DNS of a Spatially Evolving Transitional/Turbulent Boundary Layer with Impinging Shock Wave

The interaction of a spatially transitional boundary layer flow at freestream Mach number M =2.0 with an impinging oblique shock wave (β=34.09) is studied by means of direct numerical simulation of the compressible Navier-Stokes equations. High amplitude (4%) three-dimensional isotropic disturbances are superimposed on the laminar profile for Reynolds numbers based on the displacement thickness of Reδ*0=1000 at the inlet plane of the boundary layer computational box. Under the selected flow conditions incoming boundary layer undergoes separation due to adverse pressure gradient. Impinging shock-boundary layer interactions generate a shock system (incident shock, reflected waves and expansion fan) due to the three-dimensional boundary layer separation. Coherent structures are shed close to the separated point give rise to mixing layer that grows in the streamwise direction.