Interactions between a shock and turbulent features in a Mach 2 compressible boundary layer
R. Baidya, Sven Scharnowski, Matthew Bross, Christian J. Kähler
Abstract
Large field-of-view (FOV) particle image velocimetry experiments are conducted in the vicinity of a shock wave boundary layer interaction (SWBLI) at Mach 2. The current FOV covers up to 30 boundary layer thicknesses () than the other spanwise modes. The wall pressure measurements indicate that the low-frequency fluctuations arising from the oscillating shock foot are due to dampening of high-frequency contents beyond the critical frequency associated with the unstable global mode. Thus, the results suggest that low-frequency pressure oscillations are not necessarily an independent phenomenon from the turbulent features entering the SWBLI region and interacting with the shock. Instead, a large scale separation between their dominant time scales is due to the critical frequency of the unstable global mode occurring at frequencies that are orders of magnitudes slower than the dominant frequency of the very-large-scale features.