Abstract
In order to study the impact of steam excited force, due to the steam turbine seals clearance, on rotor vibration and stability, a complete structural model of single-disc and single-span continuous rotor system with double bearings and shaft seals is set up. Besides the nonlinear factors such as bending, shearing effect and shaft asymmetry, the combined influence of both steam excited force and bearing oil-film force are taken into consideration. After discretization for the rotor using finite element method, a nonlinear dynamic model of rotor system is built based on the Hamilton principle. The rotor's motion under different spin velocity are studied through numerical analysis, and the results show that the dynamic behavior of rotor has obvious nonlinear characteristics.
