Initial implementation. Still goes wrong on r1 == r2.

- shoot rays to nearest point on surface and two perpendicular rays
  (instead of always shooting in the 3 coordinate directions)

- avoid bleeding through the surface intersection

1. multi-ray shooting. It now shoots rays in all the 3 coordinate directions
from the cell centre. Before it would shoot just a single ray from the
nearest point on the surface, going through the cell centre.

There is a cost overhead in that now it shoots 6 rays (+-x, +-y, +-z)
instead of just 1.

2. bleeding of refinement. It marks the cells inside a gap and walks out
the gap-size to neighbouring cells (which are just outside the gap). This
should make for a smoother refinement pattern.

Merge branch 'feature-snappyHexMesh' of develop.openfoam.com:Development/OpenFOAM-dev-OpenCFD into feature-snappyHexMesh

The start of the layer addition loop does a synchronisation of the wanted
displacement. This also does a truncation of the displacement if it is <
minThickness. At the first iteration the displacement was initialised to
vector::one which might trigger the truncation logic (and then disable
extrusion altogether). Instead we now initialise the displacement to
vector::GREAT before entering the synchronisation.

mattijs authored 9 years ago and Andrew Heather committed 9 years ago

Refinement:
-----------
// Optionally avoid patch merging - keeps hexahedral cells
// (to be used with automatic refinement/unrefinement)
//mergePatchFaces off;

// Optional multiple locationsInMesh with corresponding optional cellZone
// (automatically generates faceZones inbetween)
locationsInMesh
(
    ((-0.09 -0.039 -0.049)  bottomAir)  // cellZone bottomAir
    ((-0.09 0.009 -0.049)   topAir)     // cellZone topAir
);

// Optional faceType and patchType specification for these faceZones
faceZoneControls
{
    bottomAir_to_topAir
    {
        faceType baffle;
    }
}

/ Optional checking of 'bleeding' of mesh through a specifying a locations
// outside the mesh
locationsOutsideMesh ((0 0 0)(12.3 101.17 3.98));

// Improved refinement: refine all cells with all (or all but one) sides refined

// Improved refinement: refine all cells with opposing faces with different
// refinement level. These cells can happen on multiply curved surfaces.
// Default on, can be switched off with
//interfaceRefine false;

Snapping
--------
// Optional smoothing of points at refinement interfaces. This will reduce
// the non-orthogonality at refinement interfaces.
//nSmoothInternal $nSmoothPatch;

Layering
--------

// Layers can be added to patches or to any side of a faceZone.
// (Any faceZone internally gets represented as two patches)

// The angle to merge patch faces can be set independently of the
// featureAngle. This is especially useful for large feature angles
// Default is the same as the featureAngle.
//mergePatchFacesAngle 45;

// Optional mesh shrinking type 'displacementMotionSolver'. It uses any
// displacementMotionSolver, e.g. displacementSBRStress
// (default is the medial-axis algorithm, 'displacementMedialAxis')
//meshShrinker displacementMotionSolver;

mattijs authored 9 years ago and Andrew Heather committed 9 years ago

Also various speed ups to do with getting volume type outside of bounding box.

Refinement:
-----------
// Optionally avoid patch merging - keeps hexahedral cells
// (to be used with automatic refinement/unrefinement)
//mergePatchFaces off;

// Optional multiple locationsInMesh with corresponding optional cellZone
// (automatically generates faceZones inbetween)
locationsInMesh
(
    ((-0.09 -0.039 -0.049)  bottomAir)  // cellZone bottomAir
    ((-0.09 0.009 -0.049)   topAir)     // cellZone topAir
);

// Optional faceType and patchType specification for these faceZones
faceZoneControls
{
    bottomAir_to_topAir
    {
        faceType baffle;
    }
}

/ Optional checking of 'bleeding' of mesh through a specifying a locations
// outside the mesh
locationsOutsideMesh ((0 0 0)(12.3 101.17 3.98));

// Improved refinement: refine all cells with all (or all but one) sides refined

// Improved refinement: refine all cells with opposing faces with different
// refinement level. These cells can happen on multiply curved surfaces.
// Default on, can be switched off with
//interfaceRefine false;

Snapping
--------
// Optional smoothing of points at refinement interfaces. This will reduce
// the non-orthogonality at refinement interfaces.
//nSmoothInternal $nSmoothPatch;

Layering
--------

// Layers can be added to patches or to any side of a faceZone.
// (Any faceZone internally gets represented as two patches)

// The angle to merge patch faces can be set independently of the
// featureAngle. This is especially useful for large feature angles
// Default is the same as the featureAngle.
//mergePatchFacesAngle 45;

// Optional mesh shrinking type 'displacementMotionSolver'. It uses any
// displacementMotionSolver, e.g. displacementSBRStress
// (default is the medial-axis algorithm, 'displacementMedialAxis')
//meshShrinker displacementMotionSolver;

Also various speed ups to do with getting volume type outside of bounding box.