[usamaubk]

Can somebody please tell me where i am making mistake in blocking of a backward facing step: I just need the mesh I will deal with grading afterwards

/*--------------------------------*- 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 0.001;

vertices
(
(0 0 0)
(110 0 0)
(110 -12.5 0)
(160 -12.5 0)
(160 0 0)
(160 100 0)
(110 100 0)
(0 100 0)
(0 0 10)
(110 0 10)
(110 -12.5 10)
(160 -12.5 10)
(160 0 10)
(160 100 10)
(110 100 10)
(0 100 10)
);

blocks
(
hex (0 1 6 7 8 9 14 15) (55 50 1) simpleGrading (1 1 1)
hex (1 2 3 4 9 10 11 12) (25 7 1) simpleGrading (1 1 1)
hex (1 4 5 6 9 12 13 14) (25 50 1) simpleGrading (1 1 1)
);

edges
(
);

boundary
(
inlet
{
type patch;
faces
(
(0 7 15 18)
);
}
outlet
{
type patch;
faces
(
(3 11 12 4)
(4 12 13 5)
);
}
fixedWalls
{
type wall;
faces
(
(0 1 9 8)
(1 2 10 9)
(2 3 11 10)
(7 6 14 15)
(6 5 13 14)
);
}
frontAndBack
{
type empty;
faces
(
(0 7 6 1)
(1 6 5 4)
(2 1 4 3)
(8 15 14 9)
(9 14 13 12)
(10 9 12 11)
);
}
);

mergePatchPairs
(
);

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

usama@usama-VB:~/OpenFOAM/usama-7/run/tutorials/incompressible/icoFoam/cavity/My_backstep_sample$ blockMesh
/*---------------------------------------------------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Website: https://openfoam.org
\\ / A nd | Version: 7
\\/ M anipulation |
\*---------------------------------------------------------------------------*/
Build : 7-1ff648926f77
Exec : blockMesh
Date : Feb 27 2020
Time : 00:12:55
Host : "usama-VB"
PID : 31702
I/O : uncollated
Case : /home/usama/OpenFOAM/usama-7/run/tutorials/incompressible/icoFoam/cavity/My_backstep_sample
nProcs : 1
sigFpe : Enabling floating point exception trapping (FOAM_SIGFPE).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster (fileModificationSkew 10)
allowSystemOperations : Allowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Creating block mesh from
"/home/usama/OpenFOAM/usama-7/run/tutorials/incompressible/icoFoam/cavity/My_backstep_sample/system/blockMeshDict"
Creating block edges
No non-planar block faces defined
Creating topology blocks
Creating topology patches

Creating block mesh topology

Check topology

Basic statistics
Number of internal faces : 2
Number of boundary faces : 14
Number of defined boundary faces : 14
Number of undefined boundary faces : 0
Checking patch -> block consistency

Creating block offsets
Creating merge list

--> FOAM FATAL ERROR:
Inconsistent number of faces between block pair 1 and 2

From function void Foam::blockMesh::calcMergeInfo()
in file blockMesh/blockMeshMerge.C at line 222.

FOAM exiting

[usamaubk]

The error was in numbering of block 2
it should be:
hex (2 3 4 1 10 11 12 9) (25 7 1) simpleGrading (1 1 1)
hope it helps some other too