[MBttR]

Hi,

I've succesfully completed the external flow research of an aircraft, rotors off, under all conditions I need. Results look meaningful. Wanting now to progress to a rotors on, MRF simulation, I'm having issues with snappyHexMesh and I'm starting to run out of things to try. First I had a very low quality mesh, but after tweaking surface and region refinement variables I got a good snap. I sometimes got a 'Killed' message but changing maxLocalCells and maxGlobalCells fixed that issue.

Now, however, I'm stuck at layers. I have tried changing the featureAngle, the amount of layers, the layer thicknesses, maxLocalCells and maxGlobalCells, .. It always results in the following error (full log later)

truncateDisplacement : Unextruded 3 faces due to non-consecutive vertices being extruded.
truncateDisplacement : Unextruded 7 faces due to stringed edges with inconsistent extrusion.
truncateDisplacement : Unextruded 0 faces due to non-consecutive vertices being extruded.
truncateDisplacement : Unextruded 0 faces due to stringed edges with inconsistent extrusion.

Setting up information for layer truncation ...
Killed

If I try to rerun it, but with castellating and snapping turned off (hence only layers), it does finish meshing (in about 13 seconds) but actually hasn't done anything, so I think there's something going wrong because of that and therefore I only run it fully.

Below is my snappyHexMeshDict, under that is the full sHM log.

Cheers! I hope someone can help me further cause I'm at a bit of a loss. I'm glad I got a good snap, now just have to get the next part.

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  4.0                                   |
|   \\  /    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       true;


// 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
{
    AC.stl
    {
        type triSurfaceMesh;
        name AC;
    }

    refinementBody
    {
        type searchableBox;
        min (-0.4 -0.35 -0.15);
        max ( 0.75  0.35 0.25);
    }

    refinementArm1
    {
        type searchableBox;
        min (-0.8 -0.1 -0.05);
        max (-0.2  0.1 0.15);
    }

    refinementArm2
    {
        type searchableBox;
        min ( -0.1 0.2 -0.1);
        max ( 0.1  0.75 0.1);
    }

    refinementArm3
    {
        type searchableBox;
        min ( 0.25 -0.1 -0.1);
        max ( 0.85 0.1  0.1);
    }

    refinementArm4
    {
        type searchableBox;
        min ( -0.1 -0.75 -0.1);
        max ( 0.1  -0.2 0.1);
    }

    gps
    {
        type searchableBox;
        min ( -0.06 -0.015 -0.145);
        max ( -0.03  0.015 0.165);
    }

    rotor1
    {
        type searchableCylinder;
        point1 ( -0.65914769291 0 0.06);
        point2 ( -0.65914769291  0 0.14);
	radius 0.4;
    }

    /*rotor2
    {
        type searchableCylinder;
        point1 ( 0 0.59384907717 0.04);
        point2 ( 0 0.59384907717 0.08);
	radius 0.4;
    }

    rotor3
    {
        type searchableCylinder;
        point1 ( 0 -0.59384907717 0.04);
        point2 ( 0 -0.59384907717 0.08);
	radius 0.4;
    }

    rotor4
    {
        type searchableCylinder;
        point1 ( 0.69501408945 0 0.027);
        point2 ( 0.69501408945 0 0.067);
	radius 0.4;
    }*/

};



// 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 1000000;

    // 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 10000000;

    // 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;

    // Allow a certain level of imbalance during refining
    // (since balancing is quite expensive)
    // Expressed as fraction of perfect balance (= overall number of cells /
    // nProcs). 0=balance always.
    maxLoadUnbalance 0.10;


    // Number of buffer layers between different levels.
    // 1 means normal 2:1 refinement restriction, larger means slower
    // refinement.
    nCellsBetweenLevels 3;



    // 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 "AC.eMesh";
            level 4;
        }
    );



    // 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
    {
        AC
        {
            // Surface-wise min and max refinement level
            level (6 8);

