[Raza Javed]

Hello Everyone,


I am using chtMultiRegionSimpleFoam and my openfoam version is 4.1.


My geometry consists of one fluid region and some other solid regions. And there is a laminar flow in the fluid region.


But when I try to model turbulent flow, then I put k and epsilon into my boundary conditions. and then I change the turbulence properties from laminar to RAS.


But when I run the solver, it gives the following error:

--> FOAM FATAL IO ERROR: 
cannot find file

file: /home/openfoam/run/final_geometry_turbulent/0/fluid/alphat at line 0.

    From function regIOobject::readStream()
    in file db/regIOobject/regIOobjectRead.C at line 72.

I don't know why it needs alphat file, because what I read is that for turbulence modelling we need k, epsilon and nut additional file.



But I take this file from one tutorial case and put it into 0 directory. and also put it into system/changeDictionaryDict for boundary conditions.


My changeDictionaryDict is given below:

boundary
{
    inlet
    {
        type            patch;
    }
    outlet
    {
        type            patch;
    }
}

T
{
    internalField   uniform 300;

    boundaryField
    {
        inlet
        {
            type            fixedValue;
            value           $internalField;
            
        }

        outlet
        {
            type            zeroGradient;
            value           $internalField;

        }

        "fluid_to_box"
        {
            type            compressible::turbulentTemperatureCoupledBaffleMixed;
            Tnbr            T;
            kappaMethod     fluidThermo;
            value           uniform 300;
        }
    }
}

U
{
    internalField   uniform (0 0 0);

    boundaryField
    {
        inlet
        {
            type            fixedValue;
            value           uniform (0 0 -1e-4);
        }

        outlet
        {
            type            zeroGradient;
        }
        "fluid_to_box"
        {
            type            noSlip;
        }
    }
}
epsilon
{
    internalField   uniform 0.01;

    boundaryField
    {
        inlet
        {
            type            fixedValue;
            value           uniform 0.01;
        }

        outlet
        {
            type            inletOutlet;
            inletValue      uniform 0.01;
        }

        ".*"
        {
            type            epsilonWallFunction;
            value           uniform 0.01;
        }
    }
}

k
{
    internalField   uniform 0.1;

    boundaryField
    {
        inlet
        {
            type            inletOutlet;
            inletValue      uniform 0.1;
        }

        outlet
        {
            type            zeroGradient;
            value           uniform 0.1;
        }

        ".*"
        {
            type            kqRWallFunction;
            value           uniform 0.1;
        }
    }
}


p_rgh
{
    internalField   uniform 0;

    boundaryField
    {
        inlet
        {
            type            zeroGradient;
            value           uniform 0;
        }

        outlet
        {
            type            fixedValue;
            value           uniform 0;
        }

        ".*"
        {
            type            fixedFluxPressure;
            value           uniform 0;
        }
    }
}

p
{
    internalField   uniform 0;

    boundaryField
    {
        ".*"
        {
            type            calculated;
            value           uniform 0;
        }
    }
}

alphat
{
    internalField   uniform 0;

    boundaryField
    {
        inlet
        {
            type            calculated;
            value           uniform 0;
        }

        outlet
        {
            type            calculated;
            value           uniform 0;
        }

        "fluid_to_.*"
        {
            type            compressible::alphatWallFunction;
            value           uniform 0;
        }

        #includeEtc "caseDicts/setConstraintTypes"
    }
}

nut
{
    internalField   uniform 0;

    boundaryField
    {
        inlet
        {
            type            calculated;
            value           uniform 0;
        }

        outlet
        {
            type            calculated;
            value           uniform 0;
        }

        "fluid_to_.*"
        {
            type            nutkWallFunction;
            value           uniform 0;
        }

        #includeEtc "caseDicts/setConstraintTypes"
    }
}

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

but when I RUN it, it now gives the following error

--> FOAM FATAL ERROR: 
cannot be called for a calculatedFvPatchField
    on patch inlet of field U in file "/home/openfoam/run/final_geometry_turbulent/0/fluid/U"
    You are probably trying to solve for a field with a default boundary condition.

    From function Foam::tmp<Foam::Field<Type> > Foam::calculatedFvPatchField<Type>::gradientInternalCoeffs() const [with Type = Foam::Vector<double>]
    in file fields/fvPatchFields/basic/calculated/calculatedFvPatchField.C at line 187.

