Fluid Dynamics最新文献

Effect of Sea Turtle Flexible Hydrofoil Flexibility and Kinematic Parameters on Hydrodynamic Performance 海龟柔性水翼柔韧性及运动学参数对水动力性能的影响

IF 0.6 4区工程技术

Fluid Dynamics Pub Date : 2025-10-07 DOI: 10.1134/S0015462825601640

H. Ding, H. P. Shi, Y. W. Zhu, H. P. Shen, Q. Gao, K. Chen

{"title":"Effect of Sea Turtle Flexible Hydrofoil Flexibility and Kinematic Parameters on Hydrodynamic Performance","authors":"H. Ding, H. P. Shi, Y. W. Zhu, H. P. Shen, Q. Gao, K. Chen","doi":"10.1134/S0015462825601640","DOIUrl":"10.1134/S0015462825601640","url":null,"abstract":"The patterns of motion of marine organisms provide a new method of propulsion for underwater vehicles, in which flapping foil propulsion is one of the more representative ones. The flexible flapping foil has better propulsion efficiency. The actual flapping foil motion is active and is passively deformed by water. However, numerical simulation is realized by setting up active deformations, making it difficult to accurately reproduce the real deformations. In the study, a pressure tester was used to measure the displacement of the flapping foil to fit the real deformation of the flapping foil, the motion of the sea turtle flapping foil is simplified to the pitching motion in a two-dimensional plane, and its kinematics is modeled. Furthermore, the effects of flexibility as well as kinematic parameters on the propulsive performance of the flapping foil were investigated by means of numerical simulation. The results show that proper flexibility (R = 0.12–0.16) is beneficial to the hydrodynamic performance of flexible foils, but too much flexibility adversely affects the propulsive performance. At a frequency of 1 Hz and an amplitude of 0.075 m, the flexibility that allows the flexible foil to achieve maximum efficiency is equal to 0.13. For the Reynolds number at 35 000 for a flapping foil, the R = 0.06 foil generates more propulsive force than the R = 0.08 foil when the Strouhal number St is smaller than 0.45. Conversely, the opposite is true. The application of these research results to the design of underwater vehicles can provide new ideas for the development of underwater vehicles.","PeriodicalId":560,"journal":{"name":"Fluid Dynamics","volume":"60 5","pages":""},"PeriodicalIF":0.6,"publicationDate":"2025-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145256580","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

Recent Developments in Unsteady Flow Characteristics over Spiked Blunt Bodies: A Survey 尖刺钝体非定常流动特性研究进展

IF 0.6 4区工程技术

Fluid Dynamics Pub Date : 2025-10-07 DOI: 10.1134/S0015462825601779

MD. G. Sarwar, D. Sahoo

引用次数: 0

Numerical Simulation and Experimental Study on the Influence of Aircraft Deicing Fluid Concentration on Wall-Flow Heat Transfer Characteristics under Multi-Ice Scenarios 多冰工况下飞机除冰液浓度对壁面换热特性影响的数值模拟与实验研究

IF 0.6 4区工程技术

Fluid Dynamics Pub Date : 2025-10-07 DOI: 10.1134/S0015462825601834

M. Gong, D. H. Yu, J. K. Lu, B. Chen

{"title":"Numerical Simulation and Experimental Study on the Influence of Aircraft Deicing Fluid Concentration on Wall-Flow Heat Transfer Characteristics under Multi-Ice Scenarios","authors":"M. Gong, D. H. Yu, J. K. Lu, B. Chen","doi":"10.1134/S0015462825601834","DOIUrl":"10.1134/S0015462825601834","url":null,"abstract":"To investigate the deicing fluid concentrations across diverse global winter regions under varying ice scenarios, this study establishes a numerical model for wall-flow heat transfer of aircraft deicing fluid, validates the model accuracy via experimental verification, examines the wall-flow heat transfer characteristics under various ice types and deicing fluid concentrations, and conducts comparative analysis of the flow field and temperature field variations across distinct parametric conditions. Results demonstrate that the differential impact of distinct ice-layer materials and deicing fluid concentrations on the wall velocity field ranges between 2.4 and 5.0%. For varied ice-layer materials, both frost ice and mixed ice achieve complete melting within 240 s, with the melting duration of frost ice being one-third that of mixed ice, glaze ice attains a melting area with a radius of approximately 65 cm. Deicing fluids at various concentrations reduce melting time by from 45 to 63% as compared to hot water at identical temperatures. The 30% concentration is optimum for small-scale ice removal due to its rapid deicing performance, while the 50% solution maintains effective deicing for large aircraft wings. The 70% formulation, with higher viscosity and lower freezing point, proves suitable for extreme cold-weather operations. These findings advance precision in deicing operations across diverse ice types, demonstrating significant potential for reducing melting duration and conserving deicing fluid consumption.","PeriodicalId":560,"journal":{"name":"Fluid Dynamics","volume":"60 5","pages":""},"PeriodicalIF":0.6,"publicationDate":"2025-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145256579","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

