Phenomenological γ-α transition model based on local onset and turbulent spot growth correlations

The latest characterization of turbulent spot growth accounting for wall temperature and compressibility effects along with a formulation of the transitional Reynolds stresses are assessed in the present gamma-alpha transition model. Additionally, previous model developments to reproduce the normal intermittency profile are now rederived based upon the exact Klebanoff profile. Furthermore, destruction and production terms of the intermittency equation are further refined assuring a more generic transition model. The construction of this transition model is primarily set up to be independent from the used turbulence model, allowing the most suitable to be selected by the user for the envisaged application. The newly developed gamma-alpha model is validated with the classical SST turbulence model for subsonic (with and without pressure gradient) and supersonic (with and without shock wave boundary layer interaction) test cases and has shown to outperform the classical gamma-Re-theta t model in onset location prediction, skin friction slope and overshoot.