Effects of the Non-Newtonian Behavior of Lubricants on the Temperature, Traction, and Film Thickness in an Elliptical EHD Contact Under Heavy Loads

Abstract

An approximate but economical approach to the non-Newtonian thermal elastohydrodynamic (EHD) lubrication in heavily loaded elliptical contacts (p0 ≥ 1 GPa) has been developed by the author. From an empirically corrected Hertzian pressure distribution, the rheology, generalized momentum, and energy equations were solved to obtain the shear stress, velocity, and temperature distributions in the film. The computerized model, incorporating a number of fluid rheological laws, has been used to examine the influences of the non-Newtonian behavior of lubricants on the temperature, film thickness, and traction in the EHD contact. In this paper, the numerical formulation and computation scheme are briefly described. Then a comparison between the results obtained with some well known rheological laws is presented. The results show that the non-Newtonian characteristic of lubricants has a significant effect on the temperature and traction for lower sliding speeds, but it has a modest influence on the film thickness. By comparison with experiment, Bair and Winer’s fluid model appears to be quite realistic.