Modeling and experimental validation of the vibration in an unbalance multi-stage rotor

Abstract

This work proposes a finite element method model to predict lateral vibration phenomena arising in the multi-stage rotor (seven stages) with unbalance, including damping and gyroscopic effects. The rotor dynamic analysis includes mathematical and experimental determination of the first and second critical speeds of the rotor and the assessment of the effects induced by the different unbalance combinations. The results show that while considering the unbalance effects in the impellers, critical speeds move to lower frequencies compared to normal conditions when the rotor is properly balanced. Finally, the results obtained analytically achieved a good degree of correspondence with experimental validation tests.