Amplification factor transport transition model for complex three-dimensional configurations in high-speed flows

A new transition model is proposed for engineering applications on complex hypersonic vehicles. Based on a one-equation amplification factor transport model for streamwise instability in high-speed flows, we introduce an individual transport equation to simulate the amplification of crossflow instabilities, and propose a modified algebraic intermittency factor to incorporate the crossflow effect. The new transition model is initially validated for a series of three-dimensional configurations tested in hypersonic wind tunnels, including an elliptic cone, a lifting body, and the X-33 vehicle. Comparisons with available experimental data indicate that the new model handles streamwise-instability- and crossflow-induced transitions and captures the effects of compressibility and the Reynolds number. The model is further applied to a full-scale airbreathing vehicle under flight conditions, and the results demonstrate its ability to predict boundary layer transition and aerodynamic heating for complex engineering configurations.