Effects of Hydrostatic Pocket Shape on the FlowPattern and Pressure Distribution

Abstract

The flow in a hydrostatic pocket is numerically simulated using a dimensionless formulation of the 2-D Navier-Stokes equations written in primitive variables, for a body fitted coordinates system, and applied through a collocated grid. In essence, we continue the work of Braun et al. 1993a, 1993b] and extend it to the study of the effects of the pocket geometric format on the flow pattern and pressure distribution. The model includes the coupling between the pocket flow and a finite length feedline flow, on one hand, and the pocket and its adjacent lands on the other hand. In this context we shall present, on a comparative basis, the flow and the pressure patterns at the runner surface for square, ramped-Rayleigh step, and arc of circle pockets. Geometrically all pockets have the same footprint, same lands length, and same capillary feedline. The numerical simulation uses the Reynolds number based on the lid(runner) velocity and the inlet jet strength F as the dynamic similarity parameters. The study aims at establishing criteria for the optimization of the pocket geometry in the larger context of the performance of a hydrostatic bearing.

A Semi-Analytical Method for the Solution of Entrance Flow Effects in Inherently Restricted Aerostatic Bearings

“…This fact together with the large amount of computing time, make these methods rather unhandy for practical bearing design. However, recent studies by Helene et al [4], Braun and Dzodzo [5], Renn and Hsiao [6] indicate their value for purpose of comparison and for handling turbulent flow conditions or non-axisymmetric geometries.…”

3D Numerical investigation of pressure field of an orifice compensated hydrostatic bearing

“…The Reynolds equation allows for the computation of the pressure distribution P (x, z, t). For an incompressible, laminar, isoviscous, and inertialess fluid, the Reynolds equation may be written as [3]:…”

“…Most of the recent studies are based on the classical Reynolds equation, or its modified forms, where turbulence or variable properties of flow are taken into account. The main operational parameters considered in the several numerical and experimental researches were shaft speed, inlet jet pressure supply and the Reynolds number [1][2][3][4][5][6][7][8][9]. Furthermore, numerous investigations indicated the significant effects of variations in the geometric structures of hybrid journal bearing systems on performance characteristics [10][11][12][13][14][15][16].…”

Tribology of dust‐stop seals of mixing machines

“…10,11 In fact, the arrangement of oil feedholes in the contact of dust-stop seals is analogous to the hydrostatic pocket seals. The specific design of such pockets and their in-flow patterns have been studied extensively, for example by Braun and Dzodzo, 12 who investigated the effect of pocket shape on the flow pattern and generated pressure distribution in pocket seals using 2D Navier-Stokes equations. They showed various swirl patterns inside the pockets with different geometries.…”