Application of non-Newtonian models to thin film flow

Abstract

The paper describes an investigation into the use of lubrication models on thin film flow. Power law, Ellis, and Carreau models are compared for free surface flow and flow within a channel. It is shown that the Ellis law (or a slight modification) can give very similar viscosity curves to Carreau. The three models are then compared for thin film flow with a constant height free surface. For low shear rates the power law model can give very inaccurate predictions. Having shown Carreau and Ellis may produce similar results we then study flow in a channel for Ellis and power law fluids. Again the power law can give inaccurate results due to the high viscosity around the turning point for the velocity. Finally, we briefly describe the modification to include surface tension in the free surface flow model.