A Deterministic Model for Lubricant Transport within Complex Geometry under Sliding Contact and its Application in the Interaction between the Oil Control Ring and Rough Liner in Internal Combustion Engines

A general deterministic hydrodynamic lubrication model [1] was modified to study the interaction between a Twin Land Oil Control Ring (TLOCR) and a liner with cross-hatch liner finish. Efforts were made to customize the general model to simulate the particular sliding condition of TLOCR/liner interaction with proper boundary conditions. The results show that model is consistent, robust, and efficient. The lubricant mass conservation was justified and discussed. Then analysis was conducted on the lubricant transport between the deep grooves/valleys and plateau part of the surface to illustrate the importance of deep grooves in oil supply to the plateau part and hydrodynamic pressure generation. Furthermore, since the TLOCR land running surface is completely flat and parallel to the nominal liner axis, the liner finish micro geometry is fully responsible for the hydrodynamic pressure rise, which was found to be sufficient to support significant portion of the total ring radial load. Moreover, continuity and size of asperity network were found to be critical to hydrodynamic pressure rise. The model is deemed to be adequate to study the liner finish effects in IC engines, which is one of the most critical areas in engine friction, wear, and oil consumption.