Experiments were executed to investigate the effect of ablative outgassing on boundary-layer instabilities on a slender cone in Mach 6 quiet flow. A half-angle cone with solid and porous nose tips was tested. The porous nose tips were of varying bluntness: nominally sharp, , and . The permeability of each nose tip was measured using a modified ISO standard, and the outflow was measured using miniature hot-wire anemometry. The model was instrumented with surface pressure transducers and an atomic layer thermopile, and high-speed schlieren was used to visualize the boundary layer. Experiments were done in the Boeing/AFOSR Mach 6 Quiet Tunnel at Purdue University at approximate Reynolds numbers of and and with varying blowing rates. Without blowing, bluntness suppressed the second-mode instability. In all cases, blowing advanced transition upstream. On the sharp cone and the geometry, second-mode instabilities were the dominant transition mechanism. With the nose tip installed, second-mode waves were not observed. However, blowing advanced transition, and a 40 kHz instability dominated laminar-to-turbulent transition on the geometry.
Boundary-Layer Instabilities on Variable Bluntness Cones with Outgassing in Hypersonic Quiet Flow
AIAA Journal ; 63 , 6 ; 2105-2121
01.06.2025
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch