Direct Numerical Simulation of Hypersonic Transition Induced by Ramp Roughness Elements

An Experimental Study of Roughness-Induced Instabilities in a Supersonic Boundary Layer

“…These past studies have been useful for identifying the key parametric trends, but they do little to reveal the physical mechanisms of roughness-induced transition. In recent years, there have been numerous direct numerical simulations (DNS) of isolated roughness-induced transition in high-speed flows [5][6][7][8][9][10][11][12][13] and a new generation of experiments have focused on obtaining off-body flow-field measurements and visualizations in the wakes of isolated roughness elements. [14][15][16][17][18][19] The DNS studies, which considered a range of roughness-element geometries and both supersonic and hypersonic Mach numbers, have provided useful insights into the transition mechanisms in the roughness wake.…”