Effects of Two-Dimensional, Sinusoidal Roughness on the Load Support Characteristics of a Lubricant Film

Abstract

An analytical study is made of the effects of two-dimensional, sinusoidal roughness on pressure and shear stress in a lubricant film between two parallel plates engaged in steady, parallel, relative motion. The effects of pressure and heating upon viscosity, as well as shear elasticity are accounted for in the case where roughness height is small relative to film thickness. Second-order influences which contribute to net load support by the film are computed in terms of the first-order solution. The results give evidence as to when boundary roughness may be negligible in its influence on hydrodynamic film calculations. Most important, however, they give evidence of a type of instability which may contribute to film breakdown in some marginal lubrication situations.