A Mach 6 flow over a 10 compression corner is investigated by Direct Numerical Simulations. A roughness patch made of sinusoidal elements is placed at two different positions upstream of the smooth-separation location in order to investigate its effects on the separation bubble. Flow separation is delayed with respect to the smooth case and the streamwise vortices induced by the patch generate a mushroom-like structure once the flow reattaches on the ramp. This structure leaves high-temperature streaks on the wall of the ramp, at the same time causing hot flow to be pushed into the freestream. When excited by freestream acoustic disturbances at 100kHz, the structure in the wake of the roughness starts to break down on the ramp, leading to a further increase in wall temperature.     «

A Mach 6 flow over a 10 compression corner is investigated by Direct Numerical Simulations. A roughness patch made of sinusoidal elements is placed at two different positions upstream of the smooth-separation location in order to investigate its effects on the separation bubble. Flow separation is delayed with respect to the smooth case and the streamwise vortices induced by the patch generate a mushroom-like structure once the flow reattaches on the ramp. This structure leaves high-temp...     »