[GPesch]

Hi,

I am trying to set up a very simple multi region case to test a solver I am working on.
The problem is that when I run "splitMeshRegions -cellZones -overwrite" I will always get the output

"Only one region. Doing nothing".

I defined a cubic block with blockMesh, which worked fine. Here's the blockMeshDict:

convertToMeters 1;

vertices
(
    (0 0 0)
    (1 0 0)
    (1 1 0)
    (0 1 0)
    (0 0 1)
    (1 0 1)
    (1 1 1)
    (0 1 1)
);

blocks
(
    hex (0 1 2 3 4 5 6 7) (10 10 10) simpleGrading (1 1 1)
);

edges
(
);

boundary
(
    maxY
    {
        type wall;
        faces
        (
            (3 7 6 2)
        );
    }
    minX
    {
        type patch;
        faces
        (
            (0 4 7 3)
        );
    }
    maxX
    {
        type patch;
        faces
        (
            (2 6 5 1)
        );
    }
    minY
    {
        type wall;
        faces
        (
            (1 5 4 0)
        );
    }
    minZ
    {
        type wall;
        faces
        (
            (0 3 2 1)
        );
    }
    maxZ
    {
        type wall;
        faces
        (
            (4 5 6 7)
        );
    }
);

mergePatchPairs
(
);

after running "blockMesh" I ran "topoSet" with the following topoSetDict:

actions
(
    // Left
    {
        name    left;
        type    cellSet;
        action    new;
        source    boxToCell;
        sourceInfo
        {
            box (0 0 0) (0.5 1 1)
        }
    }
    {
        name    left;
        type    cellZoneSet;
        action    new;
        source    setToCellZone;
        sourceInfo
        {
            set left;
        }
    }


    // Right
    {
        name    right;
        type    cellSet;
        action    new;
        source    boxToCell;
        sourceInfo
        {
            box (0.5 0 0) (1 1 1)
        }
    }
    {
        name    right;
        type    cellZoneSet;
        action    new;
        source    setToCellZone;
        sourceInfo
        {
            set right;
        }
    }
);

So actually I just want to divide it into two parts, "left" and "right". The border should be in the middle of the volume at "x = 0.5".
After doing so I get the two files "polyMesh/sets/left" and "right". Both containing 500 different numbers, I'm assuming that are the cellIds. Okay, so far so good.
But when I run "splitMeshRegions -cellZones -overwrite" I will receive the following output:

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

Create mesh for time = 0

Creating single patch per inter-region interface.

Trying to match regions to existing cell zones.


Number of regions:1

Writing region per cell file (for manual decomposition) to "/home/gp/OpenFOAM/gp-2.1.1/run/multiRegionElectrostatics/constant/cellToRegion"

Writing region per cell as volScalarField to "/home/gp/OpenFOAM/gp-2.1.1/run/multiRegionElectrostatics/0/cellToRegion"

Region    Cells
------    -----
0    1000

Region    Zone    Name
------    ----    ----
0    -1    domain0

Sizes of interfaces between regions:

Interface    Region    Region    Faces
---------    ------    ------    -----

Reading volScalarField phi
Reading volScalarField cellToRegion

Only one region. Doing nothing.
End

I am wondering—am I missing something? Is there a simple explanation why splitMeshRegions doesn't detect the two specified regions?
I am running on OF 2.1.1. if that matters.

Thank you so much for the time to read this thread and for your answer in advance.

Best regards
Georg

[zhengzh5]

hey, not sure if that's causing trouble but your definition of right zone should be
sourceInfo
{
box (0.5 1 1) (1 1 1)
}

and not
sourceInfo
{
box (0.5 0 0) (1 1 1)
}?

Originally Posted by GPesch

Hi,

I am trying to set up a very simple multi region case to test a solver I am working on.
The problem is that when I run "splitMeshRegions -cellZones -overwrite" I will always get the output

"Only one region. Doing nothing".

I defined a cubic block with blockMesh, which worked fine. Here's the blockMeshDict:

convertToMeters 1;

vertices
(
    (0 0 0)
    (1 0 0)
    (1 1 0)
    (0 1 0)
    (0 0 1)
    (1 0 1)
    (1 1 1)
    (0 1 1)
);

blocks
(
    hex (0 1 2 3 4 5 6 7) (10 10 10) simpleGrading (1 1 1)
);

edges
(
);

boundary
(
    maxY
    {
        type wall;
        faces
        (
            (3 7 6 2)
        );
    }
    minX
    {
        type patch;
        faces
        (
            (0 4 7 3)
        );
    }
    maxX
    {
        type patch;
        faces
        (
            (2 6 5 1)
        );
    }
    minY
    {
        type wall;
        faces
        (
            (1 5 4 0)
        );
    }
    minZ
    {
        type wall;
        faces
        (
            (0 3 2 1)
        );
    }
    maxZ
    {
        type wall;
        faces
        (
            (4 5 6 7)
        );
    }
);

mergePatchPairs
(
);

after running "blockMesh" I ran "topoSet" with the following topoSetDict:

actions
(
    // Left
    {
        name    left;
        type    cellSet;
        action    new;
        source    boxToCell;
        sourceInfo
        {
            box (0 0 0) (0.5 1 1)
        }
    }
    {
        name    left;
        type    cellZoneSet;
        action    new;
        source    setToCellZone;
        sourceInfo
        {
            set left;
        }
    }


    // Right
    {
        name    right;
        type    cellSet;
        action    new;
        source    boxToCell;
        sourceInfo
        {
            box (0.5 0 0) (1 1 1)
        }
    }
    {
        name    right;
        type    cellZoneSet;
        action    new;
        source    setToCellZone;
        sourceInfo
        {
            set right;
        }
    }
);

So actually I just want to divide it into two parts, "left" and "right". The border should be in the middle of the volume at "x = 0.5".
After doing so I get the two files "polyMesh/sets/left" and "right". Both containing 500 different numbers, I'm assuming that are the cellIds. Okay, so far so good.
But when I run "splitMeshRegions -cellZones -overwrite" I will receive the following output:

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

Create mesh for time = 0

Creating single patch per inter-region interface.

Trying to match regions to existing cell zones.


Number of regions:1

Writing region per cell file (for manual decomposition) to "/home/gp/OpenFOAM/gp-2.1.1/run/multiRegionElectrostatics/constant/cellToRegion"

Writing region per cell as volScalarField to "/home/gp/OpenFOAM/gp-2.1.1/run/multiRegionElectrostatics/0/cellToRegion"

Region    Cells
------    -----
0    1000

Region    Zone    Name
------    ----    ----
0    -1    domain0

Sizes of interfaces between regions:

Interface    Region    Region    Faces
---------    ------    ------    -----

Reading volScalarField phi
Reading volScalarField cellToRegion

Only one region. Doing nothing.
End

I am wondering—am I missing something? Is there a simple explanation why splitMeshRegions doesn't detect the two specified regions?
I am running on OF 2.1.1. if that matters.

Thank you so much for the time to read this thread and for your answer in advance.

Best regards
Georg

[GPesch]

Originally Posted by zhengzh5

hey, not sure if that's causing trouble but your definition of right zone should be
sourceInfo
{
box (0.5 1 1) (1 1 1)
}

and not
sourceInfo
{
box (0.5 0 0) (1 1 1)
}?

Are you sure? box(0.5 1 1) (1 1 1) is defining a flat area, not a box—or am I mistaking?