Numerical analysis of a hydrodynamic air bearing with electromagnetic assistance

Abstract

An air bearing system with active electromagnetic assistance is proposed, and its dynamic characteristics are numerically analysed. The system is based on herringbone groove hydrodynamic journal bearings. The air bearing system adopts electromagnetic force to assist in lifting the rotor and lowering the lift-off speed of the bearing and adjusting the dynamic stiffness. The characteristics of the bearings are examined using the two-way coupled fluid-structure interaction method for different operating environments. The fluid simulation is performed in ANSYS Fluent and coupled with the motion equations. The fluid-structure interaction analytical model is cross-examined with the published experimental results and is used to analyse the proposed system. The results demonstrate that the lift-off speed is lowered by 46.04% and that the electromagnetic force can compensate for the loss of stiffness at an altitude of 4000 m.