A MIXED LUBRICATION AND OIL TRANSPORT MODEL FOR PISTON RINGS USING A MASS-CONSERVING ALGORITHM

A numerical study of the interactions between hydrodynamic/boundary lu brication, oil transport, and radial dynamics of a piston ring using a mass-conserving (cavitation) algorithm is presented. The scheme outli ned in this investigation facilitates the calculation of the volume of oil accumulating at the leading and trailing edges of the piston ring as it scrapes against the liner. The calculation of this oil accumula tion is important in the estimation of lubricating oil consumption in engines. The numerical procedure employed in this study is capable of depicting the transition between the various modes of piston ring lubr ication (hydrodynamic, mixed, and boundary) over an engine cycle, incl uding the detachment of oil film from the ring and its subsequent re-a ttachment. Additionally, the effects of (a) liner lubricant availabili ty and (b) ring face profiles on the oil accumulation are also discuss ed.