Giovanni Gallavotti Equivalence of dynamical ensembles and Navier Stokes equations (113K, Postscript) ABSTRACT. a reversible version of the Navier Stokes equation is studied. A conjecture emerges stating the equivalence between the reversible equation and the usual Navier Stokes equation. The latter appears as a statement of ensembles equivalence in the limit of infinite Reynolds number, which plays the role of the thermodynamic limit.