The Temperature is User defined by default. If a Heat Transfer interface is included in the model, alternatively select the temperature for that interface. For example, if a Heat Transfer in Fluids interface is included in the model, the Temperature (ht) option is available.

This section is available when the Convection check box is selected on the interface top node. The Velocity field u (SI unit: m/s) of the solvent is specified as a feature input. The default is User defined, but if a Fluid Flow interface is included in the model, you may select the velocity field for that physics interface. For example, if a Laminar Flow interface is included in the model, the Velocity field (spf) option is available from the list.

Enter the Diffusion coefficient Dc manually, or use a value from the Materials node. The default Diffusion coefficient value is 1e-9 m2/s which is a typical order of magnitude for a species diluted in a liquid aqueous solution.

You may include Migration by enabling the Migration in electric field check box on the Electroanalysis top node.

Choose the source for where the Electrolyte potential φl (SI unit: V). Note that the migration term in the transport equation is based on the gradient of the electrolyte potential. If there is no spatial variation in φl, the migration term will be zero.

By default the Mobility (s·mol/kg) is set to be calculated based on the species diffusivity and the temperature using the Nernst-Einstein relation.

Only species with a non-negative Charge number zc (dimensionless, but requires a plus or minus sign) will be affected by the migrative transport.