  Stationary states of Navier-Stokes fluids have been proposed to be described
equivalently by several alternative equations, besides the NS equation itself.
In particular equivalence between the NS evolution and a reversible. It is
natural to test whether, assuming the Chaotic Hypothesis, the Fluctuation
Theorem can be applied to the reversible flows. Here an example is provided
which also leads to the possibility of testing the prediction of the
fluctuation theorem even in systems evolving irreversibly.
