Nav: Home

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:
  • An overall shape that integrates body and wings into a "single" flying wing. As a result, both the body and wings provide lift, allowing a slower approach and takeoff, which would reduce noise. The shape also improves fuel efficiency.

  • The elimination of the flaps, or hinged rear sections on each wing. These are a major source of airframe noise when a plane is taking off and landing.

  • Engines embedded in the aircraft with air intakes on top of the plane rather than underneath each wing. This screens much of the noise from the ground.

  • A variable-size jet nozzle that allows slower jet propulsion during takeoff and landing but efficient cruising at higher speeds.

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:

Monitoring pollen using an aircraft
Plant pollen and fungal spores can be found at variable heights in the air, even at elevations up to 2,000 meters.
Designing the fuel-efficient aircraft of the future
University of Michigan researchers are using the Stampede supercomputer to design novel, fuel-efficient, wing designs for jets, and to develop tools that can help the industry build more efficient aircraft.
Aircraft inspectors have new Sandia course to help detect composite material damage
In the midst of holiday travel season, airline customers want to feel safe in the new aircraft made of composite materials.
New material could make aircraft deicers a thing of the past
Instead of applying a deicing agent to strip ice from an aircraft's wings before winter takeoffs, airport personnel could in the future just watch chunks slide right off.
Autonomous cloud seeding aircraft successfully tested in Nevada
A team of Nevada scientists and unmanned aircraft systems (UAS) engineers have successfully flight tested the first-ever autonomous cloud seeding aircraft platform.
New electric propulsion system improves safety of light aircraft
Researchers at Universidad Carlos III de Madrid and the AXTER Aerospace firm have developed an electric propulsion system to install in small gasoline-powered planes for extra power and range in emergency situations.
Lightweight membrane can significantly reduce in-flight aircraft noise
Riding in a helicopter or airplane can be a noisy experience for passengers.
Taking aircraft manufacturing out of the oven
Aerospace engineers at MIT have now developed a carbon nanotube film that can heat and solidify a composite without the need for massive ovens.
Far-reaching technology for aircraft manufacture that pollutes less
Cutting the environmental costs of aero engine parts manufacturing, increasing freedom in their design and reducing fuel consumption and contaminating gas emissions are some of the benefits resulting from applying modern additive manufacturing techniques to the aircraft industry.
Overcoming barriers to successful use of autonomous unmanned aircraft
While civil aviation is on the threshold of potentially revolutionary changes with the emergence of increasingly autonomous unmanned aircraft, these new systems pose serious questions about how they will be safely and efficiently integrated into the existing civil aviation structure, says a new report from the National Research Council.

Related Aircraft Reading:

Aircraft: The Definitive Visual History
by DK (Author), Philip Whiteman (Contributor)

From the first prototypes of flying machines to today's supersonic jets, the history and roles of aircraft are explored in this beautifully illustrated guide.

Aviation enthusiasts of all stripes and ages will welcome learning more about key brands and big players from yesterday and today — whether it's the marvels of hot air balloons or the fantastic engines of Boeing, Lockheed, and more.

Planes are divided equally between military and commercial aircraft, and iconic aircraft of each era, such as the Supermarine Spitfire and Concorde, are showcased in beautifully photographed... View Details


Aircraft Structures (Dover Books on Aeronautical Engineering)
by David J. Peery (Author)

Still relevant decades after its 1950 publication, this legendary reference text on aircraft stress analysis is considered the best book on the subject. It emphasizes basic structural theory, which remains unchanged with the development of new materials and construction methods, and the application of the elementary principles of mechanics to the analysis of aircraft structures.
Suitable for undergraduate students, this volume covers equilibrium of forces, space structures, inertia forces and load factors, shear and bending stresses, and beams with unsymmetrical cross sections. Additional... View Details


The World's Greatest Military Aircraft: An Illustrated History
by Thomas Newdick (Author)

Ever since man first took to the air, combat aircraft have been at the cutting edge of aviation technology, resulting in some of the greatest and most complex designs ever built. The World’s Greatest Military Aircraft features 52 of the most important military aircraft of the last hundred years. The book includes all the main types, from biplane fighters and carrier aircraft to tactical bombers, transport aircraft, multi role fighters, strategic strike aircraft and stealth bombers. Featured aircraft include: the Fokker Dr.1 triplane, the legendary fighter flown by German flying ace Manfred... View Details


Aircraft Maintenance and Repair, Seventh Edition
by Michael J Kroes (Author), William A Watkins (Author), Frank Delp (Author), Ronald Sterkenburg (Author)

GET UP-TO-DATE INFORMATION TO PERFORM RETURN-TO-SERVICE AIRCRAFT MAINTENANCE AND PASS YOUR FAA AIRCRAFT CERTIFICATION!

