Transition prediction based on amplification factor and Spalart-Allmaras turbulence model

To verify the simulation accuracy of current model coupling amplification factor transport equation with Spalart-Allmaras (S-A) turbulence model, Schubauer and Klebanoff flat plate (S-K), S809 low speed airfoil, 30p30n multi-element airfoil and complicated 3-D HiLiftPW-1 configure were selected for free transition calculation, and then, simulation results were compared with experimental results. Separately, current coupling model was compared with Langtry-Menter (L-M)transition model for S809 test cases. Test examples indicate that current coupling transition model can basically capture transition location and transition process, meanwhile, current coupling model performs better than L-M transition model in separated flow transition, and simulation accuracy increases by 10%; the maximum error of multi-element airfoil's transition position simulated is 6. 5% compared with experiment data. For three dimensional high-lift configuration, comparison between full turbulence and free transition shows that considering boundary layer transition can simulate aerodynamic force coefficient more accurately and accuracy is promoted by 1%.