Effects of Oil Supply Conditions on Equivalent Damping and Circumferential Position Damping of Squeeze Film Damper

In order to study the effect of oil supply conditions on the damping characteristics of squeeze film damper, the damper modeling and numerical simulation are carried out by using computational fluid dynamics software. To ensure the correctness and rationality of the numerical simulation, the damping of the oil film is obtained by the bi-direction excitation rig based on the principle of mechanical impedance and compared with the numerical simulation results. The influence of the number of oil supply holes, the cross-sectional area of the oil supply hole, the size of the oil supply groove and the oil supply flow on the equivalent damping and circumferential damping of the damper are studied. The results show that, due to the influence of oil film pressure at the oil supply hole, the damping of the single hole oil supply damper presents the variation of the approximate harmonic function curve with the circumferential position, and the multiple symmetrically distributed feed holes can effectively suppress this effect. With three or four symmetrical feed holes in the damper, the damping of the different circumferential positions in one cycle is almost constant. For the shallow oil supply groove, the equivalent damping of the damper increases nonlinearly with the increasing of the eccentricity. When the oil supply groove is deep, the equivalent damping tends to decrease firstly and then increase with the increase of eccentricity. In addition, the damping characteristics of the damper are influenced by the width of the oil supply groove and the flow rate of the oil supply. The results will provide the basis for the design of squeeze film damper.