Characterizing the transition between regular and Mach reflections induced by a shock wave–boundary layer interaction

Abstract

Velocity field measurements by means of PIV are used in this work to characterize the flow in a shock wave–boundary layer interaction. For a free-stream Mach number of M∞=2.56, the flow over a flat plate model is deflected by a 16∘ wedge. For these flow conditions, an unsteady dual-state solution is observed where the shock switches between a regular reflection and a Mach reflection. This non-periodic mode switching is atypical for a shock wave–boundary layer interaction and causes significant changes in the flow field. The PIV measurements enable the Mach number and the flow direction to be determined from the measured velocity. In this way, both the position of the shocks and the flow defl..