Ewald summation for the rotlet singularity of Stokes flow
  Ewald summation is an efficient method for computing the periodic sums that appear when considering the Green's functions of Stokes flow together with periodic boundary conditions. We show how Ewald summation, and accompanying truncation error estimates, can be easily derived for the rotlet, by considering it as a superposition of electrostatic force calculations. 
Ludvig af Klinteberg
physics.flu-dyn physics.comp-ph