Evaluate an impicit term
 

Hello Guys,

I have a question concerning the handling of implicit terms. I added a term to my Ueqn and the solver should handle this term implicit. But I want to have this term as a field which should be written to a file for postprocessing. Is there a way to evaluate only this term?

In Detail:

tmp<fvVectorMatrix> greenWood2::dragForce(volVectorField& U) const
{
return
(
fvm::Sp(mag(U),U)
);
}

And now I want a field which contains mag(U)*U but I dont want to implement a second function. The reason is error avoiding. If I will make a change on my dragForce function I always have to remember to change the second function too. So one place, one equation but I need an idea how to evaluate a fvVectorMatrix :-D

kind regards
Fabian