Numerical Investigation on Periodically Time-Varying Dynamic Characteristics of Static Eccentric Squeeze Film Damper

To study the periodically time-varying dynamic characteristics of static eccentric squeeze film damper (SFD), two models of computational fluid dynamics were established by dynamic mesh method of transient flow field. Numerical investigation was carried out for periodically time-varying dynamic characteristics of static eccentric SFD and the results were verified by theoretical formulas. As shown by the study, due to the presence of static eccentricity, oil-film damping and stiffness present distinct periodically time-varying characteristics with precession angle and their peak values occur in different circumferential positions; excessive static eccentricity will significantly alter the distribution of oil film pressure and direction of radial force of oil film. For SFD in practice, when dynamic eccentricity is smaller, the periodically time-varying characteristics are subjected to the dual influence of oil supply hole and static eccentricity. With the augment of dynamic eccentricity, the influence from oil supply hole is reduced, and the periodically time-varying characteristics are mainly embodied as the influence of static eccentricity.