A one-equation transition model based on local variables

In order to simplify the transition model by substituting two equations with one, the local turbulence intensity and pressure gradient parameter are introduced to construct the new empirical correlations for Re_θc and F_length. The new model can be coupled with SST turbulence model, whose parameters are calibrated by the Schubauer and Klebanoff flat plate. Furthermore, by analyzing the relations of transport equations between SST and SA, f_t2 function, a part of the source terms, is corrected to realize the coupling of one equation transition model and SA turbulence model. Finally, numerical analysis are conducted on S809 airfoil and DLR F5 wing, and the results indicate that: simulations using one-equation transition models agree well with experiments in linear region, and the error of force coefficients is less than 3% for S809 foil; for DLR-F5 wing, the transition locations also meet well with the experiments except for the root part. Both of the cases demonstrate that the polished model performs quite accurately in the prediction of transition.