A PIV System for the Measurement of Compressible Air Flows and it's Application for Transonic Gas Turbine Optimization

Abstract

A particle image velocimetry (PIV) recording system, based on photographic imaging and it's application in an industrial wind Tunnel is presented. The most widespread implementation of the method images seeding particles suspended in the flow under investigation by illuminating them with a pulsed laser light sheet which is oriented normal to the imaging axis of the camera. The camera records the positions of the particle images using at least two closely spaced illumination pulses. By measuring the particle image displacement, either by particle tracking or locally applied statistical methods, the two-dimensional projection of the local velocity vector can be estimated using the magnification factor, and the laser pulse delay.