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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:

HTML Code:

type           compressible::turbulentHeatFluxTemperature;

heatSource     flux;

q                  uniform -218;

kappa            basicThermo;

value            uniform 305;

but I have this error:

HTML Code:

--> 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

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.

Greetings to all!

@Luca: Have you tried using:

Code:

kappa fluidThermo;

Best regards,
Bruno

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

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

Code:

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 :mad::mad:

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

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 :p

Thanks

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 :D

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

Code:

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:

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.
So I switched to the incompressible BC "turbulentHeatFluxTemperature":

Code:

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

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!