Some technical improvements of particle image velocimetry with regard to its application in wind tunnels

Improvements in focusing devices, seeding control, brightness control, dynamic range, accuracy, and evaluation time are described that facilitate the application of PIV (particle image velocimetry) in wind tunnels. Investigations using PIV have been carried out in a low-turbulence wind tunnel with low flow velocities as well as in transonic jet flows with Mach numbers greater than one. The experiments have shown that PIV is a useful tool for aerodynamic investigations in wind tunnels, especially for instantaneous velocity fields or in blowdown wind tunnels with a short operation time