THERMAL ELASTOHYDRODYNAMIC ANALYSIS USING A GENERALIZED NON-NEWTONIANFORMULATION WITH APPLICATION TO BAIR-WINER CONSTITUTIVE EQUATION

The governing equations together with a solution methodology are given which enables one to effectively handle an EHL line contact problem w ith simple non-Newtonian fluids including thermal effects. A computati onal algorithm is proposed that determines the equivalent viscosity as a function of shear strain rate for a specified constitutive equation . It is shown that the method effectively handles Bair-Winer's theolog ical equation in its original form and without the need for an approxi mate perturbation analysis. Among the performance parameters presented are the local behavior of the shear stress as predicted by the Bair-W iner's model and its comparison to that of the Ree-Eyrings constitutiv e equation. It is shown that these theological equations predict a qua litatively similar trend for the traction coefficient. Nevertheless, d epending on the operating conditions, the local shear stress as predic ted by the Ree-Eyring equation may exceed the material limiting shear stress. A comparison study of the traction coefficient as predicted by the Bair-Winer's fluid model and actual experimental measurements is also presented. The results are found to be in good quantitative agree ment.