solute flux¶
Module: fluid-solutes
Category: load
Type string: "solute flux"
Parameters¶
| Name | Description | Default | Units |
|---|---|---|---|
flux |
effective solute molar flux | 1 | [n/L^2.t] |
solute_id |
solute_id | -1 | [] |
Description¶
In fluid-solutes analyses the molar flux of solute \iota , given by the vector \(\mathbf{j}^{\iota}=c^{\iota}\left(\mathbf{v}^{\iota}-\mathbf{v}^{f}\right)\), is evaluated relative to the solvent (fluid); it only includes a diffusive contribution relative to the solvent. Since solute viscosity is not explicitly modeled, the tangential component of \(\mathbf{j}^{\iota}\) on a boundary surface may not be prescribed. Only the normal component of the relative solute flux, \(j_{n}^{\iota}=\mathbf{j}^{\iota}\cdot\mathbf{n}\), represents a natural boundary condition. Since a fluid-solutes mixture may contain electrically charged solutes, the solute flux that must be prescribed as a boundary condition is the effective solute flux \(\tilde{j}_{n}^{\iota}=j_{n}^{\iota}+\sum_{\gamma}z^{\gamma}j_{n}^{\gamma}\). To prescribe a value for \(\tilde{j}_{n}^{\iota}\) on a surface, use:
<surface_load type="solute flux" surface="surface1">
<flux lc="1">1.0</flux>
<solute_id>solute_name</solute_id>
</surface_load>
The parameter solute_id specifies to which solute this flux condition applies, referencing the corresponding list of solute names in the Globals section.
The flux element defines the flux magnitude. The optional attribute lc defines a load controller for the normal flux evolution. If omitted a constant flux is applied.