[lfrigeri3]

Hi,
I'm me again and I've another problem in my famous room.

The room has inlet, outlet and a window. The other walls and floor are insulated.

The window has a internal surface temperature of 18°C and I know the heat flux (-218W/m^2) , yes out is cold. I don't know conductivity and thickness of the window, so I can't calculate the gradient.

In my 0/T , how can I set the BC for the window? Is it enough if I just set 18°C as fixedValue?

I tried also with:

type           compressible::turbulentHeatFluxTemperature;
heatSource     flux;
q                  uniform -218;
kappa            basicThermo;
value            uniform 305;

but I have this error:

--> FOAM FATAL IO ERROR:
basicThermo is not in enumeration:
4
(
directionalSolidThermo
fluidThermo
lookup
solidThermo
)

How can I solve this error?
What solution is better? How can I solve this error?

Thanks

[lfrigeri3]

No answers?

[ahmmedshakil]

You can add as the heat loss from the surface as Qloss, just add the term in the governing equation. I guess this is the easiest way.

[wyldckat]

Greetings to all!

@Luca: Have you tried using:

kappa  fluidThermo;

Best regards,
Bruno

[lfrigeri3]

Yes but it doesnt work i'll send the error later

[lfrigeri3]

Ok i tried to solve some errors, but every time it give me another error ... and now i'm stuck.

Time = 1

DILUPBiCG:  Solving for Ux, Initial residual = 0.000315202, Final residual = 1.81125e-06, No Iterations 2
DILUPBiCG:  Solving for Uy, Initial residual = 0.000383197, Final residual = 2.00909e-06, No Iterations 2
DILUPBiCG:  Solving for Uz, Initial residual = 0.000448386, Final residual = 3.1772e-06, No Iterations 2


--> FOAM FATAL ERROR:

    lookup of turbulenceModel from objectRegistry region0 successful
    but it is not a turbulenceModel, it is a kOmegaSST

    From function objectRegistry::lookupObject<Type>(const word&) const
    in file /home/opencfd/OpenFOAM/OpenFOAM-2.2.2/src/OpenFOAM/lnInclude/objectRegistryTemplates.C at line 147.

FOAM aborting

#0  Foam::error::printStack(Foam::Ostream&) at ??:?
#1  Foam::error::abort() at ??:?
#2  Foam::compressible::turbulenceModel const& Foam::objectRegistry::lookupObject<Foam::compressible::turbulenceModel>(Foam::word const&) const at ??:?
#3  Foam::temperatureCoupledBase::kappa(Foam::Field<double> const&) const at ??:?
#4  Foam::compressible::turbulentHeatFluxTemperatureFvPatchScalarField::updateCoeffs() at ??:?
#5  Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh>::GeometricBoundaryField::updateCoeffs() at ??:?
#6  Foam::fvMatrix<double>::fvMatrix(Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&, Foam::dimensionSet const&) at ??:?
#7
 at ??:?
#8
 at ??:?
#9  __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
#10
 at ??:?
Aborted (core dumped)

I think I have to change something in temperature boundary condition...but i don't know how

[wyldckat]

Hi Luca,

From the description you've made on the first post, could you please create a modified case using the tutorial "heatTransfer/buoyantSimpleFoam/hotRoom", using the same settings you're using and share it with us?
I ask this because this way we (anyone reading this thread) would be able to more easily reproduce the same problem and try to find a solution.

Otherwise, it will take considerable time for anyone else to set-up the same case and attempt at reproducing the same problem.

Best regards,
Bruno

[lfrigeri3]

This is the test-case, with a very very simple mesh

I tried to manipulate this case by myself..I'm a newbie so sure there will be stupid errors.. but everyone learn from their mistakes

Thanks

[wyldckat]

Hi Luca,

Attached is a working case, albeit not realistic at all. I simply took a hammer, a few nails and made it work without wobling

This is the whole list of changes made... but very cryptic looking, aren't they:

diff -Nur Prova/0/T.org Prova2/0/T.org
--- Prova/0/T.org    2014-02-16 21:33:08.000000000 +0000
+++ Prova2/0/T.org    2014-02-22 16:28:44.768521049 +0000
@@ -22,11 +22,10 @@
 {
     floor
     {
-        type           compressible::turbulentHeatFluxTemperature;
+        type            turbulentHeatFluxTemperature;
         heatSource      flux;
         q               uniform 10;
-        kappa           fluidThermo;
-    kappaName    fluidThermo;
+        alphaEff        alphat;
         value           uniform 305;
     }
     ceiling
diff -Nur Prova/constant/transportProperties Prova2/constant/transportProperties
--- Prova/constant/transportProperties    2014-02-16 20:55:43.000000000 +0000
+++ Prova2/constant/transportProperties    2014-02-22 16:30:03.320518263 +0000
@@ -21,6 +21,7 @@
 TRef        TRef [0 0 0 1 0 0 0] 298;
 Pr              Pr [0 0 0 0 0 0 0] 0.73;
 Prt             Prt [0 0 0 0 0 0 0] 0.85;
+Cp0             1.3;
 
