what interpolation scheme should I use?
 

Dear Foamers,

I am trying to model the fluid flow of a complex fluid in a contraction, where both normal and tangential stresses are significant. I manage to simulate the simple flow of the fluid in couette flow and in the contraction using upwind to discretize the convection terms.

Now, I am trying to use higher order methods, to speed simulations and be able to use not so refined meshes and so small time increments in the simulations. Time is money and the more results I get in less time, the better (also I can buy a better computer, but no money now, it is the crisis says my goverment that continues to feed the usual leeches...) .

But, when I tried to use Gauss gammaV 0.5, I got results that were no much better that the upwind case, for the contraction flow case. In one case they were even worse, and took much more time to converge.

Does anyone know why this is happening. If this gammaV is not adequate, what scheme should I use for the contraction? By the way, where can I find a comparison between the large quantity of methods available in OpenFoam, to serve as a guide. I feel sometimes that I am shooting in the dark here...

Regards,

António Martins