Non-Newtonian fluids: Introduction and guide to classification and characteristics

This Data Item is available as part of the ESDU Sub-series on Fluid Mechanics Internal Flow. The classification of non-Newtonian fluids according to their rheological behavior are considered. The characteristic shapes of the rheograms for various classes of fluid and the constitutive equations describing their behavior are presented. Examples of fluids in the various classifications are given and methods of measuring their characteristics are described. For the particular group of non-Newtonian fluids comprising solid particles suspended in a liquid medium, the settling behavior of the particles at zero or low flow velocities is discussed in terms of the basic behavior of well dispersed, uniform sized spherical particles and the effect on this behavior of nonspherical shapes, particle concentration, and nonuniform size.