Measurements of an axisymmetric hypersonic shear-layer instability on a cone-cylinder-flare in quiet flow

Compression corners are commonly present along aircraft, such as at control surfaces, and can cause shock/boundary-layer interactions when the vehicle moves at supersonic or hypersonic speeds. By generating a separation bubble at the corner, a shear layer is present in the flow, which can potentially amplify instabilities, leading to a boundary-layer transition downstream of reattachment. We show, through experiments conducted under low-disturbance Mach-6 flow, the amplification of such a shear-layer instability by comparing measurements from two cone-cylinder-flare geometries with computations of the same.