The silent, lightweight aircraft doesn’t depend on fossil fuels or batteries.
MIT engineers have built and flown the first-ever plane with no moving parts. Instead of propellers or turbines, the light aircraft is powered by an “ionic wind” — a silent but mighty flow of ions that is produced aboard the plane, and that generates enough thrust to propel the plane over a sustained, steady flight.
Unlike turbine-powered planes, the aircraft does not depend on fossil fuels to fly. And unlike propeller-driven drones, the new design is completely silent. Such ion wind propulsion systems could be used to fly less noisy drones. Further out, ion propulsion paired with more conventional combustion systems could create more fuel-efficient, hybrid passenger planes and other large aircraft.
The team’s final design resembles a large, lightweight glider. The aircraft, which weighs about 2,2 kilograms and has a 5-meter wingspan, carries an array of thin wires, which are strung like horizontal fencing along and beneath the front end of the plane’s wing. The wires act as positively charged electrodes, while similarly arranged thicker wires, running along the back end of the plane’s wing, serve as negative electrodes.
The fuselage of the plane holds a stack of lithium-polymer batteries whichs supplies electricity at 40,000 volts to positively charge the wires via a lightweight power converter.
Once the wires are energized, they act to attract and strip away negatively charged electrons from the surrounding air molecules, like a giant magnet attracting iron filings. The air molecules that are left behind are newly ionized, and are in turn attracted to the negatively charged electrodes at the back of the plane.
As the newly formed cloud of ions flows toward the negatively charged wires, each ion collides millions of times with other air molecules, creating a thrust that propels the aircraft forward.
The team is working on increasing the efficiency of their design, to produce more ionic wind with less voltage. The researchers are also hoping to increase the design’s thrust density — the amount of thrust generated per unit area. Currently, flying the team’s lightweight plane requires a large area of electrodes, which essentially makes up the plane’s propulsion system. Ideally, they would like to design an aircraft with no visible propulsion system or separate controls surfaces such as rudders and elevators.
— Massachusetts Institute of Technology