It has long been known that liquids such as water and oil obey Newton's law of viscosity, which states that shear stress is proportional to sliding speed. In the past, oil pumps were used to transport these fluids, but with the rapid development of modern chemical industry, the use of original pumps to transport non-Newtonian viscous fluids is quite a lot.
Visible, in the chemical industry, the types of pumping liquid very much, the nature of the liquid, has the different viscosity, temperature, PH value, containing solid material type and the size of the particle size, concentration and the degree of two phase flow etc. Many factors can be used as a classification, so that the fluid for unified classification is rather difficult.
In general, when shear stress is applied to a fluid, the fluid will behave in various ways
Generally speaking, when shear stress is applied to a fluid, the fluid will show various flow states. This kind of study is called Rheology because of various mechanical effects, material changes and flow states of the fluid. In chemistry. The above fluids, commonly referred to as' special liquids', are considered most convenient to classify from this rheological point of view.
Fluids are now classified according to the field of rheology, as shown in Table 3.1.
If these fluids are expressed by flow equations, that is, rheological equations, the equations are as follows, and they are briefly described. If V represents the sliding velocity and T represents the shear stress, V is only a function of T for purely viscous fluids, that is, V = 2 (T) Newtonian fluids also belong to this category of purely viscous fluids.