FOAM aborting

#0  Foam::error::printStack(Foam::Ostream&)*** Reading solid mesh thermophysical properties for region hot2

    Adding to thermos

Selecting thermodynamics package 
{
    type            heSolidThermo;
    mixture         pureMixture;
    transport       constIso;
    thermo          hConst;
    equationOfState rhoConst;
    specie          specie;
    energy          sensibleEnthalpy;
}

    Adding to radiations

Radiation model not active: radiationProperties not found
Selecting radiationModel none
    Adding fvOptions

Creating finite volume options from "constant/fvOptions"

Selecting finite volume options model type scalarSemiImplicitSource
    Source: heatSource
    - selecting all cells
    - selected 939 cell(s) with volume 1.4e-06
*** Reading solid mesh thermophysical properties for region hot3

    Adding to thermos

Selecting thermodynamics package 
{
    type            heSolidThermo;
    mixture         pureMixture;
    transport       constIso;
    thermo          hConst;
    equationOfState rhoConst;
    specie          specie;
    energy          sensibleEnthalpy;
}

    Adding to radiations

Radiation model not active: radiationProperties not found
Selecting radiationModel none
    Adding fvOptions

Creating finite volume options from "constant/fvOptions"

Selecting finite volume options model type scalarSemiImplicitSource
    Source: heatSource
    - selecting all cells
    - selected 921 cell(s) with volume 1.4e-06
Time = 0.01


Solving for fluid region fluid
 at ??:?
#1  Foam::error::abort() at ??:?
#2  Foam::calculatedFvPatchField<Foam::Vector<double> >::gradientInternalCoeffs() const at ??:?
#3  Foam::fv::gaussLaplacianScheme<Foam::Vector<double>, Foam::SymmTensor<double> >::fvmLaplacianUncorrected(Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh> const&, Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh> const&, Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh> const&) at ??:?
#4  Foam::fv::gaussLaplacianScheme<Foam::Vector<double>, double>::fvmLaplacian(Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh> const&, Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh> const&) at ??:?
#5  Foam::fv::laplacianScheme<Foam::Vector<double>, double>::fvmLaplacian(Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh> const&) at ??:?
#6  Foam::tmp<Foam::fvMatrix<Foam::Vector<double> > > Foam::fvm::laplacian<Foam::Vector<double>, double>(Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh> const&, Foam::word const&) at ??:?
#7  Foam::tmp<Foam::fvMatrix<Foam::Vector<double> > > Foam::fvm::laplacian<Foam::Vector<double>, double>(Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh> const&) at ??:?
#8  Foam::tmp<Foam::fvMatrix<Foam::Vector<double> > > Foam::fvm::laplacian<Foam::Vector<double>, double>(Foam::tmp<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> > const&, Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh> const&) at ??:?
#9  Foam::linearViscousStress<Foam::RASModel<Foam::EddyDiffusivity<Foam::ThermalDiffusivity<Foam::CompressibleTurbulenceModel<Foam::fluidThermo> > > > >::divDevRhoReff(Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh>&) const at ??:?
#10  ? at ??:?
#11  __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
#12  ? at ??:?
Aborted (core dumped)

I don't know what is the problem with these alphat and nut entries, If i just remove these two entries from the above file. and make the flow laminar, and not even touching the other things, the solver will run smoothly again.


Can someone please help me in understanding the problem here.


I shall be very thankful if someone can help.


Thank you

[sufjanst]

Yout nut and alphat look okay. What I noticed is, that a lot of entries for internalField are set to 0. Including pressure, nut and alphat.

Maybe your initial field is not a good start. Try using realistic initial values or patch the field with setFields.

[Raza Javed]

Thank you so much for your reply.


I have one more question:


I try to explain my problem.


I am using chtMultiRegionSimpleFoam. My Openfoam version is 4.1.


I made my geometry in salome, and then imported to OpenFoam as a UNV file.


I have multiple regions in my geometry, (heaters, box, and fluid).


Both heaters and fluid are in the box.


Now, I want to simulate the turbulent flow in the fluid region. I am using kEpsilon Model.


I am trying to model incompressible flow.


I put boundary conditions for alphat, k, epsilon, nut etc in system/fluid/changeDictionaryDict file. This file is shown below:

boundary
{
    inlet
    {
        type            patch;
    }
    outlet
    {
        type            patch;
    }
}

T
{
    internalField   uniform 300;

    boundaryField
    {
        inlet
        {
            type            fixedValue;
            value           $internalField;
            
        }

        outlet
        {
            type            zeroGradient;
            value           $internalField;

        }

        "fluid_to_box"
        {
            type            zeroGradient;
        }
    }
}

U
{
    internalField   uniform (0 0 0);

    boundaryField
    {
        inlet
        {
            type            fixedValue;
            value           uniform (0 0 -1.33);
        }

        outlet
        {
            type            zeroGradient;
        }
        "fluid_to_box"
        {
            type            noSlip;
        }
    }
}

epsilon
{
    internalField   uniform 0.01;

    boundaryField
    {
        inlet
        {
            type            fixedValue;
            value           uniform 0.01;
        }

        outlet
        {
            type            zeroGradient;
            //value           uniform 0;
        }

        ".*"
        {
            type            epsilonWallFunction;
            value           uniform 0.01;
        }
    }
}

k
{
    internalField   uniform 0.1;

    boundaryField
    {
        inlet
        {
            type            fixedValue;
            value           uniform 0.1;
        }

        outlet
        {
            type            zeroGradient;
            //value           uniform 0;
        }

