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Mesh generation using blockMesh utility

Hello friends,

I am generating hexahedral grid for a rectangular channel using blockMesh utility. The problem is after the generation of the mesh when I am trying to sketch the faces which are created in the polymesh folder using the cooardinates of the pointx associated with the face, I found some face irregular in shape (It should be rectangular). Can you please tell me why this is happening?


OpenFOAM 02-03-20, 4:43 p.m. sourav0921
0

Hi Sourav,

Could you please share the blockMeshDict file?

Regards,
Ashley

26-03-20, 6:36 p.m. ashleymelvin


0

I am attatching the blockMeshDict file of the current geometry

/*--------------------------------*- C++ -*----------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Website: https://openfoam.org
\\ / A nd | Version: 6
\\/ M anipulation |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
object blockMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

convertToMeters 1;

vertices
(
(0 0 0) //0
(0.252 0 0) //1
(0.252 0.01 0) //2
(0 0.01 0) //3

(0 0 0.042) //4
(0.252 0 0.042) //5
(0.252 0.01 0.042) //6
(0 0.01 0.042) //7


(0.252 0.02 0) //8
(0 0.02 0) //9
(0 0.02 0.042) //10
(0.252 0.02 0.042) //11
);

blocks
(
hex (0 1 2 3 4 5 6 7) (100 33 130) simpleGrading (1 40 1)
hex (3 2 8 9 7 6 11 10) (100 33 130) simpleGrading (1 0.025 1)
);

edges
(
);

boundary
(
inlet
{
type cyclic;
neighbourPatch outlet;
faces
(
(0 4 7 3)
(3 7 10 9)
);
}

outlet
{
type cyclic;
neighbourPatch inlet;
faces
(
(1 2 6 5)
(2 8 11 6)
);
}

bottomWall
{
type wall;
faces
(
(0 1 5 4)

);
}
topWall
{
type wall;
faces
(
(9 10 11 8)

);
}
backWall
{
type cyclic;
neighbourPatch frontWall;
faces
(
(0 3 2 1)
(3 9 8 2)
);
}

frontWall
{
type cyclic;
neighbourPatch backWall;
faces
(
(4 5 6 7)
(7 6 11 10)
);
}

);
margePatchPairs
(
);

27-03-20, 10:42 a.m. sourav0921


0
/*--------------------------------*- C++ -*----------------------------------*\ ========= | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox \\ / O peration | Website: https://openfoam.org \\ / A nd | Version: 6 \\/ M anipulation | \*---------------------------------------------------------------------------*/ FoamFile { version 2.0; format ascii; class dictionary; object blockMeshDict; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // convertToMeters 1; vertices ( (0 0 0) //0 (0.252 0 0) //1 (0.252 0.01 0) //2 (0 0.01 0) //3 (0 0 0.042) //4 (0.252 0 0.042) //5 (0.252 0.01 0.042) //6 (0 0.01 0.042) //7 (0.252 0.02 0) //8 (0 0.02 0) //9 (0 0.02 0.042) //10 (0.252 0.02 0.042) //11 ); blocks ( hex (0 1 2 3 4 5 6 7) (100 33 130) simpleGrading (1 40 1) hex (3 2 8 9 7 6 11 10) (100 33 130) simpleGrading (1 0.025 1) ); edges ( ); boundary ( inlet { type cyclic; neighbourPatch outlet; faces ( (0 4 7 3) (3 7 10 9) ); } outlet { type cyclic; neighbourPatch inlet; faces ( (1 2 6 5) (2 8 11 6) ); } bottomWall { type wall; faces ( (0 1 5 4) ); } topWall { type wall; faces ( (9 10 11 8) ); } backWall { type cyclic; neighbourPatch frontWall; faces ( (0 3 2 1) (3 9 8 2) ); } frontWall { type cyclic; neighbourPatch backWall; faces ( (4 5 6 7) (7 6 11 10) ); } ); margePatchPairs ( );
27-03-20, 10:56 a.m. sourav0921


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Hi Sourav,

I executed your blockMesh file and it ran without any problems. The geometry, when viewed in ParaView, did not have any non-rectangular faces either. Did you try viewing your geometry in ParaView?

Regards,
Ashley

27-03-20, 9:33 p.m. ashleymelvin

Hi Ashley,

When I checked the mesh using paraview it shows no problem but when I create the cell face using the coordinates of the points associated with the face located at faces.c in polymesh folder I able to see this irregularity. Can you please tell me the cause of this problem?


31-03-20, 9:41 a.m. sourav0921

Hi Sourav,

Could you please share the snippet of the faces file (in polymesh folder), where you are seeing the irregularity?


01-04-20, 2:12 a.m. ashleymelvin

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0

Hi Ashley,

If you generate the polymesh folder using blockMesh command of OPENFOAM the face.c file will create.

01-04-20, 12:23 p.m. sourav0921

Hi Sourav, 

Can you please tell me how did you confirm if the faces defined in the faces file is rectangular or not? The faces file has the list of faces defined by the points. There will be numerous points, depending upon your meshing parameters. How did you identify the coordinates of the points to check if it's rectangular or not?


01-04-20, 1:54 p.m. ashleymelvin

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