Design of a Glass Supersonic Wind Tunnel Experiment for Mixed Compression Inlet Investigations

Mixed compression inlets offer a great increase in pressure recovery compared to conventional external compression inlets at Mach numbers above two. These inlets suffer from problems with shock wave boundary layer interactions (SBLI) which cause flow instabilities and severe performance reductions. Previous experiments conducted at the University of Michigan used a wind tunnel with glass side walls with an extensive test section to measure the SBLI associated with a single oblique shock. This work presents a redesign of the single oblique shock experimental setup, using computational fluid dynamics, to also include a downstream normal shock with a diffuser. The new experimental configuration will provide insights into the effects that combined oblique/normal shock boundary layer interactions have on the health of the boundary layer in the diffuser section of a mixed compression inlet. The extensive glass walls of the wind tunnel will allow direct access for optical measurements of the shock boundary layer interactions and the diffuser section.