Scattering, Tracking and Seeding Characteristics of TiO2 using Particle Image Velocimetry in Supersonic Flows

In this work, the particle image velocimetry (PIV) technique was applied to study the compressible supersonic flow regimes in the multi-Mach number high-speed (MMH) wind tunnel. To generate sufficient light scattering and flow across shock waves, tracer particles and the seeding technique were used, as well as scattering and tracking of particles were investigated using experimental observations and theoretical analysis. It was determined that the actual particle diameter should be around 200 nm to guarantee an adequate aerodynamic response to velocity gradients in the flow. It was further shown by the PIV measurements over a sharp cone that the uniformity of seeding particles dispersion was very important for the operations of the seeding facility. The present study indicated that the PIV technique could be an efficient method for monitoring the flow field of shock wave and subsonic flow regimes.