A novel method for studying fluid-solid interaction problems of the rotor system in air bearings with manufacturing errors

Abstract

A novel method for studying fluid–solid interaction problems of the rotor system in air bearings is proposed. The overall transfer equation of the rotor system is established based on the new version of transfer matrix method for multibody systems (NV-MSTMM), coupling with the extended transient Reynold equation, which achieves the two-way fluid–solid interaction analysis of the rotor system. The transfer matrix of the spatial flexible Timoshenko beam is first derived based on NV-MSTMM. The accuracy of the proposed approach is verified by an experiment and published literature. The influence of manufacturing errors including roundness, convexity, concavity and tapers on the dynamic performance of the rotor system is investigated comprehensively. The results show that the types and amplitude of manufacturing errors have complex effects on dynamic performance. Roundness with spatial numbers of 3 to 6, concavity and taper1 errors decrease the error motion amplitude, while convexity and taper2 errors increase it. Especially, roundness errors with spatial numbers of 1 and 2 notably increase the error motion amplitude, which should be avoided strictly.