After you interpreted (Interpreting UDFs) or compiled (Compiling UDFs) your DEFINE_ADJUST UDF, the name of the function you supplied as a DEFINE macro argument can be hooked using the User-Defined Function Hooks dialog box (Figure 6.1: The User-Defined Function Hooks Dialog Box). Note that you can hook multiple adjust UDFs to your model, if desired.

To hook the UDF to Ansys Fluent, open the User-Defined Function Hooks dialog box (Figure 6.1: The User-Defined Function Hooks Dialog Box).

 Parameters & Customization → User Defined Functions  Function Hooks...

Figure 6.1: The User-Defined Function Hooks Dialog Box

Click the Edit... button next to Adjust to open the Adjust Functions dialog box (Figure 6.2: The Adjust Functions Dialog Box).

Figure 6.2: The Adjust Functions Dialog Box

Select the function(s) you want to hook to your model from the Available Adjust Functions list. Click Add and then OK to close the dialog box. The name of the function you selected will be displayed in the Adjust field of the User-Defined Function Hooks dialog box. If you select more than one function, the number will be displayed (for example, 2 selected). Click OK in the User-Defined Function Hooks dialog box to apply the settings.

See DEFINE_ADJUST for details about defining adjust functions using the DEFINE_ADJUST macro.

After you have interpreted (Interpreting UDFs) or compiled (Compiling UDFs) your DEFINE_DELTAT UDF, the name of the function you supplied as a DEFINE macro argument will become visible and selectable in the Run Calculation task page in Ansys Fluent.

To hook the UDF to Ansys Fluent, right-click the General branch of the tree and select Transient from the Analysis Type sub-menu.

 Setup → General  Analysis Type → Transient

Then open the Run Calculation task page.

 Solution →   Run Calculation

Select User-Defined Function from the Type drop-down list, and then select the function name (for example, mydeltat::libudf) from the User-Defined Time Step Size drop-down list.

See DEFINE_DELTAT for details about defining DEFINE_DELTAT functions.

After you have interpreted (Interpreting UDFs) or compiled (Compiling UDFs) your DEFINE_EXECUTE_AT_END UDF, it is ready to be hooked to Ansys Fluent. Note that you can hook multiple at-end UDFs to your model, if desired.

To hook the UDF to Ansys Fluent, open the User-Defined Function Hooks dialog box (Figure 6.3: The User-Defined Function Hooks Dialog Box).

 Parameters & Customization → User Defined Functions  Function Hooks...

Figure 6.3: The User-Defined Function Hooks Dialog Box

Click the Edit... button next to Execute At End to open the Execute At End Functions dialog box (Figure 6.4: The Execute At End Functions Dialog Box).

Figure 6.4: The Execute At End Functions Dialog Box

Select the function(s) you want to hook to your model from the Available Execute at End Functions list. Click Add and then OK to close the dialog box. The name of the function you selected will be displayed in the Execute at End field of the User-Defined Function Hooks dialog box. If you select more than one function, the number will be displayed (for example, 2 selected). Click OK in the User-Defined Function Hooks dialog box to apply the settings.

See DEFINE_EXECUTE_AT_END for details about defining DEFINE_EXECUTE_AT_END functions.

After you have interpreted (Interpreting UDFs) or compiled (Compiling UDFs) your DEFINE_EXECUTE_AT_EXIT UDF, it is ready to be hooked to Ansys Fluent. Note that you can hook multiple at-exit UDFs to your model, if desired.

To hook the UDF to Ansys Fluent, open the User-Defined Function Hooks dialog box (Figure 6.5: The User-Defined Function Hooks Dialog Box).

 Parameters & Customization → User Defined Functions  Function Hooks...

Figure 6.5: The User-Defined Function Hooks Dialog Box

Click the Edit... button next to Execute at Exit to open the Execute at Exit Functions dialog box (Figure 6.6: The Execute at Exit Functions Dialog Box).

Figure 6.6: The Execute at Exit Functions Dialog Box

Select the function(s) you want to hook to your model from the Available Execute at Exit Functions list. Click Add and then OK to close the dialog box. The name of the function you selected will be displayed in the Execute at Exit field of the User-Defined Function Hooks dialog box. If you select more than one function, the number will be displayed (for example, 2 selected). Click OK in the User-Defined Function Hooks dialog box to apply the settings.

See DEFINE_EXECUTE_AT_EXIT for details about defining DEFINE_EXECUTE_AT_EXIT functions.

After you have interpreted (Interpreting UDFs) or compiled (Compiling UDFs) your DEFINE_INIT UDF, it is ready to be hooked to Ansys Fluent. Note that you can hook multiple initialization UDFs to your model, if desired.

