流体中速度场检测方案(粒子图像测速)

The active control of laminar and turbulent flows with dynamic actuators is of great scientific and technological interest in nearly all fields of fluid mechanics. Today, most of the well established actuator concepts are based on pneumatic and micro-mechanic bases. However, owing to their limited dynamic range, their potential seems to be limited from the present point of view [1]. Recently it was successfully demonstrated that a boundary layer flow can be efficiently controlled by using an optical actuator concept, which allows non-intrusive excitation of the flow with nearly any pulse-width and repetition-rate by heating the surface of a model with a short-focused laser pulse [2]. The drawback of the proposed and examined method was the gradual ablation of the model surface. To avoid this problem the excitation was performed above the surface in this investigation [3]. By using the phased locked stereoscopic PIV and Schlieren technique the dynamic effect of the laser induced plasma on a boundary layer flow could be examined in detail. In this contribution the main results will be summarized and the perspective of this actuation method for fundamental and applied fluid mechanics will be outlined.