Hypersonic Transition and Turbulence

Abstract

Laminar‐turbulent transition and the subsequent development of the turbulent boundary layer at hypersonic speeds affect heat‐transfer, skin friction, and boundary‐layer separation. Particularly at high‐speeds, much remains unknown about the main mechanisms and the area remains one of active current research. The goal of this chapter is to provide the reader with an introduction to the current state of understanding, so it can serve as a starting point for further reading. Transition is the result of a complex, difficult to predict laminar‐instability process that can be very sensitive to apparently small factors. The transition process is summarized, with emphasis on those events that are specific to high speeds, along with the instability process and some parametric effects. In the second part of the chapter, the main properties of high speed turbulence are described to provide an understanding of qualitative and quantitative trends in surface loads at large Mach numbers where high‐temperature effects become active.