[bizzy]

Hello,

as snappyHexMesh can not create proper boundary layers for my geometry, I try to use cfMesh and it makes very promising results. Unfortunately I could not find a way to add grading to my mesh. Either I do not understand the user guide correctly or there is a bug. With the following Dict, I try to implement some sort of grading from X=8 to x=16:

FoamFile
{
    version   2.0;
    format    ascii;
    class     dictionary;
    location  "system";
    object    meshDict;
}

surfaceFile "Vessel_Tank.ftr";

maxCellSize 1;

anisotropicSources
{
    planeFWD
    {
    type plane;
    normal (1 0 0);
    origin (8 0 0);
    scalingDistance 8;
    scalingFactor 0.5;
    }
}


surfaceMeshRefinement
{
    hull
    {
        additionalRefinementLevels  7;
        surfaceFile "Vessel_Bare.stl";
        refinementThickness 0.05;
    }
}

     

boundaryLayers
{
    patchBoundaryLayers
    {
        "hull.*"
        {
            nLayers 3;
            thicknessRatio 1.5;
            maxFirstLayerThickness 0.001;
        }
    }
}

What I get as a result is some sort of refinement, but without any grading (see screenshot). I also get the same reulst with a Box as anisotropicSource. Am I missing something or is this a bug?

[franjo_j]

Hello,

It is not a bug. Your anisotropic settings mean that within 8 meters from the plane the cells shall be compressed to 50% of their original size. Therefore, the size of the cells in the x direction is 50% smaller than in other directions. The cells are compressed uniformly.

Originally Posted by bizzy

Hello,

as snappyHexMesh can not create proper boundary layers for my geometry, I try to use cfMesh and it makes very promising results. Unfortunately I could not find a way to add grading to my mesh. Either I do not understand the user guide correctly or there is a bug. With the following Dict, I try to implement some sort of grading from X=8 to x=16:

FoamFile
{
    version   2.0;
    format    ascii;
    class     dictionary;
    location  "system";
    object    meshDict;
}

surfaceFile "Vessel_Tank.ftr";

maxCellSize 1;

anisotropicSources
{
    planeFWD
    {
    type plane;
    normal (1 0 0);
    origin (8 0 0);
    scalingDistance 8;
    scalingFactor 0.5;
    }
}


surfaceMeshRefinement
{
    hull
    {
        additionalRefinementLevels  7;
        surfaceFile "Vessel_Bare.stl";
        refinementThickness 0.05;
    }
}

     

boundaryLayers
{
    patchBoundaryLayers
    {
        "hull.*"
        {
            nLayers 3;
            thicknessRatio 1.5;
            maxFirstLayerThickness 0.001;
        }
    }
}

What I get as a result is some sort of refinement, but without any grading (see screenshot). I also get the same reulst with a Box as anisotropicSource. Am I missing something or is this a bug?

[massimiliano.tarrini]

Dear Mr Juretic,
I'm using cfMesh embedded in OpenFOAM 2006. I actually believe you did a great job.

I am trying to generate grids on hull and as you probably know anisostropic refinement is needed in order to well capture wave elevation.
I tried different combination starting from shiptutorial but i'm not getting the a good result using anisotropic sources [box].

On the other side it seems that when I use localRefinement, the anisotropic mesh doesn't penetrate in the whole domain.
I can share you privately my file if you may like to give me a short hint...
kind regards
max