Analysis of Effects of Diffusion of a Foreign Gas Into the Laminar Boundary Layer of a Supersonic Flow of Air in a Tube

edge shock at A and the wedge at B. As the wedge oscillates, the leading-edge shock will oscillate, and the change in refraction conditions at A will make point B move back and forth over the wedge surface. If there should happen to be a pressure hole in the path of B, the oscillatory pressure would change from that which would be observed in the absence of the flow discontinuity. To estimate the magnitude of the pressure signal caused by the presence of the discontinuity, consider a Mach-wave discontinuity. One may then assume isentropic conditions across it, and one has