Analysis of Flow Models for Aerostatic Thrust Bearings with Porous Material

Abstract

The numerical determination of static characteristics of bearings allows a cost-efficient and fast pre-design. In this study, two flow models for aerostatic thrust bearings with pressurized porous material are presented and analyzed. The models are based on the coupling of the Reynolds equation for lubricants (REL) and the determination of pressure drop through porous material by Darcy’s law. The simplified model is based on the assumption of a one-dimensional axial flow through porous media. The extended model considers the three-dimensional flow in the porous body. The analysis includes pressurized air from 4 to 9 bar(a) with nominal clearance of 5 to 60 µm. Commercial CFD software was used to verify the results. The extended model allows a more accurate prediction about the performance in the critical gap range. In total, the results show good agreement with CFD within a short computation time.