Akademik Veri Yönetim Sistemi
AIAA Journal, cilt.44, sa.9, ss.2133-2136, 2006 (SCI-Expanded)
The existence of steady and unsteady separation bubbles on the main-flow or the bleed-flow side of the nozzle lip of the Boeing/AFSOR Mach 6 wind tunnel was numerically investigated. Steady and time-accurate computations are performed for both the original geometry and the new designs using GASPex version. The laminar compressible Navier-Stokes equations are solved and for the modeling of inviscid fluxes, the third order Roe's scheme with Harten correction is used. Separation bubbles exist on both the main-flow and the bleed-flow sides of the bleed lip of the geometry for a stagnation pressure of 150 psi. An adverse pressure gradient is present just aft of the blunt nose on a flat plate in uniform flow, as a semi-elliptical nose becomes more slender, this gradient is reduced. It is shown that the separation bubbles which cause earlier transition in the test section of hypersonic wind tunnel can be eliminated by a slight change in the geometry of the bleed lip.