            // Optional specification of patch type (default is wall). No
            // constraint types (cyclic, symmetry) etc. are allowed.
        }
    }

    // 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
    {
        refinementBody
        {
            mode inside;
            levels ((1E15 3));
        }
        refinementArm1
        {
            mode inside;
            levels ((1E15 3));
        }
        refinementArm2
        {
            mode inside;
            levels ((1E15 5));
        }
        refinementArm3
        {
            mode inside;
            levels ((1E15 3));
        }
        refinementArm4
        {
            mode inside;
            levels ((1E15 3));
        }
        gps
        {
            mode inside;
            levels ((1E15 3));
        }
        rotor1
        {
            mode inside;
            levels ((1E15 5));
        }
        /*rotor2
        {
            mode inside;
            levels ((1E15 6));
        }
        rotor3
        {
            mode inside;
            levels ((1E15 6));
        }
        rotor4
        {
            mode inside;
            levels ((1E15 6));
        }*/
    }


    // 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 (0.39847 0.65104 0.4);


    // 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 2.0;

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

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

    // Feature snapping

        //- Number of feature edge snapping iterations.
        //  Leave out altogether to disable.
        nFeatureSnapIter 10;

        //- Detect (geometric only) features by sampling the surface
        //  (default=false).
        implicitFeatureSnap false;

        //- Use castellatedMeshControls::features (default = true)
        explicitFeatureSnap true;

        //- Detect points on multiple surfaces (only for explicitFeatureSnap)
        multiRegionFeatureSnap false;
}



// Settings for the layer addition.
addLayersControls
{
    // Are the thickness parameters below relative to the undistorted
    // size of the refined cell outside layer (true) or absolute sizes (false).
    relativeSizes true;

    // Per final patch (so not geometry!) the layer information
    layers
    {
        AC
        {
            nSurfaceLayers 2;
        }
    }

    // Expansion factor for layer mesh
    expansionRatio 1.0;

    // 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 0.3;

    // 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 0.01;

    // 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 1;

    // Advanced settings

    // When not to extrude surface. 0 is flat surface, 90 is when two faces
    // are perpendicular
    featureAngle 60;

    // At non-patched sides allow mesh to slip if extrusion direction makes
    // angle larger than slipFeatureAngle.
    slipFeatureAngle 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 10;

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

    // Reduce layer growth where ratio thickness to medial
    // distance is large
    maxThicknessToMedialRatio 0.3;

    // 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.
// Generic mesh quality settings. At any undoable phase these determine
// where to undo.
meshQualityControls
{
    //- Maximum non-orthogonality allowed. Set to 180 to disable.
    maxNonOrtho 65;

    //- Max skewness allowed. Set to <0 to disable.
    maxBoundarySkewness 20;
    maxInternalSkewness 4;

    //- Max concaveness allowed. Is angle (in degrees) below which concavity
    //  is allowed. 0 is straight face, <0 would be convex face.
    //  Set to 180 to disable.
    maxConcave 80;

    //- Minimum projected area v.s. actual area. Set to -1 to disable.
    minFlatness 0.5;

    //- Minimum pyramid volume. Is absolute volume of cell pyramid.
    //  Set to a sensible fraction of the smallest cell volume expected.
    //  Set to very negative number (e.g. -1E30) to disable.
    minVol 1e-13;
    minTetQuality 1e-30;

    //- Minimum face area. Set to <0 to disable.
    minArea -1;

    //- Minimum face twist. Set to <-1 to disable. dot product of face normal
    //  and face centre triangles normal
    minTwist 0.02;

    //- Minimum normalised cell determinant
    //  1 = hex, <= 0 = folded or flattened illegal cell
    minDeterminant 0.001;

    //- minFaceWeight (0 -> 0.5)
    minFaceWeight 0.02;

    //- minVolRatio (0 -> 1)
    minVolRatio 0.01;

    //must be >0 for Fluent compatibility
    minTriangleTwist -1;


    // Advanced

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


// Advanced

// Write flags
writeFlags
(
    scalarLevels
    layerSets
    layerFields     // write volScalarField for layer coverage
);


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


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

[MBttR]

Just bottom part of the sHM log as it is way to long for this forum..

