Rotor Dynamic Of Bearing-Rotor System Supported By Gas Foil Bearing Under Two Housing Excitations: Random Vibration And Transient Impulse

Abstract In this paper, a dynamic model of the turbo cooler bearing-rotor system was developed based on the finite element method (FEM). The elastic shaft section was constructed using Timoshenko beam unit and the impeller and thrust disc were treated as rigid concentrated mass points. A mathematical characterization model was also established to describe the random vibration and transient impulse under the operating conditions of the turbo cooler. The nonlinear vibration characteristics of the bearing-rotor system of the turbo cooler under random vibration and transient impulse were studied. Additionally, the performance of the first-generation GFB and the third-generation GFB were compared and analyzed through the stability of the bearing-rotor system. Transient impulse and random vibration can significantly affect the dynamic stability of bearing-rotor system. Therefore, optimization studies on the stiffness distribution of gas foil bearings are essential to enhance the system's capability to withstand multiple excitation conditions.