New Central Film Thickness Equation for Shear Thinning Lubricants in Elastohydrodynamic Lubricated Rolling/Sliding Point Contact Conditions

Abstract

This paper offers central film thickness formula pertaining to shearthinning lubricants under rolling/sliding point contact conditions. The shearthinning behavior of the lubricants is modeled using Carreau viscosity equation and the piezoviscous response employed herein is the freevolume based Doolittle equation in conjunction with Tait's equation of state for lubricant compressibility. The present formulation is based on reciprocal asymptotic isoviscous piezoviscous coefficient as it is a more accurate measure of the high pressure piezoviscous response of elastohydrodynamic lubricated (EHL) lubricants compared to the conventional pressure–viscosity coefficient. Comparisons between simulated, curvefitted values, and experimental results validate both the employed numerical approach and rheological model.