[farida]

Dear foamers,

I would like solve conjugate heat transfer problem with cyclic boundary condition.
I have developed conjugate heat transfer code and cyclic flow and heat transfer (in one region not in multiple region). I want to combine both codes, could you help me please.
Both codes are in the following attachments.

I can't attached my file because it exceeds the limit, How can I upload?

Thank you very much,
Best regards,
Farida

[farida]

Dear Tushar,

I would like to discuss with you about conjugate heat transfer problem with periodic flow and heat transfer boundary condition in openfoam.

I have modified code for conjugate heat transfer for incompressible flow and my problem now I have to apply periodic BC in conjugate heat transfer code. I have modified code for periodic flow and heat transfer in a pipe not include conjugate heat transfer (in openfoam I modified solver incompressible / channelFoam). I want to combine both code (CHT + periodic BC in a pipe) and I have a lot of difficulty.

Do you have any suggestion?

Best regards,
Farida

[Tushar@cfd]

Originally Posted by farida

Dear Tushar,

I would like to discuss with you about conjugate heat transfer problem with periodic flow and heat transfer boundary condition in openfoam.

I have modified code for conjugate heat transfer for incompressible flow and my problem now I have to apply periodic BC in conjugate heat transfer code. I have modified code for periodic flow and heat transfer in a pipe not include conjugate heat transfer (in openfoam I modified solver incompressible / channelFoam). I want to combine both code (CHT + periodic BC in a pipe) and I have a lot of difficulty.

Do you have any suggestion?

Best regards,
Farida

Try "groovyBC" for periodic BC.

-
Best Luck!

[wyldckat]

Greetings to all!

@Farida: I hope you don't mind, I've merged your posts into a single thread, so that this can be discussed in a single thread of discussion...
In addition, I hope you don't mind I quote the private message you sent me, because it has relevant information for this line of discussion:

Originally Posted by farida

Dear Bruno,

I would like to calculate Nusselt number in conjugate heat transfer. Actually I already have the code in following and the problem is I don't know how to write in conjugate heat transfer for incompressible flow?
If you have time please help me.

Thank you
Best regards
Farida

#include "fvCFD.H"
// modified from  wallHeatFlux
#include "singlePhaseTransportModel.H"
#include "turbulenceModel.H"
#include "wallFvPatch.H"

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

int main(int argc, char *argv[])
{
    timeSelector::addOptions();
    #include "setRootCase.H"
#   include "createTime.H"
    instantList timeDirs = timeSelector::select0(runTime, args);
#   include "createMesh.H"

    forAll(timeDirs, timeI)
    {
        runTime.setTime(timeDirs[timeI], timeI);
        Info<< "Time = " << runTime.timeName() << endl;
        mesh.readUpdate();

#       include "createFields.H"
#       include "readTransportProperties.H"

        // calculate effective diffusivity based on turbulent viscocity
        kappaEff=turbulence->nu()/Pr+turbulence->nut()/Prt;

        gradT=fvc::snGrad(T);

        surfaceScalarField heatFlux =fvc::interpolate(kappaEff*Cp0*rho0)*gradT;

        const surfaceScalarField::GeometricBoundaryField& patchGradT =
                 gradT.boundaryField();
          
        const surfaceScalarField::GeometricBoundaryField& patchHeatFlux =
                 heatFlux.boundaryField();
//
        Info<< "\nWall heat fluxes " << endl;
        forAll(patchHeatFlux, patchi)
        {
           if (typeid(mesh.boundary()[patchi]) == typeid(wallFvPatch))
            {
                Info<< mesh.boundary()[patchi].name()
                    << ": Total "
                    << sum
                       (
                           mesh.magSf().boundaryField()[patchi]
                          *patchHeatFlux[patchi]
                       )
                    << " [W] over "
                    << sum
                       (
                           mesh.magSf().boundaryField()[patchi]
                       )
                    << " [m2] ("
                    << sum
                       (
                           mesh.magSf().boundaryField()[patchi]
                          *patchHeatFlux[patchi]
                       )/
                       sum 
                       (
                           mesh.magSf().boundaryField()[patchi]
                       )
                    << " [W/m2])"
                    << endl;
            }
      }
      Info<< endl;

