基于转静子耦合的组合压气机动力特性分析

Analysis on Dynamic Characteristics of Combined Compressor Based on Coupling of Rotor and Stator

组合压气机被广泛用于中小型航空发动机,高转速和机匣薄壁化使得转、静子之间的耦合日趋严重,有必要对其转子-支承-机匣系统的动力特性进行研究。建立了不同机匣厚度的组合压气机实体模型和有限元模型,采用有限元法,分别对组合压气机转子-支承系统和转子-支承-机匣系统进行动力特性分析,对机匣部件进行模态分析,并对转子-支承-机匣系统进行不平衡响应分析。结果表明:转、静子耦合不仅使组合压气机系统多出以机匣弯曲振动为主振型的临界转速,同时对以转子弯曲振动为主振型的临界转速影响明显,在工程中需考虑转、静子耦合效应对发动机临界转速的影响。

The combined compressors are widely used in the small and medium-sized aeroengines. The dynamic coupling phe- nomenon between the rotor and stator is more and more serious because of the higher speed and thinner case. It is necessary to study the dynamic characteristics of rotor-bearing-case system of the combine compressor. The physical models and the finite element models of the combined compressor with different case thickness were established. The dynamic characteristic of the combined compressor was analyzed by the rotor-bearing system and the rotor-bearing-case system by the finite method. The model analysis was performed on the case, and the unbalance response was analyzed on the rotor-bearing-case system. The results show that a new critical speed appeared because of the coupling of rotor and stator, which main shape is the flexure vibration of the case. At the same time, the critical speeds with the rotor＇ s flexure vibration are also impacted obviously. The coupling effect of rotor and stator on the critical speed should be considered in the engineering application.