Kolmogorov flow forcing for ns2d and ns3d
It would be useful to have a forcing for Kolmogorov flow (see this interesting review).
It would be good to have it for both ns2d and ns3d based solvers.
In 3d, it would be good to be support 2 directions for the shear (y and z, let's say that the velocity is along x).
Also for turbulence studies, it could be nice to support constant forcing (standard K-flow) and "normalized K-flow" such that this energy injection would be constant.
Note that for ns3d.strat, this would be a very simple way to study sheared stratified turbulence. Very "low hanging fruit" study with Fluidsim!