Experimental investigation of stability of a hypersonic boundary layer on a cone–flare model

Stability of a hypersonic flow in the regions of laminar separation of the boundary layer on a cone–flare model is experimentally studied for a Mach number $\mathrm{M}= 5.92$. Development of natural disturbances and artificial wave packets in the boundary layer and separation region is examined. It is shown that high-frequency disturbances are predominantly amplified in the separation region; the most unstable waves are those propagating with an angle close to $60^\circ$ to the free-stream direction. It is found that separation and reattachment lines are generators of two-dimensional disturbances.