On the convergence of statistical solutions of the 3D   Navier-Stokes-$\alpha$ model as $\alpha$ vanishes
  In this paper statistical solutions of the 3D Navier-Stokes-$\alpha$ model with periodic boundary condition are considered. It is proved that under certain natural conditions statistical solutions of the 3D Navier-Stokes-$\alpha$ model converge to statistical solutions of the exact 3D Navier-Stokes equations as $\alpha$ goes to zero. The statistical solutions considered here arise as families of time-projections of measures in suitable trajectory spaces. 
Anne C. Bronzi and Ricardo M. S. Rosa
math.AP