ENAS 606 : Polymer Physics

There are several different “types” of viscosities that one may encounter in fluid dynamics. First, we differentiate between the kinematic and dynamic viscosities, referred to by symbols ν and μ or η. They are related via the density of the medium, with ν = η/ρ. The units of dynamic viscosity are Poise or Pa.s and the dimensions are [ML−1T−1]. Kinematic viscosity has dimensions of [L2T−1] and is thus sometimes referred to as a momentum diffusivity. For a complex fluid in which a solvent viscosity ηs is modified to the a concentration c of a second phase species resulting in an overall viscosity η, the following viscosities are defined in Table 1.