Fluid Dynamics最新文献_第4页

Numerical Modeling of Unsteady Oil Leakage from a Damaged Reservoir into the Water 受损油藏非定常漏油入水数值模拟

IF 0.6 4区工程技术

Fluid Dynamics Pub Date : 2025-07-30 DOI: 10.1134/S0015462824604480

I. V. Morenko

引用次数: 0

Study on the Mechanism of Unsteady Plasma Actuation to Control Trailing-Edge Vortex Shedding for Turbine Blades 非定常等离子体驱动控制涡轮叶片尾缘涡脱落机理研究

IF 0.6 4区工程技术

Fluid Dynamics Pub Date : 2025-07-30 DOI: 10.1134/S0015462824605527

J. Y. Yu, W. X. Xie, Y. N. Zhang, Q. L. He, F. Chen

{"title":"Study on the Mechanism of Unsteady Plasma Actuation to Control Trailing-Edge Vortex Shedding for Turbine Blades","authors":"J. Y. Yu, W. X. Xie, Y. N. Zhang, Q. L. He, F. Chen","doi":"10.1134/S0015462824605527","DOIUrl":"10.1134/S0015462824605527","url":null,"abstract":"This study is aimed to investigate the control of the mechanism of unsteady dielectric barrier discharge (DBD) plasma actuation in flow separation of turbine blades and vortex shedding at the trailing edge, as well as the impact of excitation frequency on the control effectiveness. For the T106A turbine blades, the large eddy simulation (LES) method was used to analyze the evolution pattern of the flow field structure under the unsteady plasma actuation. Primary flow patterns and their interactions were identified through the proper orthogonal decomposition (POD) method. The induced vortex structures generated by plasma actuation are coupled with the vortex structures at the trailing edge, which significantly weakens the intensity of vortex structures, leading to a notable improvement in the spatiotemporal structure of the flow field. Simultaneously, plasma actuation enhances the momentum of low-energy fluid, stimulates large-scale turbulent fluctuations in the flow field, and suppresses irregular small-scale turbulent fluctuations. When the excitation frequency is set at the level of 0.8, the induced flow field exhibits better coupling with the vortex structures near the trailing edge. The total pressure loss coefficient diminishes by 20.96%. As the frequency increases, the improvement on flow control effect is not obvious and the wake loss can increase slightly.","PeriodicalId":560,"journal":{"name":"Fluid Dynamics","volume":"60 2","pages":""},"PeriodicalIF":0.6,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145171477","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

Morphlight Theory Inspired by Raptor: Flexible Effects of Flight Feather on Bionic Airfoil Aerodynamic Performances of Aquila Chrysaetos 受猛禽启发的变形光理论：飞行羽毛对金凤蝶仿生翼型气动性能的柔性影响

IF 0.6 4区工程技术

Fluid Dynamics Pub Date : 2025-07-30 DOI: 10.1134/S0015462824605357

D. Tang, Y. Liu, K. Chen, Y. B. Dai, Y. B. Zhao, K. P. Wang, C. B. Zheng, D. L. Yu

{"title":"Morphlight Theory Inspired by Raptor: Flexible Effects of Flight Feather on Bionic Airfoil Aerodynamic Performances of Aquila Chrysaetos","authors":"D. Tang, Y. Liu, K. Chen, Y. B. Dai, Y. B. Zhao, K. P. Wang, C. B. Zheng, D. L. Yu","doi":"10.1134/S0015462824605357","DOIUrl":"10.1134/S0015462824605357","url":null,"abstract":"The flight feather of Aquila Chrysaetos has large flexibility and usually deforms greatly during wing beating, which changes the aerodynamic performances of Aquila Chrysaetos dramatically. However, the flexible effects of flight feather on airfoil aerodynamic performances have not yet been fully conducted, nor the aeroelastic model of flexible feather ever been built. In the current study, the geometry of a wing section with a secondary flight feather of Aquila Chrysaetos was scanned using the tracking laser scanning system to establish the bionic airfoil. The flexibility of the flight feather was measured to obtain the nonlinear beam model. The radial basis function (RBF) mesh motion approach was adopted to dynamically generate the feather mesh with large deformations at each iteration. Thereafter, an aeroelastic approach was established by coupling the CFD method and the structural dynamic systems (CSD) method. In the method, airfoil aerodynamic forces were predicted by the CFD method followed by feather deformation calculations based on the CSD method, and the data was transferred via a fluid-structure interaction interface developed using the multi-point constraint (MPC) approach. Aeroelastic performances of the bionic airfoil with a flexible feather undergoing elastic deformation were simulated by the method proposed. Results showed that feather flexibility has a great influence on aerodynamics. Obtained flexible feather effects and flow mechanisms could be an inspiration for future aircraft design.","PeriodicalId":560,"journal":{"name":"Fluid Dynamics","volume":"60 2","pages":""},"PeriodicalIF":0.6,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145171478","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

Design and Aerodynamic Optimization of a Reusable Flight Vehicle Based on Divided Free-Form Deformation Parametric Modelling and Bayesian Optimization 基于分形自由变形参数建模和贝叶斯优化的可重复使用飞行器设计与气动优化

IF 0.6 4区工程技术

Fluid Dynamics Pub Date : 2025-07-30 DOI: 10.1134/S0015462825600142

D. Y. Xu, W. Huang, Z. Y. Guo, Y. Shen, H. Zhang, J. X. Leng

{"title":"Design and Aerodynamic Optimization of a Reusable Flight Vehicle Based on Divided Free-Form Deformation Parametric Modelling and Bayesian Optimization","authors":"D. Y. Xu, W. Huang, Z. Y. Guo, Y. Shen, H. Zhang, J. X. Leng","doi":"10.1134/S0015462825600142","DOIUrl":"10.1134/S0015462825600142","url":null,"abstract":"The integrated design is of vital importance to the high-speed vehicle due to appropriate aerodynamic configuration under high-speed conditions. Especially, the blended wing body (BWB) design for integration pays great attention to the constraints of various geometric components. The free-form deformation (FFD) parameterization is wildly applied in the aerodynamic shape design as it can effectively control the variation in airfoils and reflect the transition effect of the wing-body fusion area, but take disadvantages on setting constraints for global deformation. In this study, a divided FFD parameterization that clearly distinguishes between the wing, the wing-body fusion and the fuselage in integrated design while maintaining geometric continuity is proposed. This clear definition helps to optimize the aerodynamic performance of each component while ensuring the overall design coherence and consistency. The parameterization proposed is applied to aerodynamic optimization under multiple flight conditions. A comparative analysis reveals that our method can effectively output the reasonable configurations. The optimization uses Bayesian optimization, with 50 iterations, and achieves stability after about 10 iterations. After optimization, the constrained wing section retains the geometric feature of the original configuration design, while the wing-body fusion forms a geometric transition between the two components. The lift-to-drag ratio of the reusable flight vehicle improves significantly across multiple angles of attack at an average of 32.6%.","PeriodicalId":560,"journal":{"name":"Fluid Dynamics","volume":"60 2","pages":""},"PeriodicalIF":0.6,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145171724","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

Self-Oscillations in an Axisymmetric Generator of Pulsed Jets and High-Frequency Regime Associated with Cavity Boundary Instability 轴对称脉冲射流发生器中的自振荡和与腔边界不稳定性相关的高频区

IF 0.6 4区工程技术

Fluid Dynamics Pub Date : 2025-07-20 DOI: 10.1134/S0015462825600658

S. A. Ocheretyanyi, V. V. Prokof’ev, G. V. Topeitsev, E. V. Filatov

{"title":"Self-Oscillations in an Axisymmetric Generator of Pulsed Jets and High-Frequency Regime Associated with Cavity Boundary Instability","authors":"S. A. Ocheretyanyi, V. V. Prokof’ev, G. V. Topeitsev, E. V. Filatov","doi":"10.1134/S0015462825600658","DOIUrl":"10.1134/S0015462825600658","url":null,"abstract":"Liquid jet flows in the presence of a ventilated cavity with a negative cavitation number are investigated. The studies carried out in the Institute of Mechanics of Moscow State University show that under certain conditions cavitation-induced self-oscillations can occur in the hydraulic system with highly intense pressure fluctuations. The results of an investigation of the axisymmetric model of a pulsed jet generator with liquid jet outflow through a central orifice in a diaphragm and gas blow from the periphery beyond the diaphragm are presented. The two-phase medium outflow was realized through a convergent conical nozzle. The influence of the generator parameters and the distance to a wall (screen) on the efficiency of its operation is investigated. A narrow range of comparatively small blowing, in which high-frequency pressure oscillations are recorded, while the amplitude of impact pressure pulses on the screen is considerably higher than the amplitude of pulses in high-frequency generation regimes, is revealed. This flow regime can be due to the development of two-phase structures on the unstable jet boundary interactioning with the convergent nozzle walls. The evidence for the possible existence of this flow regime has been given by the solution of the plane problem of interaction between a finite jet and an inclined plate for different pressures on the jet surfaces. The problem was solved exactly using the methods of theory of functions of a complex variable for quasi-doubly-periodic theta functions.","PeriodicalId":560,"journal":{"name":"Fluid Dynamics","volume":"60 3","pages":""},"PeriodicalIF":0.6,"publicationDate":"2025-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145167195","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

On Self-Similarity of Laminar Jets 关于层流射流的自相似性

IF 0.6 4区工程技术

Fluid Dynamics Pub Date : 2025-07-20 DOI: 10.1134/S0015462825600683

A. M. Gaifullin, A. S. Shcheglov