Scientists believe that thrusters powered by ionic wind, may be soon an efficient alternative to conventional atmospheric propulsion technologies. Image © NASA
When a current passes between two electrodes that the one is thinner than the other, it creates a wind in the air between. If enough voltage is applied, the resulting wind can produce a substantial amount of thrust.
This phenomenon, called electrohydrodynamic thrust — or, more colloquially, “ionic wind” — was first identified in the 1960s. Since then, ionic wind has largely been limited to science-fair projects and basement experiments; hobbyists have posted hundreds of how-to videos on building “ionocrafts” — lightweight vehicles made of balsa wood, aluminum foil and wire — that lift off and hover with increased voltage.
Now researchers at MIT have run their own experiments and found that ionic thrusters may be a far more efficient source of propulsion than conventional jet engines. In their experiments, they found that ionic wind produces 110 newtons of thrust per kilowatt, compared with a jet engine’s 2 newtons per kilowatt. The team has published its results in the Proceedings of the Royal Society.
Steven Barrett, an assistant professor of aeronautics and astronautics at MIT, envisions that ionic wind may be used as a propulsion system for small, lightweight aircraft. In addition to their relatively high efficiency, ionic thrusters are silent, and invisible in infrared, as they give off no heat — ideal traits, he says, for a surveillance vehicle.
“You could imagine all sorts of military or security benefits to having a silent propulsion system with no infrared signature,” says Barrett, who co-authored the paper with graduate student Kento Masuyama.
Different types of ion thrusters:
Update: Don’t confuse ion wind fans with ion thrusters, it’s the latters on the pictures. They don’t have such a thrust and work only in vacuum, but consume tens of times less fuel than rocket thrusters. The ion wind fans don’t consume fuel at all, and have very high thrust-to-power ratio, but at the cost of big physical size – because of exactly the same law that a helicopter with long slowly rotating blades uses less power than one with short and fast rotating. [by [email protected]]
Images © NASA