[zfaraday]

Hello all!

I'm working in a case with chtMultiRegionFoam where I have a solid that is generating heat power (knowing this power in W/m³) surrounded by air. I need to know how to set up this heat generation in a solid. I have read (and tried) something about fvOptions. It's said that a source of the type semiImplicitSource would do it, but I haven't been able to set up anything properly.

===1===

Is is true that I can set up a heat source using fvOptions frame of the type semiImplicitSource? If so, which would be the correct set up of the source knowing the power in W/m³?

===2===

Is there any other approach in order to set up a heat source the way I need it?


Many thanks in advance!

Alex

[derekm]

i have done
this see http://www.cfd-online.com/Forums/ope...rnal-void.html

[zfaraday]

I have thought of something like that aswell, but doing like you did I would need to define my generating zone as an external zone of my domain, wouldn't I? The point is that I'm not interested in having this zone defined as external because maybe I need to study what happens inside the heat source.

Thanks derekm for your quick answer!


Alex

[derekm]

In my case I needed a heater as the innermost region. The heater has no interface to outside of the domain.

To accomplish this a created a new region totally inside the heater region, called heaterInner..
The heat flux is across the enveloping patch of heaterInner to heater.

Thus heater increases in temperature and heaterInner decreases temperature because of the defined heat flux.

However this is a heat flux not volumetric heat generation. I will investigate semiImplicitSource further, thanks for bringing it to my attention.

[zfaraday]

You are welcome derekm!

Could you please upload your case in order to take a look into it? Because I still don't understand your approach. Otherwise you can upload an easier case if yours is too heavy to be uploaded here, I just want to se how you exactly set up what you explained.

Thanks a lot!

[BClarke352]

Hi,

I'm also trying to add a heat source to chtMultiRegionFoam using fvOptions. I've got a file in OpenFOAM format that gives the volumetric power in each cell in my geometry and would like to find out what the corresponding increase in temperature is when this cell is read and the effect on the temperature profile and flow distribution is. Could someone tell me a) how to read the file in with fvOptions and b) how to set fvOptions up for this purpose?

[BrandonCN]

Someone already solved how to put the heat source for the inner part?

[fabian_roesler]

Try using the large E in radiationProperties. This is some kind of source term for radiation. Though I never tried it for solids.
Another possibility would be to create a cellZone and creater a heat source within fvOptions. There you can fix temperature by a constraint or directly give a heat flux.
Check out the tutorials.

Cheers

Fabian

[visheshkapoor06]

Hello All,

I am trying to run a case of chtMultiRegionSimpleFoam based on the multiRegionHeaterRadiation example. My case has 8 solid blocks inside air. The air and blocks are inside a metal cabinet, and also touch the cabinet. The cabinet is in the atmosphere.
When i run the case, the temperature diverges and an error comes up. I am not able to diagnose the error. Please help!

Time = 1


Solving for fluid region domain0
DILUPBiCG: Solving for Ux, Initial residual = 1, Final residual = 0.0156926, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 1, Final residual = 0.0130481, No Iterations 1
DILUPBiCG: Solving for Uz, Initial residual = 1, Final residual = 0.0180424, No Iterations 1
DILUPBiCG: Solving for h, Initial residual = 1, Final residual = 0.0671467, No Iterations 1
Min/max T:300 7709.26
GAMG: Solving for p_rgh, Initial residual = 0.88219, Final residual = 0.00738372, No Iterations 6
time step continuity errors : sum local = 21.78, global = -18.8129, cumulative = -18.8129
Min/max rho:0.2 1.15862

Solving for fluid region domain2
DILUPBiCG: Solving for Ux, Initial residual = 1, Final residual = 0.0184007, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 1, Final residual = 0.0246227, No Iterations 1
DILUPBiCG: Solving for Uz, Initial residual = 1, Final residual = 0.0227786, No Iterations 1
[3]
[3]
[3] --> FOAM FATAL ERROR:
[3] Attempt to cast type compressible::turbulentTemperatureCoupledBaffleMix ed to type compressible::turbulentTemperatureRadCoupledMixed[0]
[3]
[3] From function refCast<To>(From&)
[3] in file /home/kav9kor/OpenFOAM/OpenFOAM-3.0.1/src/OpenFOAM/lnInclude/typeInfo.H at line 114.
[3]

[Kevin.H]

Dear Foamers,
I try to implement a volumetric heat source with fvOptions in a chtMultiRegionSimpleFoam case.

(I also used externalWallHeatFluxTemperature as a boundary condition and this works very well.)

energySource
{
    type            scalarSemiImplicitSource;
    active on; //to switch or not heat source 
    //timeStart 0;
    //duration  20;
    selectionMode cellZone;
    cellZone c0;
    scalarSemiImplicitSourceCoeffs
    {
        selectionMode   cellZone;
        cellZone        magnet;
    
        volumeMode      absolute;//specific;//
        injectionRateSuSp
        {
           h           (30 0); //   q in [W]; or in [W/m³] if you use specific  mode
        }
    }
}

I have some questions about this:
1. " h (0 0.1);" why is it write as a vector? How can I implement for example 30W?

Edit2: It´s a vector because of Source= Sc + Sp, So I think in this line my file is right.

2. I am pretty sure that I use fvOptions on the wrong way. I copied this file in the system and in the system/magnet Folder. But the temperature does not increas. Do anybody see what I have done wrong?
Thank u for your help!

Edit1: I use OF4.1 and have also noticed this threat: Adding temperature dependent heat source using fvOptions in chtMultiRegionSimpleFoam
but with the file of the user shaileshbg I get the same Problem. The temperature does not change.

[Bloerb]

Most likely because the cellZone you specified does not exist. Try selectionMode all;