Cole SOUSA, Guillaume GROSSIR, Olivier CHAZOT, Stuart LAURENCE
DOI Number: N/A
Conference number: HiSST-2025-136
Experiments are conducted in the VKI Longshot facility to investigate the development of boundary-layer and shear-layer disturbances over a slender cone/flare geometry at high hypersonic Mach numbers (M&12). Both attached (+5◦ flare) and separated (+15◦ flare) cases are examined using a high-speed calibrated schlieren diagnostic; a super-temporal reconstruction technique enables global measurements over all relevant frequencies. Second-mode waves play an important role in both configurations. For the attached case, these waves undergo significant amplification at the corner and experience further growth at higher frequencies downstream. The corner also leads to the rapid onset of flow features at second-mode super-harmonic frequencies. For the separated case, the second mode waves propagate along the shear layer and are then highly distorted by passage through the reattachment location, where substantial excitation over all frequencies is observed. Lower-frequency shear-layer disturbances also exhibit rapid growth above the separation bubble in this configuration. These disturbances radiate strongly to the outer flow, leading to growing, large-scale perturbations of the separation shock. Significant propagation of second-mode energy along the various shocks in both configurations is also noted, and appears to be somewhat more prominent than in earlier experiments at lower hypersonic Mach numbers.