Carreau

A Carreau Fluid is a generalized non-Newtonian fluid with an effective viscosity, \(\nu_{\operatorname{eff}}\), defined by:

\[\nu_{\operatorname{eff}}(\dot \gamma) = \nu_{\operatorname{\infty}} + (\nu_0 - \nu_{\operatorname{\infty}}) \left[1+\left(\lambda \dot \gamma\right) ^a \right] ^ {\frac {N-1} {a}}\]

where \(\nu_{\operatorname{\infty}}\) is the viscosity at infinite shear, \(\nu_0\) is the viscosity at zero shear, \(\lambda\) is the characteristic time, \(a\) is the transition index, and \(N\) is the power index.

Property Grid

Fluid Properties

Rheology Type

Apply Carreau rheology. Local fluid viscosity is calculated from the local shear rate using a user-defined characteristic time, power index, and infinite/zero share rate viscosities.

Density

kg/m ³ | The density of the fluid.

Carreau Lambda

s | Relaxation time.

Carreau N

Power index (-).

Carreau V0

m ² /s | Viscosity at zero shear.

Carreau Vinf

m ² /s | Viscosity at infinite shear.

Carreau Transition Index

Transition index (-).

Rheology Limits

These are user defined limits that provide a lower and upper bound on the viscosity realized in the simulation. Appropriate limits can help maintain simulation stability and maximize the allowable simulation time step.

Min Viscosity

m ² /s | The minimum fluid viscosity realized in the simulation.

Max Viscosity

m ² /s | The maximum fluid viscosity realized in the simulation.