[dandanTT]

Hi Foamers,

Have anyone used ansys generated mesh with fluentMeshToFoam as openFoam mesh input? I have tried updating the boundary in polyMesh folder to cyclic or cyclicAMI, but neither works.

My geometry is an extruded shape and the mesh needs to be unstructured. The two faces in the extrusion direction should be periodic and I'm sure their geometry can match up.

Thank you all for helping!

[Krapf]

Yes, I have done that many times.
What exactly did your polyMesh/boundary file look like after you changed it? What does “neither works” mean? Are you getting an error message? You need to provide more information so that we can help you.

[dandanTT]

Thank you so much for the reply!

The original boundary file looks like this:

FoamFile
{

10
(
    wall
    {
        type            wall;
        inGroups        1(wall);
        nFaces          21644;
        startFace       4767360;
    }
    inlet_1
    {
        type            patch;
        nFaces          420;
        startFace       4789004;
    }
    outlet
    {
        type            patch;
        nFaces          5516;
        startFace       4789424;
    }
    top
    {
        type            patch;
        nFaces          7952;
        startFace       4794940;
    }

    cyclic_front
    {
        type            patch;
        nFaces          57684;
        startFace       4808184;
    }
    cyclic_back
    {
        type            patch;
        nFaces          57684;
        startFace       4865868;
    }
)

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

The first thing I tried is to change the boundary of the cyclic_front and cyclic_back to:

    cyclic_front
    {
        type            cyclic;
        neighbourPatch  cyclic_back;
        nFaces          57684;
        startFace       4808184;
    }
    cyclic_back
    {
        type            cyclic;
        neighbourPatch  cyclic_front;
        nFaces          57684;
        startFace       4865868;
    }

The error I got, by running checkMesh, from this is:

face 0 area does not match neighbour by 143.32% -- possible face ordering problem.
patch:cyclic_front my area:3.59926e-07 neighbour area:2.18012e-06 matching tolerance:0.0001
Mesh face:4808184 fc:(0.152289 0.0103259 0.03)
Neighbour fc:(0.195758 0.0111483 0)
If you are certain your matching is correct you can increase the 'matchTolerance' setting in the patch dictionary in the boundary file.
Rerun with cyclic debug flag set for more information.

Then I add a createPatchDict as shown below to use cyclicAMI:

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  v2012                                 |
|   \\  /    A nd           | Website:  www.openfoam.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    location    "system";
    object      createPatchDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
pointSync    false;

patches
(
    {
        //- Master side patch
        name            cyclic_front;
        patchInfo
        {
            type            cyclicAMI;
            matchTolerance  0.0001;
            neighbourPatch  cyclic_back;
            transform       translational;
        }
        constructFrom patches;
        patches (cyclic_front);
    }

    {
        //- Slave side patch
        name            cyclic_back;
        patchInfo
        {
            type            cyclicAMI;
            matchTolerance  0.0001;
            neighbourPatch  cyclic_front;
            transform       translational;
        }
        constructFrom patches;
        patches (cyclic_back);
    }
);


// patches (cyclic_front cyclic_back);
patchPairs
(
    frontAndBack
    {
          // List of existing patch names
        master      cyclic_front;
        slave       cyclic_back;
        type        cyclic;
        transform   translational;
    }
);

This modified the boundary file to

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  v2012                                 |
|   \\  /    A nd           | Website:  www.openfoam.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       polyBoundaryMesh;
    location    "constant/polyMesh";
    object      boundary;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

10
(
    wall
    {
        type            wall;
        inGroups        1(wall);
        nFaces          21644;
        startFace       4767360;
    }
    inlet_1
    {
        type            patch;
        nFaces          420;
        startFace       4789004;
    }
    outlet
    {
        type            patch;
        nFaces          5516;
        startFace       4789424;
    }
    top
    {
        type            patch;
        nFaces          7952;
        startFace       4794940;
    }

    }
    cyclic_front
    {
        type            cyclicAMI;
        inGroups        1(cyclicAMI);
        nFaces          57684;
        startFace       4808184;
        matchTolerance  0.0001;
        transform       unknown;
        neighbourPatch  cyclic_back;
        AMIMethod       faceAreaWeightAMI;
        restartUncoveredSourceFace 1;
    }
    cyclic_back
    {
        type            cyclicAMI;
        inGroups        1(cyclicAMI);
        nFaces          57684;
        startFace       4865868;
        matchTolerance  0.0001;
        transform       unknown;
        neighbourPatch  cyclic_front;
        AMIMethod       faceAreaWeightAMI;
        restartUncoveredSourceFace 1;
    }
)

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

This passes checkMesh but when using $rhoCentralFoam$ or using $checkMesh -allTopology -allGeometry$ it fails with error:

Unable to set target face for source face 57683

    From virtual bool Foam::faceAreaWeightAMI::setNextFaces(Foam::label&, Foam::label&, Foam::label&, const Foam::bitSet&, Foam::labelList&, const Foam::DynamicList<int>&, bool) const
    in file AMIInterpolation/AMIInterpolation/faceAreaWeightAMI/faceAreaWeightAMI.C at line 347.

FOAM aborting

[Krapf]

Okay, I haven't had to work with cyclicAMI yet, because in my cases both surfaces were identical.
Someone reported here that “transform translational” helped: CyclicAMI: Unable to find initial target face. This does not appear in your boundary file, although you specify it in createPatchDict. What happens if you adjust the boundary file manually?

[dandanTT]

I have tried the following update in the boundary file, but the same error was obtained.

cyclic_front
    {
        type            cyclicAMI;
        inGroups        1(cyclicAMI);
        nFaces          57684;
        startFace       4808184;
        matchTolerance  0.0001;
        transform       translational;
        neighbourPatch  cyclic_back;
        AMIMethod       faceAreaWeightAMI;
         separationVector (0.0 0.0 0.0);
        restartUncoveredSourceFace 1;
    }
    cyclic_back
    {
        type            cyclicAMI;
        inGroups        1(cyclicAMI);
        nFaces          57684;
        startFace       4865868;
        matchTolerance  0.0001;
        transform       translational;
        neighbourPatch  cyclic_front;
        AMIMethod       faceAreaWeightAMI;
        separationVector (0.0 0.0 -0.03);
        restartUncoveredSourceFace 1;
    }

[Krapf]

Then unfortunately I have no idea at the moment. Is it possible for you to upload the entire case?

[Alczem]

Hey!


The separationVector should also be properly configured for the cyclic_front patch (it is set to (0 0 0) in the dictionary you posted). So in your case, it would be (0 0 0.03) I guess. If that does not work, try swapping the signs for the two vectors.


Maybe you could also try a different interpolation method:


https://www.openfoam.com/news/main-n...v2106/numerics