Experimental Investigation of an Impinging Shock-Boundary Layer Interaction on a Compliant Panel in Mach 4 Flow

The fluid structure interaction (FSI) between a compliant surface and a shock wave and turbulent boundary layer interaction (STBLI) is studied experimentally in a Mach 4 Ludwieg tube facility. A static oblique shock is generated by a 35 degree wedge shock generator and impinges at the mid-panel location on a compliant panel. The 0.254 mm thick stainless steel compliant panel is fully clamped on all edges and has an aspect ratio of b/a = 1.476. A single camera photogrammetry system is used to measure the full-field surface deformations of the compliant panel, and high-speed schlieren imagery is utilized to visualize the behavior of the flow. A modal analysis of the surface deformation measurements showed that the first vibration mode of the panel dominated the panel response under STBLI, and the leading four vibration modes account for over 98% of the energy of the panel response. A low frequency unsteadiness centered around 406 Hz was identified in the separation shock foot motion, and the range of this motion was observed to be larger in the compliant case compared to the rigid wall case.