Fluid Mechanics for Chemical Engineers: with Microfluidics, CFD, and COMSOL Multiphysics 5

Chapter 11. Non-Newtonian Fluids

11.1 Introduction

THE discussion thus far has been mainly for viscous fluids, all of which share the characteristic that they tend to deform continuously under the influence of an applied stress. However, fluids represent just one end of a wide spectrum of materials, for which a very simplified overview is given in Fig. 11.1. Solids lie at the other extreme; they, too, will deform under an applied stress but will reach a position of equilibrium, in which further deformation ceases; and—if the stress is removed—solids will recover their original shape. Thus, fluids generally exhibit viscosity, and solids typically show elasticity. In between these two extremes lie materials that, depending on the particular circumstances, ...