Publications

Abstract not provided.

Abstract not provided.

This experimental study explores the fluid-structure interactions occurring between a control surface and the hypersonic flow deflected by it. The control surface is simplified for this work as a spanwise finite wedge placed on a longitudinally sliced part of the cone. The front surface of the wedge is a thin panel which is designed to respond to the unsteady fluid loading arising from the shock-wave/boundary layer interactions. Experiments have been conducted in the Sandia Hypersonic Wind Tunnel at Mach 5 and Mach 8 at wedge angles of 10◦, 20◦ and 30◦ . High-speed schlieren and backside panel accelerometer measurements capture the unsteady flow dynamics and structural response of the thin panel, respectively. For attached or small separation interactions, the transitional regime has the strongest panel fluctuations with convective shock undulations induced by the boundary layer disturbance shown to be associated with dominant panel vibrations. For large separated interactions, shear layer flapping can excite select panel modes. Heating of the panel causes a downward shift in natural mode frequencies.

Abstract not provided.

Three-dimensional shock wave–boundary-layer interaction arising due to the deflection of a control surface on a slender cone has been studied at Mach 5 and Mach 8. The control surface has been represented as a spanwise finite wedge placed on a horizontally sliced part of the cone. The freestream Reynolds number was varied so that the upstream boundary layer entering the interaction region was either laminar, transitional or turbulent. The interaction has been studied using high-frequency surface pressure measurements, temperature-sensitive paint and high-speed schlieren. Separation length was found to vary slightly with Reynolds number in the purely laminar or turbulent regime but changed rapidly when the flow was transitional. At all Reynolds numbers, the pressure spectra near the separation point was dominated by low frequency broadband fluctuations which are presumed to be associated with separation shock unsteadiness. A characteristic decay of shear layer frequency from inception to reattachment was also captured by the surface pressure spectra. Peak non-dimensional heating was found to occur when the flow was transitional.