| Rotors mounted on fluid film bearings are suspected to experience fluid induced instabilities generating severe vibration problems. Fluid film bearings greatly contribute in the dynamic characteristics of these systems. Oil whirl and whip being the major examples of the fluid induced instabilities, they possess distinct and damaging symptoms (large forward circular precession with subsynchronous frequency).; In this thesis, the influence of rotor length, disk axial location and the disk unbalance on the fluid induced vibrations of a shaft-disk-bearing system is studied. Experiments on a rotor kit and numerical computations are carried out on the same setup. Shaft vibration data is collected and analyzed using standard instrumentations and computer software. This data is exported to spread sheet for further processing and extracting more results. In the numerical computations, a finite element software is used for mathematically modeling of the shaft, disk and bearings. The software has produced stiffness and damping maps for the bearings, the Campbell diagrams for the system and other plots used in the stability analysis. (Abstract shortened by UMI.)... |
