燃气轮机轴系的振动特性数值分析

Numerical Analysis on the Non-Synchronous Responses of Shaft System for Gas Turbine

针对非常复杂的燃气轮机轴系的振动控制,全局建模振动分析难度很大,因此把问题分别简化成对对称滑动轴承的Jefcot转子进行分析。采用用虚拟振幅法、跟踪固定点轨迹法和穷举法,通过固定支撑质量,改变转子质量,分析了不同质量比对轴系振动规律特性的影响,得出了最佳刚度、阻尼和最大振幅比与偏心率的变化关系。结果表明:在其它参数固定的情况下偏心率在小于0.378时刚度、阻尼和振幅比值稳定;在偏心率一定的情况下,随着支撑和转子质量比值的增大,最佳刚度、阻尼和振幅比值也随着增大。这于工程实际中的轴系稳定性具有参考价值。

For the very complex non-synchronous responses of shaft system for gas turbine,global modeling of vibration analysis is very difficult,so the problem is simplified into pairs symmetric slide bear- ings Jefcot rotor analysis.Using virtual amplitude method,tracking the fixed point locus method and the method of exhaustion,by fixing support mass and changing the rotor mass ,the impact of different mass ratio to law characteristics of the shaft vibration is analyzed,and the relationship of the best stiffness ,damping and the maximum amplitude ratio with the eccentricity is obtained.The results show that ：when other param- eters are fixed,and when the eccentricity is less than 0.378,the stiffness ,damping and amplitude ratio are stable; when eccentricity is fixed,optimal stiffness ,damping and amplitude ratio increase with the increas- ing of suppart and the rotor mass ratio.This is a reference value of shaft stability in engineering practice.