固定瓦-可倾瓦动压气体轴承-转子系统的非线性运动分析

Analysis of Nonlinear Motion of A Rotor System Supported by Fixed-tilting Pad Self-acting Aerodynamic Bearings

针对固定瓦-可倾瓦组合动压气体轴承-柔性转子系统,研究系统的非线性动力学行为。运用微分变换法求解了可压缩气体润滑的Reynolds方程,得到了单块瓦的非线性气膜力,通过组装技术获得了固定瓦-可倾瓦动压气体轴承非线性气膜压力的分布。基于Newmark积分法,运用轴颈中心的运动轨迹图、时间历程图和Poincaré映射图,研究了组合动压气体轴承支承的柔性转子系统的非线性不平衡动力响应。在此基础上,进一步分析了瓦块不同支点比和预负荷系数对转子系统稳定性的影响,结果表明,选取合适的支点比和较大的预负荷系数时,有助于提高转子系统的运动稳定性。

The nonlinear dynamic behaviors of a flexible rotor system with fixed-tilting pad combined aerodynamic bearings support are investigated. The compressible gas lubricated Reynolds equation is solved by the differential transformation method, and then the nonlinear gas film forces of single pad are calculated. Based on the assembly method, the pressure distribution of nonlinear gas film of the fixed-tilting pad aerodynamic bearing is obtained. Based on the Newmark integral method, the nonlinear unbalanced responses of the flexible rotor system supported by combined aerodynamic bearings are investigated using the orbit diagram, the Poincaré map diagram and the time series diagram. On this basis, the effects of different pivot ratios and preload coefficients of the pads on the stability of the rotor system are analyzed further. The numerical results show that it can be helpful to improve the stability of the rotor system when chooses the proper pivot ratios and higher preload coefficients.