diff-const-ortho¶
Module: solute
Category: materialprop
Type string: "diff-const-ortho"
Parameters¶
| Name | Description | Default | Range | Units |
|---|---|---|---|---|
free_diff |
free diffusivity | 1 | \(\gt 0\) | L^2/t |
diff |
diffusivity | \(\ge 0\) | L^2/t |
Description¶
The material type for constant orthotropic diffusivity materials is diff-const-ortho.
When the permeability is orhotropic,
\[
\mathbf{d}=\sum\limits_{a=1}^{3}d^{a}\mathbf{V}_{a}\otimes\mathbf{V}_{a}
\]
where \(\mathbf{V}_{a}\) are orthonormal vectors normal to the planes of symmetry. For this material model, \(d^{a}\)'s are constant. Therefore this model should be used only when strains are small. Note that the user must specify \(d^{a}\leqslant d_{0}\), since a solute cannot diffuse through the biphasic-solute mixture faster than in free solution.
Example:
<diffusivity name="Permeability" type="diff-const-ortho">
<free_diff>0.005</free_diff >
<diff>0.002,0.001,0.003</diff>
</diffusivity>