Iteration 5
Displacement scaling for error reduction set to 0.
Moving mesh using displacement scaling : min:0.237305  max:1
Checking faces in error :
    non-orthogonality > 65  degrees                        : 1
    faces with face pyramid volume < 1e-13                 : 73
    faces with face-decomposition tet quality < 1e-30      : 1381
    faces with concavity > 80  degrees                     : 48
    faces with skewness > 4   (internal) or 20  (boundary) : 0
    faces with interpolation weights (0..1)  < 0.02        : 0
    faces with volume ratio of neighbour cells < 0.01      : 0
    faces with face twist < 0.02                           : 178
    faces on cells with determinant < 0.001                : 0

Iteration 6
Moving mesh using displacement scaling : min:0  max:1
Checking faces in error :
    non-orthogonality > 65  degrees                        : 0
    faces with face pyramid volume < 1e-13                 : 0
    faces with face-decomposition tet quality < 1e-30      : 22
    faces with concavity > 80  degrees                     : 4
    faces with skewness > 4   (internal) or 20  (boundary) : 0
    faces with interpolation weights (0..1)  < 0.02        : 0
    faces with volume ratio of neighbour cells < 0.01      : 0
    faces with face twist < 0.02                           : 10
    faces on cells with determinant < 0.001                : 0

Iteration 7
Moving mesh using displacement scaling : min:0  max:1
Checking faces in error :
    non-orthogonality > 65  degrees                        : 0
    faces with face pyramid volume < 1e-13                 : 0
    faces with face-decomposition tet quality < 1e-30      : 0
    faces with concavity > 80  degrees                     : 0
    faces with skewness > 4   (internal) or 20  (boundary) : 0
    faces with interpolation weights (0..1)  < 0.02        : 0
    faces with volume ratio of neighbour cells < 0.01      : 0
    faces with face twist < 0.02                           : 0
    faces on cells with determinant < 0.001                : 0
Successfully moved mesh
Moved mesh in = 89.85 s


Repatching faces according to nearest surface ...
Repatched 0 faces in = 2.91 s


Edge intersection testing:
    Number of edges             : 7148447
    Number of edges to retest   : 1652548
    Number of intersected edges : 510097
Merging 106791 sets of faces.

Edge intersection testing:
    Number of edges             : 7006685
    Number of edges to retest   : 432992
    Number of intersected edges : 368366

Undo iteration 0
----------------
Checking faces in error :
    non-orthogonality > 65  degrees                        : 0
    faces with face pyramid volume < 1e-13                 : 0
    faces with face-decomposition tet quality < 1e-30      : 74
    faces with concavity > 80  degrees                     : 0
    faces with skewness > 4   (internal) or 20  (boundary) : 0
    faces with interpolation weights (0..1)  < 0.02        : 0
    faces with volume ratio of neighbour cells < 0.01      : 0
    faces with face twist < 0.02                           : 2
    faces on cells with determinant < 0.001                : 0
Masters that need to be restored:111
Edge intersection testing:
    Number of edges             : 7006818
    Number of edges to retest   : 708
    Number of intersected edges : 368499


Undo iteration 1
----------------
Checking faces in error :
    non-orthogonality > 65  degrees                        : 0
    faces with face pyramid volume < 1e-13                 : 0
    faces with face-decomposition tet quality < 1e-30      : 0
    faces with concavity > 80  degrees                     : 0
    faces with skewness > 4   (internal) or 20  (boundary) : 0
    faces with interpolation weights (0..1)  < 0.02        : 0
    faces with volume ratio of neighbour cells < 0.01      : 0
    faces with face twist < 0.02                           : 0
    faces on cells with determinant < 0.001                : 0

Merging all points on surface that
- are used by only two boundary faces and
- make an angle with a cosine of more than 0.866025.

