[Bob!]

Hello Foamers,

I'm trying to use the Solver chtMultiRegionFoam.
I'm using OpenFoam 4.1.

I started my Case out of the tutorial "snappyMultiRegionHeater". In this Tutorial the blockMesh-Geometrie is embedded to the geometry of the final geometry after using snappyHexMesh.
In my case this is not possible. Down below you'll find a picture of the problematic wall i want to build.

While using splitMeshRegions i need the created "boundaries" of the blockMesh-Dict to disappear, except of the inlet and outlet (minX and maxX).
To show you what i mean, i just uploaded one wall and the concerning code (the wall has 5 parts, Spundwand, Rohr1, Rohr2, Rohr3, Rohr4)

With a normal snappyHexMesh Dict (means evrything remains the same, except the writing of faceZone, cellZone etc at the point refinementSurfaces in the snappyHexMeshDict) it works perfectly: The wall looks like i want it to be, the "boundary" "maxY" is cut of. This is the wall the picture shows below.

As soon as the options for the cellzone writing are added, i get several domains between "maxY" and my wall, which i definitly do not want to have. It looks like it wouldn't have snapped, both "boundaries" are there, maxY and my wall.

The splitMeshRegions-option i'm using at the moment is:

 splitMeshRegions -cellZones -overwrite

Viewing this site (https://openfoamwiki.net/index.php/SplitMeshRegions) i saw several options, not knowing how to use them. I thought about the "-inside point" option, also not knowing how to use it or if it will work out (just as an idea). Should be mentioned, that i would need several points for that option, since it will be several regions i want to use.

Any suggestions? Thank you in advantage,
Robert


here is my Code:

blockMeshDict

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  4.1                                   |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      blockMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

convertToMeters 1;

vertices
(
    (0 0 0)
    (3 0 0)
    (3 1.6 0)
    (0 1.6 0)

    (0 0 4)
    (3 0 4)
    (3 1.6 4)
    (0 1.6 4)
);

blocks
(
    hex (0 1 2 3 4 5 6 7) (60 40 80) simpleGrading (1 1 1)
);

edges
(
);

boundary
(

    minX
    {
        type patch;
        faces
        (
            (0 3 7 4)
        );
    }

    maxX
    {
        type patch;
        faces
        (
            (2 1 5 6)
        );
    }

    minY
    {
        type wall;
        faces
        (
            (4 5 1 0)
        );
    }

    maxY
    {
        type wall;
        faces
        (
            (3 2 6 7)
        );
    }

    minZ
    {
        type wall;
        faces
        (
            (0 1 2 3)
        );
    }
    maxZ
    {
        type wall;
        faces
        (
            (7 6 5 4)
        );
    }
);

mergePatchPairs
(
);

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

snappyHexMeshDict

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  4.1                                   |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      snappyHexMeshDict;
}

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

// Which of the steps to run
castellatedMesh true;
snap            true;
addLayers       false;


// Geometry. Definition of all surfaces. All surfaces are of class
// searchableSurface.
// Surfaces are used
// - to specify refinement for any mesh cell intersecting it
// - to specify refinement for any mesh cell inside/outside/near
// - to 'snap' the mesh boundary to the surface
geometry
{
    Spundwand.stl
    {
        type triSurfaceMesh;
        name Spundwand;
    }

    Rohr1.stl
    {
        type triSurfaceMesh;
        name Rohr1;
    }

    Rohr2.stl
    {
        type triSurfaceMesh;
        name Rohr2;
    }

    Rohr3.stl
    {
        type triSurfaceMesh;
        name Rohr3;
    }

    Rohr4.stl
    {
        type triSurfaceMesh;
        name Rohr4;
    }


};



// Settings for the castellatedMesh generation.
castellatedMeshControls
{

    // Refinement parameters
    // ~~~~~~~~~~~~~~~~~~~~~

    // If local number of cells is >= maxLocalCells on any processor
    // switches from from refinement followed by balancing
    // (current method) to (weighted) balancing before refinement.
    maxLocalCells 100000;

    // Overall cell limit (approximately). Refinement will stop immediately
    // upon reaching this number so a refinement level might not complete.
    // Note that this is the number of cells before removing the part which
    // is not 'visible' from the keepPoint. The final number of cells might
    // actually be a lot less.
    maxGlobalCells 2000000;

    // The surface refinement loop might spend lots of iterations
    // refining just a few cells. This setting will cause refinement
    // to stop if <= minimumRefine are selected for refinement. Note:
    // it will at least do one iteration (unless the number of cells
    // to refine is 0)
    minRefinementCells 10;

    // Number of buffer layers between different levels.
    // 1 means normal 2:1 refinement restriction, larger means slower
    // refinement.
    nCellsBetweenLevels 2;



    // Explicit feature edge refinement
    // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    // Specifies a level for any cell intersected by its edges.
    // This is a featureEdgeMesh, read from constant/triSurface for now.
    features
    (

        {
            file "Spundwand.eMesh";
            level 1;
        }
        {
            file "Rohr1.eMesh";
            level 1;
        }
        {
            file "Rohr2.eMesh";
            level 1;
        }
        {
            file "Rohr3.eMesh";
            level 1;
        }
        {
            file "Rohr4.eMesh";
            level 1;
        }

    );



    // Surface based refinement
    // ~~~~~~~~~~~~~~~~~~~~~~~~

    // Specifies two levels for every surface. The first is the minimum level,
    // every cell intersecting a surface gets refined up to the minimum level.
    // The second level is the maximum level. Cells that 'see' multiple
    // intersections where the intersections make an
    // angle > resolveFeatureAngle get refined up to the maximum level.

    refinementSurfaces
    {


        Spundwand
        {
            // Surface-wise min and max refinement level
            level (1 1);

            faceZone Spundwand;
            cellZone Spundwand;
            cellZoneInside inside; 
        }

