Experimental results on unsteady shock-wave/boundary-layer interaction induced by an impinging shock

Abstract

Experiments on shock-wave/boundary-layer interaction of an impinging shock on a flat panel at Mach numbers of 3 and 4 were conducted in the trisonic wind tunnel (TMK) of the Supersonic and Hypersonic Technologies Department at DLR, Cologne. To obtain high-frequency data, the model was equipped with 12 high-speed pressure transducers for measurements at 100 kHz and high-speed schlieren photography was used. The experimental setup is designed for quick rotation of the shock generator allowing testing at different ramp angles during one wind tunnel run. The static pressure distribution and high-speed pressure fluctuations in the interaction area were analysed with regard to the spatial and temporal distribution of occurring frequencies. At the beginning of the separation and near the reattachment, a strong increase of low-frequency fluctuations of up to 1 kHz was observed. In the separation area, higher frequencies were also excited. These results were compared to the frequencies and flow topology found in the high-speed schlieren videos.