Team moves toward silent, eco-friendly plane

November 06, 2006

CAMBRIDGE, Mass.--MIT and Cambridge University researchers will unveil the conceptual design for a silent, environmentally friendly passenger plane at a press conference Monday, Nov. 6, at the Royal Aeronautical Society in London.

"Public concern about noise is a major constraint on expansion of aircraft operations. The 'silent aircraft' can help address this concern and thus aid in meeting the increasing passenger demand for air transport," said Edward M. Greitzer, the H.N. Slater Professor of Aeronautics and Astronautics at MIT.

Greitzer and Professor Ann P. Dowling of Cambridge University are the lead principal investigators on the Silent Aircraft Initiative. This collaboration of 40 researchers from MIT and Cambridge, plus many others from more than 30 companies, was launched three years ago "to develop a conceptual design for an aircraft whose noise was almost imperceptible outside the perimeter of an airfield in an urban environment."

While originally conceived to make a huge reduction in airplane noise, the team's ultimate design also has the potential to be more fuel-efficient. In a typical flight, the proposed plane, which is designed to carry 215 passengers, is predicted to achieve 124 passenger-miles per gallon, almost 25 percent more than current aircraft, according to Greitzer. (For a down-to-earth comparison, the Toyota Prius hybrid car carrying two passengers achieves 120 passenger-miles per gallon.)

The project aims to develop aircraft by 2030.

The conceptual design addresses both the engines and the structure, or airframe, of a plane. Half of the noise from a landing plane comes from the airframe.

Other key features of the design include:What will it take to turn the design into a plane by 2030?

"One major technical challenge is the integration of the propulsion system with the aircraft," Greitzer said. "The propulsion system, with engines embedded in the fuselage, is different than for traditional civil aircraft, in which the engines are located in nacelles below the wing. This presents a different set of issues to the designer."

Zoltan S. Spakovszky, C. S. Draper Associate Professor in MIT's Department of Aeronautics and Astronautics, also cited the integration of the propulsion system as a key challenge. Spakovszky and James I. Hileman, a research engineer in the department, are the chief engineers, or day-to-day managers, for the project.

He explained that in today's airplanes, with engines hanging below the wings, air flows unimpeded into the engine. In the new design, however, air traveling into the air intakes on top of the plane will behave differently. This is because the air particles flowing close to the plane's body experience friction. As a result, "the particles flow at a lower velocity near the surface of the plane than in the free (air) stream," Spakovszky said. The new engine must be designed to operate in these strongly nonuniform airflows.

A second important technical challenge involves the craft's unconventional airframe, Spakovszky said. "The structural integrity of a pressure vessel allowing this single wing-like shape needs to be ensured and poses a major challenge."

Greitzer emphasized that the collaboration between MIT, Cambridge University and their industrial partners was key to the end result.

"Collaboration and teaming occurred in essentially all aspects of the project. The Silent Aircraft Initiative has been very much an enterprise in which the whole is greater than the sum of the separate parts," he said.

Spakovszky referred to the overall team effort as the best part of the project. "Technical expectations were taken for granted, but working well across the Atlantic was not a given," he said. "It was a very, very neat experience."
-end-
The Silent Aircraft Initiative is funded by the Cambridge-MIT Institute, which has supported a wide range of research and educational collaborations between the two universities. The Knowledge Integration Community (or KIC) that created the conceptual design included academic staff and students from both institutions and participants from a wide range of industrial collaborators including Boeing and Rolls Royce.

Massachusetts Institute of Technology

Related Aircraft Articles from Brightsurf:

University of South Carolina redefining aircraft production process
The University of South Carolina College of Engineering and Computing will transform the manufacturing and simulation processes used in aircraft production through a $5.7 million NASA grant.

Small altitude changes could cut climate impact of aircraft by up to 59%
Altering the altitudes of less than 2% of flights could reduce contrail-linked climate change by 59%, says a new Imperial study.

Small altitude changes could cut the climate impact of aircraft
Contrails -- the white, fluffy streaks in the sky that form behind planes -- can harm the environment.

New electrodes could increase efficiency of electric vehicles and aircraft
The rise in popularity of electric vehicles and aircraft presents the possibility of moving away from fossil fuels toward a more sustainable future.

Composite metal foam outperforms aluminum for use in aircraft wings
The leading edges of aircraft wings have to meet a very demanding set of characteristics.

Particulate matter from aircraft engines affects airways
In a unique, innovative experiment, researchers under the leadership of the University of Bern have investigated the effect of exhaust particles from aircraft turbine engines on human lung cells.

How to ice-proof the next generation of aircraft
To prevent ice formation on aircraft during flight, current systems utilize the heat generated by burning fuel, but these high-temperature, fuel-dependent systems cannot be used on the proposed all-electric, temperature-sensitive materials of next-generation aircraft.

Putting hybrid-electric aircraft performance to the test
Although hybrid-electric cars are becoming commonplace, similar technology applied to airplanes comes with significantly different challenges.

Aircraft microbiome much like that of homes and offices, study finds
What does flying in a commercial airliner have in common with working at the office or relaxing at home?

Sequential model chips away at mysteries of aircraft
Ice accumulation on aircraft wings is a common contributing factor to airplane accidents.

Read More: Aircraft News and Aircraft Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.