Threshold Performance Optimization of a Rotor-Bearing System Subjected to Leakage Excitation

The fluid leakage in shroud of the blades and the labyrinth seal of turbomachinery may induce instability and limit the output rating. In this work, the optimization technique has been used to find the diameters of shaft elements and the bearing supports so that the optimized rotor-bearing system can sustain larger fluid leakage force. The results show that the threshold performance of rotor-bearing systems can be significantly improved by slight modification of the shaft diameters. The results also indicate that, the threshold performance can be improved more significantly by the combination of optimum bearing supports and optimum shaft diameters.