3D-shock visualization in a transonic compressor rotor

Tracer based shock visualization (TSV) is a new optical non intrusive technique to visualize the position and the structure of shocks in a transonic axial compressor. The number per volume density of particles, which are added to the flow and with it the density of the fluid are visualized with a laser light sheet and an intensified CCD camera, structures like normal and oblique shocks, λ-shocks and separation regions can be clearly identified. The 3D-shape and structure of the blade passage shock is reconstructed from the collected data. The results are in good agreement with wall pressure measurements and numerical data. The experimental difficulties of the technique are discussed.