[raro-bizarro]

Hi!

I'm new to CFD and I'm really struggling to make a mesh for a Street Canyon simulation.
I hope any of you can at least point me in the right direction.

In the next picture you can see my (poorly made) sketch of the geometry I'm trying to mesh, where the vertices are notated as z0 (-width) / z1 (+width):

https://imgur.com/a/sIhqdJc (can't paste it as an image...¿?)



Actually this is my 2nd mesh, initially I didn't include the horizontal y=1 face across the domain, and adding this was my attempt to solve the issue. Without this face, even commenting out all the boundaries, I would get the message "the mesh has multiple regions which are not connected by any face". After adding this face that message was gone, but I still get the same errors.

I'm using a .m4 script to create my blockMeshDict file. If I comment out the top and frontAndBack boundaries, I can run blockMesh and checkMesh shows no errors.
If I don't comment those out, I get the "face 0 in patch 4 vertices 4((0 0 -1) (5 0 -1) (5 4 -1) (0 4 -1)) does not have neighbor cell face: 4(0 1 40 19)" error.
This is the .m4 script:

/*--------------------------------*- C++ -*----------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Version:  7
     \\/     M anipulation  |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      blockMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //



convertToMeters 0.01;

dnl changecom(//)
changequote([,])
define(LPAREN,[(])dnl
define(RPAREN,[)])dnl
dnl
define(calc, [esyscmd(perl -e 'printf ($1)')])dnl
dnl
define(heightBuilding, 1)
define(widthBuilding, 1)
define(width, heightBuilding)
define(lengthUpst, calc(5*widthBuilding))
define(lengthDownst, calc(15*widthBuilding))
define(heightUp, calc(4*heightBuilding))
dnl
dnl === POINTS ===
//Building width = space between buildings
define(x0, 0)dnl
define(x1, lengthUpst)dnl
define(x2, calc(lengthUpst+widthBuilding))dnl
define(x3, calc(x2+widthBuilding))dnl
define(x4, calc(x3+widthBuilding))dnl
define(x5, calc(x4+widthBuilding))dnl
define(x6, calc(x5+widthBuilding))dnl
define(x7, calc(x6+widthBuilding))dnl
define(x8, calc(x7+widthBuilding))dnl
define(x9, calc(x8+lengthDownst))dnl 
define(y0, 0)dnl
define(z0, -width)dnl
define(z1, width)dnl
define(xCount, 20)dnl
define(xCount2, 100)dnl
define(xCount3, 300)dnl
define(yCount, 20)dnl
define(yCount2, 60)dnl
define(zCount, 1)dnl
dnl
dnl


vertices
(
    (x0 y0 z0)                          //0
    (x1 y0 z0)                          //1
    (x1 heightBuilding z0)              //2
    (x2 heightBuilding z0)              //3
    (x2 y0 z0)                          //4
    (x3 y0 z0)                          //5
    (x3 heightBuilding z0)              //6
    (x4 heightBuilding z0)              //7
    (x4 y0 z0)                          //8
    (x5 y0 z0)                          //9
    (x5 heightBuilding z0)              //10
    (x6 heightBuilding z0)              //11
    (x6 y0 z0)                          //12
    (x7 y0 z0)                          //13
    (x7 heightBuilding z0)              //14
    (x8 heightBuilding z0)              //15
    (x8 y0 z0)                          //16
    (x9 y0 z0)                          //17
    (x9 heightUp z0)                    //18
    (x0 heightUp z0)                    //19
    (x0 y0 z1)                          //20
    (x1 y0 z1)                          //21
    (x1 heightBuilding z1)              //22
    (x2 heightBuilding z1)              //23
    (x2 y0 z1)                          //24
    (x3 y0 z1)                          //25
    (x3 heightBuilding z1)              //26
    (x4 heightBuilding z1)              //27
    (x4 y0 z1)                          //28
    (x5 y0 z1)                          //29
    (x5 heightBuilding z1)              //30
    (x6 heightBuilding z1)              //31
    (x6 y0 z1)                          //32
    (x7 y0 z1)                          //33
    (x7 heightBuilding z1)              //34
    (x8 heightBuilding z1)              //35
    (x8 y0 z1)                          //36
    (x9 y0 z1)                          //37
    (x9 heightUp z1)                    //38
    (x0 heightUp z1)                    //39
    (x1 heightUp z0)                    //40
    (x2 heightUp z0)                    //41
    (x3 heightUp z0)                    //42
    (x4 heightUp z0)                    //43
    (x5 heightUp z0)                    //44
    (x6 heightUp z0)                    //45
    (x7 heightUp z0)                    //46
    (x8 heightUp z0)                    //47
    (x1 heightUp z1)                    //48
    (x2 heightUp z1)                    //49
    (x3 heightUp z1)                    //50
    (x4 heightUp z1)                    //51
    (x5 heightUp z1)                    //52
    (x6 heightUp z1)                    //53
    (x7 heightUp z1)                    //54
    (x8 heightUp z1)                    //55
    (x0 heightBuilding z0)              //56
    (x0 heightBuilding z1)              //57
    (x9 heightBuilding z0)              //58
    (x9 heightBuilding z1)              //59
); 