Analysis of Droplet Dynamics on Superhydrophobic Functional Surfaces 超疏水功能表面液滴动力学分析

IF 0.6 4区工程技术

Fluid Dynamics Pub Date : 2025-10-07 DOI: 10.1134/S0015462825601718

X. Y. Li, W. H. Li, Y. H. Qiu, X. F. Tang, Y. Wang, X. M. Yin, Y. W. Sun, Z. P. Zheng

{"title":"Analysis of Droplet Dynamics on Superhydrophobic Functional Surfaces","authors":"X. Y. Li, W. H. Li, Y. H. Qiu, X. F. Tang, Y. Wang, X. M. Yin, Y. W. Sun, Z. P. Zheng","doi":"10.1134/S0015462825601718","DOIUrl":"10.1134/S0015462825601718","url":null,"abstract":"This paper investigates the influence of key factors on droplet dynamics on superhydrophobic surfaces, providing theoretical guidance for their design and application. Using the fluid flow module of COMSOL Multiphysics, a two-dimensional simulation of droplet collision and coalescence–rebound was carried out on surfaces with various microstructures. The simulation results agreed well with experimental data, confirming the accuracy of the model. The study shows that as microstructural spacing increases, the solid–liquid contact area decreases, wall viscous dissipation reduces, and droplets retract and rebound more rapidly. The surface morphology, the contact angle, the droplet radius, and the initial kinetic energy strongly affect the dynamic behavior. During coalescence and bouncing, both the droplet radius and the microstructural morphology are decisive, while the higher initial velocity enhances rebound. Conversely, a smaller radii ratio between two droplets hinders detachment and may cause rebound deviation. Overall, six dominant factors were identified, namely, three related to the surface structure and three to the droplet properties. These findings establish a theoretical foundation for optimizing the design and functional application to superhydrophobic surfaces.","PeriodicalId":560,"journal":{"name":"Fluid Dynamics","volume":"60 5","pages":""},"PeriodicalIF":0.6,"publicationDate":"2025-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145256578","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

Large Eddy Simulation of Detonation Combustion and Combustion Efficiency of Liquid and Gaseous Fueled Pulse Detonation Combustors 液体和气体燃料脉冲爆轰燃烧室爆轰燃烧和燃烧效率的大涡模拟

