航空发动机转子一种振动跳跃问题及其工程控制的分岔分析

Analysis on bifurcation of a vibration jumping and engineering control in aero-engine rotor

为研究带挤压油膜阻尼器的航空发动机转子的振动跳跃问题,采用弹性支承的刚性转子模型,结合短轴承π油膜的油膜力模型,建立了系统的动力学方程.采用平均法和非线性动力学中的Chen-Langford(C-L)方法得到了关于轴承系数和转子偏心量参数平面内的转迁集,转迁集将参数平面划分为三个区域,不同区域内具有不同的分岔模式,其中区域Ⅰ为无跳跃现象的理想区域.通过一带有'软特性'非线性特性的附加结构,可以增加区域Ⅰ的范围,减小跳跃区域,扩展了系统的参数优选范围.

To investigate the problem of vibration jumping in the aero-engine with squeeze film damper,the aero-engine rotor was simplified as a rigid-rotor with elastic-support.Dynamic equations of the system were established according to the oil-film force model,which were obtained by short bearing approximation and π-film assumption.The transition set of system was obtained by averaging method and Chen-Langford （C-L） method.The parametric plane of bearing coefficient and eccentricity coefficient was divided into three different regions by the transition set.Given different characteristics of bifurcation in each region,the region Ⅰ is an ideal region without jumping phenomenon.Then,an additional structure with ＂soft characteristic＂ of nonlinearity could expand the ideal region Ⅰ,decrease the jumping interval and broaden the range of optimization parameter selection.