efficiency is evaluated under different injection angles. Numerical simulations demonstrated that in leading-edge injection configurations, the transverse jet-induced bow shock caused deflection of the X-shaped shockwave system toward the injection port in the annular combustor. Comparatively, direct particle injection into the cavity recirculation zone enhanced particle residence time; For upper-wall injection configurations, particle residence time (τ) in exhibited a positive correlation with swirl injection angle(θ), reaching τ = 9 ms at θ = 90°; In partially-covered cavity configurations, swirl injection of fuel enhanced particle residence, with optimal performance achieved at Lc = 35 mm and θ = 60°, and the particle mixing degree reached about 0.8.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"117 ","pages":"Article 110002"},"PeriodicalIF":2.6,"publicationDate":"2025-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144842236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 comparative study of the performance of lattice structures embedded with phase change materials as thermal conductivity enhancers","authors":"Farzad Ghafoorian ,&nbsp;Mehdi Mehrpooya ,&nbsp;Mahmood Shafiee","doi":"10.1016/j.ijheatfluidflow.2025.110000","DOIUrl":"10.1016/j.ijheatfluidflow.2025.110000","url":null,"abstract":"<div><div>Phase Change Materials (PCMs) are increasingly recognized as a viable alternative for passive thermal management, serving as substitutes for traditional heat sinks due to their exceptional thermal properties, particularly their high latent heat capacity. However, their low thermal conductivity presents a significant challenge, specifically in the microgravity environment, where there is only thermal conduction heat transfer. To mitigate this issue, PCMs have been integrated with porous materials, such as open-cell metal foams, which act as Thermal Conductivity Enhancers (TCEs). Lattice structures have emerged as a promising alternative to conventional open-cellular metal foams as TCEs, offering a regularly organized periodic structure that facilitates improved manufacturing. This study investigates four PCM-embedded lattice sandwich panels: Simple, Octa, Octet, and V-cube structures, utilizing the Computational Fluid Dynamics (CFD) method. All these configurations are manufactured with the same total volume and strut diameter. However, considering the pore-scale characteristics of the lattice structures, it is observed that the Octa configuration has the highest porosity value, while the Simple configuration has the lowest. This results in the highest and lowest PCM ratios of 1.07 and unity, respectively. Consequently, these differences lead to the highest and lowest time-to-steady ratios of 1.35 and unity, respectively. The results indicate that the Simple structure achieved the highest PCM transition rate and energy ratio of unity, highlighting its significant capacity for energy absorption. Conversely, the Octa structure exhibited the lowest PCM transition rate and energy ratio of 0.79 and 0.89, respectively. However, the Octa structure demonstrated the highest PCM efficacy of 87%, compared to 73% for the Simple structure, as it has the highest PCM ratio. All structures significantly improve effective thermal conductivity compared to pure PCM. Specifically, the Octet exhibits an enhancement exceeding 27 times that of pure PCM, which is attributable to its surface-to-volume ratio being more than twofold of alternative configurations.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"117 ","pages":"Article 110000"},"PeriodicalIF":2.6,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144809406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 periodic heat source conditions on melting performance of composite phase change energy storage tank: A numerical optimization","authors":"Xinyu Huang ,&nbsp;Yuan Xie ,&nbsp;Jiayi Gao ,&nbsp;Xiaohu Yang ,&nbsp;Bengt Sundén","doi":"10.1016/j.ijheatfluidflow.2025.110007","DOIUrl":"10.1016/j.ijheatfluidflow.2025.110007","url":null,"abstract":"<div><div>To improve the low thermal conductivity challenge of phase change materials (PCM) in energy storage applications, this study introduces a composite thermal energy storage (TES) unit integrating PCM with water. Numerical simulations are employed to examine the influence of a fluctuating heat source on the heat charging dynamics of the unit. Results derived from Taguchi analysis indicate that increasing the amplitude, half-period, and initial temperature of the fluctuating heat source consistently reduces the melting time. The initial temperature exhibited the most significant effect on accelerating the charging process. Furthermore, elevating the amplitude and initial temperature led to a corresponding increase in the mean energy storage rate of the PCM while extending the half-period initially enhanced, then diminished, the mean energy storage rate. The optimal heat source parameters are identified as Case 4, characterized by an amplitude of 6.5 K, a half-period of 15 s, and an initial temperature of 352 K. Compared to the baseline heat source conditions, this configuration demonstrated a 33.7 % improvement in the mean energy storage rate within the PCM, a 48.9 % increase in water, and a 21.2 % reduction in charging time. These findings indicate that the heat source fluctuation has a significant influence on the energy storage process of the complex energy storage unit.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"117 ","pages":"Article 110007"},"PeriodicalIF":2.6,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144809529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}