New Results on the Incipient Separation of Shock/Boundary-layer Interactions

Incipient separation of shock/boundary-layer interactions (SBLIs) is reexamined through RANS simulations of the turbulent flow past a sharp-edged ramp at Mach 3. Surprisingly, it was found that separation occurs for ramp angles below the accepted incipient value and for extremely small ramp angles. However, the separation bubble is very much smaller for ramp angles below incipient, which can still be regarded as a demarcation between “small-” and “large-scale” separation. Further study is recommended.