[jfw_cfd]

Hello!

After many hours of research without success, I need to open this new thread.

The following situation: I have a mesh (generated with snappyHexMesh) of a compressor with inlet and outlet boundary patches. I want to extrude an inlet channel and outlet channel, respectively, from these patches with extrudeMesh (extrude from mesh), which works fine and is already done.

But! I want to retain the original inlet and outlet boundary patch as an internal faceZone (or faceSet), since I want to do some postprocessing at these cross sections afterwards. How to do that? Any simple ideas? At the moment the sourcePatches (from the original mesh) are lost after the extrudeMesh operation.

BTW: OpenFOAM 2.4

Thanks in advance for your comments!
Regards,
Johannes

[jfw_cfd]

Hello & Hallo!

Just in case anybody is facing a similar problem, I post a solution (found by a colleague of mine) for the described problem.

My colleague found a solution/work around by using topoSet right after extrudeMesh with the following topoSetDict

FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      topoSetDict;
}

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

actions
(
    {
        name    inlet-fS;
        type    faceSet;
        action  new;
        source  cellToFace;
        sourceInfo
        {
            set addedCells;
            option  all;
        }

    }
    {
        name    bothaddedfaces-fS;
        type    faceSet;
        action  new;
        source  cellToFace;
        sourceInfo
        {
            set addedCells;
            option  both;
        }
    }
    {
        name    inlet-fS;
        type    faceSet;
        action  delete;
        source  faceToFace;
        sourceInfo
        {
            set bothaddedfaces-fS;
        }
    }
    {
        name    inlet-fS;
        type    faceSet;
        action  delete;
        source  patchToFace;
        sourceInfo
        {
            name inletDisk;
        }
    }
    {
        name    inlet-fS;
        type    faceSet;
        action  delete;
        source  patchToFace;
        sourceInfo
        {
            name inletpipe;
        }
    }
    {
        name    inlet-fZ;
        type    faceZoneSet;
        action  new;
        source  setToFaceZone;
        sourceInfo
        {
            faceSet     inlet-fS;
        }
    }
    {
        name    bothaddedfaces-fS;
        type    faceSet;
        action  remove;
    }
    {
        name    inlet-fS;
        type    faceSet;
        action  remove;
    }
    {
        name    addedCells;
        type    cellSet;
        action  remove;
    }
);

In a few words about what this topoSetDict essentially does:
1 extract all faces from extruded mesh (in this case a pipe)
2 extract only internal faces (with "both" option)
3 subtract internal faces from all faces (so only bounding faces remain)
4 subtract wall and the outside pipe end (in this case the inlet), so what remains is the inside pipe end, the internal face used for postprocessing purposes later on

Hope this might be helpful for those who didn't already know ;-)

Regards,
Johannes

[ElenaVM]

Hello Johannes

Thanks for your information. I'm trying to create a axisymmetric mesh with internal walls, the 3D mesh is well done with SnappyHexMesh and I could integrate the internal walls. But since I need a 2D mesh I use this ExtrudeMesh tool, everything is fine with the boundary patche but for the internal walls they disappear and I have no data of them neither in cellZone file nor faceZone file. I tried to use the hint you gave here but since my cellZone file has no points I think it is not working. Do you have a idea to fix this?

Thank you very much!