ABSTRACT

The manner in which the shear strain, or displacement, responds to an applied shear stress, or force, in this situation defines the mechanical or rheological characteristics of the material. The flow behavior of fluids is determined by their rheological properties, which govern the relationships between shear stress and shear rate. In principle, these properties could be determined by measurements in a "simple shear" test. When the measured values of shear stress or viscosity are plotted versus shear rate, various types of behavior may be observed depending upon the fluid properties. All fluid properties are dependent upon temperature. For most fluids, the viscosity is the property that is most sensitive to temperature changes. The following relations apply to Newtonian fluids, although for non-Newtonian fluids represented by any of the models, any model parameter having dimensions of viscosity will generally follow similar temperature dependence.