A comprehensive study of the effects of honing patterns on twin-land oil control rings friction using both a numerical model and a floating liner engine:

Engine bores are finished with a multi-stage honing process and the finished surface roughness contributes significantly to the piston ring hydrodynamic pressure generation, especially for twin-land oil control rings whose land profile is parallel to the liner surface. In this paper, five different honing patterns on a cast iron liner and one on a spray-coated aluminum liner are studied with a floating liner engine and numerical models. The liner temperature and engine speed were varied such that all the lubrication regimes, namely boundary, mixed, and fully hydrodynamic, are present. It is found that the models based on deterministic approach with a patch of carefully measured liner roughness can match the trend of the Stribeck curves for different liner finishes observed in the experiment. Furthermore, the results show that the roughness height and structure of the honing affect the twin-land oil control rings lubrication differently. With the same honing structure, although rougher liner experiences mi...