Crossflow Instability on a Yawed Cone at Mach 6

Abstract

Boundary-layer measurements were performed in a Mach 6, low-disturbance wind tunnel on a 7° cone at 5.6° angle of incidence such that the model was primarily subject to crossflow instability. Constant-temperature hot-wire anemometry was used to measure the streamwise mass flux at a series of planes normal to the cone axis. A dominant stationary wave is observed to achieve nonlinear saturation at approximately 23% with maximum rms fluctuations of approximately 8%. Additionally, traveling crossflow waves were observed in a broad frequency band centered at f = 40 kHz and secondary instabilities were observed in a broad band centered at f = 100 kHz. Measurements show excellent agreement with previously published computational results and are qualitatively similar to studies performed in subsonic flows. Transition to turbulence was not observed to occur under these conditions.