[abeda]

Hi, foamers.

I want to make a ship move from the forces generated from propeller, so my first thought was that the boatAndPropeller was a good starting point. So therefore I want to replace the hullWall in the tutorial by an STL geometry and then apply the power of snappyhexmesh.

My OF version: v2012
Platform: Ubuntu 20.04 in WSL2.
Geometry is created in Blender, using the new SnappyHexMesh add-on that supports openfoam.com.


So far I'm only able see propellerWall and rudderWall in paraView after running blockmesh, toposet/refineMesh pairs, toposets/subsetMesh pairs, snappyhexmesh and setfields. This is the sequence I'm using.

In the blockMeshDict from the original boatAndPropeller tutorial I find this line:

hex (8 9 10 11 12 13 14 15) hullBox (32 16 16) simpleGrading (1 1 1)

This line defines a cellZone named hullBox, right?
While the hullWall in the original tutorial is populated later in subsetMesh, right?
(For reference:

  hullWall
    {
        type wall;
        faces ();
    }

)
So if I uncomment and replacing this line in Allrun.pre script that populates the hullWall patch by using the keepBox cellset

runApplication -s hull topoSet -dict system/topoSetDictHull
runApplication -s hull subsetMesh keepBox -patch hullWall -overwrite

by adding this lines refinementSurfaces in SnappyHexMeshDict it should work? Or maybe I still don't understand this....

geometry
{
    hullWall
    {
        type triSurfaceMesh;
        file "hullWall.stl";
        // Min Bounds = [-2.50269e+00 -3.34423e-01 -1.43194e-01]
        // Max Bounds = [ 2.50000e+00  3.34428e-01  2.30424e-01]
        // Area = 9.23760e+00
    }
}
refinementSurfaces
    {
        hullWall
        {
            level (0 0);
            patchInfo { type wall; }
            faceZone hullWall;
            faceType boundary;
            cellZone hullWall;
            cellZoneInside inside;
        }

    }

Or should it be like this?

refinementSurfaces
    {
        hullWall
        {
            level (0 0);
            patchInfo { type wall; }
            faceZone hullBox;
            faceType boundary;
            cellZone hullBox;
            cellZoneInside inside;
        }

    }

But what do I do handle overset faces, when I use SnappyHexMesh?

overset1  //oversetHull
    {
        type        overset;
        faces
        (
            ( 8 12 15 11)
            (10 14 13  9)
            (11 15 14 10)
            ( 9 13 12  8)
            ( 9  8 11 10)
            (12 13 14 15)
        );
    }

Should I still make an entry for overset1 in blockMeshDict, or is there a more clever and elegant way in solving this? E.g is it possible to snappyhexmesh or am I forced to use toposet to do this?

I have also looked at the DTCMovingHull tutorial for inspiration, but this doesn't define overset, but it does the toposet/refinemesh pair.

But maybe I'm overcomplicating this problem?
Maybe I just can resize the hullBox in blockMeshDict so it surrounds the hullWall patch from STL file and do this instead i Allrun.pre script?

runApplication -s hull topoSet -dict system/topoSetDictHull
#runApplication -s hull subsetMesh keepBox -patch hullWall -overwrite

[abeda]

Hi, Foamers.

I never thought I was going to answer to self here.
But the release OF-2106 solved everything for me.
For the OF-2106 the boatAndPropeller was replaced by rigidBodyHull. RigidBodyHull example is using obj files for geometry.

I did some changes to the example, though. In 10 minutes I had removed the overset-2 (MRF, OverSetPatch) and did my first run with overset.

I have one question, though.
The hull geometry looks like the KVLCC2 geometry. Is that correct?

[emjaey3590]

Hello Abeda,


I am facing some problem regarding connecting overset to snappyHexMesh. I am using openfoam-2012 and it has no tutorials on how to use the snappyHexMesh and oversetmesh approach. I have seen that you wrote that you had solve it. Can you please share the solved problem of your hull?

[coke1997]

Originally Posted by
;820670

Hello Abeda,


I am facing some problem regarding connecting overset to snappyHexMesh. I am using openfoam-2012 and it has no tutorials on how to use the snappyHexMesh and oversetmesh approach. I have seen that you wrote that you had solve it. Can you please share the solved problem of your hull?

Hi emjaey3590,

I believe OpenFOAM 2012 is not compatible with overset solvers. At least, in my experiences OpenFOAM V8 has not the over* solvers available. Try this code find $FOAM_SOLVERS -iname "over*" to make sure that you have the solvers in your OF version.

Good luck!

[Yann]

Originally Posted by coke1997

Hi emjaey3590,

I believe OpenFOAM 2012 is not compatible with overset solvers. At least, in my experiences OpenFOAM V8 has not the over* solvers available. Try this code find $FOAM_SOLVERS -iname "over*" to make sure that you have the solvers in your OF version.

Good luck!

Hi,

Overset is available in the ESI-OpenCFD branch (openfoam.com) since OpenFOAM-v1706. So OpenFOAM-v2012 definitely includes overset solvers.

However, AFAIK there is no overset capabilities in the foundation branch (openfoam.org).

Cheers,
Yann