液压阻尼器对模型旋翼地面共振的影响

 分析了某采用定压阀和补油装置的液压阻尼器的非线性特性。对无铰式模型旋翼的地面共振稳定性进行了数值仿真研究,分析了两种不同的非线性液压阻尼器对地面共振稳定性的影响。结果表明：由于补油分配阀间隙的影响,阻尼器低速时的有效阻尼大大下降;在无阻尼器的模型旋翼稳定的转速区内,该阻尼器不能改善系统小扰动情况时的动稳定性;在无阻尼器的模型旋翼不稳定区内,系统将出现极限环,且极限环幅值随补油分配阀间隙的增大而增大。研究结果对液压阻尼器的设计具有参考价值。

Influence of Nonlinear Hydraulic Lag Damper on Scaled Rotor Ground Resonance

Nonlinear characteristics of a hydraulic lag damper with pressure relief valves and a filling-oil device are analyzed. Numerical simulated investigations are conducted for the ground resonance stability of a hingeless scaled rotor. Influences of two different types of nonlinear hydraulic lag dampers on ground resonance are analyzed. The results show that the equivalent damping of the lag damper at low velocities decreases significantly due to the free-play of the filling-oil valve. As a result, at each rotor angular velocity where the basic damperless rotor remains stable, the lag damper cannot improve the system dynamic stability at low perturbations. During the basic damperless rotor instability margin, stable limit cycles are present due to the nonlinear hydraulic lag dampers. The limit cycle amplitude is increased as the free-play of the filling-oil valve increases. The present investigation is of value for hydraulic lag damper design.