[vetnav]

Hello,

I am trying to run a 2D free convection case. The flow geometry is a closed box, the bottom wall is heated with air as the fluid. I have OpenFOAM-2.0.x on Fedora14.

My blockMesh looks like

PHP Code:

convertToMeters 0.01;

vertices
(
    (0  0  0)
    (60  0  0)
    (60  10  0)
    (0  10 0)
    (0 0 1)
    (60 0 1)
    (60 10 1)
    (0 10 1)
);

edges
(
);

blocks
(
    hex (0 1 2 3 4 5 6 7) (120 60 1) simpleGrading (1 1 1)
);

patches
(
    wall top
    (
        (3 7 6 2)
    )
    wall bottom
    (
        (1 5 4 0)
    )
    wall side
    (
        (2 6 5 1)
        (0 4 7 3)
    )
    empty frontAndBack
    (
        (0 3 2 1)
        (4 5 6 7)
    )
);

mergePatchPairs
(
); 


and my pressure boundary conditions file looks like

PHP Code:

dimensions      [1 -1 -2 0 0 0 0];

internalField   uniform 101325;

boundaryField
{
    top
    {
        type            zeroGradient;
    }

    bottom
    {
        type            zeroGradient;
    }

    side
    {
        type            zeroGradient;
    }

    frontAndBack
    {
        type            empty;
    }

} 


When I try to run the code, I get a Fatal error, the output is as below

PHP Code:

Build  : 2.0.x-321b2e64c9f9
Exec   : buoyantSimpleFoam
Date   : Aug 25 2011
Time   : 15:22:20
Host   : naveen
PID    : 5771
Case   : /home/naveen/OpenFOAM/naveen-2.0.x/run/TwoDfreeconv
nProcs : 1
sigFpe : Enabling floating point exception trapping (FOAM_SIGFPE).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster
allowSystemOperations : Disallowing user-supplied system call operations

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

Create mesh for time = 0


Reading g
Reading thermophysical properties

Selecting thermodynamics package hPsiThermo<pureMixture<constTransport<specieThermo<hConstThermo<perfectGas>>>>>

--> FOAM FATAL IO ERROR:

    patch type 'wall' not constraint type 'empty'
    for patch frontAndBack of field p in file "/home/naveen/OpenFOAM/naveen-2.0.x/run/TwoDfreeconv/0/p"

file: /home/naveen/OpenFOAM/naveen-2.0.x/run/TwoDfreeconv/0/p::boundaryField::frontAndBack from line 41 to line 41.

    From function emptyFvPatchField<Type>::emptyFvPatchField
(
    const fvPatch& p,
    const Field<Type>& field,
    const dictionary& dict
)

    in file fields/fvPatchFields/constraint/empty/emptyFvPatchField.C at line 100.

FOAM exiting 


As you can see the geometry has empty patches. I don't understand why it complains about empty patches. Could anyone please help me.

Thank you
Naveen

[dima]

Hi Naveen
in OpenFOAM-2.0.x the blockMeshDict is different to OpenFOAM-1.7.x

example from the shockTube tutorial

...
boundary
(
    sides
    {
        type patch;
        faces
        (
            (1 2 6 5)
            (0 4 7 3)
        );
    }
    empty
    {
        type empty;
        faces
        (
            (0 1 5 4)
            (5 6 7 4)
            (3 7 6 2)
            (0 3 2 1)
        );
    }
);
...

and the default type is wall, i think

maybe this could be the reason

regards, Dima

[vetnav]

Hi dima,

Thank you very much for the reply. Strangely, cavity test case which I copied from 1.7.1 runs fine in 2.0.x. I will try your suggestion and see.

Thank you
Naveen