Investigation of the flow tracking capabilities of tracer particles for the application of PIV to supersonic flow fields

The transport of particles is analysed for two different types of supersonic flow fields. The vicinity of a shock front and a flow field similar to a solid body rotation as an approximation of vortex centers were investigated. The influence of particle size and density are theoretically investigated by an analysis of Basset-Boussinesq-Oseen's equation which is the governing equation describing particle motion in a fluid flow. Results show that even small particles need a distance of approximately 10 mm downstream of a shock to adjust to the ambient fluid velocity. Velocity measurements with Particle-Image Velocimetry confirm the theoretical results. A theoretical investigation of a vortical flow field shows a promising low error of particle motion versus fluid flow. However the examination of the long time ejection shows an accurate motion only for small and light particles. Therefore measurements were taken at the vortical flow over a delta wing. A comparison with numerical results shows that even areas of high vorticity were accurately resolved.