The SI unit of dynamic viscosity (Greek symbol: ) is pascal-second (), which is identical to .
The dynamic viscosity is related to the kinematic viscosity by
where is the density and is the kinematic viscosity.
For the use in CFD, dynamic viscosity can be defined by different ways:
- as a constant
- as a function of temperature (e.g. piecewise-linear, piecewise-polynomial, polynomial, by Sutherland's law or by the Power law)
- by using Kinetic Theory
- by non-Newtonian models