Defining general temperature-driven mass diffusion

The Soret effect factor, κs, governs temperature-driven mass diffusion. You can define the Soret effect factor as a function of concentration, temperature, and/or field variables. See Diffusivity, for more information.

Note:

You can specify the Soret effect factor only if you select general mass diffusion behavior in the diffusivity definition. (If you select Fick's diffusion law, the Soret effect factor is calculated automatically.) For more information, see Fick's law.

  1. Define diffusivity as described in Defining diffusivity.”

  2. From the Suboptions menu in the Edit Material dialog box, select Soret Effect.

    A Suboption Editor appears.

  3. Toggle on Use temperature-dependent data to define the Soret effect factor as a function of temperature.

    A column labeled Temp appears in the Data table.

  4. Click the arrows to the right of the Number of field variables field to increase or decrease the number of field variables included in the definition of the Soret effect factor.

  5. Enter the following data in the Data table:

    kappa_s

    Soret effect factor, κs. (Units of F1/2L−1.)

    Concentration

    Mass concentration of the diffusing material.

    Temp

    Temperature.

    Field n

    Predefined field variables.

  6. Click OK to return to the Edit Material dialog box.