An investigation of the formation and propagation of horseshoe vortices in a strut-boundary layer interaction, and their effect on inlet distortion
The formation and propagation of a horseshoe vortex system forming as a result of strut-boundary layer interaction is studied to determine its effect on stagnation pressure distortion in an axisymmetric supersonic inlet geometry. The effects of strut leading edge radius, pressure gradients, and curvature of the inlet walls on the vortex system are studied parametrically by performing a CFD simulation of strut-boundary layer interaction in a simplified duct geometry with flow conditions representative of the subsonic diffuser of a supersonic inlet. Leading edge fairings are studied to determine what parameters are most important for the control of the horseshoe vortex system and the reduction of stagnation pressure distortion at the fan. A fairing is designed for struts an axisymmetric, supersonic, mixed-compression inlet which reduces circumferential distortion intensity by 48% at cruise condition with 3 degrees angle of attack. ^ Solutions are obtained to the steady state Reynolds averaged Navier-Stokes equations using WIND, a finite-difference solver developed by NASA Glenn and the USAF Arnold Engineering Development Center. The Spalart-Allmaras one equation turbulence model is used to model eddy viscosity.^
Gregory A. Blaisdell, Purdue University.