Experiments on the Dynamic Behavior of a Supercritical Rotor

Abstract

Tests have been performed on supercritical rotors to determine the sensitivity to unbalance and the suitability of balancing techniques. Results are presented for a rotor with an overhanging disk and supported on two rolling element bearings in series with squeeze-film dampers. The rotor has two flexural modes with high relative strain energy in the speed range up to 55,000 rpm. After completion of the balancing exercise the rotor could be run to maximum speed and was found to be stable and free from half-frequency whirl instability, depending on the oil inlet pressure of the dampers. Pressurization of the dampers and increasing the clearance of the dampers had a very desirable effect on the stability behavior and the unbalance response.