Viscosity of fluid

In this chapter, some types of non-Newtonian fluids are introduced. Then, some constitutive equations of non-Newtonian fluids are given. Several important concepts related to non-Newtonian fluids, such as the total viscosity and the incremental viscosity, are put forward and their differences are discussed by using some examples. Finally, commonly used rheometers are introduced, most of which are rotating styles. With a rheometer, we can experimentally measure the relationship between the shear rate and shear stress of a non-Newtonian fluid and obtain its constitutive curve.