共轴刚性旋翼桨尖间距建模与参数影响研究

共轴刚性旋翼桨尖间距是涉及直升机飞行安全的关键问题,建立了共轴刚性旋翼综合气弹分析模型,开展了升力偏置、前进比、旋翼交叉角、提前操纵角以及高阶气动载荷等因素对桨尖间距影响的数值计算和分析研究.研究结果表明,升力偏置是影响桨尖间距最重要的因素,随着升力偏置量增大,桨尖间距呈线性减小趋势,而且旋翼拉力越大,趋势直线的斜率就越大,本质上桨尖间距是由桨根动态挥舞弯矩决定的,桨尖间距不会随飞行速度的增大而减小,旋翼交叉角对桨尖间距有一定的调节作用,提前操纵角和高阶气动载荷则对桨尖间距影响很小.

Modeling AND PARAMETRIC STUDY OF tip clearance of coaxial rigid rotor

Tip clearance of a coaxial rigid rotor is a key index related to helicopter safety. In this paper, an aeroelastic model for the coaxial rigid rotor was established, and the influences of various parameters on the tip clearance were carried out, including lateral lift offset, advance ratio, rotor crossover angle, control phase and high order harmonic aerodynamic loads. The results showed that the tip clearance decreases linearly with an increase in lift offset, and the larger the tension of the rotor is, the greater the decline rate of the tip clearance is. Moreover, the tip clearance does not decrease with the increasing flight speed, and the control phase and high order harmonic aerodynamic loads have little influence on tip clearance, but the rotor crossover angle has a certain effect on the tip clearance. Therefore, the lift offset is the most import parameter affecting the tip clearance, which indicates that the rotor tip clearance is mainly controlled by the flapping bending moment at blade root.