Effects of Nose Bluntness on Hypersonic Boundary-Layer Receptivity and Stability

What is it about?

Transition to turbulence of a laminar flow is a crucial aspect of hypersonic flight, since it substantially increases drag and heat transfer. Blunting the nose can have beneficial effects by delaying transition to further downstream locations; this trend is confirmed by linear stability theory. However, experiments have shown that beyond a certain nose radius, a reversal takes place, and the transition location moves upstream, contradicting linear stability theory and posing practical constraints. The present work uses the Navier-Stokes equations with a random forcing technique to successful recreate the main aspects of the transition reversal at Mach 6, as observed in experiments. The analysis shows that the modes manifested before and after transition are different from each other.

Featured Image