Three-Dimensional Finite Element Simulation of Nonlinear Dynamic Rotor Systems of a Turbocharger

Abstract

This paper presents the modeling procedure for a high-velocity rotor system (RS) combined with sliding bearings. The equations for motion of the RS parts were derived based on the model of a rotating elastic medium. Lubrication layers have been calculated with the use of the Reynolds equations. The discretization of the RS model has been carried out using three-dimensional contact finite element method and two-dimensional method of finite differences. The integration with respect to time is performed by an absolutely stable step-by-step method. The paper also compares and discusses computed and experimental amplitude-frequency characteristics of the self-oscillating turbocharger’s RS. The values of dynamic loads in parts, as well as reactions, clearances, and losses in bearings, computed based on the presented modeling procedure make the RS designing more accurate and reliable.