Transition and Stability of High-Speed Boundary Layers

This article reviews stability and laminar-turbulent transition in high-speed boundary-layer flows, emphasizing qualitative features of the disturbance spectrum leading to new mechanisms of receptivity and instability. It is shown that the extension of subsonic and low-supersonic stability concepts and transition prediction methods to hypersonic speeds is not straightforward. The discussion focuses on theoretical models providing insights into the physics of instability and helping make proper decisions on transition control strategies.