i tried to write program for UDF in C. i used udf.h as header file but my computer is showing error msg that "header file does not exist". how to add udf header file in my computer?

hi, you must put all the files on the same work file

the header file udf.h can be found buried within the fluent directory, I think in one of the lib folders.

I don't know the exact rules but to be safe I always try and have header_file,pdf,udf,mesh,thermodynamic_database,et c,etc, in the same directory.

It's best to copy files rather than move them.