Fluid Dynamics最新文献

Three-Dimensional Simulation of Drop-on-Drop Impact: Coaxial and Offset Dynamics 落对落碰撞的三维模拟：同轴和偏移动力学

IF 1 4区工程技术

Fluid Dynamics Pub Date : 2025-05-12 DOI: 10.1134/S0015462824604881

Umesh, N. K. Singh

引用次数: 0

Performance Analysis of Hybrid Vertical Axis Wind Turbine in Low Wind Velocity Regions Using CFD 基于CFD的低风速区混合垂直轴风力机性能分析

IF 1 4区工程技术

Fluid Dynamics Pub Date : 2025-05-12 DOI: 10.1134/S0015462824604455

S. Roga, J. S. Bhausaheb, A. R. Sengupta

{"title":"Performance Analysis of Hybrid Vertical Axis Wind Turbine in Low Wind Velocity Regions Using CFD","authors":"S. Roga, J. S. Bhausaheb, A. R. Sengupta","doi":"10.1134/S0015462824604455","DOIUrl":"10.1134/S0015462824604455","url":null,"abstract":"There is a significant contribution of the wind energy to total renewable energy consumption. In vertical axis wind turbines (VAWTs), most of the experimental works are done on the Darrieus VAWT or Savonius VAWT alone. However, the experimental results cannot capture all the aerodynamic characteristics of the turbine. Therefore, computational analysis is the most powerful tool for reducing the time and cost of experimental analysis in this type of research. Recently, research on hybrid wind turbines is attaining popularity because such coaxial arrangements exhibit the improved efficiency and the better self-starting capability as compared to individual Darrieus or Savonius turbines. In this present study, firstly, a wind dataset was collected for different seasons and heights (above ground level) to get the average wind speed as an inlet boundary condition. Then two-dimensional simulation was performed on the considered hybrid VAWT using ANSYS Fluent. The steady analysis shows that the static torque is low at 90° azimuthal angle for the hybrid VAWT at different heights in all cases. For various tip speed ratios, flow visualization through a hybrid turbine showed that vortex generation is lower at the high tip speed ratio (TSR) as compared to the low TSR. At TSR = 2.5, all attachment angles achieve the highest power coefficients, which decline with increase in the attachment angles. Among all the operating conditions, the TSR = 2.5 and the 0° attachment angle revealed the optimal power coefficient value of 0.33.","PeriodicalId":560,"journal":{"name":"Fluid Dynamics","volume":"60 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143938374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Gas-Droplet Turbulent Jets with Phase Transitions and Droplet Collisions 具有相变和液滴碰撞的气滴湍流射流

IF 1 4区工程技术

Fluid Dynamics Pub Date : 2025-05-12 DOI: 10.1134/S0015462824603437

Yu. V. Zuev

引用次数: 0

Diffraction of Oblique Surface Waves by an Ice Cover in the Presence of a Current with Velocity Shear 有速度切变的水流存在时，冰盖对斜面波的衍射

IF 1 4区工程技术

Fluid Dynamics Pub Date : 2025-05-12 DOI: 10.1134/S0015462824604303

L. A. Tkacheva

引用次数: 0

Influence of the Mach Number on the Flow Field and Acoustics of a Supersonic Jet with Tabs 马赫数对带翼片超音速射流流场和声学的影响

IF 1 4区工程技术

Fluid Dynamics Pub Date : 2025-05-12 DOI: 10.1134/S0015462824604741

S. R. Lavala, S. Das

引用次数: 0

Simulation and Experimental Study on Droplet Impact Rebound Behavior on Stainless Steel Surface 不锈钢表面液滴冲击回弹行为的模拟与实验研究

IF 1 4区工程技术

Fluid Dynamics Pub Date : 2025-05-12 DOI: 10.1134/S0015462824605497

L. Yang, T. Y. Zhou, X. Y. Zhang

{"title":"Simulation and Experimental Study on Droplet Impact Rebound Behavior on Stainless Steel Surface","authors":"L. Yang, T. Y. Zhou, X. Y. Zhang","doi":"10.1134/S0015462824605497","DOIUrl":"10.1134/S0015462824605497","url":null,"abstract":"The droplet impact rebound behavior is one of the most direct ways to study the hydrophobicity of materials. Different from the previous study, a series of groove structures with the same groove to the column ratio and the column height but various width sizes were constructed on the 316L stainless steel surface. The volume of fluid (VOF) method and experiments were used to observe the morphological evolution process of droplets impacting on the surface of this series of 316L stainless steel grooves at the same speed. The simulation and experimental data reveal that the grooved structure on 316L stainless steel surfaces markedly enhances the rebound coefficient of droplets and diminishes the spreading coefficient as compared to the smooth surface. The maximum rebound coefficient of the groove structure surface with the width of 100 μm increased the most by 2.093, the maximum spreading coefficient of the groove structure surface with a width of 200 μm decreased the best by 0.805, indicating that the establishment of groove structures significantly improves hydrophobicity. At the same time, as the groove width increases from 50 to 300 μm, the wetting state of droplets on the stainless steel groove surface gradually changes from the Cassie Baxter state to the Wenzel state, and the rebound coefficient decreases with transformation of the wetting state, but the spreading coefficient is not affected transformation of the wetting state.","PeriodicalId":560,"journal":{"name":"Fluid Dynamics","volume":"60 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143938378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Thermal Effect on Dynamic Evolution of Cavitation Flows through a Cryogenic Butterfly Valve 低温蝶阀内空化流动动态演化的热效应

