What are the steps in using UDF in Ansys Fluent case file?
UDFs can be used in one of two possible ways, compiled or interpreted.
COMPILED UDFs
1. Compile the UDF
a. Define > User-Defined > Functions > Compiled
b. Browse and add the relevant .c and .h files in appropriate columns
c. Build – this will create the libudf directory
2. Click the Load button to load the UDF
3. Hook the functions in appropriate places
4. Run the simulation
INTERPRETED UDFs
1. Interpret the UDF
a. Define > User-Defined > Functions > Interpreted
b. Browse and add the relevant files
c. Interpret
2. Hook functions in appropriate places
3. Run simulation
Interpreted UDFs in Ansys Fluent have certain limitations compared to compiled UDFs. Specifically, they cannot contain go to statements, non-ANSI-C prototypes, direct data structure references, declarations of local structures, unions, pointers to functions, arrays of functions, multi-dimensional arrays, and certain types of macros such as those for communicating between host and node processes, global reduction macros, and message passing macros. Additionally, interpreted UDFs incur a performance penalty due to an extra layer of code that allows them to be shared between different architectures, operating systems, and Ansys Fluent versions. They also cannot access Ansys Fluent solver data using direct structure references but must use Ansys Fluent-supplied macros instead