Influence of Nose Bluntness on Crossflow Instability

Abstract

Much work has been focused on the initiation of crossflow instability due to roughness-induced mode excitation. Here we emphasize another aspect of the problem; how changes in nose bluntness (possibly due to ablation or other effects) may also alter the dynamics of crossflow instability via entropy layer modification. The effect of nose bluntness on crossflow instability for a Mach 6 yawed cone is considered at two different angles of attack. Linear parabolized stability equations investigation is performed on crossflow vortices along vortex lines calculated by the inflection point method. It is found that small changes in nose bluntness significantly alter the trajectory of crossflow vortices, the strength of the crossflow instability, and the most unstable wavenumber of the crossflow vortices. These results may be of particular importance to experimentalists studying the effect of ablation on crossflow instability.