[eaxyd1]

Hello everyone,

Now I am simulating flow around a 3D airfoil in OpenFOAM, and I use the C shape grid. i should define the bc used to be empty in 2D case into cyclic, but when I use createPatch, there is error like this:

Create time

Create polyMesh for time = 0



--> FOAM FATAL ERROR: 
face 4802 area does not match neighbour by 199.99% -- possible face ordering problem.
patch:back my area:0.0236307 neighbour area:979.863 matching tolerance:0.0001
Mesh face:684334 fc:(1.0005 88.1846 0)
Neighbour fc:(179.267 88.1846 1)
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.

    From function cyclicPolyPatch::calcTransforms()
    in file meshes/polyMesh/polyPatches/constraint/cyclic/cyclicPolyPatch.C at line 221.

FOAM exiting

and my boundary file:

FoamFile
{
    version     2.0;
    format      ascii;
    class       polyBoundaryMesh;
    location    "constant/polyMesh";
    object      boundary;
}

4         
(
    airfoil
    {
        type wall;
        nFaces 2352;
        startFace 677180;
    }
    back
    {
        type cyclic;
        nFaces 9604;
        startFace 679532;
        neighbourPatch  front;
        matchTolerance  0.0001;
        transform       noOrdering;
    }
    farfield
    {
        type patch;
        nFaces 7056;
        startFace 689136;
    }
    front
    {
        type cyclic;
        nFaces 9604;
        startFace 696192;
        neighbourPatch  back;
        matchTolerance  0.0001;
        transform       noOrdering;
    }
)

my createPatch file:

pointSync true;

patches
(

    {
        name            front;
        patchInfo
        {
        type            cyclic;
            matchTolerance  0.0001;
            neighbourPatch  back;
            transform       noOrdering;
        }
        constructFrom patches;
        patches (front);
        set f0;
    }

    {
        name            back;
        patchInfo
        {
         type            cyclic;
            matchTolerance  0.0001;
            neighbourPatch  front;
            transform       noOrdering;
        }
        constructFrom patches;
        patches (back);
        set f0;
    }

);

I searched in the forum but still don't know what is wrong, can anybody please help me?
Thanks a lot.

[eaxyd1]

now I tried foamUpgradeCyclics and it splits my plane into two parts, then I changed my createpatchDict follow the new generated boundary file,

pointSync true;
           
matchTolerance  0.2;

// Patches to create.
patches
(

    {
        name            front_half0;
        patchInfo
        {
        type            cyclic;
            neighbourPatch  front_half1;
            transform       noOrdering;    
        }
        constructFrom patches;
        patches (front_half0);
        matchTolerance  0.2;
        //set f0;
    }

    {
        name            front_half1;
        patchInfo
        {
        type            cyclic;
            neighbourPatch  front_half0;
            transform       noOrdering;    
        }
        constructFrom patches;
        patches (front_half1);
        matchTolerance  0.2;
        //set f0;
    }

    {
        name            back_half0;
        patchInfo
        {
         type            cyclic;
            neighbourPatch  back_half1;
            transform       noOrdering;
        }
        constructFrom patches;
        patches (back_half0);
        matchTolerance  0.2;
        //set f0;
    }

    {
        name            back_half1;
        patchInfo
        {
         type            cyclic;
            neighbourPatch  back_half0;
            transform       noOrdering;
        }
        constructFrom patches;
        patches (back_half1);
        matchTolerance  0.2;
        //set f0;
    }
);

then createPatch, new errors:

Create time

Create polyMesh for time = 0



--> FOAM FATAL ERROR: 
face 0 area does not match neighbour by 0.122856% -- possible face ordering problem.
patch:back_half0 my area:0.0236017 neighbour area:0.0236307 matching tolerance:0.0001
Mesh face:679532 fc:(0.999501 -88.1895 0)
Neighbour fc:(1.0005 88.1846 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.

    From function cyclicPolyPatch::calcTransforms()
    in file meshes/polyMesh/polyPatches/constraint/cyclic/cyclicPolyPatch.C at line 221.

FOAM exiting

did anybody know why? I am desperate...

[eaxyd1]

problem solved!

thanks for http://www.cfd-online.com/Forums/ope...tml#post378087

I really appreciate your help!