Investigation of near wall Turbulence using Multiplane Stereo PIV

Abstract

The joint probability density functions of the streamwise/wall-normal (uv) and streamwise/spanwise (uw) velocity fluctuations undergo a strong structual change in the near wall region of a fully developed turbulent boundary layer flow when approaching the wall. In order to understand the physics behind this experimental result, the spatio-temporal flow structure was investigated at several y locations, both simultaneously and separated in time, by means of multiplane stereo PIV. The size, shape and intensity of various coherent velocity structures could be determined from the spatio-temporal cross correlation functions after subdividing the flow field according to the quadrand splitting technique. Furthermore the convection velocity of the different coherent structures was measure