Schlieren visualization of the laminar-to-turbulent transition in a shock-tube boundary-layer

The laminar-to-turbulent transition in the flow of a shock-tube boundary layer is measured for shock Mach numbers of 1.06 to 1.5. Schlieren photographs show a pulsation of the boundary-layer thickness in the transition regime. The observed structure of the turbulent boundary layer can be related to the burst phenomena known for incompressible flow. The transition is also measured with hot films which are sensitive to the difference in laminar and turbulent heat transfer at the tube wall.