Shock-Induced Separation and Control in a 4.32-Aspect-Ratio Test Section

Abstract

Experimental test sections studying shock-wave–boundary-layer interactions are usually right-angled by design to replicate the supersonic engine inlets where these interactions are observed. To avoid flow separation and shock effects on the side walls, investigations are typically performed on the centerline of the test section. However, the centerlines of small-aspect-ratio test sections can be significantly affected by the flow structures generated in the corners. Results using a large-aspect-ratio test section at a freestream Mach number of 1.6 include centerline and corner flow separation topologies, schlieren images of shock structures, total pressure profiles, and surface static pressures throughout the interaction region. These results provide evidence that the large-aspect-ratio test section can produce a large area of centerline flow that is unaffected by the separation and shock structures generated in the corners, which is a significant improvement over most of the smaller-aspect-ratio test sections employed for these types of studies. Microvortex generators are also employed upstream of the interaction, and measurements indicate a five-vortex system that energizes the near-wall boundary layer enough to overcome the shock’s adverse pressure gradient while remaining attached.