Fluid Dynamics最新文献_第2页

Novel Asymmetric Surrogate Design Approach and Analysis of Supersonic Nozzle 超声速喷管非对称替代设计新方法及分析

IF 0.6 4区工程技术

Fluid Dynamics Pub Date : 2026-04-12 DOI: 10.1134/S0015462825603286

L. Dai, A. Haddad, H. Kbab, L. C. Páscoa

{"title":"Novel Asymmetric Surrogate Design Approach and Analysis of Supersonic Nozzle","authors":"L. Dai, A. Haddad, H. Kbab, L. C. Páscoa","doi":"10.1134/S0015462825603286","DOIUrl":"10.1134/S0015462825603286","url":null,"abstract":"A hybrid design approach combining the method of characteristics (MoC) for initial axisymmetric nozzle design with a geometric transformation to create an asymmetric supersonic profile is developed. The resulting asymmetric flow field is analyzed by means of 3D CFD simulations using FVM ANSYS Fluent and the k–ω SST turbulence model, and is compared to FDM available solutions. A mesh sensitivity study confirming grid independence is performed. The results demonstrate a smooth supersonic expansion to the Mach number 1.4, with less than 5% pressure deviation from the MoC predictions, attributed to solver differences. Additionally, pressure gradients along the cross-sections decrease from 5% at the throat to 0.5% at the exit, confirming effective flow homogenization. It is also found that the axisymmetric nozzle outperformed the asymmetric wedge in the thrust coefficient (6% higher) and the mass flow (34% greater), but the wedge design shows superior pressure uniformity, advantageous for integrated airframes. The methodology provides a practical framework for preliminary asymmetric nozzle design, highlighting trade-offs between the thrust efficiency and the geometric adaptability.","PeriodicalId":560,"journal":{"name":"Fluid Dynamics","volume":"61 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2026-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147737297","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

Nonlinear Oscillations of a Mechanical System with Two Fluids in Motion of a Rigid Body 刚体两流体运动机械系统的非线性振动

IF 0.6 4区工程技术

Fluid Dynamics Pub Date : 2026-04-12 DOI: 10.1134/S0015462825604504

Win Ko Ko, A. N. Temnov

{"title":"Nonlinear Oscillations of a Mechanical System with Two Fluids in Motion of a Rigid Body","authors":"Win Ko Ko, A. N. Temnov","doi":"10.1134/S0015462825604504","DOIUrl":"10.1134/S0015462825604504","url":null,"abstract":"The mechanical model of a system with a spherical pendulum corresponding to nonlinear oscillations of the interface between two fluids, that completely occupy a cylindrical vessel, during translational and rotational motions of a rigid body, is considered. The amplitude–frequency characteristics are used to analyze and compare the behavior of the mechanical model with the real system in more detail. Numerical calculations of the linear and nonlinear coefficients of the equations that describe the translational and rotational motions of the rigid body at various depths of each of the fluids are also carried out. It is shown that when the direction cosines are taken as generalized coordinates that define the position of the spherical pendulum, then the equations of motion of the equivalent mechanical analog correspond to the dynamics equations for a rigid body with two fluids up to the second order of smallness. As a result, the amplitude–frequency characteristics and instability regions of forced vibrations of the interface between liquids with different densities and levels in a cylindrical vessel during translational and angular motions of the rigid body are constructed.","PeriodicalId":560,"journal":{"name":"Fluid Dynamics","volume":"61 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2026-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147737296","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

Generalization of the Viscous Stress Tensor to the Case of Non-Small Gradients of Hydrodynamic Velocity: Path to Numerical Modeling of Turbulence Non-Locality 粘性应力张量在流体动力速度非小梯度情况下的推广：湍流非局域性数值模拟途径

IF 0.6 4区工程技术

Fluid Dynamics Pub Date : 2026-04-12 DOI: 10.1134/S0015462826600239

A. B. Kukushkin

引用次数: 0

Stochastic Motion Model of an Adhered Droplet at the Edge of a Splashing Liquid Film 飞溅液膜边缘粘附液滴的随机运动模型

IF 0.6 4区工程技术

Fluid Dynamics Pub Date : 2026-04-12 DOI: 10.1134/S0015462825604413

D. X. Guo, H. Zhang

{"title":"Stochastic Motion Model of an Adhered Droplet at the Edge of a Splashing Liquid Film","authors":"D. X. Guo, H. Zhang","doi":"10.1134/S0015462825604413","DOIUrl":"10.1134/S0015462825604413","url":null,"abstract":"In the process of splashing induced by the impact of a spherical droplet on a wall, the characteristics of the motion of an adhered droplet at the liquid-film edge directly influence the velocity, the spatial distribution, and the size distribution of splashing droplets. Particularly, when the diameter of the adhered droplets falls within the submicron or micron range, they are subjected to numerous stochastic collision forces from surrounding air molecules, leading to a pronounced stochastic motion, which, in turn, affects the splashing process. To investigate the fundamental scientific question of the stochastic motion mechanism of the adhered droplet, a stochastic dynamics approach is adopted. Based on the Itô stochastic differential equation, a stochastic differential equation describing the motion of the adhered droplet is first formulated. Subsequently, an expression for the lift coefficient of the adhered droplet is proposed, and the diffusion coefficient is derived using the π theorem. Finally, a stochastic motion model for the adhered droplet at the liquid-film edge is established. The computational results indicate that the proposed stochastic motion model can accurately capture the stochastic behavior of the adhered droplet, and the model predictions agree well with experimental measurements, thereby validating the model.","PeriodicalId":560,"journal":{"name":"Fluid Dynamics","volume":"61 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2026-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147737298","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

