Propeller planes aren’t exactly known as the pinnacle of aircraft luxury, but a new propeller engine currently being designed by Rolls-Royce makes up in efficiency what it lacks in comfort. The company claims that the engine could save an airline three million dollars and 10,000 tons of CO2 per year if it is introduced on 100-200 seater planes.
The Rolls-Royce design uses two sets of propellers that rotate in opposite directions near the engine’s rear. This effectively reduces the energy wasted when propellers twist the air instead of pushing it backwards. Additionally, the open rotor engines don’t have a casing around the propeller, thus reducing weight and drag.
Open-rotor designs are normally very noisy, but Rolls-Royce both increased the number of blades on the plane’s rotors and made the blades thinner than usual. This resulted in rotors that turn at a slower speed while still maintaining a high efficiency— all with reduced noise.
Other companies working on similar open-rotor designs include General Electric, Pratt & Whitney, and Snecma.