DNS ANALYSIS OF SHOCK WAVE / TURBULENT BOUNDARY LAYER INTERACTION AT M=2.25

In this study the interaction of a supersonic fiat plate boundary layer flow with an impinging shock (at M∞ = 2.25 and Re θ ≈ 4000, and shock angle (β = 32.7°) is analyzed by means of a direct numerical simulation. The results show that under such conditions, the flow field dynamics upstream of the impinging shock closely resembles the incompressible pattern; however, in the interaction zone the flow undergoes separation due to the adverse pressure gradient, and the recovery of the universal behavior occurs on a length scale of O(10δ 0), where δ 0 is the boundary layer thickness in the absence of the interaction. The simulations also clearly suggest severe flapping motion of the reflected shock past the interaction zone, with the generation of sound waves. The results also indicate that the localized turbulence amplification is mainly related to the formation of large vortical structures associated with boundary layer separation.