[luiscoliveira]

Hi everyone!

I'm playing around with a case similar to the multiphase DTCHull, but with a Wigley hull. I'm using OF 5.X in my main machine and 2.3.X in another one. I'm using 2.3.X because of LTSInterFoam, which I know is implemented in InterFoam solver in the newer versions.

I developed some meshes for the case and I've updated the other dictionaries to fit in but I'm currently having problems with residuals. My problem is that I can't figure out why they don't converge, so my results are kind of messy.

I tried different meshes, different schemes, and solutions but with no results.

I would appreciate if you could help me with this problem.

I attached one of my most recent case and some results.

Thank you again,
Luís

I'm editing so I can write here some of my dictionaries.

ddtSchemes
{
default localEuler rDeltaT;
}

gradSchemes
{
default Gauss linear;
limitedGrad cellLimited Gauss linear 1;
}

divSchemes
{
div(rhoPhi,U) Gauss linearUpwind grad(U);
div(phi,alpha) Gauss vanLeer;
div(phirb,alpha) Gauss linear;
div(phi,k) Gauss linearUpwind limitedGrad;
div(phi,omega) Gauss linearUpwind limitedGrad;
div((muEff*dev(T(grad(U))))) Gauss linear;
}

laplacianSchemes
{
default Gauss linear corrected;
}

interpolationSchemes
{
default linear;
}

snGradSchemes
{
default corrected;
}

fluxRequired
{
default no;
p_rgh;
pcorr;
alpha.water;
}

solvers
{
"alpha.water.*"
{
nAlphaCorr 2;
nAlphaSubCycles 1;
cAlpha 1;
icAlpha 0;

MULESCorr yes;
nLimiterIter 10;
alphaApplyPrevCorr yes;

solver smoothSolver;
smoother symGaussSeidel;
tolerance 1e-8;
relTol 0;
minIter 1;
}

pcorr
{
solver PCG;

preconditioner
{
preconditioner GAMG;

smoother GaussSeidel;
agglomerator faceAreaPair;
mergeLevels 1;
nCellsInCoarsestLevel 10;
cacheAgglomeration true;

tolerance 1e-5;
relTol 0;
};

tolerance 1e-5;
relTol 0;
};

p_rgh
{
solver GAMG;

smoother DIC;
agglomerator faceAreaPair;
mergeLevels 1;
nCellsInCoarsestLevel 10;
cacheAgglomeration true;

tolerance 1e-7;
relTol 0.01;
};

p_rghFinal
{
$p_rgh;
relTol 0;
}

"(U|k|omega).*"
{
solver smoothSolver;

smoother symGaussSeidel;
nSweeps 1;

tolerance 1e-7;
relTol 0.1;
minIter 1;
};
}

PIMPLE
{
momentumPredictor yes;

nOuterCorrectors 1;
nCorrectors 1;
nNonOrthogonalCorrectors 0;

maxCo 0.9;
maxAlphaCo 0.2;
nAlphaSweepIter 1;

rDeltaTSmoothingCoeff 0.05;
rDeltaTDampingCoeff 0.5;
maxDeltaT 1;
}

relaxationFactors
{
fields
{
}
equations
{
".*" 1;
}
}

cache
{
grad(U);
}

castellatedMesh true;
snap true;
addLayers false;


// 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
{
wigleycentre.stl
{
type triSurfaceMesh;
name hull;

patchInfo
{
type wall;
}
}
refinementBox
{
type searchableBox;
min (-1.6 -12 -0.5);
max (1.6 -11.75 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 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 0;

// 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 "wigleycentre.eMesh";
level 3;
}
);



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

resolveFeatureAngle 45;


// 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 ((1 1));
}
}


// 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 (2 0 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 4.0;
tolerance 1.0;

//- Number of mesh displacement relaxation iterations.
nSolveIter 300;

//- Maximum number of snapping relaxation iterations. Should stop
// before upon reaching a correct mesh.
nRelaxIter 10;

nFeatureSnapIter 10;
}



// 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
{
hull
{
nSurfaceLayers 3;

}
}

// Expansion factor for layer mesh
expansionRatio 1.5;


// 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 0.7;

// Minimum thickness of cell layer. If for any reason layer
// cannot be above minThickness do not add layer.
// See relativeSizes parameter.
minThickness 0.25;

