Dynamic behaviour of rotors supported by fluid-film bearings operated close to fluid-induced instability

Abstract

This paper is focused on an analysis of rotating systems with fluid-film bearings, especially on their nonlinear behaviour in the course of developing fluid-induced instability. The studied system consists of Jeffcott rotor supported by a fluid-film bearing characterised by the Reynolds equation. The steady state response of the system is investigated by means of an approximate analytical solution of the Reynolds equation while the transient response of the system is investigated using a complex numerical solution. Results suggest that the rotor exercise a bounded chaotic motion if it becomes unstable. If the fluid-induced instability further develops, the motion actually becomes less chaotic and can be characterised as quasi-periodic.