[Alan]

Hi all,

I am trying to mesh a wedge shape in blockMesh, and I am having trouble getting it to work properly. I am getting the warning:

Creating block mesh topology
--> FOAM Warning :
From function cellModel::mag(const labelList&, const pointField&)
in file meshes/meshShapes/cellModel/cellModel.C at line 134
zero or negative pyramid volume: -0.0075 for face 1

so I assume I have the ordering of some of points wrong, but I can't for the life of me figure out which ones are wrong. My blockMesh file is:

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  1.5                                   |
|   \\  /    A nd           | Web:      http://www.OpenFOAM.org               |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      blockMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

convertToMeters 1;

vertices        
(
   (0 0 -0.05)
   (1 0 -0.05)
   (1.5 0 -0.05)
   (3 0 -0.05)
   (1 0.85 -0.05)
   (1.5 0.85 -0.05)
   (1 1 -0.05)
   (1 1.15 -0.05)
   (1.5 1.15 -0.05)
   (0 2 -0.05)
   (1 2 -0.05)
   (1.5 2 -0.05)
   (3 2 -0.05)
   (3 0.85 -0.05)
   (3 1.15 -0.05)
   (0 0 0.05)
   (1 0 0.05)
   (1.5 0 0.05)
   (3 0 0.05)
   (1 0.85 0.05)
   (1.5 0.85 0.05)
   (1 1 0.05)
   (1 1.15 0.05)
   (1.5 1.15 0.05)
   (0 2 0.05)
   (1 2 0.05)
   (1.5 2 0.05)
   (3 2 0.05)
   (3 0.85 0.05)
   (3 1.15 0.05)
);

blocks          
(
    hex (0 1 10 9 15 16 25 24)   (100 200 1) simpleGrading (1 1 1)
    hex (1 2 5 4 16 17 20 19)    (50 85 1) simpleGrading (1 1 1)
    hex (4 5 6 6 19 20 21 21)    (50 15 1) simpleGrading (1 1 1)
    hex (8 7 6 6 23 22 21 21)    (50 15 1) simpleGrading (1 1 1)
    hex (7 8 11 10 22 23 26 25)  (50 85 1) simpleGrading (1 1 1)
    hex (2 3 14 5 17 18 29 20)   (150 85 1) simpleGrading (1 1 1)
    hex (5 14 13 8 20 29 28 23)  (150 30 1) simpleGrading (1 1 1)
    hex (8 13 12 11 23 28 27 26) (150 85 1) simpleGrading (1 1 1)
);

edges           
(
);

patches         
(
    patch inlet 
    (
        (0 15 24 9)
    )
    patch outlet 
    (
        (3 18 29 14)
        (14 29 28 13)
        (13 28 27 12)
    )
    symmetryPlane bottom 
    (
        (0 1 16 15)
        (1 2 17 16)
        (2 3 18 17)
    )
    symmetryPlane top 
    (
        (9 10 25 24)
        (10 11 26 25)
    (11 12 27 26)
    )
    patch obstacle
    (
        (6 8 23 21)
        (6 21 20 5)
    (5 20 23 8)
    )
);

mergePatchPairs
(
);

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

I assume the problem occurs around blocks 2 and 3 as they are the wedge shapes. If I play around with the ordering it defines the wedges as inside out (getting negative volumes) so I can't see why I have done it wrong.

Can anyone point me in the right direction here? Thanks very much in advance for your help.

Alan.