“…In particular, for the 2d Navier-Stokes equations, some ergodic properties are proved when adding a random perturbation, There is an extensive literature about the convergence of α-models to the Navier-Stokes equations, see for eg. [29,1,7,8,18,22,23,24,25]. However, only a few papers deal with the rate of convergence, see [10,15].…”