PROGRESS IN THE RESEARCH OF HYPERSONIC AND HIGHENTHALPY BOUNDARY LAYER INSTABILITIES AND TRANSITION

Boundary layer transition from laminar to turbulence is of vital importance to the design of hypersonic vehicles. With continuous expansion of flight speed and altitude domains, the hightemperature gas effects in hypersonic highenthalpy boundary layers invalidate the calorically perfect gas assumption. They can thus largely influence the flow transition process. Relevant research is multiinterdisciplinary and multiphysics coupling. In recent years, the hypersonic highenthalpy boundary layer transition has received increasing interest worldwide owing to rapid development of vehicle design. Recent progress is reviewed in this article. Firstly, commonly used hightemperature gas models are introduced, especially the thermochemical nonequilibrium models. Then, the prevailing computational methods for highenthalpy flows, including the shockcapturing, shockfitting and boundary layer equation methods are introduced. The progress in experimental techniques for highenthalpy wind tunnels and flight tests are also summarized. Afterward, the influences of hightemperature effects on the receptivity, modal growth, transient growth and nonlinear interactions in the transition process are reviewed. Here some phenomena has received wide interests that the third mode and the supersonic mode appear at relatively large growth rates in the streamwise instability. Finally, the progress is summarized, and future researches are briefly prospected. © 2022 Chinese Journal of Theoretical and Applied Mechanics Press. All rights reserved.