Performance of turbulence models for transonic flows in a diffuser

Eight turbulence models frequently used in aerodynamics have been employed in the detailed numerical investigations for transonic flows in the Sajben diffuser, to assess the predictive capabilities of the turbulence models for shock wave/turbulent boundary layer interactions (SWTBLI) in internal flows. The eight turbulence models include: the Spalart Allmaras model, the standard k - epsilon model, the RNG k - epsilon model, the realizable k - epsilon model, the standard k - omega model, the SST k - omega model, the nu(2) - f model and the Reynolds stress model. The performance of the different turbulence models adopted has been systematically assessed by comparing the numerical results with the available experimental data. The comparisons show that the predictive performance becomes worse as the shock wave becomes stronger. The (nu) over tilde (2) - f model and the SST k - omega model perform much better than other models, and the SST k - omega model predicts a little better than the (nu) over tilde (2) - f model for pressure on walls and velocity profile, whereas the (nu) over tilde (2) - f model predicts a little better than the SST k - omega model for separation location, reattachment location and separation length for strong shock case.