Evaluation of Non-bleed Shock Wave Boundary Layer Interaction Control Using a New Mixed Compression Inlet Simulator Model

Abstract

A test was conducted of a generic two-dimensional mixed compression inlet flow field simulator model in the AFRL Trisonic Gasdynamic Facility (TGF) to evaluate non-bleed Shock Wave Boundary Layer Interaction (SWBLI) flow control. The flow field simulator model incorporated a compression ramp with variable angle to allow investigation of differing shock strengths and a vertically translating upper cowl surface to allow throat height compensation for differing boundary layer thicknesses. The model also featured a rectangular to round diffuser with a 40 probe Aerodynamic Interface Plane (AIP) total pressure rake at the end of the diffuser and a primary flow plug to allow variations in mass flow. Testing was accomplished at a free stream Mach number of 3.0. A bleed optimization was performed on the ramp and cowl bleed zones with the four throat and two forward sidewall bleed zones being held constant. Center line static pressures along with bleed flow parameters and boundary layer profiles on the ramp surface were recorded. Schlieren images of the shock wave pattern along the ramp were also recorded. The ramp SWBLI bleed flow control was replaced with various micro vortex generator configurations. Test results show that several of the vortex generator configurations had the ability to effectively replace the bleed flow control and prevent inlet un-start to equivalent ramp angles as long as adjustments were made to the throat height to allow for the increased mass flow and boundary thickness. 1 Aerospace Engineer, AFRL/RBAI, 2130 8 th Street