      
      volScalarField wallHeatFlux
        (
            IOobject
            (
                "wallHeatFlux",
                runTime.timeName(),
                mesh
            ),
            mesh,
            dimensionedScalar("wallHeatFlux", heatFlux.dimensions(), 0.0)
        );

      volScalarField wallGradT
        (
            IOobject
            (
                "wallGradT",
                runTime.timeName(),
                mesh
            ),
            mesh,
            dimensionedScalar("wallGradT", gradT.dimensions(), 0.0)
        );
   
      forAll(wallHeatFlux.boundaryField(), patchi)
      {
         wallHeatFlux.boundaryField()[patchi] = patchHeatFlux[patchi];
      }

      forAll(wallGradT.boundaryField(), patchi)
      {
         wallGradT.boundaryField()[patchi] = patchGradT[patchi];
      }


      wallGradT.write();
      gradT.write();
      wallHeatFlux.write();
      kappaEff.write();

    volScalarField NusseltNumber
    (
        IOobject
        (
            "NusseltNumber",
            runTime.timeName(),
            mesh
        ),
        mesh,
        dimensionedScalar("NusseltNumber", heatFlux.dimensions(), 0.0)
    );
    forAll(NusseltNumber.boundaryField(), patchi)
    {
        NusseltNumber.boundaryField()[patchi] = length*
        patchHeatFlux[patchi]/((T_hot-T_initial)*k);
    }
    NusseltNumber.write();

    }

    Info<< "End" << endl;

    return 0;
}

As for the very first post on this thread, instructions on how to proceed to provide information in order to get help is indicated here: http://www.cfd-online.com/Forums/ope...-get-help.html - there it's stated this:

Originally Posted by linnemann

cfd-online does not provide large filesize uploads so registering a dropbox/box account and use a public link to the picture/file makes it a lot easier to share files/pics or the full case.

Now, as for your questions, I have to say I'm also having difficulty trying to understand where exactly are you going with this line of thinking. The source code you sent me only takes care of calculating post-processing data, namely the Nusselt number, the wall heat flux and wall GradT. It does not solve the flow itself... oh, wait, I re-read the PM you sent me and that's essentially what you asked about.

If I'm not mistaken, the solver chtMultiRegionFoam can be used with a single fluid region. You'll still need to set-up the case as if it was a multi-region case, but with only one region.
My advice is:

1. To take a step back from what you're trying to achieve and first reconfigure the tutorial case provided here: http://openfoamwiki.net/index.php/Ge..._-_planeWall2D - so that it only has one region and is similar to the test case you're trying to perform.
2. As Tushar indicated, groovyBC might be able to useful for setting up the periodic condition you want to define. Nonetheless, if you can be more specific about the case you want to create, it might be easier to tell you which is the best approach to preparing your case.
3. Are you 100% certain you want to use a "conjugate heat transfer" solver? I ask this because (if I'm not mistaken) the "conjugate" part relates to how the heat is transferred between the fluid and the solid objects.

Best regards,
Bruno

[farida]

Dear Bruno,

Thank you for your reply, I already solve Nusselt number in conjugate heat transfer. My problem is how to apply periodic flow and heat transfer boundary condition n conjugate heat transfer case? and Tushar suggests me to use groovy boundary condition. Could you give me information about groovy boundary condition for periodic boundary condition?

Thank you for your help and I need that information about that.

Best regards,
farida

[wyldckat]

Hi Farida,

Sorry, only now was I able to come back to your question.
It's almost been 3 months since your last post... I don't know if you've solved your problem?

If not, can you please be more specific about what do you mean by "apply periodic flow"?

Best regards,
Bruno