Investigation on the wake flow instability behind isolated roughness elements on the forebody of a blunt generic re-entry capsule

Abstract

Numerical results on modal disturbance growth in the wake flow downstream of a roughness element submerged in the boundary layer of a typical re-entry capsule at an angle of attack are presented. Laminar base flow computations were conducted for different roughness heights and planform shapes. The modal instability characteristics of the wake flow were studied by spatial two-dimensional eigenvalue analysis. For all cases considered, the varicose wake modes are most amplified in terms of maximum N-factors, with the cylindrical roughness element being the most effective shape.