Experimental Study of Aeroelastic Response and Performance of a Hypersonic Intake Ramp

The response and performance of an aeroelastic hypersonic intake was studied experimentally using fundamental geometry and structural boundary conditions. The experiments were conducted in a hypersonic wind tunnel at a Mach 5.85 condition. The most relevant deforming component was the compression ramp, which was treated as a cantilever surface to emulate the global deformation of the intake. Flowfield measurements were performed using pressure transducers, pressure-sensitive paints, and schlieren flow visualization. The dynamic structural response was measured using digital image correlation as well as feature tracking from the schlieren videos. A point measurement of total pressure in the isolator was taken using a pitot tube to quantify the effects of intake ramp deformation on the intake performance. The loss of total pressure in the isolator was found to correlate directly with the intake ramp deformation, with a direct transient correlation between the peak loss in total pressure recovery and the peak ramp deformation. While undergoing aeroelastic deformation, the total pressure recovery of the cantilever compliant ramp decreased by up to 20% from the baseline values. The analysis showed a strong coupling, along with hysteresis in dynamic response, between the intake structural deformation and the shock-wave/boundary-layer flowfield in the isolator.