blocks
(
    hex (0 1 2 56 20 21 22 57) (xCount2 yCount zCount) simpleGrading (1 1 1)      //0
    hex (56 2 40 19 57 22 48 39) (xCount2 yCount2 zCount) simpleGrading (1 1 1)   //1
    hex (2 3 41 40 22 23 49 48) (xCount yCount2 zCount) simpleGrading (1 1 1)     //2
    hex (3 6 42 41 23 26 50 49) (xCount yCount2 zCount) simpleGrading (1 1 1)     //3
    hex (4 5 6 3 24 25 26 23) (xCount yCount zCount) simpleGrading (1 1 1)        //4
    hex (6 7 43 42 26 27 51 50) (xCount yCount2 zCount) simpleGrading (1 1 1)     //5
    hex (7 10 44 43 27 30 52 51) (xCount yCount2 zCount) simpleGrading (1 1 1)    //6
    hex (8 9 10 7 28 29 30 27) (xCount yCount zCount) simpleGrading (1 1 1)       //7
    hex (10 11 45 44 30 31 53 52) (xCount yCount2 zCount) simpleGrading (1 1 1)   //8     
    hex (11 14 46 45 31 34 54 53) (xCount yCount2 zCount) simpleGrading (1 1 1)   //9     
    hex (12 13 14 11 32 33 34 31) (xCount yCount zCount) simpleGrading (1 1 1)    //10     
    hex (14 15 47 46 34 35 55 54) (xCount yCount2 zCount) simpleGrading (1 1 1)   //11     
    hex (15 58 18 47 35 59 38 55) (xCount3 yCount2 zCount) simpleGrading (1 1 1)  //12     
    hex (16 17 58 15 36 37 59 35) (xCount3 yCount zCount) simpleGrading (1 1 1)   //13     
);

//If edges are straight lines OpenFoam can infer the edges automatically from the vertices
edges
(
);

boundary
(
    inlet
    {
        type patch;
        faces
        (
            (0 56 57 20)
            (56 19 39 57)
        );
    }
    outlet
    {
        type patch;
        faces
        (
            (17 37 59 58)
            (58 59 38 18)
        );
    }
    ground
    {
        type wall;
        faces
        (
            (0 20 21 1)
            (4 24 25 5)
            (8 28 29 9)
            (12 32 33 13)
            (16 36 37 17)
        );
    }
    top
    {
        type symmetry;
        faces
        (
            (18 38 39 19)
        );
    }
    buildings
    {
        type wall;
        faces
        (
            (1 21 22 2) 
            (2 22 23 3)
            (4 3 23 24)
            (5 25 26 6)
            (6 26 27 7)
            (8 7 27 28)
            (9 29 30 10)
            (10 30 31 11)
            (12 11 31 32)
            (13 33 34 14)
            (14 34 35 15)
            (16 15 35 36)
        );
    }
    frontAndBack 
    {
        type empty;
        faces
        (
            (0 1 40 19)
	    (20 39 48 21)
	    (2 3 41 40)
	    (22 48 49 23)
	    (4 5 42 41)
	    (24 49 50 25)
	    (6 7 43 42)
	    (26 50 51 27)
	    (8 9 44 43)
	    (28 51 52 29)
	    (10 11 45 44)
	    (30 52 53 31)
	    (12 13 46 45)
	    (32 53 54 33)
	    (14 15 47 46)
	    (34 54 55 35)
	    (16 17 18 47)
	    (36 55 38 37)
        );
    }


);
 
mergePatchPairs 
(
);
 
// ************************************************************************* //

I've been trying to solve this for 3 days with no luck, so any help at all would be much appreciated.

Thanks in advance!