Oil Film Retraction by Reciprocating Piston Ring Motion Around Top Dead Center

Abstract

The mechanism of engine oil consumption due to the scraping action of the piston ring pack was investigated through experimental measurement and numerical prediction of the scraped oil amount. Since the measured amount of scraped oil was inconsistent with predictions using commercial software, a novel theoretical model of the oil film retraction phenomenon was constructed based on experimental observations when the ring descends. This model was then applied to the ring lubrication calculation. The model predicted that the barrel height of the ring sliding surface profile strongly affects whether the retracted oil film grows, which is consistent with the experimental results.