Internal Walls in mesh
 

Hi Foamers,
I created a hybrid mesh in icem by merging the geometry and mesh files into one single file. When I tried to read it in OpenFoam the internal geometry was converted to walls by default.

I tried editing the mesh file, i.e., editing the internal faces(wall by default) as interface in mesh file and then running in terminal. But that created a default_wall boundary by itself which has all those internal faces that were to be removed.
As my mesh has different number of faces in each mesh when I tried mergeOrSplitBaffles that didn't work for me .


I can't define them as patch as I do not know the boundary conditions there.

Help me out with the situation.
Following are the attachments before and after editing the mesh file.




Thank you in advance

Remove the boundary fields in the constant/polyMesh/boundary file, and you are fine.

I don´t like this attitude (don´t take it personally :)) because it feels like the community is forced to give feedback. Besides, I get different email stating: "The people at cfd-online.com are not willing to help me (no reply).", I see that people help, but we all have a problem with our timescale. Thus (for all), keep in mind, that we are providing voluntary support and offer our private time. To get feedback is not a matter of course :)

Well I would take it personally though 🤷🏻*♂️😇 and regret that i didn’t reply as I didn’t follow the thread from a little while. Thanks for the reply but I didn’t try it yet.

Hello,

I know it is a little late to answer your question, However maybe it could be useful for the other researchers,

To avoid internal faces in OpenFOAM (I am talking about meshes comes from ANSYS) use fluentMeshToFoam instead of fluent3DMeshToFoam.

In fact, as it has mentioned on openfoam wiki: fluent3DMeshToFoam can handle internal walls/patches, or at least it looks like it does.

https://openfoamwiki.net/index.php/Fluent3DMeshToFoam

Bests

Hello Tobi,

I am also facing this issue. But when I removed the unwanted boundary from the boundary file of Polymesh folder, I get the following error -

"cell 0 contains face lable out of range: 6(0 1 2 3 4 -1) Max face index = 374727"

Can you please help me out here ?

It depends. Internal walls commonly needs always duplication of the face (one for the owner and one for the neighbor cell). This happens, if we create baffles for examples. If one introduces baffles you can simply remove the data from the boundaries again (if they are not split and are identical). However, it seems that you remove faces (boundaries) that should not be removed.

• Are you removing only one boundary? Commonly a internal wall does have two entries as already stated
• The entries you remove should have the same face counts in the constant/polyMesh/boundary file

This is out of the box without testing so I am not 100 % sure if my statement is correct but it should hold.

My mistake. I had removed a wall boundary and not an internal face.