Generalized Newtonian fluid
A generalized Newtonian fluid is an idealized fluid for which the shear stress is a function of shear rate at the particular time, but not dependent upon the history of deformation. Although this type of fluid is non-Newtonian in nature, its constitutive equation is a generalised form of the Newtonian fluid. Generalised Newtonian fluids satisfy the following rheological equation:
where is the shear stress, and the shear rate. The quantity represents an apparent or effective viscosity as a function of the shear rate.
The most commonly used types of generalized Newtonian fluids are:
- Power-law fluid
- Cross fluid
- Carreau fluid
- Second-order fluid