Removing 67916 straight edge points ...

Edge intersection testing:
    Number of edges             : 7006818
    Number of edges to retest   : 357373
    Number of intersected edges : 368515

Undo iteration 0
----------------
Checking faces in error :
    non-orthogonality > 65  degrees                        : 0
    faces with face pyramid volume < 1e-13                 : 1
    faces with face-decomposition tet quality < 1e-30      : 6
    faces with concavity > 80  degrees                     : 0
    faces with skewness > 4   (internal) or 20  (boundary) : 0
    faces with interpolation weights (0..1)  < 0.02        : 0
    faces with volume ratio of neighbour cells < 0.01      : 0
    faces with face twist < 0.02                           : 0
    faces on cells with determinant < 0.001                : 0
Detected 1 error faces on boundaries that have been merged. These will be restored to their original faces.

Edge intersection testing:
    Number of edges             : 7006818
    Number of edges to retest   : 5
    Number of intersected edges : 368515

Undo iteration 1
----------------
Checking faces in error :
    non-orthogonality > 65  degrees                        : 0
    faces with face pyramid volume < 1e-13                 : 0
    faces with face-decomposition tet quality < 1e-30      : 6
    faces with concavity > 80  degrees                     : 0
    faces with skewness > 4   (internal) or 20  (boundary) : 0
    faces with interpolation weights (0..1)  < 0.02        : 0
    faces with volume ratio of neighbour cells < 0.01      : 0
    faces with face twist < 0.02                           : 0
    faces on cells with determinant < 0.001                : 0
Detected 0 error faces on boundaries that have been merged. These will be restored to their original faces.

Detected 6 error faces in mesh. Restoring neighbours of faces in error.

Edge intersection testing:
    Number of edges             : 7006818
    Number of edges to retest   : 262
    Number of intersected edges : 368515
Snapped mesh : cells:2169252  faces:7006818  points:2709354
Cells per refinement level:
    0	10285
    1	2303
    2	4998
    3	13292
    4	37679
    5	116446
    6	263117
    7	411580
    8	1309552
Writing mesh to time 2
Wrote mesh in = 141.35 s.
Mesh snapped in = 1048.24 s.

Shrinking and layer addition phase
----------------------------------

Using mesh parameters 
{
    maxNonOrtho     65;
    maxBoundarySkewness 20;
    maxInternalSkewness 4;
    maxConcave      80;
    minFlatness     0.5;
    minVol          1e-13;
    minTetQuality   1e-30;
    minArea         -1;
    minTwist        0.02;
    minDeterminant  0.001;
    minFaceWeight   0.02;
    minVolRatio     0.01;
    minTriangleTwist -1;
    nSmoothScale    4;
    errorReduction  0.75;
}



Merging all faces of a cell
---------------------------
    - which are on the same patch
    - which make an angle < 60 degrees
      (cos:0.5)
    - as long as the resulting face doesn't become concave by more than 90 degrees
      (0=straight, 180=fully concave)

Merging 2185 sets of faces.

Edge intersection testing:
    Number of edges             : 7003313
    Number of edges to retest   : 13443
    Number of intersected edges : 365017

Undo iteration 0
----------------
Checking faces in error :
    non-orthogonality > 65  degrees                        : 0
    faces with face pyramid volume < 1e-13                 : 0
    faces with face-decomposition tet quality < 1e-30      : 212
    faces with concavity > 80  degrees                     : 13
    faces with skewness > 4   (internal) or 20  (boundary) : 0
    faces with interpolation weights (0..1)  < 0.02        : 0
    faces with volume ratio of neighbour cells < 0.01      : 0
    faces with face twist < 0.02                           : 3
    faces on cells with determinant < 0.001                : 0
Masters that need to be restored:277
Edge intersection testing:
    Number of edges             : 7003654
    Number of edges to retest   : 1702
    Number of intersected edges : 365356


