摘要
基于定常吹吸气对波浪型圆柱近尾迹流动进行控制以增强柱体振动,采用大涡模拟研究了亚临界雷诺数(Re=3000)下前吹后吸和前后吸气控制方式在不同吹吸气工况对波浪型圆柱升阻力特性、时均压力系数、环量、湍动能及近尾迹流动结构的影响.研究发现:前吹后吸和前后吸气控制下波浪型圆柱在不同吹吸气动量系数工况脉动升力系数均显著提高,最大较未受控直圆柱和波浪型圆柱分别提升高达636%和391%,这主要可能归因于吹吸气控制使波浪型圆柱回流区变短,高强度涡集中向钝体后方靠拢,旋涡形成长度缩短,展向涡流与顺流向涡流相互作用在波浪型圆柱下游形成的“肋状涡”变大变长,近尾迹环量显著增大,从而导致脉动升力系数增大,这可能将诱导柱体产生更强的振动;同时两种控制方式均改变了波浪型圆柱表面的压力分布,由于在波浪型圆柱前驻点吹气使前端趋于流线型,前吹后吸在不同吹吸气动量系数下波浪型圆柱的高压区减小,但在后驻点吸气使得低压区增大,而前后吸气在不同吹吸气动量系数下波浪型圆柱的高压区基本不变,低压区增大.研究结果可为低风速地区分布式风力俘能结构俘能效率提升提供基础理论支持.
Based on the control of the near wake flow of a wavy cylinder by steady blowing and suction to enhance the vibration of the cylinder, the effects of the forward blowing and backward suction and the forward and backward suction control modes on the lift and drag characteristics, time-average pressure coefficient, circulation, turbulent kinetic energy and flow field mechanism of a wavy cylinder under different blowing and suction conditions at subcritical Reynolds number(Re = 3000) were numerically studied by large eddy simulation. It is found that the fluctuating lift coefficient of wavy cylinder under the control of forward blowing and backward suction and forward and backward suction is significantly increased under different conditions of blowing and suction momentum coefficient, and the maximum increase is as high as 636% and 391% respectively compared with that of uncontrolled cylinder and wavy cylinder. This may be mainly attributed to the shorter recirculation area of wavy cylinder under the control of blowing and suction, the concentration of high-intensity vortices towards the rear of blunt body, and the shorter vortex formation length, The "riblike vortex" formed by the interaction of spanwise vortex and streamwise vortex becomes larger and longer, and the normalized circulation near the wake increases significantly, resulting in the increase of fluctuating lift coefficient, which may lead to stronger vibration of the cylinder;At the same time, both control methods change the pressure distribution on the surface of the wavy cylinder. Because the front end tends to be streamlined due to the blowing at the front stagnation point of the wavy cylinder, the high-pressure area of the wavy cylinder decreases under different blowing and suction momentum coefficients, but the low-pressure area increases due to the suction at the rear stagnation point, while the highpressure area of the wavy cylinder is basically unchanged and the low-pressure area increases under different blowing and suction momentum coefficients. The research results can provide basic theoretical support for improving the efficiency of distributed wind energy capture structure in low wind speed areas.
作者
邹琳
左红成
柳迪伟
王家辉
徐劲力
Zou Lin;Zuo Hongcheng;Liu Diwei;Wang Jiahui;Xu Jinli(School of Mechanical and Electronic Engineering,Wuhan University of Technology,Wuhan 430070,China)
出处
《力学学报》
EI
CAS
CSCD
北大核心
2022年第11期2970-2983,共14页
Chinese Journal of Theoretical and Applied Mechanics
基金
国家自然科学基金资助项目(11972268)。
关键词
波浪型圆柱
定常吹吸气
大涡模拟
湍动能
流动控制
wavy cylinder
steady blowing/suction
large eddy simulation
turbulent kinetic energy
flow control
