Stability Analysis of Whirl Flutter in a Nonlinear Gimballed Rotor-Nacelle System
Stability Analysis of Whirl Flutter in a Nonlinear Gimballed Rotor-Nacelle System
复制标题
DOI：
10.4050/f-0075-2019-14584
复制
发表时间：
2019-05
期刊：
影响因子：
--
通讯作者：
C. Mair;D. Rezgui;B. Titurus
中科院分区：
文献类型：
--
作者：
C. Mair;D. Rezgui;B. Titurus
涡动颤振是一种气动弹性不稳定，会影响螺旋桨/旋翼及其所安装的飞机。随着非线性效应的加入，其行为和分析的复杂性显著增加。由于旋翼桨叶长而灵活，倾转旋翼飞机特别容易受到影响。本文研究了结构非线性对基本框架旋翼-吊舱模型涡振稳定性的影响，并与基线线性刚度模型进行了比较。在现有文献中采用了一个9自由度模型，该模型具有准定常气动力，叶片可以在拍打运动和超前滞后运动中循环和集体运动。本文研究的非线性是将三次和五次软化和硬化引入万向节摆动刚度。研究通过分叉和特征值分析相结合的方法进行，并辅之以时间模拟。在某些情况下，非线性会导致颤振行为存在于通过线性分析预测为稳定的参数值区域内。这种影响在重新绘制的系统稳定边界中得到了充分的体现。
Whirl flutter is an aeroelastic instability that affects propellers/rotors and the aircraft on which they are mounted. The complexity of its behaviour and analysis increases significantly with the addition of nonlinear effects. With their long and flexible rotor blades, tiltrotor aircraft are particularly susceptible. This paper investigates the impact of structural nonlinearity on the whirl flutter stability of a basic gimballed rotor-nacelle model, compared to a baseline linear stiffness version. A 9-DoF model with quasi-steady aerodynamics and blades that can move both cyclically and collectively in both flapping and lead-lag motions was adopted from existing literature. The nonlinearities investigated in this paper are cubic and quintic softening and hardening introduced to the gimbal flapping stiffness. The investigation is conducted through a combination of bifurcation and eigenvalue analyses, supplemented by time simulations. In some cases, the nonlinearities are shown to cause whirl flutter behaviour to exist in parameter value regions that are predicted to be stable by linear analysis. This impact is fully captured in the redrawn system stability boundary.