嵌入式挥舞吸振器对旋翼桨叶挥舞载荷的抑制研究

Flapwise Load Reduction of Rotor Blades by Embedded Flapwise Absorbers

为了抑制刚性旋翼桨叶的二阶挥舞交变载荷,在桨叶内部挥舞方向嵌入动力吸振器。为探究动力吸振器抑制旋翼桨根处二阶挥舞载荷的效果,通过建立旋翼桨叶与挥舞动力吸振器二自由度耦合系统模型,推导出嵌有挥舞吸振器的耦合系统的运动微分方程,比较液弹吸振器与弹性吸振器抑制挥舞方向载荷的效果,并对影响吸振器吸振性能和挥舞吸振器的动态特性的结构参数进行分析。研究表明,挥舞吸振器在旋转和不旋转时,其固有频率并未发生改变;液弹吸振器和弹性吸振器都能达到良好的降低桨叶挥舞方向低阶载荷的效果,但液弹吸振器所需行程明显小于弹性吸振器。

In order to suppress the second harmonic flapwise loads of stiff in-plane rotor blades,the dynamic absorbers need to be embedded in the blade cavity in the blade flapwise direction. To investigate the effect of the embedded absorber in the flapwise direction of the rotor blade on the second harmonic moment, the coupled dynamic model of rotor blade and flapwise dynamic absorber is established. The differential equations of motion of the rotor blade coupling system with flapwise absorber are derived by using the Lagrange equation. The comparison of load suppression effect of fluidelastic absorber and elas- tic absorber in blade flapwise direction on blade root is conducted. And the structural parameters affect- ing the absorber performance and the dynamic characteristics of flapwise absorber in rotating state are analyzed. The study shows that the natural frequency of flapwise absorber is not changed when it is rotating or not. Both fluidlastic absorber and elastic absorber can achieve good effect on reducing lower harmonic loads in the direction of flapwise of the blade, but the stroke of fluidlastic absorber is significantly less than that of the elastic absorber.