[giuse]

Hello,
I would implement a slip condition in a general form:

u = L*(grad(U)+grad(U).T) - K*grad(P)

where L is a third order tensor which varies in space on a curved patch and K a second order tensor.
I already implemented it with swak4Foam,
but, with high values of L, it is numerically instable,
so I would try to develop a new implicit boundary condition
(at least for the terms involving the velocity).
From which condition I could start?
Is there something similar already implemented in openFoam?