After you have written your UDF and have saved the source code
file with a .c extension in your working folder,
you are ready to interpret the source file. Follow the instructions
below in Interpreting a UDF Source File Using the Interpreted UDFs Dialog
Box. After it has
been interpreted, the UDF function name(s) that you supplied in the DEFINE macro(s) appear in drop-down lists in Ansys Fluent,
ready for you to hook to your CFD model.
Alternatively, if you want to compile your UDF source file, see Compiling UDFs.