The Flow Factors Considering the Elastic Deformation for the Rough Surface with a Non-Gaussian Height Distribution

Abstract

In the mixed lubrication regime, the roughness effects are very important due to the presence of interacting asperities. Patir and Cheng derived a method that rewrites the Reynolds equation in terms of the averaged flow factors. The flow factor method has been used in many applications to demonstrate the effects of surface roughness on the mixed lubrication. In this study, the flow factors considering the elastic deformation of the rough surface due to a direct contact of asperities are calculated. The pressure flow factor and the shear flow factor are evaluated for the rough surfaces with both Gaussian and non-Gaussian height distributions. The results show that there is a large difference of flow factors between the rough surface considering the elastic deformation and that assuming the rigid body due to an increase of the film thickness and a decrease of the slope of asperities after the elastic deformation of asperities.

KEY WORDS:

• Roughness Effect
• Mixed Lubrication
• Flow Factor