Entrance Flows of Non-Newtonian Fluids

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Abstract
The creeping flow of a Powell-Eyring fluid through a sudden tubular contraction is considered, and finite difference solutions of the vorticity transport and stream function equations are obtained for a range of contraction ratios, fluid properties, and apparent shear rates. Calculated axial velocity profiles, excess pressure drops, and separation effects at the 90° corner of the contraction are compared with theoretical results for Newtonian fluids and with experimental data for polymer solutions and melts. The results indicate a strong influence of nonlinear viscous effects on the magnitude of the excess entrance pressure loss and on the extent of the circulation pattern at the corner of the contraction.