By: William Huang
The very first thing you notice when an airplane flies overhead is probably the loud, agitating, and continuous noise coming from its engine. Now, imagine a plane flies right above your head, but you barely hear a sound from it. That may become a reality in the future with the invention of the ion plane.
Since the first successful powered flight over 100 years ago, every powered aircraft has been propelled by some sort of turbine, whether it be a jet engine or propellor. As you probably know, those turbines have moving systems in them and produce extremely loud, continuous noise, also known as noise pollution. However, in late November 2018, a team of MIT students, led by Professor Steven Barrett, successfully flew the first-ever virtually silent plane with no moving parts - they called it the ion plane.
A time lapse of a test flight of the ion plane in MIT [3].
How does it fly?
This plane was not powered by fossil fuels, unlike traditional turbine-powered planes. Instead, it was propelled by ionic wind thrusters: electric engines that generate thrust by creating and shooting out charged particles (ions). Ionic winds are thrusts that are created when a current passes through two electrodes that apply a voltage to the air. The voltage takes away electrons from nearby air molecules which then collide with neutral air molecules in a chain reaction to produce enough thrust to propel an aircraft. Although ionic winds were discovered in the 1920s, the 2018 MIT invention was the first aircraft that utilized the phenomenon and was “the first-ever sustained flight of a plane with no moving parts in the propulsion system”, says Professor Barrett. Additionally, because the aircraft does not use fossil fuels, it does not emit any combustion emissions - another advantage over turbine-powered aircraft.
The final design of the ion plane resembled a large glider that weighed about five pounds and had a five-meter wingspan. The electrode propulsion system was set up horizontally along the wings with the positively charged wire electrodes in front and the negatively charged wire electrodes in the back. To power the electrodes, a lithium-polymer battery was placed in the fuselage of the plane and 40,000 volts were used to supply the wires with energy. Once they were contained enough energy, the positive electrodes stripped electrons from surrounding air molecules that were then attracted to the negative electrodes in the back, creating millions of collisions between air molecules to propel the vehicle forward.
The ion plane with the horizontal electrodes along the wingspan [2].
The future of the ion plane
This first successful ion plane design opens up many new possibilities for clean and quieter air travel. However, there are still big strides that need to be made before ionic wind thrusters can be implemented in piloted aircraft. Currently, much of the plane’s area is taken up by the electrodes for propulsion, so the team is working on increasing the efficiency of the system to produce more ionic wind with less voltage. They are also working on implementing separate surfaces, such as elevators and rudders, to allow for more control during flight.
The first successful ion plane flight opened opportunities for the aerospace industry. Although the propulsion is not nearly as efficient as jet and propellor turbines, ion wind thrusters are clean, silent methods of propulsion, making them a viable option for small drones in the future.
References
Chen, A. (2018, November 21). Silent and Simple Ion Engine Powers a Plane with No Moving Parts. Retrieved from https://www.scientificamerican.com/article/silent-and-simple-ion-engine-powers-a-plane-with-no-moving-parts/.
Chu, J., & MIT News Office. (2018, November 21). MIT engineers fly first-ever plane with no moving parts. Retrieved from http://news.mit.edu/2018/first-ionic-wind-plane-no-moving-parts-1121.
MIT Flies Model Airplane Powered by the Blue Glow of Electric Fields and Ionic Winds. (2018, November 21). Retrieved from https://www.smithsonianmag.com/innovation/mit-flies-model-airplane-powered-electric-fields-and-ionic-winds-180970877/.
Plouraboué, F. (2018, November 21). Flying with ionic wind. Retrieved from https://www.nature.com/articles/d41586-018-07411-z.
Zyga, L. (2018, February 7). What causes ionic wind? Retrieved from https://phys.org/news/2018-02-ionic.html.