On the influence that the ground electrode diameter has in the   propulsion efficiency of an asymmetric capacitor in nitrogen gas
  In this work the propulsion force developed in an asymmetric capacitor will be calculated for three different diameters of the ground electrode. The used ion source is a small diameter wire, which generates a positive corona discharge in nitrogen gas directed to the ground electrode. By applying the fluid dynamic and electrostatic theories all hydrodynamic and electrostatic forces that act on the considered geometries will be computed in an attempt to provide a physical insight on the force mechanism that acts on the asymmetrical capacitors, and also to understand how to increase the efficiency of propulsion. 
Alexandre A. Martins, Mario J. Pinheiro
physics.plasm-ph