tutorials/lagrangian/rhoPisoTwinParcelFoam/rhoPisoTwinParcelFoam/UEqn.H

   1     fvVectorMatrix UEqn
   2     (
   3         fvm::ddt(rho, U)
   4       + fvm::div(phi, U)
   5       + turbulence->divDevRhoReff(U)
   6      ==
   7         thermoCloud1.SU()
   8       + kinematicCloud1.SU()
   9       + rho.dimensionedInternalField()*g
  10     );
  11
  12     UEqn.relax();
  13
  14     if (momentumPredictor)
  15     {
  16         solve(UEqn == -fvc::grad(p));
  17     }