Leading-edge receptivity of a hypersonic boundary layer on a flat plate

Experimental investigations of the boundary layer receptivity, on the sharp leading edge of a flat plate, to acoustic waves induced by two-dimensional and three-dimensional perturbers, have been performed for a free-stream Ma ch number M-infinity = 5.92. The fields of controlled free-stream disturban ces were studied. It was shown that two-dimensional and three-dimensional p erturbers radiate acoustic waves and that these perturbers present a set of harmonic motionless sources and moving sources with constant amplitude. Th e disturbances excited in the boundary layer were measured. It was found th at acoustic waves impinging on the leading edge generate Tollmien-Schlichti ng waves in the boundary layer. The receptivity coefficients were obtained for several radiation conditions and intensities. It was shown that there i s a dependence of receptivity coefficients on the wave inclination angles.