Hi

I am trying to use twice the same 2d region in CFX-Pre, as I need to apply degassing boundary conditions and domain interface at the same time. The software does not accept using twice the same region and if I omit the domain interface my results are not meaningful. Any ideas around this problem even in beta form ?

Many thanks

Catrina

U have to create two times the same region 2d for each assembly.

When you generate the domain interface between two domains, two corresponding special boundary conditions are automatically created in the two domains. These boundaries are called something like "Interface side 1" and "Interface side 2". You cannot have two boundary conditions at one surface - so when you try and add your other boundary condition, it will clash with the automatic interface boundary and you will get an error. But, don't worry yet there are 2 main options...

Option 1: Some of the boundary data associated with the 2 automatic interface boundary conditions are fixed. However, you *can* edit *some* aspects of these automatic interface boundary conditions by double clicking on their icons in the usual way. The options are fairly limited - e.g. they always have "conservative heat flux interface" on the energy equation and therefore you can't set a boundary temperature because that would not make sense! You may get more options for a multiphase calculation. So have a look and see if it provides the specific options you need.

Option 2: In addition, when you click on the interface boundaries, you can specify "boundary sources" and sinks for each equation at the interface. I think this may allow you to model degassing (perhaps you will need some CEL to control the sources too). I can't promise this will solve your problem, but I think it is certainly worth reading about them in the help and trying some simple experiments with these boundary sources to see if it will work for you. Chosing the details of the boundary sources you require to model degassing needs detailed knowledge of the problem, your modelling assumptions, and will take some time, so I cannot give you all the details here.

If you have a support contract with ANSYS I would suggest you phone them and ask - they were very helpful to me on a related question recently.

Regards, Andy

I said to create these 2 domains on icem cfd!

You can´t have two boundary conditions (b.c.) at one surface, but you can have two equal regions (2d) for the same b.c.

Give a look on my studied problem: http://rogeriofernandesbrito.googlep.../2dregions.jpg

There are 2 regions, called SOL_2D_REGION_1 and SOL_2D_REGION_2 for the same 2d region.