[anishtain4]

I was doing this tutorial from don't remember where?, it went well but when I was starting to use the snappyHexMesh at first try this came up:

......
Adding patches for surface regions
----------------------------------

Patch    Type    Region
-----    ----    ------
sylinteri:

6    wall    sylinteri_region0

Added patches in = 0 s

Selecting decompositionMethod hierarchical


--> FOAM FATAL IO ERROR: 
keyword allowFreeStandingZoneFaces is undefined in dictionary "$FOAM_RUN/gridTutorial/system/snappyHexMeshDict::castellatedMeshControls"

file: $FOAM_RUN/gridTutorial/system/snappyHexMeshDict::castellatedMeshControls from line 34 to line 51.

    From function dictionary::lookupEntry(const word&, bool, bool) const
    in file db/dictionary/dictionary.C at line 400.

FOAM exiting

I checked the snappyHexMeshDict but I couldn't find the keyword allowFreeStandingZoneFaces which is mentioned in the error, I have not used that. Any help?

[su_junwei]

Hi Mahdi
Just add a line into the dictionary castellatedMeshControls

allowFreeStandingZoneFaces true ;// false;

This keyword is used when a internal face (a faceZone keyword is defined for that face in refinementSurfaces) is on one boundary of your solution domain. This usually occurs when your internal face coincides with your backgroud mesh boundary and set allowFreeStandingZoneFaces to be true. otherwise, set it to be false.

Hope this helps.

Regards, Junwei

[anishtain4]

Yes, I got it. Thanks, I got that by comparison my case with motorbike files in the tutorial folder

[TommiPLaiho]

Hi,

I have exactly same problem:

--> FOAM FATAL IO ERROR:
keyword allowFreeStandingZoneFaces is undefined in dictionary "/home/tommi2/OpenFOAM/tommi2-2.1.1/run/system/snappyHexMeshDict::castellatedMeshControls"

file: /home/tommi2/OpenFOAM/tommi2-2.1.1/run/system/snappyHexMeshDict::castellatedMeshControls from line 54 to line 144.

From function dictionary::lookupEntry(const word&, bool, bool) const
in file db/dictionary/dictionary.C at line 400.

FOAM exiting

I added the lines to my snappyHexMeshDict like this:

};

// Settings for the castellatedMesh generation.
castellatedMeshControls allowFreeStandingZoneFaces true ;// false; 
{

...but no matter whether or not I use "true" or "false" option it gives me the same error. Please let me know what to do and thanks in advance.

PS. Here is my whole snappyHexMeshDict file in case it helps:

/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM Extend Project: Open Source CFD |
| \\ / O peration | Version: 1.6-ext |
| \\ / A nd | Web: www.extend-project.de |
| \\/ 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
{
ahmed_body.stl
{
type triSurfaceMesh;
name ahmed;
}

refinementBox
{
type searchableBox;
min (-1.5 -0.3 0.0);
max ( 0.5 0.3 0.7);
}
refinementGround { type searchableBox;
min (-4.0 -1.0 0.0); max ( 3.0 1.0 0.1);
}
refinementWake { type searchableBox;
min (0.0 -0.8 0.0); max ( 3.0 0.8 0.5); }


}


};

// 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 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;

// 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 "someLine.eMesh";
// level 2;
//}
);

// 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
{
ahmed
{
// Surface-wise min and max refinement
level (5 6);
}
ahmed_body_front_h
{
level (5 6);
}
}


// 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
{
refinementBox{
mode distance; levels ((0.1 4));
}
refinementGround{
mode inside; levels ((1E15 4));
}
refinementWake{
mode inside; levels ((1E15 3));
}
}


// 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 (3 1 0.431);
}

// 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 4.0;

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

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

// Settings for the layer addition.
addLayersControls
{

relativeSizes true;
layers
{
"(ground|ahmed).*"
{
nSurfaceLayers 1;
}
}
expansionRatio 1.0;
finalLayerThickness 0.6;

