Carreau-Yasuda¶

Module: fluid

Category: materialprop

Type string: "Carreau-Yasuda"

Parameters¶

Name	Description	Default	Units
`mu0`	zero shear rate viscosity	0	[P.t]
`mui`	infinite shear rate viscosity	0	[P.t]
`lambda`	relaxation time	0	[t]
`n`	power index	1	[]
`a`	power denominator	2	[]

The material type for a Carreau-Yasuda model [#Cho91] is Carreau-Yasuda.

The viscous shear stress for this material model is

\[ \boldsymbol{\tau}=2\mu\mathbf{D} \]

where

\[ \mu=\mu_{\infty}+\left(\mu_{0}-\mu_{\infty}\right)\left(1+\left(\lambda\dot{\gamma}\right)^{a}\right)^{\left(n-1\right)/a} \]

Here, \(\dot{\gamma}=\sqrt{2\mathbf{D}:\mathbf{D}}\) is the engineering shear rate.

Example:

<viscous type="Carreau-Yasuda">
    <mu0>0.056</mu0>
    <mui>0.0035</mui>
    <lambda>1.9</lambda>
    <n>0.22</n>
    <a>1.25</a>
</viscous>