Although the UDF capability in Ansys Fluent can address a wide range of applications, it is not possible to address every application using UDFs. Not all solution variables or Ansys Fluent models can be accessed by UDFs. If you are unsure whether a particular problem can be handled using a UDF, contact your technical support engineer for assistance.

UDFs use and return values specified in SI units, except in rare cases as noted (such as UNIVERSAL_GAS_CONSTANT ).

UDFs cannot be loaded if: Ansys Fluent is not launched in UNC mode and Host and Node processess may be launched on remote machines.

You may need to update your UDF when you use a new version of Ansys Fluent.

The default serial version of Fluent (also referred to as -t1) interacts with a host process and a single compute node process, and so all user-defined functions (UDFs) are required to be written for parallel usage.