无轴承旋翼／减摆器的气动弹性力学研究

Aeroelastic Mechanical Analysis of Bearingless Rotor with Elastomeric Lag Dampers

将无轴承旋翼的主桨叶、柔性梁和套管3个部分各自离散成若干梁单元,并将桨叶运动的物理坐标转换为挥舞、摆振、扭转方向的模态坐标,根据Hamilton原理建立旋翼气弹分析的动力学模型.采用Newton-Raphson迭代方法,用时间有限元法进行旋翼稳态响应的数值求解,并根据时域非线性黏弹减摆器模型,在直升机定常前飞条件下配平计算旋翼/黏弹减摆器耦合系统非线性气弹周期响应,然后基于Floquet理论进行稳定性分析,并讨论了桨叶载荷系数对旋翼稳定性的影响.结果表明:该减摆器模型能充分提高摆振阻尼,从而改善无轴承旋翼的稳定性.

Based on the principle of Hamilton, dividing the main blade, flexbeam and torque tube into several beam elements, the bearingless rotor is nonlinearly modeled in this paper through modal transformation. By Newton-Raphson iteration and temporal finite element method, the above nonlinear equations are solved. Based on Floquet theory, adopting a time domain nonlinear elastomeric lag damper model,through the intergration of damper into a bearingless rotor comprehensive analysis, the influence of the damper on bearingless rotor aeroelastic behavior in forward flight is examined. The results show that this damper model improves the lag damping effectively. In addition, the influence of thrust coefficient on blades; aeroelastic stability is discussed. The conclutions coincide with related literatures very well.