This model fits the viscosity at high shear rates according to:
With hoo the infinite viscosity, k the consistency and n the power law index.
The Sisko model can be used with data generated at high shear rates (where the power law model fails.)
For low shear rate data with a Newtonian plateau, the Williamson model should be used.
A more complex model describing Newtonian and infinite viscosity behavior is the Cross model.
