[decibelle]

Hello everybody,

I would like to understand how surfaceToCell works in topoSet for a cellSet source.
surfaceToCell is composed of of this arguments:
- surface
- outsidepoint
- cut
- inside
- outside
- near
- curvature

I don't understand the meaning of these arguments except "surface".

Someone can help me?

Thanks in advance

[alexeym]

Hi,

$ src
$ pwd
$HOME/OpenFOAM/OpenFOAM-4.1/src
$ find . -name 'surfaceToCell.*'
./meshTools/sets/cellSources/surfaceToCell/surfaceToCell.C
./meshTools/sets/cellSources/surfaceToCell/surfaceToCell.H
./meshTools/lnInclude/surfaceToCell.C
./meshTools/lnInclude/surfaceToCell.H
$ less ./meshTools/sets/cellSources/surfaceToCell/surfaceToCell.H

If you scroll a little bit, you find these comments:

        //- Name of surface file
        const fileName surfName_;

        //- Points which are outside
        const pointField outsidePoints_;

        //- Include cut cells
        const bool includeCut_;

        //- Include inside cells
        const bool includeInside_;

        //- Include outside cells
        const bool includeOutside_;

        //- Determine inside/outside purely using geometric test
        //  (does not allow includeCut)
        const bool useSurfaceOrientation_;

        //- If > 0 : include cells with distance from cellCentre to surface
        //  less than nearDist.
        const scalar nearDist_;

        //- If > -1 : include cells with normals at nearest surface points
        //  varying more than curvature_.
        const scalar curvature_;

Correspondence between variable names and dictionary arguments can be found in ./meshTools/sets/cellSources/surfaceToCell/surfaceToCell.C (though they are quite obvious).

[decibelle]

Originally Posted by alexeym

Hi,

$ src
$ pwd
$HOME/OpenFOAM/OpenFOAM-4.1/src
$ find . -name 'surfaceToCell.*'
./meshTools/sets/cellSources/surfaceToCell/surfaceToCell.C
./meshTools/sets/cellSources/surfaceToCell/surfaceToCell.H
./meshTools/lnInclude/surfaceToCell.C
./meshTools/lnInclude/surfaceToCell.H
$ less ./meshTools/sets/cellSources/surfaceToCell/surfaceToCell.H

If you scroll a little bit, you find these comments:

        //- Name of surface file
        const fileName surfName_;

        //- Points which are outside
        const pointField outsidePoints_;

        //- Include cut cells
        const bool includeCut_;

        //- Include inside cells
        const bool includeInside_;

        //- Include outside cells
        const bool includeOutside_;

        //- Determine inside/outside purely using geometric test
        //  (does not allow includeCut)
        const bool useSurfaceOrientation_;

        //- If > 0 : include cells with distance from cellCentre to surface
        //  less than nearDist.
        const scalar nearDist_;

        //- If > -1 : include cells with normals at nearest surface points
        //  varying more than curvature_.
        const scalar curvature_;

Correspondence between variable names and dictionary arguments can be found in ./meshTools/sets/cellSources/surfaceToCell/surfaceToCell.C (though they are quite obvious).

Thank you for your help.

but it is not yet clear for me.

If we take for example the motorbike tutorials, the outsidepoints are outside the moto but inside the domain, outside the moto and outside the domain or inside the moto?
About the cut cells, how it is possible to choose the cells cut by motorbike surface?
Inside, I think it's inside the motorbike but, in this case there are not cells inside.
Outside I think it's outside the motorbike but in the domain.
near I understand
and I don't understand the function of curvature.

[alexeym]

Hi,

Now it is not clear to me, what you are asking. You started from cellSet source in topoSet, i.e. you were selecting CELLS. Now you talk about points (though maybe it was my mistake to include this property in example).

You have surface. You can select cells of a computation domain, that are inside this surface, outside this surface, and cut by this surface. To define meaning of "inside" and "outside", you can use either reference point, or surface orientation.

Curvature works only for nearDist. And it means the following:

            Info<< "    Selecting cells with cellCentre closer than "
                << nearDist_ << " to surface and curvature factor"
                << " less than " << curvature_ << endl;

You can go further into source, to see exact mathematical expression.

[decibelle]

in my previous message I wanted to apply surfaceToCell in the motorbike case to understand. But I'm agree with you it wasn't clear. Do you know this tutorial?

[alexeym]

It is MUCH easier to understand if you really try to apply this topoSet to your problem and then post your cognitive dissonances.

I know the tutorial.

[HPE]

For future reference, the following tutorials in v1912 contain examples of `surfaceToCell`:

mesh/foamyHexMesh/flange/system/topoSetDict-background
multiphase/interFoam/laminar/waves/mangroveInteraction/system/setFieldsDict

    surfaceToCell
    {
        file            "./constant/triSurface/seaweed.stl";
        outsidePoints   ((2 0.25 0.15));
        includeCut      true;
        includeInside   true;
        includeOutside  false;
        nearDistance    -1;

        curvature       -100;

        fieldValues
        (
            volScalarFieldValue MangrovesIndex 1
        );
    }