基于本征方程的柔性机翼非线性颤振分析

柔性机翼在气动载荷作用下常常会产生较大的变形,颤振特性会随之发生变化,针对此问题线性理论常常难以进行合理的预测。以几何精确本征梁模型建立了机翼的运动方程,耦合ONERA-EDlin非线性气动模型,建立了柔性机翼的非线性气动弹性分析模型。利用Newton-Raphson和Backward-Differentiation-Formula(BDF)分别求解机翼的静态变形和动态响应,基于机翼平衡位置附近的线性化方程来判断系统的稳定性,进而确定颤振临界速度。通过算例验证了模型的准确性,并分析了不同刚度、后掠角、机翼安装角等参数对颤振速度的影响。

Nonlinear flutter analysis of flexible wing based on intrinsic equations

Flexible wing usually suffered large deformation under aerodynamic loads,which can noticeably change the wing's flutter characteristics.Linear analysis methods may lead to inaccurate result for this problem.A methodology for very flexible wing's aeroelastic analysis is presented based on geometrically exact,fully intrinsic beam theory and ONERA-EDlin dynamic stall aerodynamic model.Newton-Raphson method and Backward-Differentiation-Formula (BDF) method are used for the solutions of static equilibrium and time simulation.The perturbation equations around equilibrium state are derived for analyzing the stability of aeroelastic system,in which the flutter velocity can be determined.Through examples,the proposed model is verified,and the effects of several parameters on flutter velocity are investigated,such as ratio of flapwise bending stiffness to torsional stiffness,the incidence angle and the sweep angle.