International Journal of Heat and Fluid Flow最新文献

{"title":"New approach of the solution of physical fields of fluid dynamics: Physics-informed long short-term memory network","authors":"Zhiwei Li,&nbsp;Guihua Hu","doi":"10.1016/j.ijheatfluidflow.2025.110024","DOIUrl":"10.1016/j.ijheatfluidflow.2025.110024","url":null,"abstract":"<div><div>The essence of fluid dynamics problems is to solve the nonlinear partial differential equations (PDEs) of the system. Physics-informed neural networks (PINN) have shown significant advantages in solving nonlinear PDEs using a small number of samples. However, they have inherent limitations in capturing long-term dependencies in time series data, which limits the improvement of their predictive performance. To overcome those problems, this study proposes a novel hybrid model − physics-informed long short-term memory (PI-LSTM), which combines PINN with long short-term memory (LSTM) networks, significantly improving the prediction accuracy and model generalization ability of complex dynamic system behavior. The computational fluid dynamics (CFD) is used to obtain multiple physical field datasets at different time points under different operating conditions. PINN is employed to encode the physical constraints in depth, and obtain the internal physical laws of complex dynamic systems in high dimensions. LSTM is used to dynamically adjust the information flow through its dynamic memory controller, the collaborative update mechanism of memory encoder and state representation vector are used to deeply model the correlation across time steps. To enhance the physical consistency of the model, the control equations are embedded in the loss function in the form of a function as a regularization constraint term. Through the iterative learning process of Deep Neural Network (DNN), the network weight parameters are continuously optimized. The results of three numerical cases, i.e., the flow around the cylinder, Sandia flame D, and ethylene cracking furnace, show that the proposed PI-LSTM model improves the prediction accuracy by 57.27% and 56.22%, 55.88% and 58.23%, 56.56% and 65.39% compared to PINN and BI-LSTM, respectively. Compared with CFD methods, PI-LSTM has increased computational efficiency by 1440 times, while reducing storage space requirements by 99.62%. The proposed PI-LSTM model provides a solid technical support for the design and optimization of complex turbulent reaction coupling processes.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"117 ","pages":"Article 110024"},"PeriodicalIF":2.6,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144907088","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":"Inverse-cubic scaling of normalized static-pressure spatial variations in low-Reynolds-number air-film flows over suction-type floating stages","authors":"Hiroki Suzuki ,&nbsp;Hiroaki Oka ,&nbsp;Jun Fujiwara ,&nbsp;Toshinori Kouchi","doi":"10.1016/j.ijheatfluidflow.2025.110008","DOIUrl":"10.1016/j.ijheatfluidflow.2025.110008","url":null,"abstract":"&lt;div&gt;&lt;div&gt;This study investigates characteristics of flow kinetic energy and static pressure within a floating stage with suction holes using direct numerical simulation (DNS). The analysis targets situations where a thin film is floated and stabilized at a height of &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mn&gt;30&lt;/mn&gt;&lt;mtext&gt;–&lt;/mtext&gt;&lt;mn&gt;80&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mi&gt;μ&lt;/mi&gt;&lt;mi&gt;m&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; above the floating stage, reflecting practical applications. On this stage, jet inlets and suction holes are arranged in a grid pattern. A characteristic fundamental flow element is extracted and analyzed in this study. The flow is confirmed to be an incompressible flow governed by the continuum approximation, as evidenced by the Mach number and Knudsen number. Here, maximum Mach number: &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;mo&gt;.&lt;/mo&gt;&lt;mn&gt;17&lt;/mn&gt;&lt;mtext&gt;–&lt;/mtext&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;mo&gt;.&lt;/mo&gt;&lt;mn&gt;18&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; and Knudsen number range (for the levitation gaps of &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mn&gt;30&lt;/mn&gt;&lt;mtext&gt;–&lt;/mtext&gt;&lt;mn&gt;80&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mi&gt;μ&lt;/mi&gt;&lt;mi&gt;m&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;): &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;mo&gt;.&lt;/mo&gt;&lt;mn&gt;0009&lt;/mn&gt;&lt;mtext&gt;–&lt;/mtext&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;mo&gt;.