Couette creeping flow past a sphere in non-Newtonian power-law fluids.

The flow past a sphere, rigidly held between two parallel plates (Couette flow), was studied in a non-Newtonian, power-law fluid, numerically. The three momentum equations have been solved under the following conditions: creeping flow with Re < 1; power-law index 0.2–1; distance of sphere center from the plates 1.15–10; sphere position between the plates 0.1–0.9. Diagrams have been produced for the direct calculation of the force acting on the sphere. The numerical forecast shows a significant disparity between Newtonian and non-Newtonian fluids. All in all, the wall effect in power law fluids is less extreme than in Newtonian fluids. Furthermore, in non-Newtonian fluids, the force changes linearly when the sphere approaches the upper plate. [ABSTRACT FROM AUTHOR]