支承刚度对整机耦合振动影响的定量分析 *

Quantitative Analysisfor Effectsof Supports Stiffness on Whole Aero-Engine Coupling Vibration

关键词:  航空发动机  整机耦合振动  支承刚度  转静耦合  转静碰摩  有限元

Key words:  Aero-engine  Whole engine coupling vibration  Support stiffness  Rotor-stator coupling  Rotor-stator rubbing  Finite element method

摘要:

为研究支承刚度对航空发动机整机耦合振动的影响，以带机匣的航空发动机转子试验器为对象，建立了试验器的整机有限元模型。对试验器进行了整机模态试验，并利用试验结果对有限元模型进行了修正。在此基础上，分别改变前后支承刚度仿真分析了试验器前 3阶模态。通过定义转静耦合因子和截面转静碰摩危险系数，定量研究了支承刚度对试验器固有频率、整机模态振型、转子静子耦合程度、压气机和涡轮截面转静碰摩危险程度的影响。结果表明，支承刚度对刚体模态振型影响较大，所定义的转静截面碰摩危险系数能够定量反映截面转静碰摩危险程度，并且支承刚度对转静耦合程度和截面转静碰摩危险程度的影响呈非线性。

Abstract:

In order to study the effects of the supports stiffness on the whole aero-engine coupling vibration quantitatively，an aero-engine rotor rig with casing is selected to be the research object，and a finite element model of engine was built. The modal experiments of the rig were carried out，and the finite element model was updated and verified based on the modal experimental results. The first 3 order natural frequencies and modal shapes of the rig were calculated with different support stiffness values. By defining a rotor-stator coupling factor and a section rotor-stator rubbing risk coefficient，the effects of the supports stiffness on the natural frequencies， the whole modal shapes，the rotor-stator coupling degree and the rotor-stator rubbing risk of compressor section and turbo section were studied quantitatively. Results show that the support stiffness has a great influence on the rigid body modal shapes. The section rotor-stator rubbing risk can be quantitatively reflected by the section rotor-stator rubbing risk coefficient which defined in this paper. Moreover，the effects of the supports stiffness values on the rotor-stator coupling degree and the rotor-stator rubbing risk are nonlinear.