An analysis on the influence of air ingestion on vibration damping properties of squeeze film dampers

Considering the effect of air ingestion, a three-dimensional CFD model of open ends squeeze film damper (SFD) was established based on transient time step solution method and dynamic mesh technique. And the model was experimentally verified by bidirectional excitation experiment. Experiment and CFD simulation shows that air ingestion was caused by the pressure difference between oil film and external environment. With increasing precession frequency and eccentricity ratio, air ingestion area is gradually expanding resulting in increasing air volume, shrinking effective coverage of oil film and performance degradation of damper. Thereby, oil film damping shows the tendency to reduce. Compared with the case without considering air ingestion, the case considering air ingestion has obviously smaller peak pressure in the CFD simulation.