Doubt in term representation
 

Foamers,

I am trying to describe the flow of fluids where, besides the newtonian stresses I have to take into extra stresses. They are considered using two terms:

laplacian (nus,U) --> the standar viscous force for newtonian fluids.
div(tensor) --> the extra tensions. Note that these terms are an implicit function of the velocity field. Tensor is a tensor field.

When I formulate the momentum equation to be solved for the velocity field, I use fvm::laplacian(nuS,U) for the newtonian stress. However, when I try to do the same for the divergence of the extra tensio, i.e fvm::div(tensor), I gives an error. I am only able to do fvc::div(tensor).

Is there any way to express in implicit form (fvm) the divergence? This may be one of the reasons my calculation does not give relavant results.

Thanks,

Antonio