One-Equation Amplification-Factor-Transport Transition Model for High-Speed Flows

A one-equation transition model is proposed for high-speed transitional flows. The model is based on the amplification-factor-transport framework and involves only one transport equation for the amplification factor of streamwise instabilities. A new algebraic intermittency factor is established and applied to a turbulence model to predict transition, and the model is tested by applying it to several cases over a wide speed range. Comparisons with linear stability theory and available experimental data indicate that the model handles first- and second-mode-induced transitions in supersonic and hypersonic flows and reasonably captures the effects of Mach number, wall-to-edge temperature ratio, and nose bluntness. The new one-equation model offers reduced computational burden and simpler implementation while retaining a reasonable prediction accuracy.