CFD research on hydrodynamic gas bearings with different styles of grooves

Abstract

The gas bearing is an appealing technology which is widely used in turbo-machine in large-scale cryogenic systems for its inherent characteristic of oil-free and high-speed capability. The hydrodynamic gas bearings are more effective on cryogenic system but have less load capacity and dynamic stability by comparing with externally pressurized gas bearings. Etching some grooves on shaft or bearing is proved to be effective on improving the static and dynamic performance by experiments. The performance parameters of hydrodynamic gas bearing, such as load capacity and stiffness, are dominated by the styles and the geometric parameters of groove. In this paper, the effect of groove styles and geometric parameters on the performance parameters of hydrodynamic gas bearings is presented. And a novel style of groove is designed which can effectively improve the static and dynamic performance. The results based on the calculation of CFD show that: geometric parameters of the groove do have some influence on static and dynamic performance of hydrodynamic gas bearings, and there is an optimal objective value for each parameter of groove which makes load capacity and stiffness maximum. Compared with the spiral-style and π-style groove, the novel style of groove presented in this paper has better static performance.