A particle image velocimetry (PIV) system has been developed for use in high-speed separated air flows. The complete system was developed to improve the spatial resolution and accuracy of the PIV technique as applied in high-speed compressible flows and is the first to incorporate both birefringent image shifting and submicron seed particles for analysis of separated flowfields. The system has been proven in preliminary experiments using a simple low-speed round jet flow and has been validated for accuracy with both known displacement simulated PIV photographs and with uniform flow experiments at Mach 0.5 (170 m/s) for comparison with pressure and laser Doppler velocimeter data. PIV data have also been obtained in the separated wake region behind a two-dimensional base model in a Mach 0.4 freestream flow (135-220 m/s) with resolution of velocity in 1.0-mm2 regions, revealing features of the von Karman vortex street wake and underlying small-scale turbulence.
ASJC Scopus subject areas
- Aerospace Engineering