Influence Of Shock-Boundary Layer Interactions On The Dynamic Response Of A Flexible Panel

New approaches are needed in order to successfully analyze and design air-breathing hypersonic cruise vehicles. What is required are methods that capture the affects of the high-speed flow environment on vehicle structures, and the influence of the vehicle outer mold line (OML) structure on that local environment. The response of these vehicle structures can be path-dependent and so the correct time-phasing of the loading conditions is critically important. Current practice is to superpose the worst case loading magnitudes which inevitably results in excessive conservatism. To address these and other issues, an experimental investigation was recently initiated to better understand the impact of high-speed flow effects on the response of an aircraft-like panel configuration, and the potential impact of the structure on the local environment. Specifically, the response of a compliant panel to the effects of high-speed flow, including shock-boundary layer interaction, was studied in Mach 2 flow. A shock wave generator opposite the panel specimen resulted in the shock boundary-layer interaction (SBLI) and in a shock impingement on the panel. For the first time, full-field dynamic pressure and response were simultaneously recorded in a high-speed flow environment, providing an avenue for the validation of multi-discipline aerothermoelastic analysis methods. Panel displacement response was measured with high-speed 3D digital image correlation (DIC) simultaneously at 154 discrete locations. Dynamic pressure across the panel was measured using high-speed pressure sensitive paint (PSP), and a sound pressure level increase of 8.5-dB was calculated through the shock on the flexible panel. Full-field geometric nonlinear response of the plate from the resulting turbulent boundary layer and SBLI was recorded, and results compared with previous experimental work [1]. Initial results indicate that the pressure field observed on the compliant panel is different from the rigid case and the modes of the compliant panel can be observed in the pressure data.