不可压缩流中机翼外挂系统的分叉分析

Analysis of Bifurcation of an Airfoil with an External Store in Incompressible Flow

考虑二元机翼外挂系统的三自由度动力学模型,建立了准定常气动力作用下机翼外挂系统的运动微分方程,通过Hopf分叉理论和数值模拟,研究了具有立方刚度非线性系统的颤振问题,并研究了系统临界颤振速度随线性刚度系数的变化规律。结果表明,机翼外挂系统将出现亚临界Hopf分叉,另外,随着线性刚度系数的增加,系统的临界颤振速度将减小。

A three-degree-of-freedom dynamic model of a two-dimensional wing with an external store is considered. The governing equations of the wing/store system are established on quasi-steady aerodynamics. The flutter of the wing with cubic nonlinear stiffness in incompressible flow is studied by using Hopf bifurcation theory and numerical simulation. Furthermore, the effects of the system parameters on the flutter critical velocity are discussed. The results show that there is a sub-critical Hopf bifurcation for the wing/store system and the flutter critical speed will decrease versus increasing of the linear stiffness coefficient.