强阵风下大柔性机翼的非线性流固耦合响应分析

The geometric nonlinearity and aerodynamic nonlinearity cannot be ignored as the large flexible wing undergoes significant deformation when subjected to high gusts. In order to study the response of a large flexible wing under strong gusts, a fluid-structure interaction analysis method based on geometric nonlinear beam theory and computational fluid dynamics (CFD) was established. The fluid model and geometrically nonlinear beam model of a big flexible wing with a semi-aspect ratio of 9 were constructed, and the accuracy of the fluid-structure interaction simulation approach was confirmed by comparing wind tunnel tests of inverted flexible plate. The dynamic response characteristics of large flexible airfoils were examined at various gust ratios (R _G=0.1-0.4). In particular, the dynamic stall aerodynamic characteristics of the airfoils caused by gusts at large gust ratios (R _G=0.4) were examined. The gust response analysis was conducted at a Reynolds number of 10⁵. The results show that significant nonlinear bending deformation of the wing occurs with the increase of gust ratios, and the maximum bending deformation of the wing reaches 63% of the half-spread length at R _G=0.4. Meanwhile, the bending deformation of the wing reduces the width of the spreading distribution of the leading-edge vortex (LEV), which affects the distribution of aerodynamic forces and reduces the gust loads.