Interactions between Görtler vortices and the second mode in hypersonic boundary layer

Abstract

The interaction between Görtler vortices and the second mode is experimentally investigated in a Mach 6.5 quiet wind tunnel by using the CO2-enhanced filtered Rayleigh-scattering technique combined with fast-response pressure sensors. The results show that, for an appropriate amplitude of Görtler vortices (i.e., sufficiently low to avoid triggering a secondary instability), they stabilize the second mode. To the best of the author's knowledge, this is the first time that the stabilization of the second mode by Görtler vortices is detected experimentally in the hypersonic flow.