Pressure and flow characteristics in a shallow hydrostatic pocket with rounded pocket/land joints

Abstract

The paper studies the development of the flow and pressure maps in a shallow hydrostatic bearing pocket and, on a comparative basis, discusses the effects of the pocket-to-land exit geometry when it takes different shapes (sharp 90° angle, and rounded with different radii of curvature). The numerical simulation uses a dimensionless formulation of the Navier-Stokes equations written in primitive variables for a body fitted coordinate system, and applied through a collocated grid. The model includes on one hand the coupling between the pocket flow and a finite length feedline flow, and the pocket and the adjacent lands on the other hand. Geometrically, all pockets have the same footprint, same land length, and same capillary feedline. The numerical simulation uses the Reynolds nuber ( Re) based on the runner velocity, and the inlet jet strength ( F) as dynamic similarity parameters, while the radius of curvature of the pocket/land joint is used as a geometric parameter. The study treats the laminar ranges of the Re number.