diff-const-iso¶
Module: solute
Category: materialprop
Type string: "diff-const-iso"
Parameters¶
| Name | Description | Default | Units |
|---|---|---|---|
free_diff |
free diffusivity | 1 | [L^2/t] |
diff |
diffusivity | 1 | [L^2/t] |
Description¶
The material type for constant isotropic diffusivity materials is diff-const-iso.
When the permeability is isotropic,
\[
\mathbf{d}=d\,\mathbf{I}
\]
For this material model, \(d\) is constant. This assumption is only true when strains are small. Note that the user must specify \(d\leqslant d_{0}\), since a solute cannot diffuse through the biphasic-solute mixture faster than in free solution.
Example:
<diffusivity name="Permeability" type="diff-const-iso">
<free_diff>1e-9</ free_diff >
<diff>0.5e-9</diff>
</diffusivity>