[gmori]

Hi,all.
I am using chtMultiRegionSimpleFoam to analyze a fluid domain on top of a solid (ground). I am using the view Factor model to calculate the radiation in the fluid. The analysis conditions are shown below.
air/changeDictionaryDict:

boundary
{

".*"
{
inGroups 2(wall viewFactorWall);
}

}

U
{
internalField uniform (0 0 0);
boundaryField
{
".*"
{
type fixedValue;
value uniform (0 0 0);
}

inlet
{
type fixedValue;
value uniform (0 0 -0.6);
}

outlet
{
type zeroGradient;
}

}
}

T
{
internalField uniform 303;
boundaryField
{
".*"
{
type externalWallHeatFluxTemperature;
mode coefficient;
kappaMethod fluidThermo;
Ta constant 303.1;
h constant 3.6;
value uniform 303;
qr qr;
qrRelaxation 0.3;

}

"air_to_.*"
{
type compressible::turbulentTemperatureRadCoupledMixed;
Tnbr T;
kappaMethod fluidThermo;
qrNbr none;
qr qr;
value uniform 308;
}

inlet
{
type fixedValue;
value uniform 303.1;
}

outlet
{
type zeroGradient;
}
}
}

epsilon
{
internalField uniform 0.000278;
boundaryField
{
".*"
{
type epsilonWallFunction;
value $internalField;
}

inlet
{
type turbulentMixingLengthDissipationRateInlet;
mixingLength 0.028;
value $internalField;
}

outlet
{
type zeroGradient;
}

}
}

k
{
internalField uniform 0.00135;
boundaryField
{
".*"
{
type kqRWallFunction;
value $internalField;
}

inlet
{
type turbulentIntensityKineticEnergyInlet;
intensity 0.05; // 5%
value $internalField;
}

outlet
{
type zeroGradient;
}

}
}

p_rgh
{
internalField uniform 101325;
boundaryField
{
".*"
{
type fixedFluxPressure;
value $internalField;
}

inlet
{
type fixedFluxPressure;
value $internalField;
}

outlet
{
type fixedValue;
value uniform 101325;
}
}
}

p
{
internalField uniform 101325;
boundaryField
{
".*"
{
type calculated;
value $internalField;
}

inlet
{
type calculated;
value $internalField;
}

outlet
{
type calculated;
value $internalField;
}
}
}

qr
{
internalField uniform 0;
boundaryField
{
".*"
{
type greyDiffusiveRadiationViewFactor;
emissivityMode lookup;
qro uniform 0;
emissivity uniform 0.9;
value uniform 0;
}

"air_to_.*"
{
type greyDiffusiveRadiationViewFactor;
emissivityMode solidRadiation;
qro uniform 0;
value uniform 0;
}
}
}

G
{
internalField uniform 0;
boundaryField
{
".*"
{
type MarshakRadiation;
emissivityMode lookup;
emissivity uniform 1.0;
value uniform 0;
}

"air_to_.*"
{
type MarshakRadiation;
emissivityMode solidRadiation;
value uniform 0;
}
}
}

IDefault
{
internalField uniform 0;
boundaryField
{
".*"
{
type greyDiffusiveRadiation;
emissivityMode lookup;
emissivity uniform 1.0;
value uniform 0;
}

"air_to_.*"
{
type greyDiffusiveRadiation;
emissivityMode solidRadiation;
value uniform 0;
}
}
}

alphat
{
internalField uniform 0;
boundaryField
{
".*"
{
type compressible::alphatWallFunction;
Prt 0.85;
value $internalField;
}
inlet
{
type calculated;
value $internalField;
}
outlet
{
type calculated;
value $internalField;
}
}
}

nut
{
internalField uniform 0;
boundaryField
{
inlet
{
type calculated;
value $internalField;
}

outlet
{
type calculated;
value $internalField;
}

".*"
{
type nutkWallFunction;
value $internalField;
}
}
}

In this case, the error FOAM FATAL ERROR: Maximum number of iterations exceeded: 100 appears. I can see that there is a temperature anomaly
I can see that there is a temperature anomaly, but I can't find a solution. Can anyone help me?

Time = 268


Solving for fluid region air
DILUPBiCGStab: Solving for h, Initial residual = 0.04095449, Final residual = 0.0003494682, No Iterations 1
Min/max T:1.324802e-91 7.482229e+13

Solving for solid region soil
DICPCG: Solving for h, Initial residual = 0.03252537, Final residual = 3.142769e-05, No Iterations 1
Min/max T:300 7.886081e+11
ExecutionTime = 41.87 s ClockTime = 43 s

Time = 269


Solving for fluid region air
DILUPBiCGStab: Solving for h, Initial residual = 0.03618418, Final residual = 0.000299067, No Iterations 1
Min/max T:7.895323e-104 7.493647e+13

Solving for solid region soil
DICPCG: Solving for h, Initial residual = 0.02955888, Final residual = 2.546186e-05, No Iterations 1
Min/max T:300 8.278574e+11
ExecutionTime = 42.01 s ClockTime = 43 s

Time = 270


Solving for fluid region air
DILUPBiCGStab: Solving for h, Initial residual = 0.03243137, Final residual = 0.0002599866, No Iterations 1
Solving view factor equations for band : 0
Min/max T:4.705317e-116 7.504548e+13

Solving for solid region soil
DICPCG: Solving for h, Initial residual = 1, Final residual = 0.004184222, No Iterations 1


--> FOAM FATAL ERROR:
Maximum number of iterations exceeded: 100

From Foam::scalar Foam::species::thermo<Thermo, Type>::T(Foam::scalar, Foam::scalar, Foam::scalar, Foam::scalar (Foam::species::thermo<Thermo, Type>::*)(Foam::scalar, Foam::scalar) const, Foam::scalar (Foam::species::thermo<Thermo, Type>::*)(Foam::scalar, Foam::scalar) const, Foam::scalar (Foam::species::thermo<Thermo, Type>::*)(Foam::scalar) const) const [with Thermo = Foam::hConstThermo<Foam::rhoConst<Foam::specie> >; Type = Foam::sensibleEnthalpy; Foam::scalar = double; Foam::species::thermo<Thermo, Type> = Foam::species::thermo<Foam::hConstThermo<Foam::rho Const<Foam::specie> >, Foam::sensibleEnthalpy>]
in file /home/dexcs/OpenFOAM/OpenFOAM-v2006/src/thermophysicalModels/specie/lnInclude/thermoI.H at line 75.

