Ionocraft or "lifters" are lightweight devices that produce thrust by ionizing the air around an electrode, and then accelerating the ions toward another electrode with an electric field, during which the ions push against neutral air molecules and produce thrust.
There used to be a Wikipedia article for "Electrohydrodynamic thruster", which was deleted for not having any references. It said that the efficiency can be improved by separating the ionization and acceleration into stages, and using multiple acceleration stages:
Ionocrafts form part of this category, but their energy conversion efficiency is severely limited to less than 1% by the fact that the ioniser and accelerating mechanisms are not independent. Unlike the ionocraft, within an EHD thruster, the air gap in its second stage is not restricted or related to the Corona discharge voltage of its ionising stage.
The first stage consists of a powerful air ioniser which, when supplied by high voltage in the kilovolt to megavolt range, ionises the intake air into ion clouds which flow into the second stage of the device. The second stage consists of one or multiple stages of ion accelerators, powered by voltages in the kilovolt or megavolt range, in which the ionised fluid is moved on a straight path along the length of the accelerating unit.
Are the claims in this article realistic/true? Know any references for it? Is this well-known under a different name?
Sounds like the same principle as Electrostatic fluid accelerators? But that article says "[Generating thrust] relies on the same electrodes and electric field as the corona [ionization] process."