interface problems in a 2.5D mesh
 

hi there,

I got a quite confusing problem caused by a 2.5D mesh (2D mesh then extruded one cell) from ICEM. Simply speaking, the geometry is like this:

----------------------
Solid A
---------------------- <--interface_A_B
Fluid B
---------------------- <--interface_B_C
Fluid C
----------------------

the way how the mesh is generated is shown below:

1, generate curves and surfaces, then create individually the new parts for "interface A_B" and "interface B_C" .

2, make the block, associate edges with curves, faces with surfaces in order to have different surface mesh and curve mesh.

3, extrude one cell of the 2D mesh, carefully checked the quality and the boundary mesh, everything likes fine. then export as .cfx5 file

4, import the mesh in cfxpre, then the problem comes:

as expected, "interface_A_B" is split into two surfaces, "interface_A_B_1" and "interface_A_B_2", appear in Domain A and Domain B, individually.
However, "interface_B_C" is listed in the mesh tree as "the other 2D mesh", and is split to FOUR parts. "Pimitive 2D A", "Pimitive 2D B","Primitive 2D C", and "Pimitive 2D D".

Although I am still able to use these four parts to build a Domain-Interface, the feeling is not good........ Actually there are totally 10 interface in my real case, 6 interfaces could be automatically recognized and split correctly in cfxpre, however, i still have 4 interfaces which is decomposed into 16 primitive 2D faces.

does anyone know what kind of reasons might cause such problem?