Study on Vibration Characteristics of an Asymmetric Dual-rotor System

Abstract

Two directional sections of rotors with different principal moments of the inertia are called an asymmetric rotor. Asymmetrical rotors are widely used in engineering. Because of the complex structure of asymmetrical shafts in rotating machine, it is very important to study vibration characteristics of asymmetrical dual-rotor systems of the aero-engine. Based on the structural characteristics of the rotor system of the aero-engine, an asymmetrical dual-rotor coupling dynamic model is proposed in this paper. In the linear coupling, Runge-Kutta is used to simulate dynamic characteristics of the asymmetrical dual-rotor system. The natural frequencies, coupled natural frequencies and vibration responses of the high pressure and the low pressure rotors are analyzed systematically. The results show that the system coupling produces complex vibrations, such as the harmonic resonance and the super-harmonic resonance, when the dual-rotor systems are linear coupled. In addition, the occurring mechanism of linear vibrations is verified through numerical simulations.