The utility calcPressureFluxWeighted can evaluate simulated results in detail and reads its setup from calcPressureFluxWeightedDict, e.g. see the file francisTurbine/system/spiral/calcPressureFluxWeightedDict:

bcs
(
   inflow_inlet
);

// Factor to multiply the results with (for symmetric or axial cases)
// scaleFactor 72.;

// Density for incompressible cases
// rho rho [1 -3 0 0 0 0 0] 0.41;

// Pressure field name (default: p)
   pname pMean;

// Velocity field name (default: U)
   Uname UMean;

// ************************************************************************* //

• We use the averaged quantities *Mean to evaluate formula ().