Airplanes Designed With A Grant From NASA

MIT has taken the virtual wraps off two new airplane designs it says will reduce the amount of fuel consumed by 70 percent, and will also significantly cut nitrogen oxide (NOX) and noise pollution.

(L-R) D series, H series.  Image: MIT/Aurora Flight Sciences

The smaller airplane, dubbed "Double Bubble", is based on a positive lift fuselage and a modified "tube and wing" structure to generate additional lift. It was developed under a contract granted to MIT and three other teams by NASA in 2008 to design a new, subsonic airliner. Two teams also studied the concept of a new supersonic airliner.

The grant stipulated that the airplane design burn 70 to 75 percent less fuel than current airliners that were also quieter and less polluting. NASA also wanted an airplane that could operate from short runways.

D Series "Double Bubble".  Image: Aurora Flight Sciences

MIT says that the "Double Bubble" design would replace airplanes in the single aisle, twin engine, medium-haul class of airliners.  It also designed a 350 passenger "H" model that would target the longer-haul dual-aisle market. The "H" stands for "hybrid wing body".

The "Double Bubble" uses two partial cylinders placed side-by-side rather than a single cylinder used in current airliners. That creates a wider fuselage cross section that resembles two soap bubbles joined together, hence the "Double Bubble" designation. The engines move from the wings to the aft section of the fuselage, using slower-speed air in the wake of the airplane's body. This Boundry Layer Ingestion (BLI) allows the engines to use less fuel to produce the same amount of thrust, but also creates more stress on the engines.

H Series Hybrid Wing Body. Image: Aurora Flight Sciences

The "H" series uses a more radical triangular shape to the fuselage which blends a wider body with the wings resulting in aerodynamic improvements. MIT also says the larger center body creates forward lift that makes a horizontal stabilizer unnecessary.

The MIT team says it expects NASA to make a decision in several months as to which teams will receive a second round of funding.

FMI: http://web.mit.edu/newsoffice/2010/nplus3-0517.html