[chrisb2244]

I can generate a mesh if I omit the 'mergePatchPairs' section, but in that case, 'checkMesh' informs me I have x-many regions that are not connected by any faces.

If I remove duplicate vertices, I get errors relating to 'inconsistent number of faces' when running blockMesh.

When I add a 'mergePatchPairs' section, blockMesh fails. In this case, the error is given as

--> FOAM FATAL ERROR: 
Face 16384 reduced to less than 3 points.  Topological/cutting error A.
Old face: 2(20622 23184) new face: 2(20622 23184)

    From function void slidingInterface::coupleInterface(polyTopoChange& ref) const
    in file slidingInterface/coupleSlidingInterface.C at line 1481.

FOAM aborting

however I have also (for similar blockMeshDict) had a error relating to a 'slicing error'.

My intention is to provide a 2:1 refined initial mesh so as to bypass difficulties with 2D AMR (since the region of interest is very simple - just the middle)

Does anyone know what I'm doing wrong? (and if there is a solution more trivial than "Go back to coding a modified fvRefineHexMesh class"?)

My blockMeshDict is as follows:

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2.2.1                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version        2.0;
    format        ascii;
    class        dictionary;
    object        blockMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

vertices
(
    (0 0.0 0)
    (160.0 0.0 0)
    (160.0 11.0 0)
    (0 11.0 0)
    (0 0.0 10.0)
    (160.0 0.0 10.0)
    (160.0 11.0 10.0)
    (0 11.0 10.0)
    (0 11.0 0)
    (160.0 11.0 0)
    (160.0 11.5 0)
    (0 11.5 0)
    (0 11.0 10.0)
    (160.0 11.0 10.0)
    (160.0 11.5 10.0)
    (0 11.5 10.0)
    (0 11.5 0)
    (160.0 11.5 0)
    (160.0 11.625 0)
    (0 11.625 0)
    (0 11.5 10.0)
    (160.0 11.5 10.0)
    (160.0 11.625 10.0)
    (0 11.625 10.0)
    (0 11.625 0)
    (160.0 11.625 0)
    (160.0 16.0 0)
    (0 16.0 0)
    (0 11.625 10.0)
    (160.0 11.625 10.0)
    (160.0 16.0 10.0)
    (0 16.0 10.0)
    (0 16.0 0)
    (160.0 16.0 0)
    (160.0 24.0 0)
    (0 24.0 0)
    (0 16.0 10.0)
    (160.0 16.0 10.0)
    (160.0 24.0 10.0)
    (0 24.0 10.0)
    (0 24.0 0)
    (160.0 24.0 0)
    (160.0 28.375 0)
    (0 28.375 0)
    (0 24.0 10.0)
    (160.0 24.0 10.0)
    (160.0 28.375 10.0)
    (0 28.375 10.0)
    (0 28.375 0)
    (160.0 28.375 0)
    (160.0 28.5 0)
    (0 28.5 0)
    (0 28.375 10.0)
    (160.0 28.375 10.0)
    (160.0 28.5 10.0)
    (0 28.5 10.0)
    (0 28.5 0)
    (160.0 28.5 0)
    (160.0 29.0 0)
    (0 29.0 0)
    (0 28.5 10.0)
    (160.0 28.5 10.0)
    (160.0 29.0 10.0)
    (0 29.0 10.0)
    (0 29.0 0)
    (160.0 29.0 0)
    (160.0 40.0 0)
    (0 40.0 0)
    (0 29.0 10.0)
    (160.0 29.0 10.0)
    (160.0 40.0 10.0)
    (0 40.0 10.0)
);

