ON THE NON-LINEAR DYNAMICS OF A FLEXIBLE ROTOR SUPPORTED ON POROUS OIL JOURNAL BEARINGS

摘要

In the present analysis dynamic response of a flexible rotor with a rigid disk under unbalance excitation mounted on porous oil journal bearings at the two ends is investigated. The system equation of motion is obtained by finite element formulation of Timoshenko Beam and the disk. The non-linear oil-film forces are calculated from the solution of the modified Reynolds equation simultaneously with Darcy’s equation. The system equation of motion is then solved by the Wilson- θ method. The effect of various non-dimensional rotorbearing parameters on the bifurcation behaviour of the system is studied. It is shown that the system undergoes Hopf bifurcation as the speed increases. Further, slenderness ratio and material properties of the rotor have profound effect on the bifurcation characteristics of the rotor-bearing system.