Turbulent boundary layer investigations with conventional and stereoscopic PIV

Abstract

In order to obtain detailed information about coherent structures, instantaneous velocity fields were measured in two flat plate boundary layer flows applying high resolution Particle Image Velocimetry. The experiments were performed in two wind tunnels with different PIV technique.The plane normal to the wall was investigated using the conventional PIV technique. Planes parallel to the wall were measured with a digital stereo system which provided all three velocity components simultaneously. The statistical properties of the velocity obtained by ensemble averaging of the PIV recordings are in reasonable agreement with results obtained by other measurement techniques. Two dimensional correlations yielded the average dimensions of the vortical structures in different planes parallel to the wall. The observed dimensions are in agreement with hot wire results of other investigations.