After three years of work, a team of researchers from the Massachusetts Institute of Technology and Cambridge University have come up with a concept for a quiet aircraft.
The design, the initial goal of the Silent Aircraft Initiative, comes from a collaboration of over 40 university researchers, plus others from more than 30 companies. It not only addresses the issue of noise, a major constraint on expanding aircraft operations, but also makes for a more fuel-efficient airliner. It's estimated that the proposed plane, which caries 215 passengers, will get 124 passenger-miles/gallon. This is almost 25% more than current airliners.
The aircraft, a modified flying wing, generates lift with its fuselage and wings, which lets it take off and land at lower speeds. The smooth shape also improves fuel efficiency. There are no flaps or hinged sections on the rear of the wing, a major source of noise when conventional planes take off and land. The jet engines are embedded in the aircraft with air intakes on the upper surface of the fuselage. This lets the plane's body screen noise from the ground. And a variable-size jet nozzle lets the plane use less thrust for landing and taking off, but still be efficient at high-speed cruising.
The team hopes to turn the design into a flying prototype by 2030. The biggest challenges, according to one of the researchers, will be embedding the engine in the fuselage, a change from conventional airliners, and building a lifting body with the structural integrity to be a pressure vessel.