Undo iteration 1
----------------
Checking faces in error :
    non-orthogonality > 65  degrees                        : 0
    faces with face pyramid volume < 1e-13                 : 0
    faces with face-decomposition tet quality < 1e-30      : 0
    faces with concavity > 80  degrees                     : 0
    faces with skewness > 4   (internal) or 20  (boundary) : 0
    faces with interpolation weights (0..1)  < 0.02        : 0
    faces with volume ratio of neighbour cells < 0.01      : 0
    faces with face twist < 0.02                           : 0
    faces on cells with determinant < 0.001                : 0

Merging all points on surface that
- are used by only two boundary faces and
- make an angle with a cosine of more than 0.5.

Removing 2313 straight edge points ...

Edge intersection testing:
    Number of edges             : 7003654
    Number of edges to retest   : 17457
    Number of intersected edges : 365375

Undo iteration 0
----------------
Checking faces in error :
    non-orthogonality > 65  degrees                        : 0
    faces with face pyramid volume < 1e-13                 : 0
    faces with face-decomposition tet quality < 1e-30      : 13
    faces with concavity > 80  degrees                     : 2
    faces with skewness > 4   (internal) or 20  (boundary) : 0
    faces with interpolation weights (0..1)  < 0.02        : 0
    faces with volume ratio of neighbour cells < 0.01      : 0
    faces with face twist < 0.02                           : 0
    faces on cells with determinant < 0.001                : 0
Detected 5 error faces on boundaries that have been merged. These will be restored to their original faces.

Edge intersection testing:
    Number of edges             : 7003654
    Number of edges to retest   : 41
    Number of intersected edges : 365375

Undo iteration 1
----------------
Checking faces in error :
    non-orthogonality > 65  degrees                        : 0
    faces with face pyramid volume < 1e-13                 : 0
    faces with face-decomposition tet quality < 1e-30      : 11
    faces with concavity > 80  degrees                     : 0
    faces with skewness > 4   (internal) or 20  (boundary) : 0
    faces with interpolation weights (0..1)  < 0.02        : 0
    faces with volume ratio of neighbour cells < 0.01      : 0
    faces with face twist < 0.02                           : 0
    faces on cells with determinant < 0.001                : 0
Detected 0 error faces on boundaries that have been merged. These will be restored to their original faces.

Detected 11 error faces in mesh. Restoring neighbours of faces in error.

Edge intersection testing:
    Number of edges             : 7003654
    Number of edges to retest   : 463
    Number of intersected edges : 365378

Checking mesh manifoldness ...

Checking initial mesh ...
Checking faces in error :
    non-orthogonality > 65  degrees                        : 0
    faces with face pyramid volume < 1e-13                 : 0
    faces with face-decomposition tet quality < 1e-30      : 0
    faces with concavity > 80  degrees                     : 0
    faces with skewness > 4   (internal) or 20  (boundary) : 0
    faces with interpolation weights (0..1)  < 0.02        : 0
    faces with volume ratio of neighbour cells < 0.01      : 0
    faces with face twist < 0.02                           : 0
    faces on cells with determinant < 0.001                : 0
Detected 0 illegal faces (concave, zero area or negative cell pyramid volume)

Adding in total 0 inter-processor patches to handle extrusion of non-manifold processor boundaries.

Handling points with inconsistent layer specification ...

Handling non-manifold points ...

Checking patch manifoldness ...
Outside of local patch is multiply connected across edges or points at 0 points.
Set displacement to zero for all 0 non-manifold points

Handling feature edges ...

Handling cells with warped patch faces ...
Set displacement to zero on 98 warped faces since layer would be > 0.5 of the size of the bounding box.

