The Role of Heat Partition in Elastohydrodynamic Lubrication

The article is concerned with thermal elastohydrodynamic lubrication (TEHL) modeling of rolling/sliding contacts and in particular with relating the results of such models to experiments. Two kinds of lubricated rolling/sliding contact experiments are considered: (i) traction experiments where the overall frictional resistance to motion at the TEHL contact is measured and (ii) heat partition experiments where, in addition to the frictional resistance, the temperature distribution in the contacting components is measured and the heat flux into the individual components is determined. The article discusses the problem of choosing an accurate rheological model of the lubricant film that can reproduce the measurements of each of the experiments. It considers the difficulties in distinguishing between the commonly used non-Newtonian lubricant models of the shear thinning and the limiting shear stress types. It is suggested that the ability of the lubricant rheological model to replicate experimental heat partition behavior is a much more discriminating test of rheological behavior than the ability to reproduce experimental traction curves.