用激光进行流场非介入控制技术前景展望
The active control of laminar and turbulent flows with dynamic actuators is ofgreat scientific and technological interest in nearly all fields of fluid mechanics.Today, most of the well established actuator concepts are based on pneumatic andmicro-mechanic bases. However, owing to their limited dynamic range, their potentialseems to be limited from the present point of view [1]. Recently it was successfullydemonstrated that a boundary layer flow can be efficiently controlled byusing an optical actuator concept, which allows non-intrusive excitation of the flowwith nearly any pulse-width and repetition-rate by heating the surface of a modelwith a short-focused laser pulse [2]. The drawback of the proposed and examinedmethod was the gradual ablation of the model surface. To avoid this problem theexcitation was performed above the surface in this investigation [3]. By using thephased locked stereoscopic PIV and Schlieren technique the dynamic effect of thelaser induced plasma on a boundary layer flow could be examined in detail. In thiscontribution the main results will be summarized and the perspective of this actuationmethod for fundamental and applied fluid mechanics will be outlined.