双掠结构旋翼桨叶动力学特性研究

双掠旋翼桨叶不仅能够提高旋翼的气动性能，也能够有效降低旋翼噪声，但是由于双掠桨叶几何结构的特殊性，前掠角度和后掠角度的变化对其动力学特性有很大影响，有必要对双掠桨叶动力学特性开展研究。运用Harmilton原理推导桨叶的运动方程，采用有限元法对旋翼系统进行简化，通过求解广义特征值，得到桨叶的各阶固有频率.在此基础上,分析了前掠角度和后掠角度的变化对桨叶动特性的影响，得到参数影响规律。结果表明：前掠角度和后掠角度的变化对桨叶前三阶固有频率影响较小，随着后掠角度的增大，桨叶的四阶和五阶频率逐渐变小。研究结论对双掠结构桨叶优化设计提供了技术支持。

Study on Dynamic Charcteristics of Composite Double-Swept Blade

The rotor blade double-swept-tip geometry can not only improve the aerodynamic performance ,but also effectively reduce the rotor noise. However,due to the particularity of the geometric structure of the double swept blade,the changes of the sweep-forward angle and the backward sweep angle have a great impact on its dynamic characteristics,so it is necessary to study the dynamic characteristics of the double swept blade. The motion equation of the balde was derived with the Hamilton theory,the rotor system was simplified with the finite element method,the natural frequency of the blade were obtained by solving the generalized eigenvalue.In this basis,the influence of sweep-forward angle and sweep-backward angle on blade dynamic characteristics were analyzed,the results showed that sweep-forward angle and sweep-backward angle have little influence on the low natural frequencies of the balde,and the fourth and fifth natural frequencies of the blade gradually decrease with the increase of sweep-backward angle.The research results provide technical support for the optimization design of double-swept blades.