setting two interface
 

Hi experts.
I'm trying to model a rectangular channel with a weir in the middle of it. I defined 3 body in ICEM with two interfaces. But when I set interfaces a message says that I used one domain in two interfaces settings and it is related to domain placed in the middle of channel. Did I do it wrong? how can I fix it?

Why do you need to use interfaces at all? Can you show an image of your geometry?

Because I use three types of mesh in this channel and I can't merge them.

You can still model this with a single domain, but you will need GGI interfaces to join the mismatched grid interfaces up. Note that ICEM has some pretty useful tools for matching the mesh up which would mean you can make this a contiguous mesh with no need for GGIs.

Note that a single boundary face can only be used in 1 GGI. So if the outer boundary is a single GGI it will not work, you will have to split it into an upstream and a downstream boundary.

thank you so much. my problem is related to domain placed between two other domains. How can I split it?! I placed one interface at the first of the weir and another one at the end of that. you mean that I have to split the second domain. If yes how?

In ICEM you will have to make one boundary for the first interface, another for the second and I would do another one for the top and another for the bottom as well.

This is basic use of ICEM - have a look at the ICEM tutorials. Also the geometry and meshing forum is best for this type of question.

Thank you glenn.
I know how to create boundaries. I set three domains with two interfaces. But when I set interfaces I have to use middle domain twice and CFX says every domain should be used in one intrface whereas it's common in both interfaces.