Prediction of Cavitation in Journal Bearings Using a Boundary Element Method

Abstract

In this paper, a boundary element cavitation algorithm is utilized to predict cavitation in journal bearings with axially variable clearance. Film rupture and reformation boundary conditions, obtained from the JFO theory, are directly combined with the generalized boundary integral equation which is derived from Elrod’s universal differential equation. The two boundaries are simulated by two confluent interpolation polynomials: The governing equation is transformed into an undetermined boundary problem. The procedure effectively eliminates the phenomenon of solution oscillation experienced by finite difference cavitation algorithms and caused by unadaptable grid shape and density. It also eliminates the discontinuous derivative of the fractional film content. The results for aligned and misaligned journal bearings are compared with those obtained using the finite difference method. Tapered, barrel, and hourglass Journal bearings are also analyzed. The computational results demonstrate the effects of the journal geometric parameters on journal bearing performance.