Ever since the Wright Brothers flew the world’s first plane more than a century ago, aircraft have typically flown with the help of moving parts such as propellers, turbine blades and fans, and powered by the combustion of fossil fuels or battery packs. Massachusetts Institute of Technology (MIT) engineers are attempting a revolutionary change. They have built and flown a prototype plane with no moving parts.
Instead of propellers or turbines, the aircraft is powered by electrohydrodynamic thrust or the so-called “ionic wind", a phenomenon first identified in the 1960s. When a current passes between two electrodes, it creates a wind in the air between. If enough voltage is applied, the resulting “ionic wind" can produce a thrust without the help of motors or fuel and power a small plane.
Steven Barrett, associate professor of aeronautics and astronautics at MIT, and his team flew the plane 60m across the gymnasium at MIT’s duPont Athletic Center, and found that it produced enough ionic thrust to sustain flight the entire time. They repeated the flight 10 times, with similar results that were published in the journal Nature.
“This was the simplest possible plane we could design that could prove the concept that an ion plane could fly," Barrett said in a press statement. He did acknowledge, though, that the design was “still some way away from an aircraft that could perform a useful mission".
While inspiration for the team’s ion plane came partly from the movie and television series Star Trek, which Barrett watched as a child, he has been exploring the possibility of flying such a plane for the past nine years.
Nine years later, the team’s final design resembles a large, lightweight glider. The aircraft, which weighs about five pounds and has a five-metre wingspan, carries an array of thin wires that act as positively charged electrodes. Similarly arranged thicker wires, running along the back end of the plane’s wing, serve as negative electrodes.
In the near term, Barrett and his team believe that ion propulsion, paired with more conventional combustion systems, can create fuel-efficient, hybrid passenger planes, and other large aircraft.
This is not the first time that researchers have explored aircraft without moving parts. BAE Systems and the University of Manchester, for instance, announced on 13 December that they had successfully completed the first phase of flight trials with MAGMA, a small-scale unmanned aerial vehicle (UAV), which does away with the need for mechanical moving parts used to move flaps to control the aircraft during flight. This could give greater control as well as reduce weight and maintenance costs, allowing for lighter, stealthier, faster and more efficient military and civil aircraft in the future, the researchers explained in a press statement.
The researchers used two technologies towards this end. The first was Wing Circulation Control, which takes air from the aircraft engine and blows it supersonically through the trailing edge of the wing to provide control for the aircraft. The second was Fluidic Thrust Vectoring, which uses blown air to deflect the exhaust, allowing for the direction of the aircraft to be changed.