Development of a detailed model for piston-ring lubrication in IC engines with circular and non-circular cylinder Bores

Abstract

Over recent years a detailed model for piston-ring lubrication has been developed by the authors. The computer model incorporates a finite difference solution of the two-dimensional Reynolds equation with the squeeze effect for fully flooded lubrication as well as a flow-continuity algorithm for `starved' lubrication. It can be used to evaluate the tribological performance of piston rings operating in both circular and distorted bores. The influences of many factors, such as level of bore distortion, ring conformability, axial motion of the ring, and circumferential variation of the ring face profile are taken into account. An improved method for determining oil availability in a ring pack was also developed by considering the effect of relative locations of rings on the piston and oil accumulation in front of the ring. This paper summarises the development of the model and presents some selected results. It should be noted that much of the material presented has been drawn from other publications by the authors for the purpose of review and summary.