        "fluid_to_box"
        {
            type            kqRWallFunction;
            value           uniform 0.1;
        }
    }
}


p_rgh
{
    internalField   uniform 0;

    boundaryField
    {
        inlet
        {
            type            zeroGradient;
            value           uniform 0;
        }

        outlet
        {
            type            fixedValue;
            value           uniform 0;
        }

        ".*"
        {
            type            fixedFluxPressure;
            value           uniform 0;
        }
    }
}

p
{
    internalField   uniform 0;

    boundaryField
    {
        ".*"
        {
            type            calculated;
            value           uniform 0;
        }
    }
}

alphat
{
    internalField   uniform 0;

    boundaryField
    {
        inlet
        {
            type            calculated;//fixedValue;
            value           uniform 0;
        }

        outlet
        {
            type            calculated;
            value           uniform 0;
        }

        "fluid_to_box"
        {
            type            alphatJayatillekeWallFunction;
            value           uniform 0;
        }

    }
}

nut
{
    internalField   uniform 0;

    boundaryField
    {
        inlet
        {
            type            calculated;
            value           uniform 0;
        }

        outlet
        {
            type            calculated;
            value           uniform 0;
        }

        "fluid_to_box"
        {
            type            nutkWallFunction;
            value           uniform 0;
        }
    }
}

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

The error I posted before, I started getting when I shifted from laminar to Turbulent.


Now, I have the following doubts:


1. How and where actually we define that out flow would be incompressible?
2. As you can see in the file above, in the alphat portion, for the boundary fluid_to_box, I have put the wall function. before it was compressible written before the wall function, but I removed it because I am trying to simulate incompressible. But it gave error that:

--> FOAM FATAL IO ERROR: 
Unknown patchField type alphatJayatillekeWallFunction for patch type mappedWall

Valid patchField types are :

112
(
MarshakRadiation
MarshakRadiationFixedTemperature
advective
atmBoundaryLayerInletEpsilon
atmBoundaryLayerInletK
calculated
codedFixedValue
codedMixed
compressible::alphatJayatillekeWallFunction
compressible::alphatWallFunction
compressible::thermalBaffle1D<hConstSolidThermoPhysics>
compressible::thermalBaffle1D<hPowerSolidThermoPhysics>
compressible::turbulentHeatFluxTemperature
compressible::turbulentTemperatureCoupledBaffleMixed
compressible::turbulentTemperatureRadCoupledMixed
convectiveHeatTransfer
cyclic
cyclicACMI
cyclicAMI
cyclicSlip
directionMixed
empty
energyJump
energyJumpAMI
epsilonLowReWallFunction
epsilonWallFunction
externalCoupled
externalCoupledTemperature
externalWallHeatFluxTemperature
extrapolatedCalculated
fWallFunction
fan
fanPressure
fixedEnergy
fixedFluxExtrapolatedPressure
fixedFluxPressure
fixedGradient
fixedInternalValue
fixedJump
fixedJumpAMI
fixedMean
fixedPressureCompressibleDensity
fixedProfile
fixedUnburntEnthalpy
fixedValue
freestream
freestreamPressure
gradientEnergy
gradientUnburntEnthalpy
greyDiffusiveRadiation
greyDiffusiveRadiationViewFactor
inletOutlet
inletOutletTotalTemperature
kLowReWallFunction
kqRWallFunction
mapped
mappedField
mappedFixedInternalValue
mappedFixedPushedInternalValue
mixed
mixedEnergy
mixedUnburntEnthalpy
nonuniformTransformCyclic
nutLowReWallFunction
nutTabulatedWallFunction
nutURoughWallFunction
nutUSpaldingWallFunction
nutUWallFunction
nutkAtmRoughWallFunction
nutkRoughWallFunction
nutkWallFunction
omegaWallFunction
outletInlet
outletMappedUniformInlet
partialSlip
phaseHydrostaticPressure
plenumPressure
porousBafflePressure
prghPressure
prghTotalHydrostaticPressure
prghTotalPressure
processor
processorCyclic
rotatingTotalPressure
sliced
slip
symmetry
symmetryPlane
syringePressure
timeVaryingMappedFixedValue
totalFlowRateAdvectiveDiffusive
totalPressure
totalTemperature
turbulentInlet
turbulentIntensityKineticEnergyInlet
turbulentMixingLengthDissipationRateInlet
turbulentMixingLengthFrequencyInlet
uniformDensityHydrostaticPressure
uniformFixedGradient
uniformFixedValue
uniformInletOutlet
uniformJump
uniformJumpAMI
uniformTotalPressure
v2WallFunction
variableHeightFlowRate
wallHeatTransfer
waveSurfacePressure
waveTransmissive
wedge
wideBandDiffusiveRadiation
zeroGradient
)

3. In case of incompressible, which wall function shall I put here on the boundary fluid_to_box(mappedwall)?
4. Can I use other boundary conditions, other than wallfunctions on this boundary fluid_to_box(mappedwall)?


I tried to explain my problem, but if you need any other information, I would be happy to give.


Thank you