[Dami]

Dear Foamers,

I have been trying to mesh a multi-region for a system of two process vessels as shown in the attached image. I created and meshed the geometry in Salome, and then exported as STL from the mesh module in Salome. I meshed the STL in OpenFOAM 5.0 using snappyHexMesh. The simulation ran successfully, but the result was not what I anticipated. The explosion seems to ignore the boundary of the vessels (attached image). Instead of venting through the vent panels, it simply expanded as if there were no vessels or present. My two main questions are: (1) how can I place a vent directly on the vessel/geometry and specify that it opens when a certain pressure (release pressure) is reached within the vessel? (2) How can I make my geometry (using snappyHexMesh, multi-region meshing, or any other method) to achieve my aim? Your contributions are highly anticipated and appreciated. My snappyHexMeshDict is shown below. Thanks.



/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 5 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
object snappyHexMeshDict;
}

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

castellatedMesh true;
snap true;
addLayers false; //false


geometry
{
tank01.stl
{
type triSurfaceMesh;

regions
{
Vent_1 { name Vent_1; }
wall_1 { name wall_1; }
}
}
tank02.stl
{
type triSurfaceMesh;

regions
{
Vent_2 { name Vent_2; }
wall_2 { name wall_2; }
}
}
box_1.stl
{
type triSurfaceMesh;
name box_1;
}
box_2.stl
{
type triSurfaceMesh;
name box_2;
}
tank_1.stl
{
type triSurfaceMesh;
name tank_1;
}
tank_2.stl
{
type triSurfaceMesh;
name tank_2;
}
ref_cyl_1.stl
{
type triSurfaceMesh;
name ref_cyl_1;
}
ref_cyl_2.stl
{
type triSurfaceMesh;
name ref_cyl_2;
}
};

// Settings for the castellatedMesh generation.
castellatedMeshControls
{

// Refinement parameters
// ~~~~~~~~~~~~~~~~~~~~~
maxLocalCells 1000000;
maxGlobalCells 2000000;
minRefinementCells 10;
nCellsBetweenLevels 3;



// Explicit feature edge refinement
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
features
(
{
file "box_1.eMesh";
level 3;
}
{
file "box_2.eMesh";
level 3;
}
{
file "tank01.eMesh";
level 1;
}
{
file "tank02.eMesh";
level 1;
}
);



// Surface based refinement
// ~~~~~~~~~~~~~~~~~~~~~~~~

refinementSurfaces
{
tank01
{
// Surface-wise min and max refinement level
level (3 3);

faceZone tank01;
cellZone tank01;
cellZoneInside inside;

regions
{
Vent_1 { level (1 1); patchInfo { type patch; }}
wall_1 { level (1 1); patchInfo { type wall; }}
}
}

tank02
{
// Surface-wise min and max refinement level
level (3 3);

faceZone tank02;
cellZone tank02;
cellZoneInside inside;

regions
{
Vent_2 { level (1 1); patchInfo { type patch; }}
wall_2 { level (1 1); patchInfo { type wall; }}
}
}
}
// Resolve sharp angles
resolveFeatureAngle 30;


// Region-wise refinement
// ~~~~~~~~~~~~~~~~~~~~~~

refinementRegions
{
box_1
{
mode inside;
levels ((1E15 4));
}
box_2
{
mode inside;
levels ((1E15 4));
}
}


// Mesh selection
// ~~~~~~~~~~~~~~
locationInMesh (0.000 0.000 0.1);
allowFreeStandingZoneFaces false;
}



// Settings for the snapping.
snapControls
{

nSmoothPatch 3;
tolerance 1.0;
nSolveIter 30;
nRelaxIter 5;
nFeatureSnapIter 10;
}



// Settings for the layer addition.
addLayersControls
{
relativeSizes true;

layers
{
tank01
{
nSurfaceLayers 3;
}
tank02
{
nSurfaceLayers 3;
}
}

// Expansion factor for layer mesh
expansionRatio 1.3;
finalLayerThickness 1;
minThickness 0.1;
nGrow 0;
featureAngle 30;
nRelaxIter 3;
nSmoothSurfaceNormals 1;
nSmoothNormals 3;
nSmoothThickness 2;
maxFaceThicknessRatio 0.5;
maxThicknessToMedialRatio 1;
minMedianAxisAngle 90;
nBufferCellsNoExtrude 0;
nLayerIter 50;
}


meshQualityControls
{
#include "meshQualityDict"

nSmoothScale 4;
//- Amount to scale back displacement at error points
errorReduction 0.75;
}
mergeTolerance 1e-6;


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