Microramp Control of Supersonic Oblique Shock-Wave/Boundary-Layer Interactions

Abstract

The potential of microramp sub-boundary-layer vortex generators for flow control in supersonic engine inlets is investigated. In particular, the study focuses on the ability of these devices to beneficially affect oblique shock-wave/ boundary-layer interactions. Experiments have been conducted at Mach 2.5 to determine the nature of flow controlled by microramps and to investigate their ability to delay separation in a reflected shock interaction. Various ramp heights between 30 and 90% of the boundary-layer thickness were investigated. The details of the vortical flow generated by such devices were identified. The general flow features were found to scale with device height and it is suggested that smaller devices need to be placed closer to the expected adverse pressure gradients. When applied to a separated oblique shock-wave/boundary-layer interaction generated with a 7 degree wedge, microramps were not able to completely eliminate flow separation, although they were shown to break up separated regions. Other performance indicators across the shock-wave/boundary-layer interaction were also improved through the application of the devices.