后掠翼边界层横流不稳定转捩预测模型

通过对经典Falkner-Skan-Cooke三维边界层相似解的理论分析和数值求解,结合二维边界层转捩判据的思想,采用由试验数据标定的C1准则关系式求解横流不稳定转捩位移厚度雷诺数,建立了针对固定前缘后掠角机翼的横流转捩判据,并且通过方程求解和数据拟合得到了该转捩判据的数学结果.应用该模型对30°前缘后掠角的ONERA-M6机翼和45°前缘后掠角的NLF(2)-0415无限展长机翼进行了横流不稳定转捩数值模拟.模拟结果显示:改进后的转捩模型预测所得到的转捩位置精度较高,均与后掠翼横流试验数据吻合较好,从而证明了构建的横流不稳定转捩判据的合理性和实用性. 

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.