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September 22, 2019 05:10 |
Creating baffes with snappyHexMesh
Helleo everyone,
I am working on a project in OF to model a fan as a pressurejump via a patch in steady state solved with simpleFoam.
However I have some problems. When I create a baffle via snappyHexMesh and process this one via createPatch the master and slave patch show up like expected in the Boundary file, however when I run reconstructParMesh it will remove the correct cyclics and replaces them with a wall which is based on the surface refinement given in the snappyHexMesh. Anybody seen this before or knows a solution?
Dicts for the snappyHexMesh and createPatch (reconstructParMesh has not been changed):
Code:
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: v1812 |
| \\ / A nd | Web: www.OpenFOAM.com |
| \\/ 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
{
fan.stl
{
type triSurfaceMesh;
name fanObject;
}
}
// Settings for the castellatedMesh generation.
castellatedMeshControls
{
// Refinement parameters
maxLocalCells 1000000;
maxGlobalCells 80000000;
minRefinementCells 3000;
maxLoadUnbalance 0.10;
nCellsBetweenLevels 4;
allowFreeStandingZoneFaces true;
resolveFeatureAngle 30;
planarAngle 30;
features
(
{ file "fan.eMesh"; level 6; }
);
// Surface based refinement
// ~~~~~~~~~~~~~~~~~~~~~~~~
refinementSurfaces
{
fanObject
{
level (1 1);
faceZone fanFaces;
faceType baffle;
}
}
refinementRegions
{
}
locationInMesh (3.0001 3.0001 0.43);
}
// Settings for the snapping.
snapControls
{
nSmoothPatch 5;
tolerance 2.0;
nSolveIter 150;
nRelaxIter 5;
nFeatureSnapIter 15;
implicitFeatureSnap false;
explicitFeatureSnap true;
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
{
}
// Expansion factor for layer mesh
expansionRatio 1.2;
// 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 0.5;
// 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 0.001;
// 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 1.7.x! (didn't do anything in 1.7.x)
nGrow 0;
// Advanced settings
// When not to extrude surface. 0 is flat surface, 90 is when two faces
// are perpendicular
featureAngle 180;
// At non-patched sides allow mesh to slip if extrusion direction makes
// angle larger than slipFeatureAngle.
slipFeatureAngle 75;
// Maximum number of snapping relaxation iterations. Should stop
// before upon reaching a correct mesh.
nRelaxIter 5;
// Number of smoothing iterations of surface normals
nSmoothSurfaceNormals 3;
// Number of smoothing iterations of interior mesh movement direction
nSmoothNormals 4;
// 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 1.7.x! 90 degrees corresponds to 130
// in 1.7.x.
minMedialAxisAngle 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 300;
}
// 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
// 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;
// ************************************************************************* //
Code:
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 4.1.0 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
object createPatchDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
// This application/dictionary controls:
// - optional: create new patches from boundary faces (either given as
// a set of patches or as a faceSet)
// - always: order faces on coupled patches such that they are opposite. This
// is done for all coupled faces, not just for any patches created.
// - optional: synchronise points on coupled patches.
// 1. Create cyclic:
// - specify where the faces should come from
// - specify the type of cyclic. If a rotational specify the rotationAxis
// and centre to make matching easier
// - always create both halves in one invocation with correct 'neighbourPatch'
// setting.
// - optionally pointSync true to guarantee points to line up.
// 2. Correct incorrect cyclic:
// This will usually fail upon loading:
// "face 0 area does not match neighbour 2 by 0.0100005%"
// " -- possible face ordering problem."
// - in polyMesh/boundary file:
// - loosen matchTolerance of all cyclics to get case to load
// - or change patch type from 'cyclic' to 'patch'
// and regenerate cyclic as above
// Do a synchronisation of coupled points after creation of any patches.
// Note: this does not work with points that are on multiple coupled patches
// with transformations (i.e. cyclics).
pointSync false;
// Patches to create.
patches
(
{
// Name of new patch
name fan_in;
// Dictionary to construct new patch from
patchInfo
{
type cyclic;
neighbourPatch fan_out;
// Optional: explicitly set transformation tensor.
// Used when matching and synchronising points.
//transform rotational;
//rotationAxis (1 0 0);
//rotationCentre (0 0 0);
// transform translational;
// separationVector (1 0 0);
// Optional non-default tolerance to be able to define cyclics
// on bad meshes
//matchTolerance 1E-2;
}
// How to construct: either from 'patches' or 'set'
constructFrom patches;
// If constructFrom = patches : names of patches. Wildcards allowed.
patches (fan);
// If constructFrom = set : name of faceSet
//set f0;
}
{
// Name of new patch
name fan_out;
// Dictionary to construct new patch from
patchInfo
{
type cyclic;
neighbourPatch fan_in;
// Optional: explicitly set transformation tensor.
// Used when matching and synchronising points.
//transform rotational;
//rotationAxis ( 0 0 1 );
//rotationCentre ( 0.3 0 0 );
}
// How to construct: either from 'patches' or 'set'
constructFrom patches;
// If constructFrom = patches : names of patches. Wildcards allowed.
patches (fan_slave);
// If constructFrom = set : name of faceSet
//set f0;
}
);
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