Instability of Hypersonic Flow Post Blunt Cones

Abstract

The M*&#618.0 hypersonic, laminar, axisymmetric mean flows past blunt, circular cones at zero angle of attack are calculated and their instability are analyzed by means of primary, local, linear stability theory taking into account the cones' metric. According to the experiment of Stetson et al. the freestream unit Reynolds number is set to Re*/ft.&#612.5X10*. The investigated cones have a half angle of 7* and nose radii of RN&#610.15in., RN&#610.7in., and RN&#611.68in. For the wall temperature either adiabatic or isothermal conditions are prescribed. The isothermal wall temperatures are selected to be 1.2, 0.9, 0.8, 0.6 and 0.3 times the adiabatic wall temperature at the position S/RN&#61175 for the cone with a nose radius RN&#610.15in. The larger bluntnesses are calculated with adiabatic conditions only. The mean flow is either calculated by a thin-layer Navier-Stokes code or by an Euler/second-order boundary-layer approach (for RN&#610.15in. only).