Abstract
This paper presents the analysis of a large turbine-generator system with foundation effects. Approximate modal analysis is used to analyze the complicated rotor-foundation system. The system is decomposed into 1) rotors including gyroscopic effects, 2) bearings having nonsymmeric and speed dependent properties, and 3) flexible support structure. The dynamic characteristics of the bearing and support structure have significant effects on the rotor dynamics. The rotors are identified by finite element method. The stiffness and damping of the bearing are analyzed by the thermo-hydrodynamic lubrication analysis considering the deformation of the pads and bearings. The stiffness of the bearing spherical seat is analyzed by finite element method and verified by the scale test. The foundation properties are identified by finite element method and the shaker test. Typical rotor is used as an example to illustrate the application of this analysis. This method enables an efficient approach to predict the system vibration properties.
