A numerical model for the solution of thermal elastohydrodynamic lubrication in coated circular contacts

Abstract

This paper presents a finite element model for the solution of thermal elastohydrodynamic lubrication in coated circular contacts. The model is based on a full-system finite element resolution of the elastohydrodynamic and heat transfer equations. The effects of the coating's thermal and mechanical properties on lubrication performance are investigated. Two categories of surface coatings are considered based on thermal properties: high and low thermal inertia. It is found that low thermal inertia surface coatings act as insulators leading to a localized increase in the lubricant's temperature at the center of the contact. Therefore, friction can be significantly reduced while film thickness is barely affected. The opposite effect is observed for high thermal inertia coatings. These effects increase with coating's thickness.