&lt;/mo&gt;&lt;mn&gt;002&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, respectively. Meanwhile, the bulk Reynolds number indicates that the flow is within the applicability range of the Reynolds lubrication equation, allowing the use of governing equations that exclude inertial terms. Here, the bulk Reynolds numbers examined: 200, 50, and 12.5. Three key parameters are defined to characterize this flow: the ratio of the inlet radius to the suction hole radius &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;in&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;out&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, the non-dimensionalized floating height &lt;span&gt;&lt;math&gt;&lt;mi&gt;h&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt;, and the horizontal domain width of the fundamental flow element &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;L&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;x&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;. The DNS is performed using a validated computational code previously applied to direct numerical simulations of turbulent channel flows. The results are verified in terms of grid convergence and zero viscous divergence required by mass conservation. Subsequent analysis is then applied to elucidate the flow kinetic energy and static pressure characteristics. The results demonstrate that the steady-state values of the flow kinetic energy and the spatial root mean square (RMS) of the static pressure variation, normalized by their respective values at &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;h&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, are independent of &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;in&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;out&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; and &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;L&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;x&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;. These quantities are inversely proportional to &lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;h&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msu","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"117 ","pages":"Article 110008"},"PeriodicalIF":2.6,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144896081","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":"Partitioned design strategy-based topology optimization of manifold microchannels incorporating flow distribution characteristics: Fluidic and thermal performance analysis","authors":"Jianfei Zhang,&nbsp;Zhengyang Wang,&nbsp;Wenhao Li,&nbsp;Jing Meng,&nbsp;Zhiguo Qu","doi":"10.1016/j.ijheatfluidflow.2025.110009","DOIUrl":"10.1016/j.ijheatfluidflow.2025.110009","url":null,"abstract":"<div><div>Manifold microchannels exhibit excellent performance in electronic device thermal management. By incorporating topology optimization and designing enhanced heat transfer ribs within the channels, the cooling performance can be further improved. However, existing research on manifold microchannels topology optimization mainly focuses on individual channel based on the assumption of uniform flow distribution. Additionally, few studies have conducted topology optimization on the heated surface of manifold microchannels. This paper employs a partitioned strategy to conduct topology optimization on the heated surface of manifold microchannel heat sink considering the uneven flow distribution characteristics within individual channels. Based on a typical Z-type manifold microchannel, two topology-optimized rib structures were developed by employing average temperature minimization as the optimization objective under different pressure drop constraints. Subsequently, a comparison was performed between the topology-optimized structures and existing inline pin fin structures with geometrically optimized configuration. The study found that both topology-optimized manifold microchannels configurations outperformed the pin fins manifold microchannels in terms of overall performance, average temperature of the heated surface, temperature uniformity of the heated surface, thermal resistance, and pumping power consumption. Specifically, the temperature uniformity of the heated surface improved by an average of 12 % and 11.2 %, total thermal resistance decreased by 7.9 % and 6.7 % on average, and when the average temperature of the heated surface was maintained at 65 °C, the required pumping power was reduced by 12.4 % and 5.2 %, respectively. The performance evaluation criterion values of both topology-optimized structures are higher than the corresponding inline pin fin structures, reaching up to 1.52, demonstrating superior overall performance. This study provides a new perspective for the structural design of manifold microchannels flow passages.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"117 ","pages":"Article 110009"},"PeriodicalIF":2.6,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144892914","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":"Thermal analysis and performance optimization of supercritical carbon dioxide Brayton cycle based on ship waste heat","authors":"Junshuai Lv ,&nbsp;Yuwei Sun ,&nbsp;Chengqing Yuan ,&nbsp;Tianyang Qin ,&nbsp;Wenkang Ding ,&nbsp;Ruipeng Sun","doi":"10.1016/j.ijheatfluidflow.2025.110020","DOIUrl":"10.1016/j.ijheatfluidflow.2025.110020","url":null,"abstract":"<div><div>The global shipping industry is increasingly focused on energy conservation and emission reduction, driving the development of green technologies. Utilizing supercritical carbon dioxide (SCO₂) power generation to recover waste heat from marine engines has proven to be an effective approach to improve energy efficiency and reduce carbon emissions. In this study, waste heat from the main engine of a 9000 TEU container ship serves as the heat source for an SCO₂ power cycle incorporating a CO₂-propane (C₃H₈) binary mixture. A convolutional neural network (CNN) model was developed to predict system performance, using split ratio, mixing ratio, main compressor (MC) inlet temperature, and turbine inlet temperature as inputs. The results show that the determination coefficients R² of the model were 0.941 and 0.931 for the training set, while they were 0.922 and 0.912 for the test set. Multi-objective optimization based on response surface methodology (RSM) identified the optimal operating conditions as a split ratio of 0.39, mixing ratio of 14.2 %, MC inlet temperature of 34.17 °C, and turbine inlet temperature of 472.85 °C. Under these conditions, the SCO₂ system achieves a thermal efficiency of 25.81 % and an exergy efficiency of 41.55 %. These results demonstrate the significant potential of CO₂-C₃H₈ mixtures to enhance waste heat recovery in marine applications, contributing to cleaner and more efficient shipping energy systems.