Unbalance Response of a Flexible Rotor Supported by a Squeeze Film Damper

Abstract

This paper investigates the unbalance response of a squeeze film damper-mounted flexible rotor, Both concentric and eccentric damper operations are examined. Comparison between predicted and experimental results shows that the ’0’ film model is preferred to the π film model. Near the first pin-pin critical speed the ’0’ film model underestimates the damping effect and overestimates the centralizing force of the damper. By choosing a lower film rupture pressure in the theoretical model, better matches to the experimental results are obtained. The effects of air entrainment are shown to produce unsteady responses and jump phenomena of softening spring type. It is concluded that damper models having constant film rupture pressures do not truly represent the cavitation problem in squeeze film dampers.