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

Abstract

There exist several sources of instability and mechanisms leading to turbulence which are specific to hypersonic flows over blunt capsules. One of them are discrete surface inhomogeneities such as attachment-point cavities, compression pads, gaps or steps between heat shield tiles or unevenly ablated thermal protection material, which can lead to premature laminar-turbulent transition downstream of the protuberance element or even bypass transition if the roughness height/cavity depth is sufficiently large.