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"117 ","pages":"Article 110020"},"PeriodicalIF":2.6,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144892915","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":"An experimental study on three-dimensional icing characteristics of compressor blades in the low-temperature atmospheric environment","authors":"Yongpeng Ren,&nbsp;Xiaobin Liu,&nbsp;Xiaohu Chen,&nbsp;Zhongyi Wang,&nbsp;Haiou Sun","doi":"10.1016/j.ijheatfluidflow.2025.110026","DOIUrl":"10.1016/j.ijheatfluidflow.2025.110026","url":null,"abstract":"<div><div>Gas turbine blade icing is a significant issue that poses a serious threat to the safe operation of the equipment. Current research on three-dimensional blade icing has limitations that hinder the advancement of icing mechanisms and gas turbine design theories. This study combines a traditional wind tunnel with a low-temperature natural environment to obtain experimental data on the icing characteristics of three-dimensional compressor inlet guide vanes. A comparative analysis was conducted to examine the effects of environmental temperature and liquid water content on the blade icing shape, icing area, icing thickness, and icing limits. The experimental results show that ice accretion on the blades mainly concentrates on the leading edge, trailing edge, and pressure side. And the blade icing exhibits significant three-dimensional characteristics. In the spanwise direction, the total icing area rate of the blade exhibits a high-middle and low-end characteristic. In the chordwise direction, the icing thickness exhibits a trend of being thicker at the leading edge, gradually thinning along the pressure side, and increasing again at the trailing edge. When liquid water content is 2.75 g/m³, the maximum total icing area rate increases by approximately 114.05 % as the temperature decreases from −5.5 °C to −9.5 °C. When the temperature is −3°C, the maximum total icing area rate increases by approximately 9.41 % as liquid water content rises from 0.63 g/m³ to 0.99 g/m³. The research results can provide an experimental foundation for further studies on the icing mechanisms and anti-icing methods of compressor inlet guide vanes.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"117 ","pages":"Article 110026"},"PeriodicalIF":2.6,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144891903","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":"Performance enhancement of surface heat exchangers enabled by graphene aerogel based PCM array architectures","authors":"Zhixin Yang ,&nbsp;Kecheng Liang ,&nbsp;Zhilong Cheng ,&nbsp;Ting Ma ,&nbsp;Kai Chen ,&nbsp;Qiuwang Wang","doi":"10.1016/j.ijheatfluidflow.2025.110021","DOIUrl":"10.1016/j.ijheatfluidflow.2025.110021","url":null,"abstract":"<div><div>The compactness of the heat exchanger serves as a crucial factor, especially in vehicles. One method is to reject heat directly through the exposed area to the ambient air, known as a surface heat exchanger. However, the constraints imposed on the air side of the surface heat exchanger represent a significant impediment to the further enhancement of its thermal performance. A surface heat exchanger integrated with graphene aerogel/paraffin wax composite phase change materials (CPCMs) is proposed to eliminate the problem. This exploits the temperature-invariant characteristic of CPCMs during endothermic melting, increasing the average heat transfer temperature difference within the surface heat exchanger and serving as an additional heat sink. In this article, the benefits of using CPCMs are demonstrated and a detailed investigation is performed considering the effects of operating conditions and thermophysical properties of CPCMs. The obtained results demonstrate that surface heat exchangers incorporating CPCMs achieve a 14.60 % higher heat transfer rate compared to finned ones under an air convective heat transfer coefficient of 110 W·m⁻²·K⁻¹ and a liquid inlet velocity of 0.03 m·s⁻¹. It is further found that surface heat exchangers with CPCMs can meet the requirements of different operating conditions by modifying the thermal conductivity and latent heat of the CPCMs. Through a comprehensive analysis, the heat transfer per unit mass of the surface heat exchanger with CPCMs is 40.50 % higher than that of the base surface heat exchanger during the operation period of the CPCMs. Additionally, the operating period of CPCMs is 2.55 times longer than the recovery period.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"117 ","pages":"Article 110021"},"PeriodicalIF":2.6,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144887466","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":"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}