Jets and Drones Powered by a Mighty Wind
CREDIT: General Atomics
Will tomorrow’s jets and drones be powered by the same technology currently used in toy hovercrafts? A new study by researchers at MIT suggests that ionic thrusters aren’t just for play; they also provide a super-stealth, ultra-efficient alternative to conventional atmospheric propulsion systems.
Ionic thrusters are powered by a phenomenon known as electrohydrodynamic thrust, or “ionic wind.” This wind is created when a current of electricity is passed between two electrodes- one thinner than the other.
If both the space between the electrodes and the voltage applied between the electrodes are sufficiently large, then the “ionic wind” can become a full-blown thrust, with enough power to propel an object forward without the help of a motor or fuel.
Scientists have been aware of this phenomenon since the 1960s, but because researchers believed that ionic thrusters were inefficient, they have been relegated to the realm of science fair projects and basement experiments.
But the new study might just bring electrodynamic technology out of the basement. A team of researchers led by Steven Barrett, assistant professor of aeronautics and astronautics at MIT, found that ionic wind produces 110 newtons of thrust per kilowatt, which is significantly greater than a jet engine’s two newtons per kilowatt thrust.
According to Barrett, ionic thrust has the potential to be used as a propulsion system for small, lightweight aircraft. Such a system would be particularly useful in surveillance vehicles, as ionic thrusters are both silent and invisible to infrared.
“You could imagine all sorts of military or security benefits to having a silent propulsion system with no infrared signature,” said Barrett.
Ned Allen, chief scientist and senior fellow at Lockheed Martin Corp., also believes in the potential benefits of this emerging technology, saying that ionic thrust “offers nearly miraculous potential” because of its high efficiency compared to conventional, combustion reaction devices like rocket or jet thrusters.
Allen said Lockheed is looking into thrust technology as a potential means of propulsion for its future aircraft. However, both Allen and Barrett acknowledge that there are some drawbacks to using ionic thrusters to power even small vehicles.
For one thing, thrusters would have to be huge in order to create enough thrust to get aircraft with off the ground. Lift off would also require a lot of voltage, which would have to be supplied by lightweight power sources-like solar panels.
Despite these obstacles, Barrett said that the efficiency of electrodynamic thrust technology makes it a promising option for use in both aircraft design as well as smaller propulsion systems, such as the cooling systems used in laptops.
[See also: Drones Large and Small Coming to US]