[Chris T]

Dear OpenFoam users,

I work with a chtMultiregion case. In one of the fluid regions I have implemented the fiewFactor radiation model. Now I want, for the same region, to specify a non-uniform external radiation heat flux (basically to simulate concentrated sunlight). How does one go about implementing this?
I looked in the documentation and I didn't find a clear answer.
I did notice the viewFactor.H file refers to a quantity "Ho" the same quantity in viewFactor.C is refer to as "external heatFlux". But I have no idea how to specify this quantity it seem it's something for the solver and not user specified.
The other thing I found which seem more promising is the qro field shown here in the documentation qro under the "greyDiffusiveViewFactorFixedValueFvPatchScalarFie ld Class Reference" in documentation. Does anyone know how to use it? I would imagine it is just another field but it's definition is weird

<patchName>    

 {
         type            greyDiffusiveRadiationViewFactor;
          qro             uniform 0;
         emissivityMode  solidRadiation;
          value           uniform 0;
     }

as you can see both qro and value are specified as uniform 0;. Which is the actual value of qro? Also how is qro coupled/relate to qr ?
I can imagine I should change the bountaries for qr from

{
        type            greyDiffusiveRadiationViewFactor;
        value           uniform 0;
        emissivityMode  solidRadiation;//lookup;
        qro             uniform 0;
        emissivity      uniform 0.7;
    }

to

{
        type            greyDiffusiveRadiationViewFactor;
        value           uniform 0;
        emissivityMode  solidRadiation;//lookup;
        qro             qro;
        emissivity      uniform 0.7;
     }

to point to the new file fro the qro field.



Any help will be appreciated.


Best,
Chris

[armin69me]

Hi
Did you find a solution for this? I have the same issue with qr in viewfactor model.

[Chris T]

Hi.
I haven't work on the problem for a while. I had also the problem of accurately generating the heat flux and matching it to my mesh.


If you don't have the same problem just try to input your external heat flux into the surface boundary condition for eithe qr or qr0