Hydrodynamic lubrication behavior under miscellaneous operational conditions via CGB numerical model

Abstract

The current study is basically focused on investigating the possible ways to enhance the lubricating oil film performance and hence ship energy efficiency of marine journal bearings in general terms. For the intended purpose, a novel numerical Circumferential Grooved Bearing (CGB) model was developed to assess journal bearing operating conditions based on versatile simulation analyses. Prior to all conducted test trials, the model validation has been confirmed based on the conformity between numerical outcomes and those derived from experimental procedures depending on Universal Journal Bearing Test Rig. CGB performance was evaluated at slow speed variations from 25 rpm up to 125 rpm and different applied loads utilizing the two lubricant oil grades of 5W40 and 0W30. Reducing shaft rotational speed by 80% was found to incur a reduction in the maximum oil film pressure value by 1.17 bar and 0.97 bar for the two aforementioned lubricants respectively. Further, the increase of applied loads from 1079 N up to 1471 N at a constant speed of 75 rpm reduces the maximum oil film pressure ratio by 0.14 and 0.18 for the two oil grades subsequently.

Keywords

• Hydrodynamic lubrication
• Circumferential grooved bearing
• Operating conditions