[sergimart7]

Hello to all,

I have been 6 months trying to get an understanding on OpenFOAM so I can do my thesis with it, but I am having so much trouble, please I could appreciate some help!

The case I want so simulate is conjugated heat transfer between a resin sample and a furnace. Between those two there is air.

Initial conditions are T=300K for the sample (mostra) and the air (aire_forn), the walls of the furnace are constantly at 473K.
There is no inlet/outlet, so I assumed initial conditions of 0 m/s for U.
I want to study Temperature, air flows and heat flows.

I have used the chtMultiRegionFoam as example, and all init. conditions and boundaries are defined via changeDict. I do not know if they are 100% correct though..

Mesh is done via the new multi-grading of OF 2.4 and I'm running UBUNTU 14.4.
CheckMesh is OK.

The last problem is when I try to run chtMultiRegionFoam and I get the following error:

/*---------------------------------------------------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2.4.0                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
Build  : 2.4.0-f0842aea0e77
Exec   : chtMultiRegionFoam
Date   : Aug 11 2015
Time   : 16:33:30
Host   : "sergimart-N50Vn"
PID    : 13204
Case   : /home/sergimart/OpenFOAM/sergimart-2.3.0/run/PROJECT/provaeq
nProcs : 1
sigFpe : Enabling floating point exception trapping (FOAM_SIGFPE).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster
allowSystemOperations : Allowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Create fluid mesh for region aire_forn for time = 0

Create solid mesh for region mostra for time = 0

*** Reading fluid mesh thermophysical properties for region aire_forn

    Adding to thermoFluid

Selecting thermodynamics package 
{
    type            heRhoThermo;
    mixture         pureMixture;
    transport       const;
    thermo          hConst;
    equationOfState perfectGas;
    specie          specie;
    energy          sensibleEnthalpy;
}

--> FOAM Warning : 
    From function Field<Type>::Field(const word& keyword, const dictionary&, const label)
    in file /opt/openfoam240/src/OpenFOAM/lnInclude/Field.C at line 318
    Reading "/home/sergimart/OpenFOAM/sergimart-2.3.0/run/PROJECT/provaeq/0/aire_forn/T.boundaryField.maxY" from line 26 to line 27
    expected keyword 'uniform' or 'nonuniform', assuming deprecated Field format from Foam version 2.0.
--> FOAM Warning : 
    From function Field<Type>::Field(const word& keyword, const dictionary&, const label)
    in file /opt/openfoam240/src/OpenFOAM/lnInclude/Field.C at line 318
    Reading "/home/sergimart/OpenFOAM/sergimart-2.3.0/run/PROJECT/provaeq/0/aire_forn/T.boundaryField.minX" from line 31 to line 32
    expected keyword 'uniform' or 'nonuniform', assuming deprecated Field format from Foam version 2.0.
--> FOAM Warning : 
    From function Field<Type>::Field(const word& keyword, const dictionary&, const label)
    in file /opt/openfoam240/src/OpenFOAM/lnInclude/Field.C at line 318
    Reading "/home/sergimart/OpenFOAM/sergimart-2.3.0/run/PROJECT/provaeq/0/aire_forn/T.boundaryField.maxX" from line 36 to line 37
    expected keyword 'uniform' or 'nonuniform', assuming deprecated Field format from Foam version 2.0.
--> FOAM Warning : 
    From function Field<Type>::Field(const word& keyword, const dictionary&, const label)
    in file /opt/openfoam240/src/OpenFOAM/lnInclude/Field.C at line 318
    Reading "/home/sergimart/OpenFOAM/sergimart-2.3.0/run/PROJECT/provaeq/0/aire_forn/T.boundaryField.minY" from line 41 to line 42
    expected keyword 'uniform' or 'nonuniform', assuming deprecated Field format from Foam version 2.0.
--> FOAM Warning : 
    From function Field<Type>::Field(const word& keyword, const dictionary&, const label)
    in file /opt/openfoam240/src/OpenFOAM/lnInclude/Field.C at line 318
    Reading "/home/sergimart/OpenFOAM/sergimart-2.3.0/run/PROJECT/provaeq/0/aire_forn/T.boundaryField.minZ" from line 46 to line 47
    expected keyword 'uniform' or 'nonuniform', assuming deprecated Field format from Foam version 2.0.
--> FOAM Warning : 
    From function Field<Type>::Field(const word& keyword, const dictionary&, const label)
    in file /opt/openfoam240/src/OpenFOAM/lnInclude/Field.C at line 318
    Reading "/home/sergimart/OpenFOAM/sergimart-2.3.0/run/PROJECT/provaeq/0/aire_forn/T.boundaryField.maxZ" from line 51 to line 52
    expected keyword 'uniform' or 'nonuniform', assuming deprecated Field format from Foam version 2.0.
    Adding to rhoFluid

