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-   -   inconsistent number of faces between block pair A & B for a quarter of pipe (https://www.cfd-online.com/Forums/openfoam-pre-processing/126377-inconsistent-number-faces-between-block-pair-b-quarter-pipe.html)

AmirBaqa1987 November 15, 2013 11:13

inconsistent number of faces between block pair A & B for a quarter of pipe
 
Hi everyone
I want to model a quarter of pipe by using blockMeshDict.
the dimension of pipe is 0.3meter length and 0.003meter radius.
I want to generate full structured mesh so I've created 3 blocks.

the blockMeshDict is exactly like below:

Code:

convertToMeters 1;

vertices
(
    (0 0 0)      //0
    (0 0 0.001)
    (0 0.001 0.001)      //2
    (0 0.001 0)
    (0 0 0.003)  //4
    (0 0.0021213 0.0021213)
    (0 0.003 0 )      //6

    (0.3 0 0)      //7
    (0.3 0 0.001)
    (0.3 0.001 0.001)      //9
    (0.3 0.001 0)
    (0.3 0 0.003)  //11
    (0.3 0.0021213 0.0021213)
    (0.3 0.003 0 )      //13
   
);

blocks
(
    hex (7 8 9 10 0 1 2 3) (300 10 10) simpleGrading (1 1 1)
    hex (8 11 12 9 1 4 5 2) (300 10 50) simpleGrading (1 1 1)
    hex (10 9 12 13 3 2 5 6) (300 50 10) simpleGrading (1 1 1)
);

edges
(
    arc 4 5 (0 0.001148 0.00277)
    arc 5 6 (0 0.00277 0.001148)
    arc 11 12 (0.3 0.001148 0.00277)
    arc 12 13 (0.3 0.00277 0.001148)
);
boundary
(
    inlet
    {
        type patch;
        faces
        (
            (0 1 2 3)
            (1 4 5 2)
            (2 5 6 3)
        );
    }

    outlet
    {
        type patch;
        faces
        (
            (7 10 9 8)
            (8 9 12 11)
            (9 10 13 12)
        );
    }

    side1
    {
        type cyclic;
        neighbourPatch side2;
        faces
        (
            (0 7 8 1)
            (1 8 11 4)
        );
    }

    side2
    {
        type cyclic;
        neighbourPatch side1;
        faces
        (
            (0 3 10 7)
            (3 6 13 10)
        );

    }

    walls
    {
        type wall;
        faces
        (
            (4 11 12 5)
          (5 12 13 6)
        );
    }

 
);


but when I execute blockMesh in terminal, the following fatal Error appears;

Code:

--> FOAM FATAL ERROR:
Inconsistent number of faces between block pair 0 and 1

    From function blockMesh::calcMergeInfo()
    in file blockMesh/blockMeshMerge.C at line 221.

FOAM exiting

i know it is about number of cells for patches between the blocks but I have not been able to make it correct .

can anybody help?

thanks.
Arjang

nimasam November 15, 2013 12:00

it should be like this:
Quote:

blocks
(
hex (7 8 9 10 0 1 2 3) (10 10 300) simpleGrading (1 1 1)
hex (8 11 12 9 1 4 5 2) (10 10 300) simpleGrading (1 1 1)
hex (10 9 12 13 3 2 5 6) (10 10 300) simpleGrading (1 1 1)
);

AmirBaqa1987 November 15, 2013 12:21

Thanks Dear Nima

I want to set the following simpleGrading:

hex (7 8 9 10 0 1 2 3) (10 10 300) simpleGrading (1 1 1)
hex (8 11 12 9 1 4 5 2) (50 10 300) simpleGrading (0.1 1 1)
hex (10 9 12 13 3 2 5 6) (10 50 300) simpleGrading (1 0.1 1)

but terminal says :
Code:

--> FOAM FATAL ERROR:
face 3001 area does not match neighbour by 1.41456% -- possible face ordering problem.
patch:side1 my area:5.54069e-08 neighbour area:5.46286e-08 matching tolerance:0.0001
Mesh face:973101 fc:(0.2985 0 0.0010277)
Neighbour fc:(0.2995 0.00108272 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.

where can I increase the 'matchTolerance' ?

nimasam November 16, 2013 05:15

but im afraid that it solves your problem
Quote:

type cyclic;
neighbourPatch side2;
faces
(
(0 7 8 1)
(1 8 11 4)
);
matchTolerance 0.01;


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