共轴式直升机地面共振的旋翼参数影响分析

建立了共轴式直升机地面共振分析模型,采用特征值分析法计算得到了直升机地面共振模态特性,分析了上下旋翼间距、旋翼摆振铰外伸量、摆振刚度及摆振阻尼比等旋翼设计参数对共轴式直升机动稳定性的影响。研究发现,减小上下旋翼间距可提高系统动稳定性,且不稳定中心远离工作转速;增大摆振刚度及旋翼摆振铰外伸量可提高系统动稳定性,且不稳定中心远离工作转速;增大摆振阻尼比可提高系统动稳定性,但不稳定中心稍接近工作转速。

Analysis of Rotor Parameters of Coaxial Helicopter Ground Resonance

An analytical model of coaxial articulated rotor helicopter ground resonance was established, and the modalcharacteristics of the ground resonance was got with method of eigenvalue analysis. The distance between upper and lowerrotor, rotor lag hinge offset, lag rigidity and lag damping ratio of rotor design parameters were analyzed on the influence ofcoaxial helicopter dynamic stability. The results showed that reducing of the distance between upper and lower rotor, thedynamic stability of the system improved, and dynamic instability center away from operating speed; increasing of lag rigid.ity and rotor lag hinge offset, the dynamic stability of the system improved, and dynamic instability center away from oper.ating speed; increasing of lag damping ratio, the dynamic stability of system improved, but dynamic instability center a lit.tle closer to operating speed.