存在轴向分布不平衡质量多盘拉杆转子非线性动力学特性

Nonlinear Dynamic Characteristics of Multi-disc Rod Fastening Rotor with Axial Unbalance Mass Distribution

多级透平叶片故障是燃气轮机气路故障的主要模式,叶片故障表现为质量在轴向分布不均匀。对存在轴向分布不平衡质量的多盘拉杆转子动力学特性展开研究,使用集中质量法建立了四盘拉杆转子模型,采用不同盘上的质量不平衡模拟不同部位的叶片故障,并考虑油膜力与轮盘接触效应等非线性因素。使用四阶龙格-库塔法对模型进行求解,得出轴承处的频谱、轴心轨迹等曲线图。分析不同转速下当转子两个盘上存在叶片故障时,故障位置对转子动力学特性的影响,结果表明当两个盘故障位置发生变化时,轴承频谱、轴心轨迹和相位差的变化具有一定规律性。此结果能为燃机转子的状态监测和故障诊断提供一定的理论依据。

Multi-stage turbine blade fault is the main mode of gas path fault of gas turbines,and blade fault is manifested by uneven axial mass distribution.The dynamic characteristics of a multi-disc rod fastening rotor with axial unbalance mass distribution is studied.A four-disc rod fastening rotor model is established by lumped mass method.The mass unbalance of different discs is used to simulate blade faults in different parts,and the nonlinear factors such as oil film force and disc contact effect are considered.The fourth order Runge-Kutta method is used to solve the model,and the spectrum and axis trajectory curves are obtained.The influence of fault location on rotor dynamic characteristics is analyzed when there are blade faults on the two disks of the rotor at different speeds.The results show that when the fault location of the two disks changes,the changes of bearing spectrum,shaft center trajectory and phase difference have a certain regularity.The results can provide a theoretical basis for gas turbine rotor condition monitoring and fault diagnosis.