[Voulet]

Let's say I've my momentum equation with a volumic body force :



It's well know that one have to integer it over the volume in oder to discretize it thus the last term become for a specic cell :



My question is the following. Does this volumic body force have to be multiplied by the volume of the cell when setting it in the momentum equation or is it automaticaly done by OF ?


Do I have to write this :

tmp<fvVectorMatrix> tUEqn
(
    fvm::div(phi, U)
  + MRF.DDt(U)
  + turbulence->divDevReff(U)
 ==
    my_own_custom_body_force
);

or this ?

tmp<fvVectorMatrix> tUEqn
(
    fvm::div(phi, U)
  + MRF.DDt(U)
  + turbulence->divDevReff(U)
 ==
    my_own_custom_body_force*V
 );

Thanks a lot.