hi..I was using CFX-4 some ages ago i had a model sort of pipe in pipe system where the inner pipe was cut in the midle so i was was using thin walls boundaries to repredsent the patches in cfx-4 and that worked nice. Im trying to do this in CFX-5, when i try to define those inner walls (the faces) as walls i get the message that the faces im trying to define are not part of an external boundary . Any of you have an idea on how to define those internal walls?

Best regards

As long as there's a surface region there, it should work. There's also a toggle button in Pre which allows you to create the matching opposite face of the wall. Try that.

Jeff

thanks Jeff that worked fine!