[TommyJ]

Hello to all,

I have a unit square mesh with patches: left, right, top and bottom.

I would like to compute the sum of the fluxes across all patches.

How can I achieve this with a functionObject?

    leftVolumetricFlux  
    {
         type           surfaceFieldValue;
         libs           ("libfieldFunctionObjects.so");
         fields         (phi);
         writeFields    no;
         regionType     patch;
         name           left;  
         operation      sum;
    }



    rightVolumetricFlux  
    {
         type           surfaceFieldValue;
         libs           ("libfieldFunctionObjects.so");
         fields         (phi);
         writeFields    no;
         regionType     patch;
         name           right;  
         operation      sum;
    }


    topVolumetricFlux  
    {
         type           surfaceFieldValue;
         libs           ("libfieldFunctionObjects.so");
         fields         (phi);
         writeFields    no;
         regionType     patch;
         name           top;  
         operation      sum;
    }


    bottomVolumetricFlux  
    {
         type           surfaceFieldValue;
         libs           ("libfieldFunctionObjects.so");
         fields         (phi);
         writeFields    no;
         regionType     patch;
         name           bottom;  
         operation      sum;
    }

And then do the summation by hand? Is there a way to put everything in one FO?

[Yann]

Hello Tommy,

If your are using ESI-OpenCFD branch, this should do the job:

volumetricFlux  
    {
         type           surfaceFieldValue;
         libs           ("libfieldFunctionObjects.so");
         fields         (phi);
         writeFields    no;
         regionType     patch;
         names          (left right top bottom);  
         operation      sum;
    }

Source: https://develop.openfoam.com/Develop...ceFieldValue.H

It depends on which OpenFOAM version you are using, I'm not sure this works in the OpenFOAM foundation branch.

Cheers,
Yann