Application of γ-Re_θt̄-SA transition model in numertical simulation of flows around airfoils

The γ-Re_θt̄-SA transition model, which is composed of Spalart-Allmaras (S-A) one-equation turbulence model and γ-Re_θt̄ transition model, has been described in details, together -with the correction of the parameters in the model. Besides, the ambient source term method, which is proposed by Spalart in order to controlling the free flow turbulence attenuation, has been introduced in this model. Based on an in- house RANS solver, the γ-Re_θt̄-SA transition model has been developed, and been verified in simulations of the flow around various airfoils, including Aerospatiale-A, S809, and 30P30N multi-element foil. The results of simulation have been compared with the experimental data, which indicate that the model can predict transition accurately in various types of flow conditions, such as natural transition, separated transition and relaminarization. Moreover, the study cases have shown that the model meet engineering requirement in both precision and efficiency. Finally, the developed model profits the establishment of a hybrid RANS-LES model with the transition predicting capability in the future.