Enhancement of Aerofoil Performance Using a Dual Injection System 使用双喷射系统提高翼型性能

IF 0.6 4区工程技术

Fluid Dynamics Pub Date : 2026-04-12 DOI: 10.1134/S0015462825602980

H. C. Mahajan, K. V. Gosai, K. A. Vasvani, K. Balaji, S. Jamkatel

引用次数: 0

Axisymmetric Ferrohydrodynamic Flows in Thrombosisted Blood Vessels 血栓形成血管中的轴对称铁流体动力学流动

IF 0.6 4区工程技术

Fluid Dynamics Pub Date : 2026-04-12 DOI: 10.1134/S0015462825602967

A. Yu. Musikhin, A. Yu. Zubarev

引用次数: 0

Analysis of the Suppressive Effect of Secondary Flow Circulation Configuration on Inlet Separation Zones 二次流循环构型对进口分离区的抑制效果分析

IF 0.6 4区工程技术

Fluid Dynamics Pub Date : 2026-03-19 DOI: 10.1134/S0015462825603973

Z. H. Li, Y. H. Tao, C. Y. Liu, W. Huang

{"title":"Analysis of the Suppressive Effect of Secondary Flow Circulation Configuration on Inlet Separation Zones","authors":"Z. H. Li, Y. H. Tao, C. Y. Liu, W. Huang","doi":"10.1134/S0015462825603973","DOIUrl":"10.1134/S0015462825603973","url":null,"abstract":"When a ramjet engine inlet operates under off-design conditions, the large-scale separation zone formed by the shock wave/boundary layer interaction significantly degrades engine performance, making separation control critically important. Based on a five-stage mixed-compression inlet designed for shock-on-lip condition under inviscid assumptions, six secondary flow circulation configurations with different locations for suction and blowing ports were designed. For comparison, two boundary layer suction configurations were also developed as baseline models. The numerical results demonstrate that under sub-rated conditions (M = 4), the suction port should be located away from the shoulder, while the blowing port should be positioned within the isolator. Comparing with the boundary layer suction method, the secondary flow circulation method increased the total pressure recovery coefficient by 11.00%, reduced the total pressure distortion index by 14.80%, and improved the mass flow coefficient by 1.75%. Under super-rated conditions (M = 8), the suction port should also be away from the shoulder, but the blowing port should be located on the first wedge. Compared with the boundary layer suction, the secondary flow circulation method resulted in a 6.59% decrease in the total pressure recovery coefficient. However, it reduced the total pressure distortion index by 4.24% and increased the mass flow coefficient by 0.98%. Furthermore, a feasible wide-speed-range flow control method with the use of the secondary flow circulation is proposed, offering a potential flow control strategy for enhancing the performance of ramjet inlets across a broad operational envelope.","PeriodicalId":560,"journal":{"name":"Fluid Dynamics","volume":"61 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2026-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147560312","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

Study on the Performance Enhancement of H-Type Blunt Trailing-Edge VAWTs with the Bionic V-Riblets Structure via External Control Bodies 外控制体增强仿生v纹结构h型钝尾缘vawt性能的研究

IF 0.6 4区工程技术

Fluid Dynamics Pub Date : 2026-03-19 DOI: 10.1134/S0015462825604267

X. Zhang, Y. L. Qi, J. T. Ruan, L. S. Cui, W. Li

{"title":"Study on the Performance Enhancement of H-Type Blunt Trailing-Edge VAWTs with the Bionic V-Riblets Structure via External Control Bodies","authors":"X. Zhang, Y. L. Qi, J. T. Ruan, L. S. Cui, W. Li","doi":"10.1134/S0015462825604267","DOIUrl":"10.1134/S0015462825604267","url":null,"abstract":"External control bodies can adjust the operational environment by changing the incoming wind speed and direction, and so are considered to enhance the aerodynamic performance of H-type vertical axis wind turbines (VAWTs) with V-riblets structure and blunt trailing-edge. For a single blunt trailing-edge wind wheel with the V-riblets structure, the effects of four control bodies at the longitudinal position with different shapes are first explored on the wind energy utilization and velocity distributions in wake region, and those of the lateral position and size of the control body with optimal shape are further analyzed on the wind energy utilization, velocity distributions in wake region, and flow characteristics. For wind turbines with interaction, the effects of the number and arrangement of control bodies with optimal shape and size are investigated on the velocity distributions and output characteristics. The results show that control bodies with different shapes improve the wind energy utilization, and the rectangular control body has the most significant effects. The wind energy utilization increases first and then decreases with the lateral distance between the control body and the wind turbine, and increases with the size of the rectangular control body. The number and arrangement of control bodies obviously change the interaction mechanism among wind turbines and the flow field, affecting the velocity distributions around wind wheels, thereby improving the overall output performance.","PeriodicalId":560,"journal":{"name":"Fluid Dynamics","volume":"61 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2026-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147560313","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

