Experimental study of turbulence beginning and transition control in a supersonic boundary layer on swept wing

The paper is devoted to an experimental study of controlled disturbances evolution in supersonic boundary layer of swept wing. We obtained, that the evolution of disturbances at frequencies of 10, 20, and 30 kHz are similar to the development of traveling waves for subsonic velocities. We shown, that mechanism of secondary cross-flow instability play main role in laminar-turbulent transition in 3-D supersonic boundary layer. On the basis of the obtained data the technique of laminar-turbulent transition control with the help of the distributed roughness was developed. Usage of this technique, has allowed as to bring transition upstream by 30% to delay downstream by 40%.