Study on the Vibration Mitigation Characteristic of Dual Clearance Squeeze Film Damper

In this paper, a novel model of dual clearance squeeze film damper (DCSFD) was constructed considering convection effect and the vibration mitigation characteristic of DCSFD was researched. The DCSFD film force linearity was proposed. The response characteristics of rigid rotor containing DCSFD were studied based on the DCSFD model. A response experiment of the DCSFD was arranged, and the model was verified. A good consistence was achieved between the simulation and experiment. The experiment and simulation result manifests that the unbalance response of DCSFD was smaller than that of SFD at every excitation frequency. The DCSFD could inhibit the nonlinear vibration such as the bistability and bifurcation due to big mass eccentricity, and nonlinear film force for the DCSFD film force linearity was bigger than that for SFD. The thickness ratio of inner and outer film, pressure loss coefficient, and inner film thickness were the important parameters that have great influence on DCSFD vibration mitigation characteristic.