applications/solvers/lagrangian/porousExplicitSourceReactingParcelFoam/UEqn.H

   1     fvVectorMatrix UEqn
   2     (
   3 //        fvm::ddt(rho, U)
   4         pZones.ddt(rho, U)
   5       + fvm::div(phi, U)
   6       + turbulence->divDevRhoReff(U)
   7      ==
   8         rho.dimensionedInternalField()*g
   9       + parcels.SU()
  10       + momentumSource.Su()
  11     );
  12
  13     pZones.addResistance(UEqn);
  14
  15     if (momentumPredictor)
  16     {
  17         solve(UEqn == -fvc::grad(p));
  18     }
  19