 CrossPowerLawCoeffs
 {
diff -Nur Prova/system/fvSchemes Prova2/system/fvSchemes
--- Prova/system/fvSchemes    2014-02-16 21:26:43.000000000 +0000
+++ Prova2/system/fvSchemes    2014-02-22 16:38:19.752500655 +0000
@@ -16,42 +16,40 @@
 
 ddtSchemes
 {
-    default Euler;
+    default         steadyState;
 }
 
 gradSchemes
 {
     default         Gauss linear;
-    grad(p)         Gauss linear;
-    grad(U)         Gauss linear;
 }
 
 divSchemes
 {
-    default          none;
-    div(phi,U)       Gauss  linearUpwind Gauss;
-    div(phi,k)       Gauss  upwind;
-    div(phi,epsilon) Gauss  upwind;
-    div(phi,omega)   Gauss  upwind;
-    div((muEff*dev(T(grad(U))))) Gauss linear;
+    default         none;
+    div(phi,U)      bounded Gauss upwind;
+    div(phi,T)      bounded Gauss upwind;
+    div(phi,k)      bounded Gauss upwind;
+    div(phi,epsilon) bounded Gauss upwind;
     div((nuEff*dev(T(grad(U))))) Gauss linear;
+    div(phi,omega) bounded Gauss linear;
 }
 
 laplacianSchemes
 {
-    default                     none;
-    laplacian(nuEff,U)             Gauss linear corrected;
-    laplacian((1|A(U)),p)        Gauss linear corrected;
-    laplacian(DkEff,k)             Gauss linear corrected;
-    laplacian(DomegaEff,omega)         Gauss linear corrected;
-    laplacian(DepsilonEff,epsilon)      Gauss linear corrected;
-    laplacian(1,p)                      Gauss linear corrected;
+    default         none;
+    laplacian(nuEff,U) Gauss linear corrected;
+    laplacian(Dp,p_rgh) Gauss linear corrected;
+    laplacian(alphaEff,T) Gauss linear corrected;
+    laplacian(DkEff,k) Gauss linear corrected;
+    laplacian(DepsilonEff,epsilon) Gauss linear corrected;
+    laplacian(DREff,R) Gauss linear corrected;
+    laplacian(DomegaEff,omega) Gauss linear corrected;
 }
 
 interpolationSchemes
 {
     default         linear;
-    interpolate(U)  linear;
 }
 
 snGradSchemes
@@ -62,7 +60,7 @@
 fluxRequired
 {
     default         no;
-    p;
+    p_rgh           ;
 }
 
 // ************************************************************************* //
diff -Nur Prova/system/fvSolution Prova2/system/fvSolution
--- Prova/system/fvSolution    2014-02-16 21:24:56.000000000 +0000
+++ Prova2/system/fvSolution    2014-02-22 16:36:54.124503691 +0000
@@ -24,58 +24,52 @@
 
 solvers
 {
-
-    p PCG
+    p_rgh
     {
-        maxIter          1000;
-        preconditioner   DIC;
-        tolerance        1e-06;
-        relTol           0;
-    };
+        solver          PCG;
+        preconditioner  DIC;
+        tolerance       1e-08;
+        relTol          0.01;
+    }
 
-    U PBiCG
-    {
-        preconditioner   DILU;
-        tolerance        1e-05;
-        relTol           0;
-    };
-    k PBiCG
-    {
-        preconditioner   DILU;
-        tolerance        1e-05;
-        relTol           0;
-    };
-    omega PBiCG
+    "(U|T|k|epsilon|R|omega)"
     {
-        preconditioner   DILU;
-        tolerance        1e-05;
-        relTol           0;
-    };
-    epsilon PBiCG
-    {
-        preconditioner   DILU;
-        tolerance        1e-05;
-        relTol           0;
-    };
-
+        solver          PBiCG;
+        preconditioner  DILU;
+        tolerance       1e-05;
+        relTol          0.1;
+    }
 }
 
 SIMPLE
 {
-    nNonOrthogonalCorrectors  2;
-pRefCell            0;
-    pRefValue           0;
+    nNonOrthogonalCorrectors 0;
+    pRefCell        0;
+    pRefValue       0;
 
+    residualControl
+    {
+        p_rgh           1e-2;
+        U               1e-4;
+        T               1e-2;
+
+        // possibly check turbulence fields
+        "(k|epsilon|omega)" 1e-3;
+    }
 }
 
 relaxationFactors
 {
-    p        0.3;
-    U        0.7;
-    k        0.7;
-    epsilon  0.7;
-    omega    0.7;
+    fields
+    {
+        p_rgh           0.7;
+    }
+    equations
+    {
+        U               0.3;
+        T               0.5;
+        "(k|epsilon|R)" 0.7;
+    }
 }
 
-
 // ************************************************************************* //

Essentially, what I've done was:

1. Looked into the source code for the boundary condition "compressible::turbulentHeatFluxTemperature". Guess what, this boundary condition cannot be used with the solver buoyantBoussinesqSimpleFoam, because it's an incompressible solver with the Boussinesq approximation for buoyancy.
2. So I switched to the incompressible BC "turbulentHeatFluxTemperature":
   

       floor
       {
           type            turbulentHeatFluxTemperature;
           heatSource      flux;
           q               uniform 10;
           alphaEff        alphat;
           value           uniform 305;
       }

3. Had to add the entry "Cp0" to the file "constant/transportProperties". The value I used is completely random. You'll have to define the correct one for your own case.
4. Configured the files "system/fvSchemes" and "system/fvSolution" based on the tutorial "heatTransfer/buoyantBoussinesqSimpleFoam/hotRoom/" and added in the entries that the solver complained about.

Note: The solver crashes after 400 and something iterations, because the temperature goes well beyond the 15 degree Celsius that the Boussinesq approximation allows for.

Best regards,
Bruno

[lfrigeri3]

Thanks a lot!!

Later I will try .. even if for my thesis I'm using another set of BC and, compared to the experimental result, it seems quite good.

Then in the conclusions I will talk about this (probably better) possibility!

Thanks again!