IF 0.6 4区工程技术

Fluid Dynamics Pub Date : 2025-10-07 DOI: 10.1134/S0015462825601354

P. Debnath, K. M. Pandey

{"title":"Large Eddy Simulation of Detonation Combustion and Combustion Efficiency of Liquid and Gaseous Fueled Pulse Detonation Combustors","authors":"P. Debnath, K. M. Pandey","doi":"10.1134/S0015462825601354","DOIUrl":"10.1134/S0015462825601354","url":null,"abstract":"The numerical research work is carried out for the deflagration and detonation combustion process and pollution formation for a stoichiometric (ϕ = 1) mixture of zero carbon and a hydrocarbon fuel–air mixture in the pulse detonation combustor. Furthermore, the combustion efficiency also has been analyzed for hydrogen, kerosene and octane fuel–air mixtures inside the combustor. The SIMPLE algorithm with the finite volume discretization method is used for laminar finite rate chemistry with volumetric reaction in Ansys Fluent platform. The LES turbulence model is used to carry out calculations of the reliable and repeatable detonation wave in the pulse detonation combustor near thin boundary layer formed by the Shchelkin spiral. From the simulation, the detonation wave velocity of 2000 m/s and the reaction enthalpy of 71.4 MJ/kg are obtained for hydrogen–air combustion, which is higher as compared to those in kerosene and octane fuel–air combustion. The minimum pollutant number of 0.00000479 is obtained for hydrogen–air detonation and this magnitude is lower as compared to that for kerosene and octane–air combustion. Furthermore, the maximum combustion efficiency of 87% is obtained for hydrogen–air combustion in the detonation combustion process, which is comparatively higher than that for kerosene and octane fuel–air mixtures. Also, the combustion efficiency is more in detonation combustion for aforesaid liquid and gaseous fuel–air mixture combustion as compared to the deflagration combustion process.","PeriodicalId":560,"journal":{"name":"Fluid Dynamics","volume":"60 5","pages":""},"PeriodicalIF":0.6,"publicationDate":"2025-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145256655","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

Experimental Study on the Enhancement of Blowing Lift of a Near-Wave Water Wing 提高近波水翼吹升力的实验研究

IF 0.6 4区工程技术

Fluid Dynamics Pub Date : 2025-09-29 DOI: 10.1134/S0015462825600713

J. X. Pan, W. B. Wang, Y. Wang, X. Zhang, P. Shen, F. Tong

引用次数: 0

Vorticity Generation and Transport Characteristics in Flow around a Wall-Mounted Hemisphere and the Influence on Flow Structures 壁挂式半球绕流涡度的产生和输运特性及其对流动结构的影响

IF 0.6 4区工程技术

Fluid Dynamics Pub Date : 2025-09-29 DOI: 10.1134/S0015462825601123

X. Qiu, X. L. Zhang, Y. Fu, X. L. Xie, Y. Z. Tao, Y. L. Liu

{"title":"Vorticity Generation and Transport Characteristics in Flow around a Wall-Mounted Hemisphere and the Influence on Flow Structures","authors":"X. Qiu, X. L. Zhang, Y. Fu, X. L. Xie, Y. Z. Tao, Y. L. Liu","doi":"10.1134/S0015462825601123","DOIUrl":"10.1134/S0015462825601123","url":null,"abstract":"In this study, direct numerical simulation (DNS) is carried out to investigate flow around a wall-mounted hemisphere at a Reynolds number Re = 1000. The generation and transport characteristics of vorticity are analyzed based on the simulation results, deepening the understanding of the evolution mechanisms of vortex structures. The main flow features include near-wall recirculation vortices wrapping around the hemisphere, a large recirculation zone formed by flow separation at the apex, and hairpin vortices shedding downstream of the recirculation region along with several secondary vortical structures. From a vortex dynamics perspective, spanwise vorticity consistently dominates, contributing more than 60% to the total enstrophy. In the upstream recirculation vortices, spanwise vorticity is mainly amplified by stretching, while streamwise vorticity is generated through transfer from spanwise vorticity, manifested as spanwise stretching, spreading, and streamwise twisting of the recirculation structures. Vorticity generation occurs primarily on the windward face and upstream of the separation points due to fluid–surface interaction, followed by redistribution under the influence of surface curvature. In the near-wake evolution of arch vortices, strong transfer from wall-normal and spanwise vorticity to streamwise vorticity is identified as the key mechanism for the formation of hairpin vortices.","PeriodicalId":560,"journal":{"name":"Fluid Dynamics","volume":"60 5","pages":""},"PeriodicalIF":0.6,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145184177","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

Investigation of the Force Characteristics of a Cylinder in Internal Wave Environments with a Complex Topography 复杂地形内波环境中圆柱体受力特性研究

