A boundary layer transition criteria on three-dimensional flow for high-speed aircraft

Boundary layer transition of high-Mach vehicles, which could greatly affect the vehicle’s aerodynamic performance and thermal characteristics, is an inevitable flow phenomenon during flight. The aerodynamic shape of advanced high-Mach vehicles is very complex, leading to distinct three-dimensional flow characteristics. In this paper, an applicable method based on a three-dimensional flow field is developed to predict the transition by identifying the boundary layer characteristic parameters. The influence of various flight parameters on the boundary layer transition has been analyzed. It indicates that this developed method can accurately predict the boundary layer transition caused by streamwise and crossflow instability, which is of great significance for improving the thermodynamic design and avoiding the risks during the flight tests.