6.6.1 Hooking DEFINE_ANISOTROPIC_DIFFUSIVITY UDFs

After you have interpreted (Chapter  4) or compiled (Chapter  5) your DEFINE_ANISOTROPIC_DIFFUSIVITY UDF, the name of the function you supplied as the first DEFINE macro argument will become visible and selectable in ANSYS FLUENT.

To hook the UDF to ANSYS FLUENT, you will first need to open the User-Defined Scalars dialog box.

Define $\rightarrow$ User-Defined $\rightarrow$ Scalars...

In the User-Defined Scalars dialog box, specify the Number of User-Defined Scalars (e.g., 2) and click OK. Next, open the Materials task page.

Materials

Select one of the materials in the Materials list and click Create/Edit... to open the Create/Edit Materials dialog box (Figure  6.6.1).

Figure 6.6.1: The Create/Edit Materials Dialog Box

Scroll down the Properties group box in the Create/Edit Materials dialog box (Figure  6.6.1), and select defined-per-uds from the UDS Diffusivity drop-down list. This will open the UDS Diffusion Coefficients dialog box (Figure  6.6.2).

Figure 6.6.2: The UDS Diffusion Coefficients Dialog Box

In the UDS Diffusion Coefficients dialog box, select a scalar equation (e.g., uds-0) and select user-defined-anisotropic from the drop-down list under Coefficient. This will open the User-Defined Functions dialog box. Select the name of the UDF (e.g., cyl_ortho_diff::libudf) you wish to hook, and click OK. The name of the UDF will be displayed in the text box below the Coefficient drop-down list in the UDS Diffusion Coefficients dialog box. Click OK, and then click Change/Create in the Create/Edit Materials dialog box.

Note that you can hook a unique diffusion coefficient UDF for each scalar transport equation you have defined in your model.

See Section  2.7.2 for details about defining DEFINE_ANISOTROPIC_DIFFUSIVITY UDFs and the User's Guide for general information about UDS anisotropic diffusivity.