An Investigation of Cavity Vortex Generators in Supersonic Flow

The purpose of this report is to document the results of experiments performed at the University of Kansas and at the NASA Langley Research Center (LaRC) into the use of shaped cavities to generate vortices in supersonic flow, as well as the progress made in simulating the observed flow using the PAB3D flow solver. The investigation was performed on 18 different cavity configurations installed in a convergent-divergent nozzle at the Jet Exit Facility at the LaRC. Pressure sensitive paint, static-pressure ports, focusing Schliern, and water tunnel flow visualization techniques were used to study the nature of the flow created by these cavities. The results of these investigations revealed that a shaped cavity can generate a pair of counter-rotating streamwise vortices in supersonic flow by creating weak, compression Mach waves and weak shocks. The PAB3D computer program, developed at the LaRC, was used to attempt to reproduce the experimental results. Unfortunately, due to problems with matching the grid blocks, no converged results were obtained. However, intermediate results, as well as a complete definition of the grid matching problems and suggested courses of actions are presented.