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Cross

Module: fluid

Category: materialprop

Type string: "Cross"

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]
m power 2 []

Description

The material type for a Cross model 1 is Cross.

The viscous shear stress for this material model is

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

where

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

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

Example:

<viscous type="Cross">
    <mu0>0.056</mu0>
    <mui>0.0035</mui>
    <lambda>1.0</lambda>
    <m>1.0</m>
</viscous>


  1. Cho, Y I and Kensey, K R, "Effects of the non-Newtonian viscosity of blood on flows in a diseased arterial vessel. Part 1: Steady flows", Biorheology 28, 3-4 (1991), pp. 241-62.