Boundary layer measurements on a slender body using long-distance PIV

Abstract

This study reports the development and application of long-distance high magnification Particle Image Velocimetry (PIV) to measure the mean and fluctuating velocity components in a turbulent boundary layer. A 400 mm lens coupled with an extension tube and a novel aperture control mechanism has enabled high resolution images at a working distance of 1.5 m. The PIV results were found to compare well with established probe measurements along a slender axisymmetric body. The boundary layer thickness and mean streamwise velocity was found to conform to a traditional turbulent boundary layer in the parallel mid-body section of the body.