        Rohr1
        {
            // Surface-wise min and max refinement level
            level (1 1);

           faceZone Rohr1;
            cellZone Rohr1;
            cellZoneInside inside; 
        }
        Rohr2
        {
            // Surface-wise min and max refinement level
            level (1 1);

            faceZone Rohr2;
            cellZone Rohr2;
            cellZoneInside inside; 
        }
        Rohr3
        {
            // Surface-wise min and max refinement level
            level (1 1);

            faceZone Rohr3;
            cellZone Rohr3;
            cellZoneInside inside;
        }
        Rohr4
        {
            // Surface-wise min and max refinement level
            level (1 1);

            faceZone Rohr4;
            cellZone Rohr4;
            cellZoneInside inside;
        }

    }

    // Resolve sharp angles
    resolveFeatureAngle 30;


    // Region-wise refinement
    // ~~~~~~~~~~~~~~~~~~~~~~

    // Specifies refinement level for cells in relation to a surface. One of
    // three modes
    // - distance. 'levels' specifies per distance to the surface the
    //   wanted refinement level. The distances need to be specified in
    //   descending order.
    // - inside. 'levels' is only one entry and only the level is used. All
    //   cells inside the surface get refined up to the level. The surface
    //   needs to be closed for this to be possible.
    // - outside. Same but cells outside.

    refinementRegions
    {
Gesant {mode distance; levels ((0.01 1) (0.05 1) (0.1 1));}
        //refinementBox
        //{
        //    mode inside;
        //    levels ((1E15 4));
        //}
    }


    // Mesh selection
    // ~~~~~~~~~~~~~~

    // After refinement patches get added for all refinementSurfaces and
    // all cells intersecting the surfaces get put into these patches. The
    // section reachable from the locationInMesh is kept.
    // NOTE: This point should never be on a face, always inside a cell, even
    // after refinement.
    locationInMesh (1 1 1);


    // Whether any faceZones (as specified in the refinementSurfaces)
    // are only on the boundary of corresponding cellZones or also allow
    // free-standing zone faces. Not used if there are no faceZones.
    allowFreeStandingZoneFaces true;
}



// Settings for the snapping.
snapControls
{
    //- Number of patch smoothing iterations before finding correspondence
    //  to surface
    nSmoothPatch 3;

    //- Relative distance for points to be attracted by surface feature point
    //  or edge. True distance is this factor times local
    //  maximum edge length.
    tolerance 1.0;

    //- Number of mesh displacement relaxation iterations.
    nSolveIter 30;

    //- Maximum number of snapping relaxation iterations. Should stop
    //  before upon reaching a correct mesh.
    nRelaxIter 5;

    //- Highly experimental and wip: number of feature edge snapping
    //  iterations. Leave out altogether to disable.
    //  Of limited use in this case since faceZone faces not handled.
    nFeatureSnapIter 10;
}



// Settings for the layer addition.
addLayersControls
{
    relativeSizes true;

    // Per final patch (so not geometry!) the layer information
   layers
    {

    Spundwand
        {nSurfaceLayers 1;} // was 3

    Rohr1
        {nSurfaceLayers 1;} // was 3
    Rohr2
        {nSurfaceLayers 1;} // was 3
    Rohr3
        {nSurfaceLayers 1;} // was 3
    Rohr4
        {nSurfaceLayers 1;} // was 3

    }

    // Expansion factor for layer mesh
    expansionRatio 1.3;

    // Wanted thickness of final added cell layer. If multiple layers
    // is the thickness of the layer furthest away from the wall.
    // Relative to undistorted size of cell outside layer.
    // See relativeSizes parameter.
    finalLayerThickness 1;

    // Minimum thickness of cell layer. If for any reason layer
    // cannot be above minThickness do not add layer.
    // Relative to undistorted size of cell outside layer.
    minThickness 0.1;

    // If points get not extruded do nGrow layers of connected faces that are
    // also not grown. This helps convergence of the layer addition process
    // close to features.
    // Note: changed(corrected) w.r.t 17x! (didn't do anything in 17x)
    nGrow 0;

    // Advanced settings

    // When not to extrude surface. 0 is flat surface, 90 is when two faces
    // are perpendicular
    featureAngle 30;

    // Maximum number of snapping relaxation iterations. Should stop
    // before upon reaching a correct mesh.
    nRelaxIter 3;

    // Number of smoothing iterations of surface normals
    nSmoothSurfaceNormals 1;

    // Number of smoothing iterations of interior mesh movement direction
    nSmoothNormals 3;

    // Smooth layer thickness over surface patches
    nSmoothThickness 2;

    // Stop layer growth on highly warped cells
    maxFaceThicknessRatio 0.5;

    // Reduce layer growth where ratio thickness to medial
    // distance is large
    maxThicknessToMedialRatio 1;

    // Angle used to pick up medial axis points
    // Note: changed(corrected) w.r.t 17x! 90 degrees corresponds to 130 in 17x.
    minMedianAxisAngle 90;

    // Create buffer region for new layer terminations
    nBufferCellsNoExtrude 0;

    // Overall max number of layer addition iterations. The mesher will exit
    // if it reaches this number of iterations; possibly with an illegal
    // mesh.
    nLayerIter 50;
}



// Generic mesh quality settings. At any undoable phase these determine
// where to undo.
meshQualityControls
{
    #include "meshQualityDict"

    // Advanced

    //- Number of error distribution iterations
    nSmoothScale 4;
    //- Amount to scale back displacement at error points
    errorReduction 0.75;
}


// Advanced

// Merge tolerance. Is fraction of overall bounding box of initial mesh.
// Note: the write tolerance needs to be higher than this.
mergeTolerance 1e-6;


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