To hook the UDF to Ansys Fluent, open the User-Defined Function Hooks dialog box (Figure 6.7: The User-Defined Function Hooks Dialog Box).

 Parameters & Customization → User Defined Functions  Function Hooks...

Figure 6.7: The User-Defined Function Hooks Dialog Box

Click the Edit... button next to Initialization to open the Initialization Functions dialog box (Figure 6.8: The Initialization Functions Dialog Box).

Figure 6.8: The Initialization Functions Dialog Box

Select the function(s) you want to hook to your model from the Available Initialization Functions list. Click Add and then OK to close the dialog box. The name of the function you selected will be displayed in the Initialization field of the User-Defined Function Hooks dialog box. If you select more than one function, the number will be displayed (for example, 2 selected). Click OK in the User-Defined Function Hooks dialog box to apply the settings.

See DEFINE_INIT for details about defining DEFINE_INIT functions.

After you have interpreted (Interpreting UDFs) or compiled (Compiling UDFs) your DEFINE_ON_DEMAND UDF, the name of the function you supplied as a DEFINE macro argument will become visible and selectable in the Execute On Demand dialog box (Figure 6.9: The Execute On Demand Dialog Box) in Ansys Fluent.

To hook the UDF to Ansys Fluent, open the Execute On Demand dialog box.

 Parameters & Customization → User Defined Functions  Execute on Demand...

Figure 6.9: The Execute On Demand Dialog Box

Select the function name (for example, on_demand_calc::libudf) in the Execute On Demand drop-down list and click Execute. Ansys Fluent will execute the UDF immediately. Click Close to close the dialog box.

See DEFINE_ON_DEMAND for details about defining DEFINE_ON_DEMAND functions.

After you have interpreted (Interpreting UDFs) or compiled (Compiling UDFs) your DEFINE_RW_FILE or DEFINE_RW_HDF_FILE UDF, it is ready to be hooked to Ansys Fluent. Note that you can hook multiple read/write file UDFs to your model, if desired.

To hook the UDF to Ansys Fluent, open the User-Defined Function Hooks dialog box (Figure 6.10: The User-Defined Function Hooks Dialog Box).

 Parameters & Customization → User Defined Functions  Function Hooks...

Figure 6.10: The User-Defined Function Hooks Dialog Box

You have the choice of hooking a UDF to read and write a case and data file. Below is a description of what each function does.

To hook a read legacy case file UDF, for example, click the Edit... button next to Read Case to open the Read Legacy Case Functions dialog box (Figure 6.11: The Read Case Functions Dialog Box).

Figure 6.11: The Read Case Functions Dialog Box

Select the function(s) you want to hook to your model from the Available Read Legacy Case Functions list. Click Add and then OK to close the dialog box. The name of the function you selected will be displayed in the Read Case field of the User-Defined Function Hooks dialog box. If you select more than one function, the number will be displayed (for example, 2 selected). Click OK in the User-Defined Function Hooks dialog box to apply the settings.

See DEFINE_RW_FILE and DEFINE_RW_HDF_FILE for details about defining DEFINE_RW_FILE and DEFINE_RW_HDF_FILE functions.

You can store values computed by your UDF in memory so that they can be retrieved later, either by a UDF or for postprocessing within Ansys Fluent. In order to have access to this memory, you will need to allocate memory by specifying the Number of User-Defined Memory Locations and Number of User-Defined Node Memory Locations in the User-Defined Memory dialog box (Figure 6.12: The User-Defined Memory Dialog Box).

To improve performance, you can limit the user-defined memory (UDM) to specific zones by enabling Zone-Based Memory Allocation, and selecting the desired zones in the Select UDM Zones dialog box (accessed by clicking Edit... within the User-Defined Memory dialog box).

 Parameters & Customization → User Defined Memory  Edit...

Figure 6.12: The User-Defined Memory Dialog Box

The macros C_UDMI, F_UDMI, or N_UDMI can be used in your UDF to access a particular user-defined memory location in a cell, face, or node. See Cell Macros and Face Macros for details.

Field values that have been stored in user-defined memory or user-defined node memory will be saved to the data file. These fields will also appear in the User Defined Memory... category in the drop-down lists in Ansys Fluent’s postprocessing dialog boxes. They will be named User Memory 0, User Memory 1, and so on, and User Node Memory 0, User Node Memory 1, and so on, based on the memory and node memory location index, respectively. The total number of memory locations is limited to 500. For large numbers of user-defined memory locations, system memory requirements will increase.