A review of hydro-turbine unit rotor system dynamic behavior: Multi-field coupling of a three-dimensional model

The dynamic behavior of hydro-turbine rotor system is a complex multi-field and nonlinear problem, which has been studied by many researchers. The analysis of the rotor system dynamic characteristics is usually carried out based on the behavior analysis of bearings, hydraulics, electromagnetics, etc., while the thermo-elasto-hydrodynamic characteristics of bearings are extremely important to numerical accuracy. Therefore, this paper first summarizes the research progress in bearing lubrication performance, and further summarizes the research on hydro-turbine rotor system dynamic characteristics, including the modal characteristics and dynamic response characteristics. Finally, this paper summarizes the main research progress of the hydro-turbine rotor system and proposes possible directions in future research. Literature review shows that the hydro-turbine runners and bearings have achieved multi-field coupling analysis of three-dimensional (3D) models, and some work on multi-field coupling of rotor systems has been carried out. The transition of 3D multi-field coupling from single component to rotor system is significant to accurately predict the rotor system dynamic characteristics and the solution of engineering problems, which requires further in-depth research on the multi-field coupling theory, numerical methods, 3D model integrity, simulation software, etc., and the spatiotemporal synergy between multi-fields should be fully considered.