Getting element integral values on each element?

[jessecarterMOOSE]

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Question

Is there a way (VectorPostprocessor maybe?) to get the integral of a material property for each element? Kind of like ElementIntegralMaterialProperty Postprocessor but return the value on each element instead of summing them up.

[GiudGiud]

Hello

The MaterialPropertyAux acting on a CONSTANT MONOMIAL will get you the average effectively:

      for (_qp = 0; _qp < _qrule->n_points(); _qp++)
        value += _JxW[_qp] * _coord[_qp] * computeValue();
      value /= (_bnd ? _current_side_volume : _current_elem_volume);

Then the VolumeAux the volume, and a ParsedAux can get back the integral with a parsed expression of the multiplication

Guillaume

[jessecarterMOOSE]

ok good point I was looking in the Exodus file. Let me check the VPP and try your idea

[jessecarterMOOSE]

It appears to be the ParsedAux auxvar that is lagging. I have a postprocessor that gets the average value, which is lagging and so are the values in the VPP. The other components in the parsed expression are up-to-date because I output those too.

[GiudGiud]

so the auxvar created by the parsed aux is lagging compared to what you need
OR an auxvar used in the parsed aux is lagging?

Is the VPP depends on by any auxkernel? That would have made it sorted into the PREAUX group and we need it in the POSTAUX, with force_postaux = true if needed

[jessecarterMOOSE]

It's the auxvar that gets filled in by the parsed aux that is lagging

The VPP is just to output the values of the auxvar

[GiudGiud]

ok seems weird because material properties are definitely re-computed in the auxkernel loop, so the auxvar computation should be updated.
The log from Debug/show_execution_order=ALWAYS might give enough info to see what should be executed before