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 thermoplastic or elastomer liner partial arc bearings. Adequate design and analysis tools for these bearings are not currently available. Thus, it is difficult to optimize bearing designs for new and in-service applications. Development must rely on approximate design methods and costly testing.To meet these needs, Xdot is proposing to develop and experimentally validate new bearing analysis software which is capable of accurately predicting performance over the full operating envelope, including the boundary, mixed and hydrodynamic regimes. The Phase II goal is to advance the analysis tool software to Technology Readiness Level 7. The effort to achieve this goal includes software development, continued testing with the Phase I bearing test rig, production of a new enhanced bearing test rig, and testing with the new rig.