Spatial DNS of an Isothermal Flat Plate Supersonic Turbulent Boundary Layer with/out Impinging Shock Wave

Abstract

Spatial direct numerical simulation results are presented for transitional/turbulent supersonic isothermal flat plate boundary layers at M = 2.0 and impinging shock wave-boundary layer interactions. The numerical results show the formation and development of three-dimensional vortical structures such as hairpin packets and streak-breakdown, and secondary and tertiary hairpins as well. These characteristic vortical structures create a significant fraction of the supersonic turbulent boundary layer structure. An incident shock wave impinging upon the transitional boundary layer with streaks and hairpins, and unsteady reflected waves from the mildly separation boundary layer are observed. Expansion waves after the impinging point and compression waves due to the boundary layer reattachment are also identified. Across the interacting shock, turbulence is enhanced with finer hairpins generated inside, and it undergoes a relaxation process to higher Reynolds turbulent boundary layers far downstream.