Flow of non-Newtonian polymeric solutions through fibrous media

The equations of motion (continuity and momentum) describing the steady flo w of incompressible power law liquids in a model porous medium consisting o f an assemblage of long cylinders have been solved numerically using the fi nite difference method. The field equations as well as the pertinent bounda ry conditions have been re-cast in terms of the stream function and vortici ty. The inter-cylinder interactions have been simulated using a simple "con centric cylinders" cell model. Extensive information on the detailed struct ure of the flow field in terms of the surface vorticity distribution, strea mlines, and viscosity distribution on the surface of the solid cylinder as well as on the values of the pressure and friction drag coefficients under wide ranges of physical(0.4 less than or equal to epsilon less than or equa l to 0.95; 1 greater than or equal to n greater than or equal to 0.4) and k inematic (0.01 less than or equal to Re less than or equal to 10) condition s have been obtained. The numerical results presented herein have been vali dated using the experimental results for the flow of Newtonian and power la w fluids available in the literature; the match between the present predict ions and the experiments was found to be satisfactory. (C) 2000 John Wiley & Sons, Inc.