blocks
(
    hex (0 1 2 3 4 5 6 7)    (320 22 1) simpleGrading (1 1 1)
    hex (8 9 10 11 12 13 14 15)    (640 2 1) simpleGrading (1 1 1)
    hex (16 17 18 19 20 21 22 23)    (1280 1 1) simpleGrading (1 1 1)
    hex (24 25 26 27 28 29 30 31)    (2560 70 1) simpleGrading (1 1 1)
    hex (32 33 34 35 36 37 38 39)    (5120 256 1) simpleGrading (1 1 1)
    hex (40 41 42 43 44 45 46 47)    (2560 70 1) simpleGrading (1 1 1)
    hex (48 49 50 51 52 53 54 55)    (1280 1 1) simpleGrading (1 1 1)
    hex (56 57 58 59 60 61 62 63)    (640 2 1) simpleGrading (1 1 1)
    hex (64 65 66 67 68 69 70 71)    (320 22 1) simpleGrading (1 1 1)
);

edges
(
);

boundary
(
    side_left
    {
        type patch;
        faces
        (
            (0 3 7 4)
            (8 11 15 12)
            (16 19 23 20)
            (24 27 31 28)
            (32 35 39 36)
            (40 43 47 44)
            (48 51 55 52)
            (56 59 63 60)
            (64 67 71 68)
        );
    }

    side_right
    {
        type patch;
        faces
        (
            (1 5 6 2)
            (9 13 14 10)
            (17 21 22 18)
            (25 29 30 26)
            (33 37 38 34)
            (41 45 46 42)
            (49 53 54 50)
            (57 61 62 58)
            (65 69 70 66)
        );
    }

    bottom
    {
        type wall;
        faces
        (
            (0 4 5 1)
        );
    }

    top
    {
        type wall;
        faces
        (
            (67 66 70 71)
        );
    }

    frontAndBack
    {
        type empty;
        faces
        (
            (1 0 3 2)
            (5 4 7 6)
            (9 8 11 10)
            (13 12 15 14)
            (17 16 19 18)
            (21 20 23 22)
            (25 24 27 26)
            (29 28 31 30)
            (33 32 35 34)
            (37 36 39 38)
            (41 40 43 42)
            (45 44 47 46)
            (49 48 51 50)
            (53 52 55 54)
            (57 56 59 58)
            (61 60 63 62)
            (65 64 67 66)
            (69 68 71 70)
        );
    }

    pm0
    {
        type ;
        faces
        (
            (2 6 7 3)
        );
    }

    ps0
    {
        type ;
        faces
        (
            (9 8 12 13)
        );
    }

    pm1
    {
        type ;
        faces
        (
            (10 14 15 11)
        );
    }

    ps1
    {
        type ;
        faces
        (
            (17 16 20 21)
        );
    }

    pm2
    {
        type ;
        faces
        (
            (18 22 23 19)
        );
    }

    ps2
    {
        type ;
        faces
        (
            (25 24 28 29)
        );
    }

    pm3
    {
        type ;
        faces
        (
            (26 30 31 27)
        );
    }

    ps3
    {
        type ;
        faces
        (
            (33 32 36 37)
        );
    }

    pm4
    {
        type ;
        faces
        (
            (34 38 39 35)
        );
    }

    ps4
    {
        type ;
        faces
        (
            (41 40 44 45)
        );
    }

    pm5
    {
        type ;
        faces
        (
            (42 46 47 43)
        );
    }

    ps5
    {
        type ;
        faces
        (
            (49 48 52 53)
        );
    }

    pm6
    {
        type ;
        faces
        (
            (50 54 55 51)
        );
    }

    ps6
    {
        type ;
        faces
        (
            (57 56 60 61)
        );
    }

    pm7
    {
        type ;
        faces
        (
            (58 62 63 59)
        );
    }

    ps7
    {
        type ;
        faces
        (
            (65 64 68 69)
        );
    }

);

mergePatchPairs
(
    ( pm0 ps0 )
    ( pm1 ps1 )
    ( pm2 ps2 )
    ( pm3 ps3 )
    ( pm4 ps4 )
    ( pm5 ps5 )
    ( pm6 ps6 )
    ( pm7 ps7 )
);

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

The blockMeshDict is generated by a python3 script.