Research Note: The Downstream Influence of Inertia on Simple Gas Bearing Element Performance

Abstract

In laminar flow between flat plates for parallel, radial inward, and in some circumstances radial outward flow, the flow velocity increases as the density falls. If the bearing is long enough, and the ambient pressure low enough, the film will ‘choke’, i.e. the pressure gradient at exit becomes infinite. An increase in the pressure at entry to the film then results in an exit plane pressure greater than ambient. The conditions for the above flows to choke are examined, and the effect on the performance of a simple, orifice-compensated, parallel-flow bearing element is described. It is found that load capacity is enhanced, but optimum stiffness reduced, when compared with an inertialess flow prediction.