IF 1 4区工程技术

Fluid Dynamics Pub Date : 2025-05-12 DOI: 10.1134/S0015462824604418

G. Zhang, K. Wang, W. W. Wang, D. S. Chen, Z. Lin

{"title":"Thermal Effect on Dynamic Evolution of Cavitation Flows through a Cryogenic Butterfly Valve","authors":"G. Zhang, K. Wang, W. W. Wang, D. S. Chen, Z. Lin","doi":"10.1134/S0015462824604418","DOIUrl":"10.1134/S0015462824604418","url":null,"abstract":"In cryogenic butterfly valves, the obstruction caused by the valve core leads to the localized pressure drop in flow of cryogenic media. This cavitation phenomenon is induced when the localized pressure of the cryogenic medium falls below the saturation vapor pressure corresponding to the local temperature. In comparison to the fluid medium with normal temperature, the thermal sensitivity of cryogenic media affects the precision of the numerical simulations for cavitation flow fields at cryogenic conditions when employing conventional cavitation models. In this study, the traditional Zwart–Gerber–Belamri (ZGB) cavitation model is modified by considering the thermal effect of cryogenic medium. A modified cavitation model is obtained to accurately predict cryogenic cavitation flows and verified by experimental results. By utilizing the modified cavitation model and large eddy simulation model, the cavitation flow field and the cavitation evolution of liquid nitrogen through a cryogenic butterfly valve was studied at various temperatures and the valve opening degree of 80%. Using the ω-criterion, the spatial and temporal correlations between the cavitation and vortex structures are discussed and analyzed in detail.","PeriodicalId":560,"journal":{"name":"Fluid Dynamics","volume":"60 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143938613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Numerical Study of the Turbulent Boundary Layer with an Adverse Pressure Gradient in Compressible Gas Flow 可压缩气体流动中具有逆压梯度的湍流边界层数值研究

IF 1 4区工程技术

Fluid Dynamics Pub Date : 2025-05-08 DOI: 10.1134/S0015462824604583

V. G. Lushchik, S. S. Popovich

引用次数: 0

Numerical Analysis of Gas–Liquid Flow Characteristics in Annular Microreactors 环形微反应器内气液流动特性的数值分析

IF 1 4区工程技术

Fluid Dynamics Pub Date : 2025-05-08 DOI: 10.1134/S001546282460439X

J. Y. Bai, P. Yan, H. B. Jin, S. H. Yang, G. X. He, L. Ma

引用次数: 0

Investigations on a Supersonic Combustor with Ramps and Cavities for Sustained Combustion 具有持续燃烧的斜腔超音速燃烧室的研究

IF 1 4区工程技术

Fluid Dynamics Pub Date : 2025-05-08 DOI: 10.1134/S0015462824605436

G. Amba Prasad Rao, J.V.S. Moorthy

{"title":"Investigations on a Supersonic Combustor with Ramps and Cavities for Sustained Combustion","authors":"G. Amba Prasad Rao, J.V.S. Moorthy","doi":"10.1134/S0015462824605436","DOIUrl":"10.1134/S0015462824605436","url":null,"abstract":"The ignition process in supersonic flows is complex, influenced by the fuel ratios, design, and flow conditions. The cavity combustors stabilize regions for ignition, whereas ramps aid in mixing fuel and air. The shock waves generated by these ramps interact with the fuel stream, enhancing micro-mixing and creating recirculation zones to improve fuel-air mixing. In supersonic flow, these vortices contribute to macro-mixing, while the interaction between shocks and the fuel stream generates boroclinic torque at the air-fuel interface, further improving micromixing. A full-scale experimental combustor facility is designed and tests are done on a supersonic combustor incorporated with ramps and cavities, using aviation kerosene. The combustor wall pressures and temperatures are obtained using the instrumentation. Numerical studies examined the effects of the Mach number on flow. ANSYS-based simulations revealed that the combustor configuration and the Mach number play a vital role. It is inferred that a staged injection improves mixing and thrust. At a combustor entry Mach number equal to 2, in the diverging section the static pressures initially rise, then decrease with time, indicating supersonic combustion, with a wall pressure increase of about 1.3 bar the exit static pressures rise to equalize with ambient conditions. The adopted strategies resulted in sustained supersonic combustion.","PeriodicalId":560,"journal":{"name":"Fluid Dynamics","volume":"60 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143925660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0