profile in icoFoam
 

Hi everyone!


Iḿ trying to solve a profile with icoFoam (i want to try with a easy solver first) and I have some problems, but I don know where !


When I solve, what I obtan is the next message error:


--> FOAM FATAL ERROR:
This mesh contains patches of type empty but is not 1D or 2D
by virtue of the fact that the number of faces of this
empty patch is not divisible by the number of cells.

From function emptyFvPatchField<Type>::updateCoeffs()
in file fields/fvPatchFields/constraint/empty/emptyFvPatchField.C at line 150.




So I will try to explain the organization and the content. The mesh was made with snappyHexMesh and I obtain the files I need: boundary, faces, neighbour, owner and points. This files are situated in >constant>polymesh. I add an image of the mesh.



The boundary conditions can be seen in the file boundary:


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

5
(
inlet
{
type patch;
nFaces 48;
startFace 2098769;
}
outlet
{
type patch;
nFaces 48;
startFace 2098817;
}
topAndBottom
{
type patch;
nFaces 150;
startFace 2098865;
}
frontAndBack
{
type empty;
nFaces 76249;
startFace 2099015;
}
wing_5degrees.obj_WALL10
{
type wall;
nFaces 49792;
startFace 2175264;
}
)

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


In >contant I situated the file transport Properties.


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

nu nu [ 0 2 -1 0 0 0 0 ] 1.1e-6;


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


In the system folder I situated the files ControlDict, fvSchemes and fvSolution. I add this files next, may be the problem is here...


controlDict
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

application icoFoam;

startFrom startTime;

startTime 0;

stopAt endTime;

endTime 1;

deltaT 0.15;

writeControl timeStep;

writeInterval 2;

purgeWrite 0;

writeFormat ascii;

writePrecision 6;

writeCompression uncompressed;

timeFormat general;

timePrecision 6;

runTimeModifiable yes;


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


fvSchemes
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

ddtSchemes
{
default Euler;
}

gradSchemes
{
default Gauss linear;
grad(p) Gauss linear;
}

divSchemes
{
default none;
div(phi,U) Gauss linear;
}

laplacianSchemes
{
default none;
laplacian(nu,U) Gauss linear corrected;
laplacian((1|A(U)),p) Gauss linear corrected;
}

interpolationSchemes
{
default linear;
interpolate(HbyA) linear;
}

snGradSchemes
{
default corrected;
}

fluxRequired
{
default no;
p ;
}


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


fvSolution
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

solvers
{
p
{
solver PCG;
preconditioner DIC;
tolerance 1e-06;
relTol 0;
}

U
{
solver PBiCG;
preconditioner DILU;
tolerance 1e-05;
relTol 0;
}
}

PISO
{
nCorrectors 2;
nNonOrthogonalCorrectors 0;
pRefCell 0;
pRefValue 0;
}


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




Finally, in the 0 folder, i define the files p and U. You can see next;


U
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions [0 1 -1 0 0 0 0];

internalField uniform (0.05 0 0);

boundaryField
{

inlet
{
type freestream;
freestreamValue uniform (0.05 0 0);
}

outlet
{
type freestream;
freestreamValue uniform (0.05 0 0);
}

topAndBottom
{
type fixedValue;
value uniform (0 0 0);
}

frontAndBack
{
type empty;
}

wing_5degrees.obj_WALL10
{
type fixedValue;
value uniform (0 0 0);
}
}

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




p
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions [0 2 -2 0 0 0 0];

internalField uniform 0;

boundaryField
{

inlet
{
type freestreamPressure;
}

outlet
{
type freestreamPressure;
}

topAndBottom
{
type zeroGradient;
}

frontAndBack
{
type empty;
}

wing_5degrees.obj_WALL10
{
type zeroGradient;
}
}

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


Any idea ? Does someone know where can be the problem?


Thanks a lot everyone. I hope you can help me...

Is it possible that you mixed up the boundary conditions?

For type 'empty' the layerthikness only 1 cell is allowed.
It seems that you mixed up top/bottom and front/back.

ey...
 

Ey, thanks for your reply.!


I changed the boundary conditions, so now I have top, bottom, front and back separately and I the same problem appears.


I don`t understand very good when you say “for type 'empty' the layerthikness only 1 cell is allowed”... I add two cells in transversal direction (there was one) , is his what you mean ?

thinking, thinking and thinking....
 

May be the problem is in the "fvSolution" file, that is the same than the cavity case, very different to the original problem (profile).

Look in the constant/polymesh/boundary file to see wich boundarys you realy have. I think yes. Sry for the 'english' ;) Try it with onle 1 cell in 'transversal' direction.