Prediction model of cross-flow instability transition in swept wing boundary layers

Through the theoretical analysis and numerical solution of classic Falkner-Skan-Cooke three-dimensional boundary layer similar solution, combining with the thought of two-dimensional boundary layer transition criteria, using the C1 criteria calibrated by the experimental data to get the cross-flow instability transition displacement thickness Reynolds number, the cross-flow transition criteria was established for fixed swept angle of wing leading edge by solving the equations and data fitting. The model was applied to conduct the numerical simulation of cross-flow instability transition on the ONERA-M6 wing with 30 degree swept angle of leading edge and NLF(2)-0415 infinite swept wing with 45 degree swept angle of leading edge. The simulated results show that the improved transition model can predict the location of cross-flow instability transition of swept wing precisely and be in good agreement with the experimental data. Therefore, the results indicate that the cross-flow instability transition criterion built is practical and valuable.