A novel nonlinear model of rotor/bearing/seal system and numerical analysis

作者：Li, Wei^*; Yang, Yi; Sheng, Deren; Chen, Jianhong

来源：Mechanism and Machine Theory, 2011, 46(5): 618-631.

DOI：10.1016/j.mechmachtheory.2011.01.002

• Steam excitation
• Hamilton principle
• Rotor
• Dynamic characteristics

A novel nonlinear model of rotor/bearing/seal system based on the Hamilton principle is proposed for steam turbine systems in power plants. The Musznyska model and unsteady bearing oil-film force model were applied to describe the nonlinear steam excitation force and oil-film force. The Runge-Kutta method was used to solve the motion equation of the rotor/seal/bearing system. The dynamic characteristics of the rotor/bearing/seal system were analyzed with bifurcation diagrams, time-history diagrams, trajectory diagrams, Poincare maps and frequency spectrums. The numerical analysis indicates that the seal force and the oil-film force influence the nonlinear dynamic characteristics of the rotor system. With the increase of rotation speed, the rotor system exhibits rich forms of periodic, double-periodic, multi-periodic, quasi-periodic and chaotic motion. The combined impact of steam excitation force and bearing oil-film force may cause a severe vibration which seriously affects the safety and stability of the rotor. The presented model provides a theoretic foundation for further research on the ultra-supercritical steam turbines.

• 出版日期2011-5
• 单位浙江大学