Abstract: Experiments were carried out in order to investigate the rectangular cavity flow of length-to-depth ratio of 5:1 using time-resolved particle image velocimetry (TR-PIV) technique. Three different passive control methods, including cylinder, sawtooth and rectangle body, were studied experimentally, having the same upstream velocity, i.e. 34 m/s. The experimental results show that the cylinder control method can increase shear layer thickness and effectively reduce the shear layer speed pulse and vorticity. Rectangle and sawtooth control methods will obviously raise shear layer to mainstream area, leading to no frontal impinging between the shear layer and the trailing edge of the cavity edge.

Key words: acoustics, cavity, flow control, aerodynamic body

摘要： 采用高频响粒子图像测速技术，对长深比为5的管道空腔流场进行实验研究。同时在空腔前缘安置三种不同形状和具有相同扰动速度（34 m/s）的扰流体（圆柱形、锯齿形和矩形）对空腔流动进行被动控制。实验结果表明，圆柱扰流体能够增大剪切层厚度，并且可减小剪切层速度脉动和涡量值。矩形和锯齿形扰流体明显地将剪切层向主流区抬起，导致剪切层与空腔后缘未发生正面碰撞。

关键词: 声学, 空腔, 流动控制, 气动扰流体