直升机桨叶挥舞单摆吸振器吸振性能研究

The Study on Vibration Reducing Performance of HelicopterBlade Flapwise Pendulum Absorbers

设计了一种桨叶挥舞单摆吸振器,用来降低直升机旋翼系统的5阶垂向振动载荷。为了研究挥舞单摆吸振器的吸振性能,基于桨叶三维梁有限元模型,建立了旋翼与挥舞单摆吸振器的耦合动力学分析模型。以旋翼系统的固有频率和垂向载荷振幅为考核指标,开展旋翼-吸振器耦合动力学模型的动特性分析与吸振性能仿真分析,并研究了吸振器摆长与吸振频率的关系,以及不同吸振频率对吸振性能的影响。研究结果表明:旋翼加装挥舞单摆吸振器后,旋翼自身动特性变化很小,可以忽略吸振器对旋翼自身动特性的影响;通过合理选择吸振器吸振频率,旋翼5阶垂向振动载荷可以降低39%,减振效果良好;吸振器重量仅占目标旋翼系统重量的4%左右,具有显著的重量优势。

A blade flapwise pendulum absorber was designed to reduce the 5th harmonic flapwise loads of helicopter rotor system.In order to study the vibration reducing performance of the flapwise pendulum absorber,the coupling dynamic analysis model of the rotor and the flapwise pendulum absorber was established based on the three-dimensional blade beam finite element model.Taking the natural frequency and flapwise loads amplitude of the rotor system as the evaluation index,the dynamic characteristic analysis and vibration reducing performance simulation analysis of the rotor-absorber coupling dynamic model were carried out,and the relationship between the pendulum length and the vibration reducing frequency,as well as influence of different vibration reducing frequency on the vibration reducing performance were studied.The simulation result showed that the rotor’s own dynamic change very little after the rotor was installed with the flapwise pendulum absorber,and the influence of the absorber on the rotor’s own dynamic characteristics could be ignored.Through reasonable selection of the vibration reducing frequency of the vibration absorber,the 5th harmonic flapwise loads of the rotor could be reduced by 39%with satisfying performance.The absorber accounted for about 4%of the weight of the target rotor system,giving it a significant weight advantage.