Modeling and analysis of dynamic behaviors for a flexible rotor system supporte d in tilting pad aerodynamic b earings

The dynamic behaviors of the flexible rotor with the three-tilting pad aerodynamic bearings support are investigated. The unsteady lubrication equation of single pad is solved by the differential transformation method, and the nonlinear gas film forces of three-tilting pad aerodynamic bearing are obtained by an assembly approach. The motion model of the aerodynamic bearing-flexible stepped rotor system is established by considering the equilibrium condition in the joint of stepped axis. The gyroscopic effect, moment of inertia and transmission of power are taken into account in the model. The dynamic behaviors and bifurcation phenomenon of the aerodynamic bearing-flexible rotor system under different rotating velocities are investigated by the orbit diagram, Poincare maps, bifurcation diagram and frequency spectrum diagram. The responses characteristics of flexible rotor system supported in three-tilting pad aerodynamic bearing with different load carrying capacities are analyzed. And then the influence of the preload, pivot ratio and mass eccentricity on the dynamic responses of the rotor system is also studied. (C) 2022 Elsevier Inc. All rights reserved.