    Adding to UFluid

    Adding to phiFluid

    Adding to gFluid

    Adding to turbulence

Selecting turbulence model type laminar
    Adding to ghFluid

    Adding to ghfFluid

Selecting radiationModel none
    Adding to KFluid

    Adding to dpdtFluid

    Adding fvOptions

No finite volume options present

*** Reading solid mesh thermophysical properties for region mostra

    Adding to thermos

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

    Adding to radiations

Selecting radiationModel opaqueSolid
Selecting absorptionEmissionModel constantAbsorptionEmission
Selecting scatterModel none
Selecting sootModel none
    Adding fvOptions

No finite volume options present

Region: aire_forn Courant Number mean: 0 max: 0
Region: mostra Diffusion Number mean: 3.9771616e-09 max: 4.3402778e-09
deltaT = 0.01
Region: aire_forn Courant Number mean: 0 max: 0
Region: mostra Diffusion Number mean: 3.9771616e-07 max: 4.3402778e-07
deltaT = 0.01
Time = 0.01


Solving for fluid region aire_forn
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCG:  Solving for Ux, Initial residual = 1, Final residual = 1.42986e-10, No Iterations 3
DILUPBiCG:  Solving for Uy, Initial residual = 1, Final residual = 1.3385838e-10, No Iterations 3
DILUPBiCG:  Solving for Uz, Initial residual = 1, Final residual = 8.5829661e-11, No Iterations 3
DILUPBiCG:  Solving for h, Initial residual = 1, Final residual = 3.6004323e-10, No Iterations 3
Min/max T:300 473
#0  Foam::error::printStack(Foam::Ostream&) at ??:?
#1  Foam::sigFpe::sigHandler(int) at ??:?
#2  ? in "/opt/openfoam240/platforms/linuxGccDPOpt/lib/libOpenFOAM.so"
#3  Foam::divide(Foam::Field<double>&, Foam::UList<double> const&, Foam::UList<double> const&) at ??:?
#4  ? at ??:?
#5  ? at ??:?
#6  __libc_start_main in "/lib/i386-linux-gnu/libc.so.6"
#7  ? at ??:?
Floating point exception (core dumped)

Attached you will find all the directory case. (wetransfer because attached files on the forum did not work)

https://www.wetransfer.com/downloads...1144029/dbcaaa


Please, could you consider my case and give me advise?
All of you have been of great help when I was reading other posts! I would be very satisfied if I could learn more and become useful in the community to help others.

PD: Sorry for my bad English, you can also contact me at sergimart7@hotmail.com

Many thanks,

Sergi

[sergimart7]

I have realised that the crash is most probably a bad programming issue.
My main concern is the last lines of the crash:

#0  Foam::error::printStack(Foam::Ostream&) at ??:?
#1  Foam::sigFpe::sigHandler(int) at ??:?
#2  ? in "/opt/openfoam240/platforms/linuxGccDPOpt/lib/libOpenFOAM.so"
#3  Foam::divide(Foam::Field<double>&, Foam::UList<double> const&, Foam::UList<double> const&) at ??:?
#4  ? at ??:?
#5  ? at ??:?
#6  __libc_start_main in "/lib/i386-linux-gnu/libc.so.6"
#7  ? at ??:?
Floating point exception (core dumped)

As you can see there are not locations to the archives that could contain the issues, so I'm totally lost!

Please, could someone help me?

Many thanks!

[maHein]

Hello,

try setting your boundary type for p_rgh to fixedFluxPressure and set all initial values to 1e5 Pa. This should solve your problem.

Regards,

Martin

[sergimart7]

Thank you for answering Martin.

I already have initial conditions and boundaries for p_rgh set to fixedFluxPressure at 1e5 Pa, as you can see in the changeDictionaryDict file in "aire_forn", which is the air inside the furnace enveloping the resin sample:

p_rgh
    {
        internalField   uniform 1e5;

        boundaryField
        {
            ".*"
            {
                type            fixedFluxPressure;
                value           uniform 1e5;
            }

        }
    }

So I don't think that is the problem...
Did you get it to work with the files I attached?

Thank you so much!

[maHein]

When you have a look at "0/aire_forn/p_rgh", all the types are set to calculated.

The file "0/p_rgh" has the settings you mentioned. Have you executed changeDictionary for the specific region?

[sergimart7]

Hello Martin,

so I am now scrapping changeDictionaryDict and entering the values manually since it didn`t fully worked. As I test with the conditions you said I will come back to you.

My doubt now is for the boundary condition between the air and the solid, should I put in p_rgh the same condition?
Also, I have to put the same conditions of p_rgh in p?

Thank you very much

[maHein]

To be honest, I am not that familiar with CHT simulations. Unfortunately, I cannot help you with this one

[sergimart7]

The simmulation is now running, I will see the results and try to find the most adecuate boundary conditions.

Thank you again!!!

If somebody else can give me a hand too I would be very thankful =)