[Nickul]

I've managed to get so far with snappy after a fair few errors but this last set have got me stumped. It seems to struggle reading in the stl file.

i get the following error from the terminal

/*---------------------------------------------------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 4.1 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
Build : 4.1
Exec : snappyHexMesh
Date : Jul 20 2017
Time : 12:36:14
Host : "Nick-492"
PID : 5301
Case : /home/nick/openFoam/Tutorials/SnappyFuz1
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 mesh for time = 0

Read mesh in = 0.05 s

Overall mesh bounding box : (-1 -1 -1) (2 0 1)
Relative tolerance : 1e-06
Absolute matching distance : 3.74166e-06

Reading refinement surfaces.
--> FOAM Warning :
From function Foam::refinementSurfaces::refinementSurfaces(const Foam::searchableSurfaces&, const Foam::dictionary&, Foam::label)
in file refinementSurfaces/refinementSurfaces.C at line 221
Reading "/home/nick/openFoam/Tutorials/SnappyFuz1/system/snappyHexMeshDict.castellatedMeshControls.refineme ntSurfaces" from line 109 to line 109
Not all entries in refinementSurfaces dictionary were used. The following entries were not used : 1(SnappyFuz1.stl)
Read refinement surfaces in = 0.01 s

Reading refinement shells.
Read refinement shells in = 0 s

Setting refinement level of surface to be consistent with shells.
Checked shell refinement in = 0 s

Reading features.


--> FOAM FATAL IO ERROR:
Could not open "/home/nick/openFoam/Tutorials/SnappyFuz1/constant/triSurface/Fuz1.eMesh"

file: /home/nick/openFoam/Tutorials/SnappyFuz1/system/snappyHexMeshDict.castellatedMeshControls.features from line 88 to line 89.

From function void Foam::refinementFeatures::read(const Foam:bjectRegistry&, const Foam::PtrList<Foam::dictionary>&)
in file refinementFeatures/refinementFeatures.C at line 97.

FOAM exiting

My snappy dictionary is as follows

/*--------------------------------*- 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; //switch on creation of the castellated mesh
snap true; //switch on surface snapping stage
addLayers true; //switch on surface layer insertion



// 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
{
SnappyFuz1.stl
{
type triSurfaceMesh;
name SnappyFuz1;
}
}



// 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;

// 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 "Fuz1.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
{
SnappyFuz1.stl
{
// Surface-wise min and max refinement level
level (2 2);
// regions
// Optional specification of patch type (default is wall). No
// constraint types (cyclic, symmetry) etc. are allowed.
// patchInfo
}
// type wall;
// inGroups (Fuzwall);
//
// }
}

// 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 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 -0.5 0);


// 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
// {
// "(lowerWall|motorBike).*"
// {
// 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.
// 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 0.1;

// 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 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.
meshQualityControls
{
// #include "meshQualityDict"
maxNonOrtho 65;
maxBoundarySkewness 20;
maxInternalSkewness 4;
maxConcave 80;
minFlatness 0.5;
minTetQuality 1e-15;
minVol 1e-13;
minArea -1;
minTwist 0.05;
minDeterminant 0.001;
minFaceWeight 0.05;
minVolRatio 0.01;
minTriangleTwist -1; //must be >0 for Fluent compatibility


// 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
//}
//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;


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

any ideas as to where I'm going wrong would be greatly appreciated?

I've attached an image of the blockmesh file and the stl file imported in. You're looking at my intended symetry plane and half of an aircraft fuselage

thanks Nick

[akidess]

1. You didn't generate a featureEdgeMesh.
2. The refinement surfaces dictionary does not use filenames. Have a look at the tutorials.

[Nickul]

thanks, I missed the fact you need to run surfaceFeatureExtract first to generate the emesh file.

it has run now.