IF 0.6 4区工程技术

Fluid Dynamics Pub Date : 2025-09-29 DOI: 10.1134/S0015462825600919

H. Z. Lin, Y. Wang, Y. Liu, Z. Li, G. C. Li, C. H. Zhang

{"title":"Investigation of the Force Characteristics of a Cylinder in Internal Wave Environments with a Complex Topography","authors":"H. Z. Lin, Y. Wang, Y. Liu, Z. Li, G. C. Li, C. H. Zhang","doi":"10.1134/S0015462825600919","DOIUrl":"10.1134/S0015462825600919","url":null,"abstract":"The trapezoidal slope-coupled terrain model that comprises a trapezoidal obstacle and a two-layer slope based on the topography of guyots and gentle continental slope shelves in the South China Sea is proposed. The large eddy simulation (LES) technology is employed to investigate the propagation characteristics of internal waves (IWs) over complex terrain and their impact on cylindrical structures. The results indicate that complex terrain induces a multistage response in the forces exerted on the cylinder. As compared with the single-slope terrain, the trapezoidal slope terrain, influenced by the secondary bank slope terrain, transforms the force response from a single-negative peak stage to a double-negative peak stage, with the second-stage negative peak exceeding the first. The trapezoidal obstacle effectively weakens the impact of internal waves on the cylinder, particularly in the first stage, when it impedes the flow of the lower layer, thereby reducing the internal wave energy. In the second stage, influenced by the secondary slope terrain, internal waves undergo reflection and interact with trailing waves, leading to drastic changes in the flow field structure and a reversal of the force direction on the upper and lower parts of the cylinder. Furthermore, as wave amplitude increases, the weakening effect of the trapezoidal barrier becomes more pronounced, especially in the second stage.","PeriodicalId":560,"journal":{"name":"Fluid Dynamics","volume":"60 5","pages":""},"PeriodicalIF":0.6,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145184178","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

Aerodynamic Analysis of a Stagger Supersonic Biplane Airfoil with Leading Edge Flap 带前缘襟翼的错开超音速双翼型气动分析

IF 0.6 4区工程技术

Fluid Dynamics Pub Date : 2025-09-29 DOI: 10.1134/S0015462825601494

V. K. Patidar, MD. G. Sarwar, S. Joshi, D. Sahoo

引用次数: 0

Fast Response Implementation of Electroosmotic Stress Control Method in Microfluidic Chip 电渗透应力控制方法在微流控芯片上的快速响应实现

IF 0.6 4区工程技术

Fluid Dynamics Pub Date : 2025-09-29 DOI: 10.1134/S0015462825600361

Y. Li, M. S. Jin, X. Tang, K. L. Xie

{"title":"Fast Response Implementation of Electroosmotic Stress Control Method in Microfluidic Chip","authors":"Y. Li, M. S. Jin, X. Tang, K. L. Xie","doi":"10.1134/S0015462825600361","DOIUrl":"10.1134/S0015462825600361","url":null,"abstract":"Stress response hysteresis behavior exists in the stress controlling by the electroosmotic effect. In this study, the response of microfluidic chip is investigated by modeling a three-dimensional resistive network, and the evolution of a number of randomly distributed viscous particles in the Polydimethylsiloxane (PDMS) matrix is calculated demonstrating that the change in the conductance of the microfluidic chip is determined by the amount of tunneled particles of solution in the reservoir. Besides, when the interval of agglomerated particles is below the cutoff distance of 150.58 nm, it has a wide range of the relative resistance rate of change. Therefore, the high sensitivity of the microfluidic chip is effectively obtained by adding PDMS matrix material particles to the conductive liquid to fully fill the spacing of the agglomerated particles. Moreover, by comparing the sensitivity and hysteresis of conductive liquids containing different proportions of KCl, it is proved that the conductive liquid containing 2 mol % KCl has the higher sensitivity and the lower hysteresis. On this basis, the corresponding stress control process is analyzed. It is proved that the stress response characteristic of microfluidic chip is proportional to the control voltage. Moreover, under the control of voltage with continuous waveform, by overshooting the control voltage and advancing the phase by π/12, the phase compensation of the unknown time loss in the control method is carried out to ensure that the stress response hysteresis is reduced. When the phase difference between the character of stress output and the waveform of input voltage is within 0.5 s, the character of stress output has ideal and stable waveform characteristic. Therefore, this study realizes the fast response in the process of stress regulation by electroosmotic effect, which provides the technical support and innovative application for precise stress control by the electroosmotic effect.","PeriodicalId":560,"journal":{"name":"Fluid Dynamics","volume":"60 5","pages":""},"PeriodicalIF":0.6,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145184179","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