柔性隔板对固定圆柱绕流结构影响的实验研究

项目名称： 柔性隔板对固定圆柱绕流结构影响的实验研究

项目编号： No.11302018

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 数理科学和化学

项目作者： 胡烨

作者单位： 北京航空航天大学

项目金额： 30万元

中文摘要： 对于钝体绕流周期性脱落的反对称涡会诱发涡致振动这一现象，人们采用了多种方法对其进行控制，加装后缘隔板是其中一种简单有效的手段。本课题提出在静止圆柱的后缘安装柔性隔板，采用氢气泡流动显示和PIV速度测量技术，利用相位本征正交分解(POD)、动力学模态分解（DMD)等方法，探讨柔性隔板长度、来流雷诺数等对圆柱绕流结构和特性的影响规律；分析柔性隔板对静止圆柱的减阻效果及抑制振动的机理。研究工作不仅有利于揭示柔性隔板对静止圆柱绕流及涡致振动的影响机制，而且在一定程度上将解释柔性翼面在昆虫和鱼类运动过程中的重要性。

中文关键词： 流动控制；绕流结构；圆柱；分隔板；

英文摘要： Antisymmetric vortices shed periodical from the shear layers of a bluff body and lead to a fluctuating lift force which could cause a structure to vibrate (vortex-induced vibration). Many methods have been applied to control this flow phenomenon and the passive control technique as a splitter plate behind a bluff body is an easy and effective one. In this experiment, a flexible film which is attached to a stationary cylinder is induced to vibrate by the unsteady vortices. Hydrogen bubble visualization technique and Particle Imaging Velocimetry (PIV) are utilized to investigate the flow structures of the cylinder affected by the length of flexible film and Reynolds number. Different data processing techniques, such as proper orthogonal decomposition (POD) and dynamic mode decomposition (DMD), will be adopted to analyze the mechanisms. The drag of the stationary cylinder with a flexilbe film is measured and then the relationships between the flow structures and aerodynamic characteristics will been explained. These investigations not only clarify the mechanisms of the flow structure and drag reduction for the cylinder with a flexible film, but also shed light on the significance of flexible wing for flapping motions.

英文关键词： flow control；flow structure；circular cylinder；flexible splitter plate；