FOAM aborting

#0 Foam::error:rintStack(Foam::Ostream&) at ??:?
#1 Foam::error::exitOrAbort(int, bool) at ??:?
#2 Foam::heSolidThermo<Foam::solidThermo, Foam:ureMixture<Foam::constIsoSolidTransport<Foa m::species::thermo<Foam::hConstThermo<Foam::rhoCon st<Foam::specie> >, Foam::sensibleEnthalpy> > > >::calculate() at ??:?
#3 Foam::heSolidThermo<Foam::solidThermo, Foam:ureMixture<Foam::constIsoSolidTransport<Foa m::species::thermo<Foam::hConstThermo<Foam::rhoCon st<Foam::specie> >, Foam::sensibleEnthalpy> > > >::correct() at ??:?
#4 ? in ~/OpenFOAM/mori-v2006/platforms/linux64GccDPInt32Opt/bin/chtMultiRegionSimpleFoam
#5 __libc_start_main in /lib/x86_64-linux-gnu/libc.so.6
#6 ? in ~/OpenFOAM/mori-v2006/platforms/linux64GccDPInt32Opt/bin/chtMultiRegionSimpleFoam

[peterhess]

Hello!
The conditions looks good.
The only change I could suggest is to change the velocity at the outlet from zeroGradient to inputOutput.

Is ist possible, that your mesh has wrong dimensions and is too big?
Run checkMesh please and post the results.

Try also emissivityMode lockup;
for G and IDefault in the region air_to_.*

Regards
Peter

[gmori]

Thank you for reply!


I'll change the outlet condition and the emissivitymode!

The results of checkMesh are attached below.

Create time

Create mesh for time = 0

Time = 0

Mesh stats
points: 813483
faces: 2387600
internal faces: 2335600
cells: 787200
faces per cell: 6
boundary patches: 16
point zones: 0
face zones: 0
cell zones: 2

Overall number of cells of each type:
hexahedra: 787200
prisms: 0
wedges: 0
pyramids: 0
tet wedges: 0
tetrahedra: 0
polyhedra: 0

Checking topology...
Boundary definition OK.
Cell to face addressing OK.
Point usage OK.
Upper triangular ordering OK.
Face vertices OK.
Number of regions: 1 (OK).

Checking patch topology for multiply connected surfaces...
Patch Faces Points Surface topology
soilmaxY 1440 1573 ok (non-closed singly connected)
soilminX 960 1053 ok (non-closed singly connected)
soilmaxX 960 1053 ok (non-closed singly connected)
soilminY 1440 1573 ok (non-closed singly connected)
soilminZ 9600 9801 ok (non-closed singly connected)
glassmaxY 4800 4961 ok (non-closed singly connected)
glassminX 3200 3321 ok (non-closed singly connected)
glassmaxX 3200 3321 ok (non-closed singly connected)
glassminY 4800 4961 ok (non-closed singly connected)
twincarbmaxY 3600 3751 ok (non-closed singly connected)
twincarbminX 2400 2511 ok (non-closed singly connected)
twincarbmaxX 2400 2511 ok (non-closed singly connected)
twincarbminY 3600 3751 ok (non-closed singly connected)
roof 9472 9703 ok (non-closed singly connected)
inlet 64 81 ok (non-closed singly connected)
outlet 64 81 ok (non-closed singly connected)

Checking faceZone topology for multiply connected surfaces...
No faceZones found.

Checking basic cellZone addressing...
CellZone Cells Points Volume BoundingBox
soil 115200 127413 2.88 (0 0 0) (6 4 0.12)
air 672000 695871 81.12 (0 0 0.12) (6 4 3.5)

Checking geometry...
Overall domain bounding box (0 0 0) (6 4 3.5)
Mesh has 3 geometric (non-empty/wedge) directions (1 1 1)
Mesh has 3 solution (non-empty) directions (1 1 1)
Boundary openness (-3.451071e-18 -3.69474e-17 2.42457e-17) OK.
Max cell openness = 1.845451e-16 OK.
Max aspect ratio = 5 OK.
Minimum face area = 0.0005. Maximum face area = 0.0025. Face area magnitudes OK.
Min volume = 2.5e-05. Max volume = 0.000125. Total volume = 84. Cell volumes OK.
Mesh non-orthogonality Max: 0 average: 0
Non-orthogonality check OK.
Face pyramids OK.
Max skewness = 1.421085e-13 OK.
Coupled point location match (average 0) OK.

Mesh OK.

End

[peterhess]

The mesh looks good.

Take a look here and see, if the radiation setups in your case are right:

Adding Radiations in chtMultiRegionSimpleFoam

Post the case if you want, so I could have a closer look to it.

openFoam version?

Regards

Peter

[gmori]

Thanks for the info!
I am using OpenFOAM ver2006.

I also changed the output condition to inletOutlet and the emissivityMode to lookup, but the error was not resolved.