A Finite Element Model for Non-Newtonian Starved Thermal-Elastohydrodynamic Lubrication of 3D Line Contact

A finite element model for the non-Newtonian starved thermal-elastohydrodynamic lubrication of 3D line contact is developed. The model integrates the mutually dependent solutions of the pressure, film thickness, and temperature in a coupled system. The finite difference Elrod algorithm is introduced in the constructed solution scheme to realize the starvation condition and determine the fractional film content. The lubricant velocity and shear rate of three typical non-Newtonian lubricants are derived by using the separation flow method. The interacted solutions are sequentially determined by their corresponding governing equations. After the model validation, the lubrication performances of the three non-Newtonian lubricants are studied at different levels of inlet lubricant supply. The results show that non-Newtonian rheological behaviors have substantial effects on the lubricant temperature, viscosity, shear rate, velocity, and shear stress, which further affect the accuracy of the predictions of friction and lubrication failure. The solutions of lubrication of machined rough surfaces are also presented to demonstrate the generality of the developed model.