[rachele]

Hello everyone, I am working on a multi-region mesh with SHM to define different components of an electric motor. Some of the stl are correctly turned into cellZone as required in the code, other instead do not produce cellZone but only faceZone. All stl used are closed surfaces controlled with surfaceCheck. I can't share the stl but following I report the snappy hex mesh dict.

Is there any constrains that I should respect in the cellZone definition like order of definition? I have tried also whit the definition of the inside point, solution that works for surface_in cell zone but for example not for shaft_cooling_duct for example.

I dont understand why just some of them is correctly defined. If some has any suggestion it will be appreciated. Thanks.


geometry
{
surface_out
{
type triSurfaceMesh;
file "surface_out.stl";

}

surface_in
{
type triSurfaceMesh;
file "surface_in.stl";

}

cooling_channels
{
type triSurfaceMesh;
file "cooling_channels.stl";

}

cooling_shaft
{
type triSurfaceMesh;
file "cooling_shaft.stl";

}

shaft
{
type triSurfaceMesh;
file "shaft.stl";

}

shaft_cooling_duct
{
type triSurfaceMesh;
file "shaft_cooling_duct.stl";

}

shaft_cooling_flow
{
type triSurfaceMesh;
file "shaft_cooling_flow.stl";

}

rotor_component_1
{
type triSurfaceMesh;
file "rotor_component_1.stl";

}

rotor_component_2
{
type triSurfaceMesh;
file "rotor_component_2.stl";

}

rotor_windings
{
type triSurfaceMesh;
file "rotor_windings.stl";

}

hole_shaft
{
type triSurfaceMesh;
file "hole_shaft.stl";

}

external_duct
{
type triSurfaceMesh;
file "external_duct.stl";

}




};

castellatedMeshControls
{
maxLocalCells 1000000000;
maxGlobalCells 2000000000;
minRefinementCells 0;
maxLoadUnbalance 0.10;
nCellsBetweenLevels 4;

features
(

{
file "surface_out.eMesh";
level 3;
}

{
file "surface_in.eMesh";
level 3;
}

{
file "cooling_channels.eMesh";
level 4;
}

{
file "cooling_shaft.eMesh";
level 4;
}

{
file "shaft.eMesh";
level 4;
}

{
file "shaft_cooling_duct.eMesh";
level 5;
}

{
file "shaft_cooling_flow.eMesh";
level 5;
}

{
file "rotor_component_1.eMesh";
level 2;
}

{
file "rotor_component_2.eMesh";
level 2;
}

{
file "rotor_windings.eMesh";
level 4;
}

{
file "hole_shaft.eMesh";
level 2;
}

{
file "external_duct.eMesh";
level 2;
}
);


refinementSurfaces
{
surface_out // rimuovere celle esterne
{
level (3 3);
}

external_duct
{
level (2 2);
}

surface_external
{
level (2 2);
faceZone surface_out_surface;
cellZone surface_out;
mode inside;
}

external_duct_zone //definizione cellzone dello spessore del guscio motore
{
level (3 3);
faceZone external_duct_surface;
cellZone external_duct;
mode inside;
}

surface_in
{
level (3 3);
faceZone internal_surface;
cellZone internal;
cellZoneInside insidePoint;
insidePoint (10 57 -109);
}

cooling_channels
{
level (5 5);
faceZone cooling_channels_surface;
cellZone cooling_channels;
mode inside;

}

cooling_shaft
{
level (5 5);
faceZone cooling_shaft_surface;
cellZone cooling_shaft;
mode inside;

}

rotor_component_1 //cilindro
{
level (2 2);
faceZone rotor_component_1_surface;
cellZone rotor_component_1;
mode inside;

}

rotor_component_2 //cilindro dentro il quale ci sono gli avvolgimenti
{
level (2 2);
faceZone rotor_component_2_surface;
cellZone rotor_component_2;
mode inside;

}

shaft
{
level (3 3);
faceZone shaft_surface;
cellZone shaft;
mode inside;
}

shaft_cooling_duct
{
level (5 5);
faceZone shaft_cooling_duct_surface;
cellZone shaft_cooling_duct;
cellZoneInside insidePoint;
insidePoint (0.5 0 0);

}

shaft_cooling_flow
{
level (2 2);
faceZone shaft_cooling_flow_surface;
cellZone shaft_cooling_flow;
mode inside;
}

rotor_windings
{
level (4 4);
faceZone rotor_windings _surface;
cellZone rotor_windings ;
mode inside;
}

hole_shaft
{
level (2 2);
faceZone hole_shaft_surface;
cellZone hole_shaft;
mode inside;
}


}

refinementRegions
{

}


locationInMesh (5 37 43);

resolveFeatureAngle 5;

}

// Settings for the snapping.
snapControls
{

nSmoothPatch 3;
tolerance 4.0;
nSolveIter 300;
nRelaxIter 5;
nFeatureSnapIter 10;
implicitFeatureSnap false;
explicitFeatureSnap true;
multiRegionFeatureSnap true;

}

[Hr_kules]

there probably is a right answer to that, but i wasted 3/4 of year trying to understand multiregion meshing in snappyHexMesh. If you are willing to try, i would investigate the heated duct tutorial for chtMultiregionFoam. However, if your application must be done with more cellZones i would probably switch to gmsh. It is quite easy to learn and i haven't done a multi region mesh with gmsh that wasn't good.

[AtoHM]

Only thing that sticks out to me is that you sometimes use insidePoint and sometimes use inside for cellZoneInside.
Honestly, I never used insidePoint and do not know what purpose it serves as inside worked fine in any case I meshed. Could be a thing relating to ESI/Foundation divergence?