Local Stability Analysis of Laminar-Turbulent Boundary Layer Transition on Blunt Generic Re-Entry Capsules

Abstract

Numerical results on laminar-turbulent transition in the boundary layer of typical re-entry capsules at an angle of attack are presented. Laminar basic flow computations were conducted for a blunt body with a pure spherical forebody and for sphere-cone models with varying cone angles at cold hypersonic windtunnel conditions. Stability calculations on first and cross-flow modes were performed and the influence of different forebody shapes on the stability properties are discussed. Pressure gradient distribution along the leeward line of symmetry turned out to be the dominant factor of influence for first-mode transition. The stability results reveal a strong dependency of the obtained cross-flow instability N-factors on the sphere-cone angle.