A NASA aircraft design competition — known as “N+3” to denote three generations beyond today’s commercial fleet — has produced the blueprint of an aircraft that will save 70% fuel, produce less noise and less pollution while travelling at subsonic speed.
Using Boeing 787 Dreamliner as the basis of “N”, NASA awarded research contracts worth a total of $12.4 million to six industry teams to study advanced concepts for subsonic and supersonic commercial transport aircraft — known as the “N+3” generation. The outcomes are expected to become part of commercial aircraft in 25 to 30 years.
NASA estimates worldwide air travel to double by 2035. To meet the needs of tomorrow’s air traffic NASA requires the new designs to be highly fuel efficient, radically reducing noise and pollution levels and use shorter runway to land and takeoff.
A group of engineers at the Massachusetts Institute of Technology (MIT) designed what they called a D-series “double bubble” subsonic jet (see picture).
“Aircraft silhouettes have basically remained the same over the past 50 years,” said Ed Greitzer, Professor of Aeronautics and Astronautics at MIT, referring to the “tube-and-wing” structure of current aircraft designs.
Set about challenging the conventional wisdom “double bubble” is engineered to be different. Its main body is much wider compared to today’s aircraft, composed of two partial cylinders fused together in an aerodynamic shape. Instead of mounting the engines below the wings it has also moved them to the rear of the airplane to allow the engines to suck in slower-moving air and increase efficiency. The prototype also features smaller tail, narrower wings and is constructed using lighter material.
Meeting the criteria set out by NASA, “double bubble” is expected to burn 70 per cent less fuel, emit 75 per cent less nitrogen oxides (NOx) than current airplanes and could take off using significantly shorter runways.
In addition to the MIT team NASA also awarded funding to research teams from Boeing, GE Aviation, Lockheed Martin and Northrop Grumman.