Growing non-extrusion points by one layer ...
Set displacement to zero for an additional 1001 points.

patch   faces    layers avg thickness[m]
                        near-wall overall
-----   -----    ------ --------- -------
AC      365427   2      0.000497  0.000992

Selecting externalDisplacementMeshMover displacementMedialAxis
displacementMedialAxis : Calculating distance to Medial Axis ...
displacementMedialAxis : Smoothing normals ...
    Iteration 0   residual 0.0342433
displacementMedialAxis : Inserting points on patch front if angle to nearest layer patch > 30 degrees.
displacementMedialAxis : Inserting points on patch back if angle to nearest layer patch > 30 degrees.
displacementMedialAxis : Inserting points on patch inlet if angle to nearest layer patch > 30 degrees.
displacementMedialAxis : Inserting points on patch outlet if angle to nearest layer patch > 30 degrees.
displacementMedialAxis : Inserting points on patch lowerWall if angle to nearest layer patch > 30 degrees.
displacementMedialAxis : Inserting points on patch upperWall if angle to nearest layer patch > 30 degrees.
displacementMedialAxis : Smoothing normals in interior ...
    Iteration 0   residual 0.0667835

Layer addition iteration 0
--------------------------

Determining displacement for added points according to pointNormal ...
Detected 1995 points with point normal pointing through faces.
Reset displacement at 1995 points to average of surrounding points.

displacementMedialAxis : Smoothing using Medial Axis ...
displacementMedialAxis : Reducing layer thickness at 40978 nodes where thickness to medial axis distance is large 
displacementMedialAxis : Removing isolated regions ...
displacementMedialAxis : Number of isolated points extrusion stopped : 6864
displacementMedialAxis : Smoothing field ...
    Iteration 0   residual 5.43147e-06
displacementMedialAxis : Moving mesh ...
displacementMedialAxis : Iteration 0
Moving mesh using displacement scaling : min:1  max:1
Checking faces in error :
    non-orthogonality > 65  degrees                        : 5
    faces with face pyramid volume < 1e-13                 : 12
    faces with face-decomposition tet quality < 1e-30      : 420
    faces with concavity > 80  degrees                     : 15
    faces with skewness > 4   (internal) or 20  (boundary) : 0
    faces with interpolation weights (0..1)  < 0.02        : 0
    faces with volume ratio of neighbour cells < 0.01      : 0
    faces with face twist < 0.02                           : 9
    faces on cells with determinant < 0.001                : 0
displacementMedialAxis : Iteration 1
Moving mesh using displacement scaling : min:0.75  max:1
Checking faces in error :
    non-orthogonality > 65  degrees                        : 6
    faces with face pyramid volume < 1e-13                 : 6
    faces with face-decomposition tet quality < 1e-30      : 222
    faces with concavity > 80  degrees                     : 9
    faces with skewness > 4   (internal) or 20  (boundary) : 0
    faces with interpolation weights (0..1)  < 0.02        : 0
    faces with volume ratio of neighbour cells < 0.01      : 0
    faces with face twist < 0.02                           : 2
    faces on cells with determinant < 0.001                : 0
displacementMedialAxis : Iteration 2
Moving mesh using displacement scaling : min:0.5625  max:1
Checking faces in error :
    non-orthogonality > 65  degrees                        : 5
    faces with face pyramid volume < 1e-13                 : 1
    faces with face-decomposition tet quality < 1e-30      : 143
    faces with concavity > 80  degrees                     : 6
    faces with skewness > 4   (internal) or 20  (boundary) : 0
    faces with interpolation weights (0..1)  < 0.02        : 0
    faces with volume ratio of neighbour cells < 0.01      : 0
    faces with face twist < 0.02                           : 0
    faces on cells with determinant < 0.001                : 0
displacementMedialAxis : Iteration 3
displacementMedialAxis : Displacement scaling for error reduction set to 0.
Moving mesh using displacement scaling : min:0.421875  max:1
Checking faces in error :
    non-orthogonality > 65  degrees                        : 3
    faces with face pyramid volume < 1e-13                 : 1
    faces with face-decomposition tet quality < 1e-30      : 127
    faces with concavity > 80  degrees                     : 3
    faces with skewness > 4   (internal) or 20  (boundary) : 0
    faces with interpolation weights (0..1)  < 0.02        : 0
    faces with volume ratio of neighbour cells < 0.01      : 0
    faces with face twist < 0.02                           : 1
    faces on cells with determinant < 0.001                : 0
displacementMedialAxis : Iteration 4
Moving mesh using displacement scaling : min:0  max:1
Checking faces in error :
    non-orthogonality > 65  degrees                        : 0
    faces with face pyramid volume < 1e-13                 : 1
    faces with face-decomposition tet quality < 1e-30      : 16
    faces with concavity > 80  degrees                     : 1
    faces with skewness > 4   (internal) or 20  (boundary) : 0
    faces with interpolation weights (0..1)  < 0.02        : 0
    faces with volume ratio of neighbour cells < 0.01      : 0
    faces with face twist < 0.02                           : 0
    faces on cells with determinant < 0.001                : 0
displacementMedialAxis : Iteration 5
Moving mesh using displacement scaling : min:0  max:1
Checking faces in error :
    non-orthogonality > 65  degrees                        : 0
    faces with face pyramid volume < 1e-13                 : 0
    faces with face-decomposition tet quality < 1e-30      : 2
    faces with concavity > 80  degrees                     : 0
    faces with skewness > 4   (internal) or 20  (boundary) : 0
    faces with interpolation weights (0..1)  < 0.02        : 0
    faces with volume ratio of neighbour cells < 0.01      : 0
    faces with face twist < 0.02                           : 0
    faces on cells with determinant < 0.001                : 0
displacementMedialAxis : Finished moving mesh ...
truncateDisplacement : Unextruded 3 faces due to non-consecutive vertices being extruded.
truncateDisplacement : Unextruded 7 faces due to stringed edges with inconsistent extrusion.
truncateDisplacement : Unextruded 0 faces due to non-consecutive vertices being extruded.
truncateDisplacement : Unextruded 0 faces due to stringed edges with inconsistent extrusion.

