Developing and validating a model to understand mixed lubrication regions for fluid-film bearings

Seawater lubricated propulsor (i.e., stern tube) bearings are one of the most important bearings aboard a ship. The performance and life of these bearings directly affects the vessel's operational capabilities, life cycle costs, and overall availability. In a single shaft vessel such as an Ohio class SSBN, any failure of this bearing is extremely problematic. In certain applications such as submersibles, these bearings are rubber liner partial arc bearings. Adequate design and analysis tools for these bearings are not currently available. A key stumbling block is the lack of good, public domain experimental data. To meet these needs, Xdot is proposing a program which includes both experimental and analysis tool development efforts. During Phase I, a subscale test rig will be design, fabricated and commissioned to produced an initial database of performance measurements. Development and preliminary validation of models for boundary and mixed lubrication will occur in parallel with this experimental effort. Starting in Phase I, and continuing into Phase II, these models will be integrated into an existing Xdot bearing analysis code which has already demonstrated the capability to analyze compliant hydrodynamic bearings with significant surface deflections.