The Characterization and Simulation of Cylinder Liner Surface Finishes

Abstract

This paper presents an investigation into the characterization and performance prediction of different cylinder liner surfaces commonly used in modern internal combustion engines. The topography of liner specimens was measured, and the friction and wear between a piston ring and each liner surface was measured using a horizontal reciprocating bench tester. The load, speed, and lubricant supply during testing were chosen to ensure that the piston ring and liner operated primarily in a mixed lubrication regime. A computer program was developed to model the performance of the piston ring and liner specimens under the conditions observed during the reciprocating bench test. The Greenwood and Tripp statistical asperity contact model was employed to describe the rough surface contact behavior between the liner specimen and piston ring. Two different methods of characterizing the liner specimen surface roughness and determining the inputs required for the Greenwood and Tripp model from the surface measurements were considered. The friction observed experimentally was compared to the friction predicted by the model, and the ability of the model to predict the absolute friction for a given surface and the relative difference in friction between two different surfaces was investigated.