Analysis and Observation of Cavities in a Journal Bearing Considering Flow Continuity

Abstract

Steady-state cavities in a journal bearing are analyzed in two contexts: first, an approximate thermohydrodynamic theory developed earlier is applied to additional cases, and comparisons are made between temperatures predicted by the theory and measured temperatures reported in the literature. Parametric variation of the size of a layer of fluid adhered to the journal is conducted. The best agreement between theory and experiment over a variety of cases is obtained when the adhered layer is chosen to be 0.42 times the gap height at the film rupture location. Second, an experiment was conducted to measure the widths of fluid streamers in the cavitated zone of a journal bearing. Measured streamer widths enable the calculation of the size of adhered layer that would be present to satisfy flow continuity. Results of the experiment support the existence of an adhered layer, which varies in size from 11 to 32% of the gap height at the rupture boundary.

KEY WORDS:

• Lubrication
• Bearings
• Cavitation