[dasith0001]

Hi Foamers,

I am attempting to get to perfect mesh using blockMesh. my geometry has a curved channel, please see the figure.

So far the mesh is error free but checkMesh complains over high orthogonal cells. Theses cells are located along the y-axis, at the very edge of the curved channel ( along the curved line towards the end of top right).

I've tried edge grading to make those cells bigger as possible which seems to solve the problem but I am losing the smoothness of the curve.

I've attached the blockMesh file as well.

PHP Code:

/*--------------------------------*- 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;
    object      blockMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

scale   1;

upperLevel 0.1;
blockBx 10;
blockBz 100;


vertices
(

(    0.302195033    -0.039764330    0.053750000    )    //    0 A
(    0.321082223    -0.042249600    0.053750000    )    //    1
(    0.3324025    -0.032730084    0.053750000    )    //    2
(    0.303333079    -0.029867757    0.053750000    )    //    3

(    0.302195033    -0.039764330    $upperLevel    )    //    4
(    0.321082223    -0.042249600    $upperLevel    )    //    5
(    0.3324025    -0.032730084    $upperLevel    )    //    6
(    0.303333079    -0.029867757    $upperLevel    )    //    7

(    0.303333079    -0.029867757    0.053750000    )    //    8 B
(    0.332402500    -0.032730084    0.053750000    )    //    9
(    0.334010000     0.000000000    0.053750000    )    //    10
(    0.304800000     0.000000000    0.053750000    )    //    11

(    0.303333079    -0.029867757    $upperLevel    )    //    12 
(    0.332402500    -0.032730084    $upperLevel    )    //    13
(    0.334010000     0.000000000    $upperLevel    )    //    14
(    0.304800000     0.000000000    $upperLevel    )    //    15

(    0.331155391    0.043575078    0.053750000    )    //    16 C
(    0.302195033    0.039764330    0.053750000    )    //    17
(    0.331155391    0.043575078    $upperLevel    )    //    18
(    0.302195033    0.039764330    $upperLevel    )    //    19


);

edges
(

arc    3    0        (    0.302804490     -0.034820693     0.05375    )    // A
arc    2    1        (    0.322635444     -0.0367596656     0.05375    )    //
arc    7    4        (    0.302804490     -0.034820693     $upperLevel    )    //
arc    6    5        (    0.322635444     -0.0367596656     $upperLevel    )    //

arc    11    8        (    0.304433049    -0.014951879    0.05375        )    //
arc    10    9        (    0.333607883    -0.016384768    0.05375        )    //
arc    15    12        (    0.304433049    -0.014951879    $upperLevel    )    //
arc    14    13        (    0.333607883    -0.016384768    $upperLevel    )    //

arc    17    11        (    0.304148061    0.019924782    0.05375        )    //
arc    16    10        (    0.333295584    0.02183424    0.05375        )    //
arc    19    15        (    0.304148061    0.019924782    $upperLevel    )    //
arc    18    14        (    0.333295584    0.02183424    $upperLevel    )    //


);


blocks
(
    //hex (0 1 2 3 4 5 6 7) (20 20 100) edgeGrading (0.1 10 10 0.1 1 50 50 1 1 1 1 1) // - A
    hex (0 1 2 3 4 5 6 7) (20 20 100) edgeGrading (1 10 10 1 1 50 50 1 1 1 1 1) // - A

    hex (8 9 10 11 12 13 14 15) ($blockBx 20 $blockBz) simpleGrading (1 1 1) // (x y z) // 1 - B

    hex (11 10 16 17 15 14 18 19) ($blockBx 30 $blockBz) simpleGrading (1 1 1) // (x y z) // 1 - C

);    


boundary
(

    front
    {
        type symmetry;
        faces
        (
        (0 1 5 4)
        
        );
    }

    back
    {
        type symmetry;
        faces
        (
        (18 16 17 19)  
        );
    }

    minZ
    {
        type patch;
        faces
        (
        (0 3 2 1)
        (8 11 10 9)
        (11 17 16 10)     
        );
    }

    maxZ
    {
        type patch;
        faces
        (
        (4 5 6 7)
        (12 13 14 15)
        (15 14 18 19)    
        );
    }

    axis
    {
        type wall;
        faces
        (
        (0 4 7 3)
        (8 12 15 11)
        (11 15 19 17)    
        );
    }

    maxY
    {
        type wall;
        faces
        (
   
        );
    }

    interWall
    {
        type wall;
        faces
        (
        (1 2 6 5)    
        );
    }

    masterA1
    {
        type wall;
        faces
        (
        (2 3 7 6)   
        );
    }

    slaveB1
    {
        type wall;
        faces
        (
        (9 8 12 13)    
        );
    }


);

mergePatchPairs
(
            (masterA1 slaveB1)

);

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


What can I do to improve the mesh if I want to stick with blockMesh. ( which I really do).
Or do I have to say good buy to my good old friend (blockMesh) and turned into snappy ?

your thoughts on this highly appreciated.
Thank you

PS: my mesh could be fine as it is but I am always too sceptical about it.