I have problems to understand if my results do make sense or not.
I have the geometry of a square, x=6, y=3, z=100 meters. The upper surface works as a source of heat, where all the time 303°K are streaming in. All the other sides are zero gradient, and the internal temperature is 293°K. The thermophysical parameters are similar to sand. (kappa =2, Cv=1000, rho=2200)
I run with chtMultiRegionFoam and OF8.
Inside the square I have 2 tubes filles with water, but for this simulation the temperatures are as well 293°K and the velocity is 0.
My expectacion is, that after a certain time everything should be heated up the surface temperature, since there is no other source of heat than the surface.
If I select steadyState exactly this happens, in the end everything is heated up to 303°K.
If I repeat the same calculation with Euler, it takes around 5 days, while the square is constantly heating up from the upper surface, when the heating process seems to be stopping. Actually its not stopping completly, but the diference for the same cell between day 5 and day 10 is like 0.000001°K, so almost nothing.
But the square is far away from having the upper surface temperature, in the lower regions it is still at 293°K, the starting value.
So I expected, that steadyState and Euler produce in the end the same result, is this not true?
Because if it is true, than I dont know why my calculation is with Euler not coming to that point. There must be some problem in my settings?
Do you have any idea if
1. Euler and steadyState come to the same results or not?
2. If yes, what could be the problem in my settings?
I expect problems in the system-files, so I show you my fvSolution, fvSchemes and controlDict.
fvSolution for region soil:
Code:
/*--------------------------------*- C++ -*----------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Website: https://openfoam.org
\\ / A nd | Version: 6
\\/ M anipulation |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
object fvSolution;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
solvers
{
e
{
solver PCG;
preconditioner DIC;
tolerance 1e-06;
relTol 0.1;
}
eFinal
{
$e;
tolerance 1e-06;
relTol 0;
}
}
PIMPLE
{
nNonOrthogonalCorrectors 0;
outerCorrectorResidualControl
{
e
{
tolerance 1e-5;
relTol 0;
}
}
}
relaxationFactors
{
equations
{
e 0.5;
eFinal 1;
}
}
// ************************************************************************* //
fvSchemes for region soil:
Code:
/*--------------------------------*- C++ -*----------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Website: https://openfoam.org
\\ / A nd | Version: 6
\\/ M anipulation |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
object fvSchemes;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
ddtSchemes
{
default Euler; // Euler steadyState
}
gradSchemes
{
default Gauss linear;
}
divSchemes
{
default none;
}
laplacianSchemes
{
default none;
laplacian(alpha,e) Gauss linear uncorrected;
}
interpolationSchemes
{
default linear;
}
snGradSchemes
{
default uncorrected;
}
// ************************************************************************* //
controlDict
Code:
/*--------------------------------*- C++ -*----------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Website: https://openfoam.org
\\ / A nd | Version: 8
\\/ M anipulation |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
location "system";
object controlDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
application chtMultiRegionFoam;
startFrom latestTime;
startTime 0;
stopAt endTime;
endTime 864000;
deltaT 1;
writeControl adjustableRunTime;
writeInterval 3600;
purgeWrite 0;
writeFormat ascii;
writePrecision 22;
writeCompression off;
timeFormat general;
timePrecision 6;
runTimeModifiable true;
adjustTimeStep true;
maxCo 1;
functions
{
#includeFunc "residuals_fluid"
avT_fluid_outlet
{
type surfaceFieldValue;
libs ("libfieldFunctionObjects.so");
log yes;
writeControl runTime;
writeInterval 3600;
writeFields false;
surfaceFormat none;
regionType patch;
name outlet;
region fluid;
operation areaAverage;
fields
(
T
);
}
yPlus_fluid
{
type yPlus;
libs ("libfieldFunctionObjects.so");
executeControl writeTime;
writeControl writeTime;
region fluid;
}
wallHeatFlux_fluid
{
type wallHeatFlux;
libs ("libfieldFunctionObjects.so");
executeControl writeTime;
writeControl writeTime;
region fluid;
}
wallShearStress_fluid
{
type wallShearStress;
libs ("libfieldFunctionObjects.so");
executeControl writeTime;
writeControl writeTime;
region fluid;
}
turbulenceIntensity_fluid
{
type turbulenceIntensity;
libs ("libfieldFunctionObjects.so");
executeControl writeTime;
writeControl writeTime;
region fluid;
}
}
libs (
"libOpenFOAM.so"
"libsimpleSwakFunctionObjects.so"
"libswakFunctionObjects.so"
"libgroovyBC.so"
);
// ************************************************************************* //
general fvSolution
Code:
/*--------------------------------*- C++ -*----------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Website: https://openfoam.org
\\ / A nd | Version: 6
\\/ M anipulation |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
object fvSolution;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
PIMPLE
{
// momentumPredictor yes;
nOuterCorrectors 50;
nCorrectors 2;
nNonOrthogonalCorrectors 0;
consistent true;
pRefCell 0;
pRefValue 0;
}
// ************************************************************************* //
