Transition model for predicting crossflow instabilities

As the γ- Re_θt̄ boundary layer transition model proposed by Langtry and Menter could only predict the transition along the streamwise, it is necessary to develop a γ- Re_θt̄ transition model so that it could conduct the numerical simulation of crossflow instabilities transition. With the theoretical analysis and numerical solution of Falkner-Skan-Cooke (FSC) three-dimensional boundary layer, combining the Thwaites pressure gradient factor with local swept angle to build the relationships for solving the Hartree pressure gradient factor β_H and the shape factor H₁₂, using the C1 criterion calibrated by the test data to get the crossflow instabilities transition displacement thickness Reynolds number, the crossflow transition criterion is established for complex configuration by solving the equations and data fitting. The model has been applied to conducting the numerical simulation of crossflow instabilities transition on the ONERA-M6 wing with 30° swept angle of leading edge, the DLR-F5 wing with variational swept angle of leading edge and the 6:1 prolate spheroids standard model. The numerical results show that the improved transition model could predict the location of crossflow instabilities transition of swept wing in good agreement with the test data. Therefore, the results indicate that the crossflow instabilities transition criterion built is reasonable and practical.