Characterization of an incipiently separated shock wave/turbulent boundary layer interaction

International audienceThe turbulence structure in a shock wave/turbulent boundary layer interaction at incipient separation was investigated in order to get insight into turbulence generation and amplification mechanisms in such flow fields. The flow along a two-dimensional \(11.5^{\circ }\) compression corner was studied experimentally at a Mach number of \(M=2.53\) and with a momentum-thickness Reynolds number of \(\mathrm{Re}_{\theta }=5370\). From hot-wire boundary layer traverses and surface heat-flux density fluctuation measurements with the fast-response atomic layer thermopile, the turbulence structure and amplification was described. Space–time correlations of the mass-flux fluctuations across the boundary layer and the surface heat-flux density fluctuations were measured to further characterize the development of the turbulence structure across the interaction. The large-scale boundary layer structures are concealed by shock-related effects in the strongly disturbed shock-foot region. Shortly downstream, however, large-scale structures dominate the signal again, just as in the incoming flow. A mechanism explaining this behavior is suggested