后掠机翼的横流不稳定性分析及转捩预测

后掠机翼边界层的流动稳定性及转捩对翼型的设计及优化有着重要的参考价值，而横流失稳是引起后掠机翼边界层转捩的关键因素之一.以NLF（2）-0415翼型为研究对象，采用三维可压缩Navier-Stokes方程并结合γ-Re_θt转捩模式计算了展向无限长后掠机翼的基本流场.由于原始γ-Re_θt模式只能预测流向边界层转捩，因此在原始转捩模式中添加横流间歇因子项，进而对复杂构型进行横流不稳定性转捩预测.计算结果显示，利用改进后γ-Re_θt转捩模式预测得到的后掠翼型的转捩位置与实验数据吻合较好，证明了修正的转换模式的合理性和实用性. 

Cross-flow Instability Analysis and Transition Prediction of Swept Wing

The stability and transition of swept wing boundary layers have important reference value to the design and optimization of airfoil. The cross-flow instability is one of the key parameters for boundary layer transition. Based on the NLF(2)-0415 airfoil profile, the mean flow of the swept-wing boundary layer was calculated by numerically solving the three-dimensional compressible Navier-Stocks equation with γ-Re_θt transition model. Considering the original transition model could only predict the transition along streamwise, cross-flow intermittency factor was established to the original transition model to conduct the numerical simulation of cross-flow instabilities transition for complex configuration. The numerical results show that the improved transition model could predict the location of cross-flow instability transition of swept wing which is in good agreement with the test data. Therefore, improved transition model is reasonable and practical.