// 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;

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

// 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;

// Max number of iterations after which relaxed meshQuality controls
// get used. Up to nRelaxIter it uses the settings in meshQualityControls,
// after nRelaxIter it uses the values in meshQualityControls::relaxed.
nRelaxedIter 20;
}



// Generic mesh quality settings. At any undoable phase these determine
// where to undo.
meshQualityControls
{
#include "meshQualityDict"
}


// 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;

convertToMeters 1;

vertices
(
(-15 -24 -9) //0
(-8 -24 -9) //1
(2 -24 -9) //2
(7.5 -24 -9) //3
(7.5 -12 -9) //4
(2 -12 -9) //5
(-8 -12 -9) //6
(-15 -12 -9) //7
(7.5 0 -9) //8
(2 0 -9) //9
(-8 0 -9) //10
(-15 0 -9) //11
(-15 -24 -0.75) //12
(-8 -24 -0.75) //13
(2 -24 -0.5) //14
(7.5 -24 -0.75) //15
(7.5 -12 -0.75) //16
(2 -12 -0.75) //17
(-8 -12 -0.75) //18
(-15 -12 -0.75) //19
(7.5 0 -0.75) //20
(2 0 -0.75) //21
(-8 0 -0.75) //22
(-15 0 -0.75) //23
(-15 -24 0.75) //24
(-8 -24 0.75) //25
(2 -24 0.75) //26
(7.5 -24 0.75) //27
(7.5 -12 0.75) //28
(2 -12 0.75) //29
(-8 -12 0.75) //30
(-15 -12 0.75) //31
(7.5 0 0.75) //32
(2 0 0.75) //33
(-8 0 0.75) //34
(-15 0 0.75) //35
(-15 -24 2.25) //36
(-8 -24 2.25) //37
(2 -24 2.25) //38
(7.5 -24 2.25) //39
(7.5 -12 2.25) //40
(2 -12 2.25) //41
(-8 -12 2.25) //42
(-15 -12 2.25) //43
(7.5 0 2.25) //44
(2 0 2.25) //45
(-8 0 2.25) //46
(-15 0 2.25) //47



);

blocks
(
//bellow 6
hex (7 6 10 11 19 18 22 23) (20 50 30) simpleGrading (0.8 5 0.1)
hex (6 5 9 10 18 17 21 22) (55 50 30) simpleGrading (1 5 0.1)
hex (5 4 8 9 17 16 20 21) (18 50 30) simpleGrading (1 5 0.1)

//middle 6
hex (19 18 22 23 31 30 34 35) (20 50 20) simpleGrading (0.8 5 1)
hex (18 17 21 22 30 29 33 34) (55 50 20) simpleGrading (1 5 1)
hex (17 16 20 21 29 28 32 33) (18 50 20) simpleGrading (1 5 1)

//upper 6
hex (31 30 34 35 43 42 46 47) (20 50 10) simpleGrading (0.8 5 5)
hex (30 29 33 34 42 41 45 46) (55 50 10) simpleGrading (1 5 5)
hex (29 28 32 33 41 40 44 45) (18 50 10) simpleGrading (1 5 5)
);

edges
(
);

boundary
(
atmosphere
{
type patch;
faces
(
(43 42 46 47)
(42 41 45 46)
(41 40 44 45)
);
}
inlet
{
type patch;
faces
(
(4 8 20 16)
(16 20 32 28)
(28 32 44 40)
);
}
outlet
{
type patch;
faces
(
(7 19 23 11)
(19 31 35 23)
(31 43 47 35)
);
}
bottom
{
type symmetryPlane;
faces
(
(7 11 10 6)
(6 10 9 5)
(5 9 8 4)
);
}
side_left
{
type symmetryPlane;
faces
(
(7 6 18 19)
(19 18 30 31)
(31 30 42 43)
(6 5 17 18)
(18 17 29 30)
(30 29 41 42)
(5 4 16 17)
(17 16 28 29)
(29 28 40 41)
);
}
side_right
{
type symmetryPlane;
faces
(
(11 23 22 10)
(10 22 21 9)
(9 21 20 8)
(23 35 34 22)
(22 34 33 21)
(21 33 32 20)
(35 47 46 34)
(34 46 45 33)
(33 45 44 32)
);
}
);

mergePatchPairs
(
);