Structure of the wall pressure fluctuations in a shock-induced separated turbulent flow

This paper presents the results of an experimental study of the unsteady nature of a shock wave/turbulent boundary layer interaction. The interaction was generated using an unswept compression ramp. The incoming freestream Mach number was 2.9 and the flow was separated at the corner. An array of flush mounted miniature high frequency pressure transducers was used to make multi-channel measurements of the fluctuating wall pressure within the interaction. From the present results, an overall picture of the instantaneous structure of the unsteady shock system (as inferred from the wall pressure signals) can be constructed. The flow ahead of the corner can be considered as composed of two regions, namely the 'intermittent' region where there is essentially a single leading shock which exhibits significant streamwise 'flapping' and spanwise 'rippling', and the separated region where the flow experiences continuous compression.