涡轴发动机弹性支撑外挤压油膜涡动特征频率

针对某型涡轴发动机整机台架测振时频谱分量多且对应激振源或调制因素不明确的问题，采用经验模式分解（empirical mode decomposition，简称EMD）对其振动数据进行滤波处理，发现某一中低频分量包含了原始数据较为显著的信息。经过多传感器、多状态测量，将测振参数进行时频分析，证明该频率分量为燃气发生器联合转子的亚同步频率，且二者之比为0.443。通过排除法和整机断滑油实验，确定该分量为燃气发生器转子前定心弹性支撑外挤压油膜涡动的特征频率。

Characteristic Frequency of Externally Squeeze Oil Whirl of Elastic Support on Turbo-Shaft Engine

In view of the fact that the frequency spectrum components of a turbo-shaft engine are numerous and unclear for vibration source or modulation, when it tested on test bed, the vibration data is filtered by empirical mode decomposition (EMD). It is found that the low-frequency component contains more significant information from the original data. After further multi-sensor and multi-state measurement and time-frequency analysis, it is demonstrated that the frequency component is the subsynchronous frequency of the gas generator combined with the rotor, and the ratio between them is 0.443. Finally, through the elimination method and the oil interruption of the whole engine, it is determined that this component is the characteristic frequency of the externally squeeze oil whirl of front elastic support on the gas generator combined withthe rotor.