// 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
{
minZ
{
nSurfaceLayers 1;
}
motorBike_frt-fairing:001%1
{
nSurfaceLayers 1;
}
motorBike_windshield:002%2
{
nSurfaceLayers 1;
}
motorBike_rr-wh-rim:005%5
{
nSurfaceLayers 1;
}
motorBike_rr-wh-rim:010%10
{
nSurfaceLayers 1;
}
motorBike_fr-wh-rim:011%11
{
nSurfaceLayers 1;
}
motorBike_fr-wh-brake-disk:012%12
{
nSurfaceLayers 1;
}
motorBike_frame:016-shadow%13
{
nSurfaceLayers 1;
}
motorBike_rear-susp:014%14
{
nSurfaceLayers 1;
}
motorBike_rear-susp:014-shadow%15
{
nSurfaceLayers 1;
}
motorBike_frame:016%16
{
nSurfaceLayers 1;
}
motorBike_rr-wh-rim:005-shadow%17
{
nSurfaceLayers 1;
}
motorBike_rr-wh-chain-hub:022%22
{
nSurfaceLayers 1;
}
motorBike_rearseat%24
{
nSurfaceLayers 1;
}
motorBike_frt-fairing%25
{
nSurfaceLayers 1;
}
motorBike_windshield%26
{
nSurfaceLayers 1;
}
motorBike_headlights%27
{
nSurfaceLayers 1;
}
motorBike_driversseat%28
{
nSurfaceLayers 1;
}
motorBike_rear-body%29
{
nSurfaceLayers 1;
}
motorBike_fuel-tank%30
{
nSurfaceLayers 1;
}
motorBike_exhaust%31
{
nSurfaceLayers 1;
}
motorBike_rr-wh-rim%32
{
nSurfaceLayers 1;
}
motorBike_fr-mud-guard%33
{
nSurfaceLayers 1;
}
motorBike_fr-wh-rim%34
{
nSurfaceLayers 1;
}
motorBike_fr-wh-brake-disk%35
{
nSurfaceLayers 1;
}
motorBike_fr-brake-caliper%36
{
nSurfaceLayers 1;
}
motorBike_fr-wh-tyre%37
{
nSurfaceLayers 1;
}
motorBike_hbars%38
{
nSurfaceLayers 1;
}
motorBike_fr-forks%39
{
nSurfaceLayers 1;
}
motorBike_chain%40
{
nSurfaceLayers 1;
}
motorBike_rr-wh-tyre%41
{
nSurfaceLayers 1;
}
motorBike_square-dial%42
{
nSurfaceLayers 1;
}
motorBike_round-dial%43
{
nSurfaceLayers 1;
}
motorBike_dial-holder%44
{
nSurfaceLayers 1;
}
motorBike_rear-susp%45
{
nSurfaceLayers 1;
}
motorBike_rear-brake-lights%46
{
nSurfaceLayers 1;
}
motorBike_rear-light-bracket%47
{
nSurfaceLayers 1;
}
motorBike_frame%48
{
nSurfaceLayers 1;
}
motorBike_rear-mud-guard%49
{
nSurfaceLayers 1;
}
motorBike_rear-susp-spring-damp%50
{
nSurfaceLayers 1;
}
motorBike_fairing-inner-plate%51
{
nSurfaceLayers 1;
}
motorBike_clutch-housing%52
{
nSurfaceLayers 1;
}
motorBike_radiator%53
{
nSurfaceLayers 1;
}
motorBike_water-pipe%54
{
nSurfaceLayers 1;
}
motorBike_water-pump%55
{
nSurfaceLayers 1;
}
motorBike_engine%56
{
nSurfaceLayers 1;
}
motorBike_rear-shock-link%57
{
nSurfaceLayers 1;
}
motorBike_rear-brake-fluid-pot-bracket%58
{
nSurfaceLayers 1;
}
motorBike_rear-brake-fluid-pot%59
{
nSurfaceLayers 1;
}
motorBike_footpeg%60
{
nSurfaceLayers 1;
}
motorBike_rr-wh-chain-hub%61
{
nSurfaceLayers 1;
}
motorBike_rear-brake-caliper%62
{
nSurfaceLayers 1;
}
motorBike_rider-helmet%65
{
nSurfaceLayers 1;
}
motorBike_rider-visor%66
{
nSurfaceLayers 1;
}
motorBike_rider-boots%67
{
nSurfaceLayers 1;
}
motorBike_rider-gloves%68
{
nSurfaceLayers 1;
}
motorBike_rider-body%69
{
nSurfaceLayers 1;
}
motorBike_frame:0%70
{
nSurfaceLayers 1;
}
motorBike_frt-fairing:001-shadow%74
{
nSurfaceLayers 1;
}
motorBike_windshield-shadow%75
{
nSurfaceLayers 1;
}
motorBike_fr-mud-guard-shadow%81
{
nSurfaceLayers 1;
}
motorBike_fr-wh-brake-disk-shadow%83
{
nSurfaceLayers 1;
}
motorBike_rear-mud-guard-shadow%84
{
nSurfaceLayers 1;
}
motorBike_rear-susp-spring-damp-shadow%85
{
nSurfaceLayers 1;
}
motorBike_radiator-shadow%86
{
nSurfaceLayers 1;
}
motorBike_rear-shock-link-shadow%87
{
nSurfaceLayers 1;
}
motorBike_rear-brake-fluid-pot-bracket-shadow%88
{
nSurfaceLayers 1;
}
motorBike_rr-wh-chain-hub-shadow%89
{
nSurfaceLayers 1;
}
}

// 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.
// 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 0.1;

//- 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.
nGrow 1;

// Advanced settings

//- When not to extrude surface. 0 is flat surface, 90 is when two faces
// make straight angle.
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 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
minMedianAxisAngle 130;

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

// Overall max number of layer addition iterations
nLayerIter 50;
}

// 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;

//- 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

// Flags for optional output
// 0 : only write final meshes
// 1 : write intermediate meshes
// 2 : write volScalarField with cellLevel for postprocessing
// 4 : write current intersections as .obj files
debug 0;

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

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