Effects of Lubricant Rheology and Kinematic Conditions on Micro-Elastohydrodynamic Lubrication

Abstract

The effects of lubricant rheology and surface kinematic conditions on micro-elastohydrodynamic (EHD) lubrication are analyzed under isothermal line-contact conditions. Micro-EHD lubrication is modeled by introducing a surface irregularity in the form of an asperity or a furrow into the contact zone. Under simple sliding conditions, the pressure generated in the vicinity of the irregularity and the resulting surface deformation depend strongly on the lubricant rheology. The surface kinematic conditions have profound effects on micro-EHD lubrication. In general, a stationary surface irregularity produces a relatively strong downstream effect when it is in the inlet region of the contact, and a moving surface irregularity produces a relatively strong upstream effect after it enters the Hertzian central region. The simulated results agree qualitatively with previous experimental measurements and observations.