Experiments will be conducted aimed at clarifying the predominant mechanism leading to the generation of streamwise vortices at the wall in wall-bounded flows. A flush, wall mounted actuator will introduce distortions into a base laminar flow, ranging from pure strain to pure vorticity. Diagnostics will be from LIPA (Laser Induced Photochemical Anemometry). The experiments will quantitatively identify near-wall events initiating flow distortion, and have strong relevance to active boundary layer control.
