Response and bifurcation of rotor with squeeze film damper supported on elastic foundation

Past researchers generally assumed rotor with squeeze film damper (SFD) to be rigidly supported. Very few researchers considered rotor with SFD to be elastically supported but did not analyze bifurcation. We now present our results on not only the response but also the bifurcation of rotor with SFD damper supported on elastic foundation. In the full paper, we present our method and results in much detail; here we give only a briefing. To analyze the bifurcation of nonlinear response of SFD rotor, we, like past researchers, determine the Floquet multiplier by solving the perturbation equations with numerical method. Unlike past researchers, whose method for determining Floquet multiplier was greatly handicapped by the fact that violent oscillations of the solution frequently occur in the initial stage of numerical integration, our novel method can bypass such violent oscillations. Simulation results are given in two figures. One figure, which consists of six subfigures, gives the effect of rotating speed on the response of SFD damper supported on elastic foundation; with increasing rotating speed, the nonlinear response evolves from quasi-period to period, then jumps between different periods, and finally returns to quasi-period; the corresponding bifurcations are saddle-node bifurcation and secondary Hopf bifurcation. The second figure, which consists of four subfigures, show that; the support stiffness has large influence on the response of bearings and film force in SFD; large support stiffness can lead to oil whirl in SFD.