JEFFEREY-HAMEL FLOW OF POWER-LAW FLUIDS FOR EXPONENT VALUES CLOSE TO THE CRITICAL VALUE

The equations governing the flow of a power-law fluid between two non-parallel planes are singular for a specific value of the power-law index. In this paper, we numerically study flows when the power-law index is close to the critical value. We find that the flows exhibit a boundary layer structure even when inertial terms are ignored in the equations of motion, the boundary layers being a manifestation of the presence of material non-linearities in the model. We study both shear-thinning and shear-thickening fluids.