[letoppina]

Hello,

I would like to give as input a heat flux in my fvOptions related to one region. This is the file I have:

PHP Code:

fixedTemperature
{
    type            fixedTemperatureConstraint;
    active          yes;
    selectionMode   all;

    mode            uniform;

    temperature     constant 298.15; // Set temperature (K)
}

fixedPower
{
    type            scalarSemiImplicitSource;
    active          no;
    selectionMode   all;

    volumeMode      absolute;

    power           100;          // Set power (W)

    injectionRateSuSp
    {
        e           ($power 0);
        h           ($power 0);
    }
} 


So, my issue is that I would like to give, instead of a value of power in W, a value of heat flux in W/m2 (iso-flux conditions). How do I do that?
Also, what do e and h mean on injectionRateSuSp?

Thank you in advance!

[tobiasS]

Hi,
If you switch volumeMode from absolute to "specific" the power will be in W/m³. But if you really want to specify heat flux in W/m² or even htc in W/ m².K on certainwalls you should use externallWallHeatFluxTemperature bc on the respective wall.
Regards,
Hussam

[tobiasS]

Btw: h and e are the source terms for enthalpy and internal energy. Dependind on which option is selected in physicalProperties, the respective value stated in fvOptions/fvModels will be used.

[letoppina]

Originally Posted by tobiasS

Hi,
If you switch volumeMode from absolute to "specific" the power will be in W/m³. But if you really want to specify heat flux in W/m² or even htc in W/ m².K on certainwalls you should use externallWallHeatFluxTemperature bc on the respective wall.
Regards,
Hussam

Hi Hussam,

Thank you for your reply! How do I add such a boundary condition? Do I have to add a new file on the desired region or can I add the script on an existing file (I am new in using OpenFOAM).

Thank you!

[tobiasS]

Hi, I would suggest to use the foamInfo utility, to help get more information about openfoam features. For this case:
"foamInfo externallWallHeatFluxTemperature"
will return
detailed usage information and examples from the tutorials about the topic. For this bc you can find an example in the tutorial "reverseBurner".. check it out.