  The present work intends to compare the propulsion force developed in an
asymmetric capacitor, according to the number of positive ion sources used. The
ion source is a corona wire, which generates a positive corona discharge in
nitrogen gas directed towards the ground electrode. We are going to apply the
known theory of electrohydrodynamics (EHD) and electrostatics in order to
compute all hydrodynamic and electrostatic forces that act on the considered
geometry in an attempt to provide a physical insight on the force mechanism
that acts on each asymmetrical capacitor, and also to compare propulsion
efficiencies.