Setting up information for layer truncation ...
Killed

[MBttR]

Figured the checkMesh might be handy as well..

/*---------------------------------------------------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  4.0                                   |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
Build  : 4.0-665f1db4c1f1
Exec   : checkMesh
Date   : Aug 11 2016
Time   : 16:24:21
Host   : "bruno-VirtualBox"
PID    : 4849
Case   : /home/bruno/OpenFOAM/bruno-4.0/run/ACrotors/AC
nProcs : 1
sigFpe : Enabling floating point exception trapping (FOAM_SIGFPE).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster
allowSystemOperations : Allowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Create polyMesh for time = 1

Time = 1

Mesh stats
    points:           2812212
    faces:            7148447
    internal faces:   6635203
    cells:            2169252
    faces per cell:   6.3541
    boundary patches: 7
    point zones:      0
    face zones:       0
    cell zones:       0

Overall number of cells of each type:
    hexahedra:     1913198
    prisms:        0
    wedges:        0
    pyramids:      0
    tet wedges:    0
    tetrahedra:    0
    polyhedra:     256054
    Breakdown of polyhedra by number of faces:
        faces   number of cells
            6   78329
            8   407
            9   120861
           10   38
           11   133
           12   35220
           13   5
           14   124
           15   19887
           17   15
           18   1032
           21   3

Checking topology...
    Boundary definition OK.
    Cell to face addressing OK.
    Point usage OK.
    Upper triangular ordering OK.
    Face vertices OK.
    Number of regions: 1 (OK).

