[ROY4]

Hello

During modeling a bubble column, I would like to use a drag model through a subroutine. My problem is that no matter how much I read the tutorial and CFX guides, I couldn't understand how I should enter my Drag.txt into the CFX. I would really appreciate if any one can help me. I'm new in CFX using User subroutines.
I open the user subroutine in CFX-Pre. After that it asks me for a calling name and library name.. what should I do about these? How can I read my text drag subroutine?

By the way, do I need to install visual basic (like fluent) in order to read subroutines?

Thanks in advance