Parametric Study of the Unbalance Response of an Eccentric Sueeze Film Damper-Mounted Rigid Rotor

Abstract

This paper presents a limited parametric study of the unbalanced response of a rigid rotor supported by an eccentric squeeze film damper bearing. The rotor unbalance response is approximated by a trigonometric series whose coefficients are determined by the collocation method. The results indicate that for small static misalignments and unbalances, nonsynchronous components are negligible and the rotor response is an offset ellipse. Nonsynchronous components increase as both the unbalance and the static misalignment are increased. However, the amplitude of the rotor response is independent of the static misalignment direction. There is a tendency for the rotor to self-center in the vicinity of the resonance. This self-centering effect is more pronounced as the unbalance is increased and it is reduced as the static misalignment is increased. For large unbalances and static misalignments, both main resonant jump and secondary resonant jump are predicted at speeds above twice the system critical speed.