High-Speed Schlieren Imaging and Hot-wire Characterization of Cylinder-Induced Hypersonic Shock Boundary Layer Interactions
Conference Paper
Overview
Identity
Other
View All
Overview
abstract
2018, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved. An experimental study was performed to characterize the role of the incoming boundary layer on the dynamics of a shock-wave boundary layer interaction at Mach 6. A right circular cylinder perpendicularly mounted on a 2-D, 1.3-degree wedge was used to generate the interaction. The boundary layer state was controlled from laminar through transitional to fully turbulent through a combination of trips and unit Reynolds number variation over a range of Re = 2x106 m-1 to 8x106 m-1. The first step in the analysis was to quantify the freestream disturbances and boundary layer structure without the cylinder via hot-wire anemometry. The root-mean-square fluctuation profile shapes, with and without the trips, had consistent extrema that were systematically dependent on axial and spanwise position with respect to the persistent hot and cold streaks associated with the trips. A potential instability peak was observed between 40 and 50 kHz. Spectral broadening was seen at x = 302 mm at Re = 6.9x106 m-1, which suggested the boundary layer was late transitional or turbulent. The presence of the cylinder has been shown to enhance transition. Second, high-speed schlieren videos were acquired of the interaction region as the boundary state was varied with the cylinder present. These studies provided insight into the unsteady shock structure and streamwise extent of the separation. Flow structures were observed to traverse the cylinder in a frequency band centered near 20 kHz.