Anomalous Heat Transfer Enhancement for the Developed Laminar Channel Flow with a Single-row Array of Inclined Oval-trench Dimples with Variable Values of the Trench Length at the Fixed Dimple Depth and Spot Area 在固定凹窝深度和斑点面积下，单排倾斜椭圆凹窝阵列改变凹窝长度对发达层流通道的异常换热增强

IF 0.6 4区工程技术

Fluid Dynamics Pub Date : 2026-03-19 DOI: 10.1134/S0015462826600082

S. A. Isaev, M. S. Gritckevich, E. A. Osiuk, D. V. Nikushchenko, V. B. Kharchenko, Dehai Kong

{"title":"Anomalous Heat Transfer Enhancement for the Developed Laminar Channel Flow with a Single-row Array of Inclined Oval-trench Dimples with Variable Values of the Trench Length at the Fixed Dimple Depth and Spot Area","authors":"S. A. Isaev, M. S. Gritckevich, E. A. Osiuk, D. V. Nikushchenko, V. B. Kharchenko, Dehai Kong","doi":"10.1134/S0015462826600082","DOIUrl":"10.1134/S0015462826600082","url":null,"abstract":"Simulation of the developed laminar channel flow with a single-row array of inclined oval‑trench dimples with variable values of the trench length is carried out at the fixed dimple area and dimple depth. To evaluate the heat transfer enhancement, VP2/3 (Velocity–Pressure 2D/3D) in‑house code is used to solve Navier–Stokes and energy equations with the use of the multiblock computational technologies. The performed numerical analysis showed that four types of dimples with small, moderate, medium, and large values of the trench length could be distinguished. The flow and heat transfer features for small dimples are comparable to those of the spherical dimples with thermohydraulic efficiency of about 1.0. A significant change of the vortex structure is observed for moderate dimples which is accompanied with a significant increase of the thermohydraulic efficiency. For medium dimples a secondary separation area is formed whereas the thermohydraulic efficiency slightly grows. For large dimples the maximum value of the thermohydraulic efficiency of about 1.73 is observed for the trench length of about 5.0 whereas it decreases for larger values of the trench length. The origin of the significant heat transfer intensification is attributed to the formation of the extraordinary static pressure difference between the dimple leading and trailing edges with the value normalized by the doubled dynamic pressure of about 0.35–0.4.","PeriodicalId":560,"journal":{"name":"Fluid Dynamics","volume":"61 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2026-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147559769","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 Investigation of Elliptic Jet Control using Airtabs 利用Airtabs控制椭圆射流的实验研究

IF 0.6 4区工程技术

Fluid Dynamics Pub Date : 2026-03-19 DOI: 10.1134/S0015462825603900

M. Stefaniya, S. Thanigaiarasu

{"title":"Experimental Investigation of Elliptic Jet Control using Airtabs","authors":"M. Stefaniya, S. Thanigaiarasu","doi":"10.1134/S0015462825603900","DOIUrl":"10.1134/S0015462825603900","url":null,"abstract":"An elliptical nozzle (the aspect ratio AR is equal to 2) with an equivalent diameter of 10 mm is experimentally investigated at the Mach number M = 0.4 with the secondary fluidic injection of M = 0.6 minijets with four air tabs placed diametrically opposite to another at the nozzle exit plane. The high-speed jet facility is used to characterize the jet behaviour of the manipulated jet with the uncontrolled open jet. The effects of the minijet mass flow rate and the diameter ratio (air tab diameter/nozzle exit diameter) are analysed. In this experimental investigation four air tabs of 0.4, 0.5, 1 mm diameters being placed at the elliptical convergent nozzle exit at 90° to each another. As distinct from the circular nozzle, non-uniform vortices may be generated from the larger and shorter curvature of the major and minor axis of the elliptical nozzle, thus increasing the mass entrainment from the ambient to the main jet core. Air tabs not only generating the streamwise vortices and also induces Kelvin–Helmholtz instability due to the momentum difference in the primary jet due to the secondary jet thus promoting the mixing which reflects in the rapid reduction in pressure in the potential core region of the jet. Compared to the uncontrolled jet, the percentage of reduction in potential core is obtained as 40, 45, and 80% with the 0.4, 0.5 and 1 mm air tabs, respectively. Also, from the radial profile, a significant jet distortion is observed due to the amount of the energy added in the primary jet and the penetration of the secondary jets which is more significant in the minor axis as compared to the major axis of the elliptical nozzle. From the pressure plots and the analytical investigation, it is documented that 1 mm air tabs which sustain more momentum flux thus enhancing the entrainment ratio to the primary jet as compare to the 0.4 and 0.5 mm air tabs-controlled jets.","PeriodicalId":560,"journal":{"name":"Fluid Dynamics","volume":"61 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2026-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147560307","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