STRUCTURE OF A TURBULENT DOUBLE-FIN INTERACTION AT MACH-4

This paper examines the three-dimensional shock-wave/turbulent boundar y-layer interaction in an inletlike geometry consisting of symmetrical ly placed 15-deg fins on a plate in an oncoming Mach 4 flow. Two diffe rent implicit numerical methods are employed to solve the full three-d imensional mean compressible Navier-Stokes equations: 1) a high resolu tion upwind scheme with the Baldwin-Lomax algebraic turbulence model a nd 2) the traditional Beam-Warming approach with a k-epsilon model, Th e comparison with experiment is very good for surface pressures, pitot pressure surveys, and surface shear patterns, although discrepancies with skin friction data are evident in the trailing portion of the int eraction, Both computational schemes, despite major differences in mod eling, predict similar flow structures in agreement with previous resu lts at Mach 8. The flow is described in terms of a separated, nonreatt aching boundary layer, a vortex interaction, longitudinal centerline v ortices, and entrainment. The computed and experimental shock patterns are related to the streamline structure to provide a unified understa nding of the flow field.