[Utkan]

I am a newbie in OpenFOAM and I desperately need any type of help or guidance in my situation. I want to simulate the forced cooling of a radiator with air by a fan. I will simplify the case and apply a flowRateInletVelocity BC on the air side. However, the amount of fin/capillary details of this radiator makes it impossible to mesh with a commercial meshing tool. Hence, I'm going for the porosity approach. There is an example case under chtMultiregionFoam matching with my approach called the heatExchanger, where the heat transfer between two fluids; air and water. Water is considered a porous fluid of which the porous parameters are given in the fvOptions.

the fvOptions for both regions is as follows;

For air region;

airToporous
{
    type            constantHeatTransfer;

    interpolationMethod cellVolumeWeight;
    nbrRegionName   porous;
    master          false;

    nbrModel        porousToair;
    fields          (h);
    semiImplicit    no;
}

porosityBlockage
{
    type            interRegionExplicitPorositySource;

    interRegionExplicitPorositySourceCoeffs
    {
        interpolationMethod cellVolumeWeight;
        nbrRegionName   porous;

        type            DarcyForchheimer;

        d   (-1000 -1000 1e4);
        f   (0 0 0);

        coordinateSystem
        {
            type    cartesian;
            origin  (0 0 0);
            coordinateRotation
            {
                type    axesRotation;
                e1      (0 1 0);
                e2      (0 0 1);
            }
        }
    }
}

and fvOptions for the porous water region;

porousToair
{
    type            constantHeatTransfer;

    interpolationMethod cellVolumeWeight;
    nbrRegionName   air;
    master          true;

    nbrModel        airToporous;
    fields          (e);
    semiImplicit    no;
}

My problem is when I solve the case with chtMultiRegionFoam I get an error of;

Solving for fluid region air
--> FOAM Warning : 
    From function virtual void Foam::fv::option::checkApplied() const
    in file cfdTools/general/fvOptions/fvOption.C at line 125
    Source airToporous defined for field h but never used
--> FOAM Warning : 
    From function virtual void Foam::fv::option::checkApplied() const
    in file cfdTools/general/fvOptions/fvOption.C at line 125
    Source airToporous defined for field h but never used
DILUPBiCGStab:  Solving for Ux, Initial residual = 0.482431, Final residual = 0.00171369, No Iterations 1
DILUPBiCGStab:  Solving for Uy, Initial residual = 0.398939, Final residual = 0.00157473, No Iterations 1
DILUPBiCGStab:  Solving for Uz, Initial residual = 0.487783, Final residual = 0.00156028, No Iterations 1
--> FOAM Warning : 
    From function virtual void Foam::fv::option::checkApplied() const
    in file cfdTools/general/fvOptions/fvOption.C at line 125
    Source airToporous defined for field h but never used
--> FOAM Warning : 
    From function virtual void Foam::fv::option::checkApplied() const
    in file cfdTools/general/fvOptions/fvOption.C at line 125
    Source airToporous defined for field h but never used
DILUPBiCGStab:  Solving for e, Initial residual = 0.0231261, Final residual = 0.00011219, No Iterations 1
Min/max T:292.885 298
--> FOAM Warning : 
    From function virtual void Foam::fv::option::checkApplied() const
    in file cfdTools/general/fvOptions/fvOption.C at line 125
    Source airToporous defined for field h but never used
GAMG:  Solving for p_rgh, Initial residual = 0.502419, Final residual = 0.00477312, No Iterations 11
time step continuity errors : sum local = 0.00614597, global = -0.00172087, cumulative = -0.00172087
--> FOAM Warning : 
    From function virtual void Foam::fv::option::checkApplied() const
    in file cfdTools/general/fvOptions/fvOption.C at line 125
    Source airToporous defined for field h but never used
--> FOAM Warning : 
    From function virtual void Foam::fv::option::checkApplied() const
    in file cfdTools/general/fvOptions/fvOption.C at line 125
    Source airToporous defined for field h but never used
DILUPBiCGStab:  Solving for epsilon, Initial residual = 0.0638423, Final residual = 0.00040656, No Iterations 1
--> FOAM Warning : 
    From function virtual void Foam::fv::option::checkApplied() const
    in file cfdTools/general/fvOptions/fvOption.C at line 125
    Source airToporous defined for field h but never used
--> FOAM Warning : 
    From function virtual void Foam::fv::option::checkApplied() const
    in file cfdTools/general/fvOptions/fvOption.C at line 125
    Source airToporous defined for field h but never used
DILUPBiCGStab:  Solving for k, Initial residual = 0.611649, Final residual = 0.0056648, No Iterations 1

My assumption is that I need to specify the touching surfaces of air and the porous region as "airToporous" and "porousToair" and couple them to be able to use the "compressible::turbulentTemperatureCoupledBaffleMi xed" BC for the T directories. I've tried using the topoSetDict to create external boundaries for both regions to couple them, to later splitMeshRegions and createBaffles. But when I try to create any type of geometry using the topoSet function, I always end up getting 0 sized entities.

Reading topoSetDict

Time = 0
    mesh not changed.
Created cellSet airToporousCells
    Applying source boxToCell
    Adding cells with center within boxes 1((2 3 6.001) (24 17 6.002))
    cellSet airToporousCells now size 0

I don't know if I'm going in the right direction or not. ANY type of guidance would make me very happy. Even understanding the error in the solver and guiding me to a proper tutorial would make me very happy. Thank you in advance.