[ivan_cozza]

Hi to everybody!
I need to control explicitly the interpolation scheme used in the fvc::grad operator. I read that if I use fvc::grad(phi), where phi is a vol<type>Field, the gradient is performed with the linear interpolation of phi on the cell-faces, while if I whant to control the interpolation scheme I have to set phi to a surface<type>Field.
The problem is that if I put

surfaceTensorField phi = mesh.Sf()*u1;

it doesn't work!
What's wrong?
Thank you, Ivan