Modal analysis of a two-stage turbine rotor with gyroscopic effects

In this paper, the rotation of a two-stage turbine rotor is studied. The goal of this article is to present a practical understanding of terminology and behavior based in visualizing how a shaft vibrates, and examining issues that affect vibration. Analytical solutions to predict critical speeds are developed with the aid of the Lagrange method and the Modal analysis. Results are given in tables and diagrams. The matrix solution showed that the critical speeds change as the rotating speed of the shaft increases. It was inferred from the results that even new critical speeds could be generated. Due to the gyroscopic effects, the rotor undergoes some precession which is indicated by the Campbell diagrams.

Keywords:

rotordynamics , gyroscopic effects , Campbell diagrams