Reverse Flow in Submerged Journal Bearings

In this study, the Navier-Stokes equations, solved by a computational fluid dynamics (CFD) method with the two-phase flow, are used to analyze the flow in submerged journal bearings. The "tongue"-shaped reverse flow, which was observed experimentally near the end of the cavitation zone, is predicted with the presented model. The effects of various design and operational parameters, including eccentricity ratio, supply pressure, rotational speed, oil viscosity, and radial clearance, on the location, length, and frequency of the reverse flow are presented and explained. The load-carrying capacity of the journal bearing is found to fluctuate with the same pattern as that of the reverse flow, which may result in a vibration of the entire shaft-bearing system. Comparisons with experimental results of pressure distribution validate the present model in solving reverse flow near the cavitation region.