Elastohydrodynamic Film Forming With Shear Thinning Liquids

Abstract

Recent advances in high pressure rheometry have elucidated the shear response of liquid lubricants at the high shear stress characteristic of the traction generating region of lubricated concentrated contacts. These new measurement techniques are used to characterize the shear response of shear thinning liquids at low (<10 MPa) shear stress. A recently developed numerical scheme for calculating film thickness is extended to accommodate sliding. Film thickness predictions are compared with measurements using shear thinning liquids including a polymer/mineral oil blend, a highly elastic liquid, and synthetic base oils. Useful insights are provided concerning the effects of pressure-viscosity behavior for Newtonian liquids, sliding, and starvation for non-Newtonian liquids and the relevant shear stress for film forming.