[xavi]

Hi,
Does anyone know the difference between the boundary condition interface and interior for a surface? I have a surface which is wall and i want the air to pass through, with conformal mesh, I don't know waht to use (interfaece or interior)
cheers

[-mAx-]

let's take 2 cylinders as example.
The 2 cylinders are connected at the same surface A.
If you mesh the 2 volumes, the mesh on A will be used as source for both volumes.
Now if you export the mesh, you won't see surface A in the BC
If you want to use this surface for postprocessing, you may define it as Interior in the BC (--> the surface will be visible in the fluent-BC panel)

Now you delete the 2 volume meshes, you copy one with a translation in axial direction.
You delete the volume from which you obtain your copy.
Then you move the copy in the opposite direction as earlier.
Normally you have the 2 volumes, BUT NOT CONNECTED.
you mesh one volume with a size 1 (for instance), and the second with size 0.1
As you see the 2 volumes aren't connected anymore and you have 2 superposed surfaces in place of A.
if you export this mesh in fluent, you will have 2 walls at this location.
If you want your fluid to pass through, then you have to set both surfaces as interface, and to define the couple of interfaces in fluent.
This is usefull in sliding mesh computation.

[xavi]

Originally Posted by -mAx-

let's take 2 cylinders as example.
The 2 cylinders are connected at the same surface A.
If you mesh the 2 volumes, the mesh on A will be used as source for both volumes.
Now if you export the mesh, you won't see surface A in the BC
If you want to use this surface for postprocessing, you may define it as Interior in the BC (--> the surface will be visible in the fluent-BC panel)

Now you delete the 2 volume meshes, you copy one with a translation in axial direction.
You delete the volume from which you obtain your copy.
Then you move the copy in the opposite direction as earlier.
Normally you have the 2 volumes, BUT NOT CONNECTED.
you mesh one volume with a size 1 (for instance), and the second with size 0.1
As you see the 2 volumes aren't connected anymore and you have 2 superposed surfaces in place of A.
if you export this mesh in fluent, you will have 2 walls at this location.
If you want your fluid to pass through, then you have to set both surfaces as interface, and to define the couple of interfaces in fluent.
This is usefull in sliding mesh computation.

Hi Max, thanks for the answer. So, I have to use interface but how can I define the couple of interfaces in Fluent?

[-mAx-]

if they are already defined as Interface, you can go to define/grid interfaces

[xavi]

ok, many thanks...