Nonlinear dynamic behavior research on high-speed turbo-expander refrigerator rotor

摘要

Low-frequency coupled vibrations significantly affect the stability and safety of the high-speed turbo-machinery. This study focused on the nonlinear dynamic behaviors of high-speed turbo-expander refrigerator supported on aerostatic bearings. The critical speed characteristics changing with bearing gas supply pressure are given by numerical calculation and modal experiment methods. The results show that the restrained modal tests are closer to the results of operational tests, which provides the basic data for the dynamic analysis and fault diagnosis of the bearing-rotor system. The coupled vibration phenomenon are presented and discussed in the paper, and the adjustment measures for eliminating the coupled vibration are used to improve the stability of gas bearing-rotor system.