[Zacho]

Hi all,
I am trying to simulate an industrial boiler with the walls of the boiler being a heat sink in OpenFOAM 2412. To extract the heat I use the externalWallHeatFluxTemperature type of boundary condition for T with the settings below.

walls
{
type externalWallHeatFluxTemperature;
mode coefficient;
Ta constant 497.15; //[K]
h constant 1820; //[W/m2-K]
thicknessLayers (0.0045 0.055 0.045); //[m], fouling, refrac, steel in order.
kappaLayers (0.3 1.35 44); //[W/m-K]
nLayers 3;
kappaMethod fluidThermo;
kappa kappa;
emissivity 0.8;
value uniform 497.15;
}

I am comparing my results to a simulation done with shell conduction with layers set up in the same way. I am well aware that the shell conduction method is two dimensional, but my results from OpenFOAM are so far off, that this cannot be the only explanation.
I have also tried “lookup” as kappaMethod, however, here I get the following OpenFOAM fatal error;

[1] --> FOAM FATAL ERROR: (openfoam-2506)
[1] Did not find field 'kappa' on mesh region0 patch walls
Please set 'kappa' to the name of a volScalar or volSymmTensor field, or use another method
(directionalSolidThermo fluidThermo function lookup solidThermo)
[1]
[1]
[1] From virtual Foam::tmp<Foam::Field<double> > Foam::temperatureCoupledBase::kappa(const scalarField&) const
[1] in file derivedFvPatchFields/temperatureCoupledBase/temperatureCoupledBase.C at line 383.
[1]
FOAM parallel run exiting

I have a kappa-file in 0/ with the following settings:

/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: v2412 |
| \\ / A nd | Website: www.openfoam.com |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/

FoamFile
{
version 2.0;
format ascii;
class volScalarField;
location "0";
object kappa;
}

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

dimensions [1 1 -3 -1 0 0 0]; // W/m/K

internalField uniform 1;

boundaryField
{
mass-flow-inlet-1
{
type fixedValue;
value uniform 1;
}

walls
{
type fixedValue;
value uniform 1.05;
}

outlet
{
type fixedValue;
value uniform 1;
}
}

Does anyone know what I’m doing wrong here, I can’t seem to find good documentation to help me, especially with the problem using lookup.

Thanks in advance.

Best regards, Zacho