Checking patch topology for multiply connected surfaces...
                   Patch    Faces   Points                  Surface topology
                   front      594      646  ok (non-closed singly connected)
                    back      594      646  ok (non-closed singly connected)
                   inlet      324      361  ok (non-closed singly connected)
                  outlet      324      361  ok (non-closed singly connected)
               lowerWall      594      646  ok (non-closed singly connected)
               upperWall      594      646  ok (non-closed singly connected)
                 AC   510220   514603      ok (closed singly connected)

Checking geometry...
    Overall domain bounding box (-4 -3 -3) (7 3 3)
    Mesh has 3 geometric (non-empty/wedge) directions (1 1 1)
    Mesh has 3 solution (non-empty) directions (1 1 1)
    Boundary openness (-1.40386e-17 -1.27896e-17 2.60202e-18) OK.
    Max cell openness = 2.18586e-16 OK.
    Max aspect ratio = 1.001 OK.
    Minimum face area = 1.69442e-06. Maximum face area = 0.111116.  Face area magnitudes OK.
    Min volume = 2.20614e-09. Max volume = 0.0370393.  Total volume = 395.961.  Cell volumes OK.
    Mesh non-orthogonality Max: 25.2575 average: 9.8377
    Non-orthogonality check OK.
    Face pyramids OK.
    Max skewness = 1.00077 OK.
    Coupled point location match (average 0) OK.

Mesh OK.

Time = 2

Mesh stats
    points:           2709354
    faces:            7006818
    internal faces:   6635203
    cells:            2169252
    faces per cell:   6.28881
    boundary patches: 7
    point zones:      0
    face zones:       0
    cell zones:       0

Overall number of cells of each type:
    hexahedra:     1807960
    prisms:        46256
    wedges:        0
    pyramids:      0
    tet wedges:    208
    tetrahedra:    2
    polyhedra:     314826
    Breakdown of polyhedra by number of faces:
        faces   number of cells
            4   34291
            5   25244
            6   77710
            7   253
            8   258
            9   120682
           10   57
           11   107
           12   35203
           13   1
           14   116
           15   19854
           17   15
           18   1032
           21   3

Checking topology...
    Boundary definition OK.
    Cell to face addressing OK.
    Point usage OK.
    Upper triangular ordering OK.
    Face vertices OK.
    Number of regions: 1 (OK).

Checking patch topology for multiply connected surfaces...
                   Patch    Faces   Points                  Surface topology
                   front      594      646  ok (non-closed singly connected)
                    back      594      646  ok (non-closed singly connected)
                   inlet      324      361  ok (non-closed singly connected)
                  outlet      324      361  ok (non-closed singly connected)
               lowerWall      594      646  ok (non-closed singly connected)
               upperWall      594      646  ok (non-closed singly connected)
                 AC        368591   411745      ok (closed singly connected)

Checking geometry...
    Overall domain bounding box (-4 -3 -3) (7 3 3)
    Mesh has 3 geometric (non-empty/wedge) directions (1 1 1)
    Mesh has 3 solution (non-empty) directions (1 1 1)
    Boundary openness (-3.06106e-17 -1.16104e-17 -2.30344e-17) OK.
    Max cell openness = 3.66091e-16 OK.
    Max aspect ratio = 6.43551 OK.
    Minimum face area = 1.24113e-08. Maximum face area = 0.111119.  Face area magnitudes OK.
    Min volume = 1.48059e-10. Max volume = 0.0370393.  Total volume = 395.962.  Cell volumes OK.
    Mesh non-orthogonality Max: 64.9425 average: 10.8713
    Non-orthogonality check OK.
    Face pyramids OK.
 ***Max skewness = 5.54032, 7 highly skew faces detected which may impair the quality of the results
  <<Writing 7 skew faces to set skewFaces
    Coupled point location match (average 0) OK.

Failed 1 mesh checks.

End

[akidess]

http://stackoverflow.com/questions/7...rocess-and-why

[MBttR]

Originally Posted by akidess

http://stackoverflow.com/questions/7...rocess-and-why

Thanks, increasing RAM in VM did push me a bit further, but now I'm running into some other issues, depending on my settings. Either it still gets killed or layers arent't created. Didn't know meshing was so taxing on memory. Might have to switch to a permanent Linux distro so I can use my 16GB instead of the 10-ish I can pass through VM.

Cheers Anton! Say hi to Delft for me.