悬停状态下直升机尾桨/尾梁耦合动力稳定性分析

Dynamic Stability of Coupled Tail Rotor and Boom of a Helicopter in Hovering

针对直升机尾桨/尾梁动力稳定性分析问题,采用有限元方法,建立了一种考虑尾桨及尾梁相互作用的耦合振动模型。在此基础上,考虑桨叶上的气动力、气动力矩及其引起的桨毂附加激振力,建立了耦合的尾桨/尾梁气动弹性稳定性分析模型。研究了悬停状态下某直升机尾桨/尾梁耦合系统的动力稳定性问题。研究结果显示:不考虑尾桨气动力时,在较低阻尼水平下,该系统是动力稳定的;考虑尾桨气动力的作用后,在一定的阻尼水平下才能保证耦合系统的气动弹性稳定性。

In helicopter engineering, the dynamic stability of coupled tail rotor and boom is critical. A dynamic model of coupled tail rotor and boom of a helicopter in hovering was developed by finite element method for stability analysis. Furthermore, quasi-steady aerodynamics on the blades and its induced force on the rotor hub were introdueed to the coupled vibration system and the aeroelastic equation was formulated. Coupled vibration stability and aeroelastic stability were investigated for the coupled tail rotor and boom system of a helicopter in hovering. Numerical results show that the coupled vibration system is stable at very low damping level but higher damping is needed for the coupled aeroelastic system to keep stable.