Specific features of wave train development in a streamwise disturbance of a supersonic boundary layer

Distributions of the amplitude of controlled disturbances in space and time and their frequency-wave characteristics are obtained from experimental results on weakly nonlinear development of the wave train in the region of a stationary wake inside the boundary layer on a flat plate at the Mach number $\mathrm{M}=2$. A stationary streamwise disturbance is generated by a pair of weak oblique shock waves. Controlled disturbances are inserted into the flow by a local high-frequency glow discharge located inside the model. The development of controlled disturbances is analyzed on the basis of the linear theory of hydrodynamic stability. Typical resonant wave triplets are identified. It is found that flow inhomogeneity suppresses the mechanisms of interaction of controlled disturbances.