Theoretical Analysis of Piston Ring Frictional Loss in an Innovative Rotating Liner Internal Combustion Engine

This paper presents a new lubrication model to predict piston ring friction. The average Reynolds equation is adopted to obtain the hydrodynamic component of restoring force against the cylinder liner surface. The dry or boundary lubricated component is derived from Greenwood-Tripp model. The influence of surface irregularities or roughness on the lubricant flow will be described by statistical parameters. Unlike classical piston ring mixed lubrication models, a sideslip rolling friction model is incorporated with contact simulation. Numerical results show that piston ring friction is reduced dramatically by the liner rotation.