Effect of Concaves Added by Piston Skirt Profile and Pattern Coating on Skirt Friction Loss

Abstract

A pattern coating on the piston skirt and an optimization of piston shape are applied to the piston skirt to reduce friction loss on pistons in internal combustion engines. The reduction at skirt friction loss is realized by an increase in the oil film thickness on the skirt due to the wedge action of the oil in the concave area of the pattern coating. In order to reduce skirt friction loss, a numerical method is performed to optimize the skirt profile and the coating pattern positions that affect the wedge action of the oil.