Interfaces between different 3 domains
 

Hi all,

I have been struggling some days now with an ICEM interface problem, ANY help would be much appreciated.

I attached some self-explaining images of the geometry and the mesh. These images and questions are related to a reduced model of my real problem (three annular tubes inside a fluid domain).

In the underlying model, I have 3 domains: two fluid domains and a solid domain (the tube). The external domain is fluid which encompasses an annular tube with some wall thickness. Fluid is also flowing through (inside) the tube.

When a mesh the external fluid, the face against the tube should be an interface between it and both the tube and the inner fluid. However, while I have just one interface at the external fluid domain I got 2 faces touching it: one from the tube and another from the inner fluid.

When I open this mesh in CFX-Pre it eighter tells me that I can only use one face from each domain to create a domain interface or put this face as a "default wall" (in case I don't assign a boundary condition to it).

Any help would be much appreciated since I have tried many unsuccessful tricks.

My problem is actually that I have interfaces with different sizes. Anyone has ever faced such a problem?