SnappyHexMesh and MultiRegion - get regions from Salome to OF
 

Hello Foamers

I tried many things and read a lot of snappyHexMesh threads but still I do not get it working to define regions in Salome and get them as patches in OF.
Mesh preparation in Salome:
Construct 2 bodies, here cylinder1 and cylinder2. The cylinders have a intersection.

I exploded the bodies into faces and meshed them with tetras.

I want to define regions at this state to find them in my case structure and set them as boundary.
Here cylinder2 is exploded to faces, the highlighted submesh is a face called cyl2botaussen.stl to be found as a patch.

After meshing, all faces are written out as cyl1*.stl
(total 3:

Code:

---

  cyl1bot.stl cyl1top.stl  cyl1wall.stl

---

) merged into one file

Code:

---

cyl1.stl

---

and cyl2*.stl
(total 4:

Code:

---

cyl2botaussen.stl  cyl2botinner.stl cyl2top.stl  cyl2wall.stl

---

)
merged into

Code:

---

cyl2.stl

---

.

cyl2botinner and cyl1top are the interface between the cylinders, the mesh is matching/the same.

The salome-hdf and the resulting stl file one can be found here:
https://www.dropbox.com/sh/bkalhcqwv...pEOPQ2fz9KAMva

SHM:
For the next steps, I use this standard case structure. Meshing2 contains the mesh preparation folders. cyl1.stl and cyl2.stl are copied to /constant/triSurfaces.

The snappyHexmesh is invoked by the steps (=makeMesh.sh):

ideasUnvToFoam outbox.unv
surfaceFeatureExtract
snappyHexMesh -overwrite
splitMeshRegions -cellZones -overwrite
paraFoam -touchAll

After snappyhexmesh I get the expected 3 regions domain:
cylinder1, cylinder2, domain0
and the default patches inbetween.

My snappyHexmeshDict has the sections:

Code:

---

geometry
 {
    cyl1.stl
    {
        type triSurfaceMesh;
        name cylinder1;
   
    }
 

    cyl2.stl
    {
        type triSurfaceMesh;
    name cylinder2;
    regions
    {
        cyl2botaussen        { name cylinder2aussen; }
    }
    }
 };
 (...)
    features
    (
        {
            file "cyl1.eMesh";
            level 2;
        }
        {
            file "cyl2.eMesh";
            level 2;
        }     
    );
  (...)
 refinementSurfaces
    {
        cylinder1
        {
            // Surface-wise min and max refinement level
            level (2 3);
            faceZone cylinder1;
            cellZone cylinder1;
            cellZoneInside inside;
        }
         
        //cyl2.stl
    cylinder2
        {
          level (2 3);
          faceZone cylinder2;
          cellZone cylinder2;
          cellZoneInside inside;
 //        regions    -- must this be here?
 //          {
 //          cylinder2aussen { level (3 3);  }
 //          }
    }
    }
  (...)

---

I want to see „cylinder2aussen“ in paraview as a patch.

What is going wrong, why my patch „cylinder2aussen“ is lost after SHM and and how can I get it? (Do I need putting the desired patch in a separate stl-file? Different entries in the snappyHexMeshDict? In SurfaceFeatureExtractDict?) None of the tutorials and threads could really help me.

Maybe somebody can give me the missing link. Thanks for reading and support :)
dirk


All files and the complete case are here:
https://www.dropbox.com/s/awk8noaanm...ppyMRFEasy.tgz
(on Salome 7.2.0 and OF 2.2.2)





https://www.dropbox.com/s/n44jvqrniofw6zw/salome1.png

... FYI there was an answer on another thread http://www.cfd-online.com/Forums/openfoam-meshing/135307-splitmeshregion.html#post503707
using
splitMeshRegions -cellZonesOnly -useFaceZones
but this issue still not solved for me yet.

fyi, latest updates are in that thread:
http://www.cfd-online.com/Forums/openfoam-meshing/135307-splitmeshregion.html#post509069