[zfaraday]

Hello FOAMers,

I started with OpenFOAM in September, so I'm quite new in this world. My first steps in OF took me to solve some basic and easy cases of heat transmission in solids using laplacianFoam. I spent a couple of months getting some self-training in OF while I was solving some basic (mainly 2D) cases. After that I left OF aside for a while. However, some weeks ago I had to get back to OF but this time I had to run it with chtMultiRegionSimpleFoam. As I had no experience with it (I had only run and tried to understand the tutorial cases and the planeWall2D tutorial some months ago, when I was solving basic cases with laplacianFoam), for the last few weeks I have been studying deeply the tutorial cases and the planeWall2D in order to be able to set up a case I have to solve.

In the attached pic you can see the geometry of my case. It consists of a sample which is heated (mainly by radiation) by a heater cylinder by means of an electrical current. These elements are covered by a metallic shield, whose function is to prevent from heat loss. The sistem is placed within a box (shell). As you can see, I have only generated a quarter of the whole geometry because of its symmetry.

After all the information I have been looking for the last few weeks in order to solve my case I have found a couple of things I still don't know how to implement:

- On the one hand, I need to set a heat source of a known generated power ("X" W/m³). With all the knowledge I have been gathering I concluded I need to use fvOptions, but I'm not much aware how to use it. I read things about codedSource, semiImplicitSource and some other types, but I still don't see it clear...

-On the other hand, I also need to use radiation in my calculations but it is even more complicated to me to understand than the heat source setting. First I thought about using View Factors method because it's the only one I have studied before but after having read a little deeper I think that this method is not suitable for my case. However I think the proper method is fvDOM instead, but I still don't know how to use it...


As I had to face all this problems when I was just beginning with chtMultiRegionFoam I decided to go on straight without using these options by now (anyway, if you want to give me a hint about these issues it will be much appreciated, otherwise I will probably open a new thread in the future if I haven't found a solution on my own). Thus, I just set a fixed temperature within the heater cells and let convection do the rest.

I set up the case following the steps of the multiRegionHeaterRadiation tutorial. I copied all the files from this tutorial to my case and I just adapted the boundary and initial conditions to fulfill my requirements but I haven't modified anything else. I got some errors during the process that I was capable to solve by myself but now I got an error message that I can't understand what it says. The error message is the following:

/*---------------------------------------------------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2.2.1                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
Build  : 2.2.1-57f3c3617a2d
Exec   : chtMultiRegionSimpleFoam
Date   : Apr 03 2014
Time   : 20:30:43
Host   : "ubuntu"
PID    : 9515
Case   : /home/alex/OpenFOAM/alex-2.2.1/run/PFC/Proves/quarterCilinder
nProcs : 1
sigFpe : Enabling floating point exception trapping (FOAM_SIGFPE).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster
allowSystemOperations : Disallowing user-supplied system call operations

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

Create fluid mesh for region aire for time = 0

Create fluid mesh for region aire1 for time = 0

Create fluid mesh for region aire2 for time = 0

Create solid mesh for region mostra for time = 0

Create solid mesh for region generacio for time = 0

Create solid mesh for region shield for time = 0

*** Reading fluid mesh thermophysical properties for region aire

    Adding to thermoFluid

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

    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 fvOptions

No finite volume options present

*** Reading fluid mesh thermophysical properties for region aire1

    Adding to thermoFluid

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

    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 fvOptions

No finite volume options present

*** Reading fluid mesh thermophysical properties for region aire2

    Adding to thermoFluid

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

#0  Foam::error::printStack(Foam::Ostream&) in "/opt/openfoam221/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
#1  Foam::sigFpe::sigHandler(int) in "/opt/openfoam221/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
#2   in "/lib/x86_64-linux-gnu/libc.so.6"
#3  Foam::heRhoThermo<Foam::rhoThermo, Foam::pureMixture<Foam::constTransport<Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie> >, Foam::sensibleEnthalpy> > > >::calculate() in "/opt/openfoam221/platforms/linux64GccDPOpt/lib/libfluidThermophysicalModels.so"
#4  Foam::rhoThermo::addfvMeshConstructorToTable<Foam::heRhoThermo<Foam::rhoThermo, Foam::pureMixture<Foam::constTransport<Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie> >, Foam::sensibleEnthalpy> > > > >::New(Foam::fvMesh const&, Foam::word const&) in "/opt/openfoam221/platforms/linux64GccDPOpt/lib/libfluidThermophysicalModels.so"
#5  Foam::autoPtr<Foam::rhoThermo> Foam::basicThermo::New<Foam::rhoThermo>(Foam::fvMesh const&, Foam::word const&) in "/opt/openfoam221/platforms/linux64GccDPOpt/lib/libfluidThermophysicalModels.so"
#6  Foam::rhoThermo::New(Foam::fvMesh const&, Foam::word const&) in "/opt/openfoam221/platforms/linux64GccDPOpt/lib/libfluidThermophysicalModels.so"
#7  
 in "/opt/openfoam221/platforms/linux64GccDPOpt/bin/chtMultiRegionSimpleFoam"
#8  __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
#9  
 in "/opt/openfoam221/platforms/linux64GccDPOpt/bin/chtMultiRegionSimpleFoam"
Floating point exception (core dumped)

If you can help me to solve this I would be much grateful, since I would be able to keep going into my first attempt with chtMultiRegionFoam.


Regards,

Alex

[zfaraday]

Hello again,

Fianally I found the solution for the error comented previously. It was just the definition of the boundary condition in the changeDictionaryDict-file for the variable T, which was set to

type    calculated;
value   0;

After that I was able to keep going into my approach to solve the problem mentioned. I have been finding some other errors that I have solved but now I found another one I cannot solve by myself. The error message shown was:

--> FOAM FATAL ERROR: 

    gradientInternalCoeffs cannot be called for a calculatedFvPatchField
    on patch up of field h in file "/home/alex/OpenFOAM/alex-2.2.1/run/PFC/Proves/quarterCilinder2/0/generation/h"
    You are probably trying to solve for a field with a default boundary condition.

    From function calculatedFvPatchField<Type>::gradientInternalCoeffs() const
    in file fields/fvPatchFields/basic/calculated/calculatedFvPatchField.C at line 199.

FOAM exiting

Any hint will be much welcome, because there isn't any default boundary condition in that region (generation) as it is suggested. There was one default boundary condition defined in the prior solved region (sample) and I got the same error message. For this reason I tried to give a name to that default face (it actually was just an axis, not a face but the axis of the cylinder) to avoid this error but I got another error instead. After several attempts to solve that issue I finally got rid of it, but I didn't really do anything important because I eventually left it as it was at the start (no name for the default faces-axis-). Thus, it was just a kind of magic to my eyes....
After that, I got the same error in the next region, which, as I said, it has no default faces in it.

Many thanks in advance!


Alex