Aircraft Maintenance & Repair, Seventh Edition, is a valuable resource for students of aviation technology that provides updated information needed to prepare for an FAA airframe technician certification ― and can be used with classroom discussions and practical application in the shop and on aircraft. This expanded edition includes recent advances in aviation technology to help students fi nd employment as airframe and powerplant mechanics and other technical... View Details


Aircraft Propulsion
by Saeed Farokhi (Author)

New edition of the successful textbook updated to include new material on UAVs, design guidelines in aircraft engine component systems and additional end of chapter problems

Aircraft Propulsion, Second Edition follows the successful first edition textbook with comprehensive treatment of the subjects in airbreathing propulsion, from the basic principles to more advanced treatments in engine components and system integration.

This new edition has been extensively updated to include a number of new and important topics. A chapter is now included on General Aviation and... View Details


Aircraft Inspection, Repair & Alterations: Acceptable Methods, Techniques & Practices (FAA AC 43.13-1B and 43.13-2B) (FAA Handbooks series)
by Federal Aviation Administration (FAA)/Aviation Supplies & Academics (ASA) (Author)

This title's pub date will be changed to Jan.2013 via a database correction form after the submission is accepted and the ISBN is in the system.

This handbook for Aviation Maintenance Technicians (AMTs), repair stations, aircraft owners and homebuilders details the standards for acceptable methods, techniques, and practices for the inspection, repair, and alteration of aircraft. It is a combination of the two most important Advisory Circulars (ACs) written by the Federal Aviation Administration (FAA) on this topic—namely, "Acceptable Methods, Techniques, and Practices: Aircraft... View Details


Introduction to Aircraft Flight Mechanics: Performance, Static Stability, Dynamic Stability, Classical Feedback Control, and State-Space Foundations (AIAA Education) (AIAA Education Series)
by Thomas R Yechout (Author)

Introduction to Aircraft Flight Mechanics, Second Edition revises and expands this acclaimed, widely adopted textbook. Outstanding for use in undergraduate aeronautical engineering curricula, it is written for those first encountering the topic by clearly explaining the concepts and derivations of equations involved in aircraft flight mechanics. It begins with a review of basic aerodynamics and propulsion and continues through aircraft performance, equations of motion, static stability, linearizing equations of motion, dynamic stability, classical feedback control, stability and control... View Details


Aircraft Powerplants, Eighth Edition
by Thomas W. Wild (Author), Michael J Kroes (Author)

The most comprehensive, current guide to aircraft powerplants

Fully revised to cover the latest industry advances, Aircraft Powerplants, Eighth Edition, prepares you for certification as an FAA powerplant technician in accordance with the Federal Aviation Regulations (FAR). This authoritative text has been updated to reflect recent changes in FAR Part 147.

This new edition features expanded coverage of turbine-engine theory and nomenclature; current models of turbofan, turboprop, and turboshaft engines; and up-to-date details on turbine-engine fuel, oil, and ignition systems.... View Details


Aircraft Weight and Balance Handbook: FAA-H-8083-1B (FAA Handbooks series)
by Federal Aviation Administration (FAA)/Aviation Supplies & Academics (ASA) (Author)

Weight and balance is an important aspect to the safety of flight. An overweight aircraft, or one whose center of gravity is outside the allowable limits, is inefficient and dangerous to fly. The responsibility for proper weight and balance control begins with the engineers and designers, and extends to the pilot and mechanic who flies and maintains the aircraft. This Federal Aviation Administration (FAA) publication addresses this safety-crucial topic and in studying this handbook, pilots and Aviation Maintenance Technicians (AMTs) will gain the necessary knowledge on the subject of aircraft... View Details


Flight: 100 Greatest Aircraft
by Mark Phelps (Author), Flying Magazine Editors of (Author), Robert Goyer (Editor)

A comprehensive look at the world's great aircraft from the experts at Flying magazine, featuring spectacular full-color photographs, fascinating and informative text, and detailed specifications that will delight die-hard data fans.

Of all humanity’s dazzling innovations, perhaps none capture our imaginations or fuel our inventive spirits as much as flight. In our quest to soar higher, faster, and farther, we’ve dreamed up airborne wonders that are a sight to behold—like the supersonic F-22 Raptor, stealthily soaring above the clouds, or the Boeing-Stearman PT-17 Biplane,... View Details

Best Science Podcasts 2018

We have hand picked the best science podcasts for 2018. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

The Big Five
What are the five biggest global challenges we face right now — and what can we do about them? This hour, TED speakers explore some radical solutions to these enduring problems. Guests include geoengineer Tim Kruger, president of the International Rescue Committee David Miliband, political scientist Ian Bremmer, global data analyst Sarah Menker, and historian Rutger Bregman.
Now Playing: Science for the People

#456 Inside a Conservation NGO
This week we take a close look at conservation NGOS: what they do, how they work, and - most importantly - why we need them. We'll be speaking with Shyla Raghav, the Climate Change Lead at Conservation International, about using strategy and policy to tackle climate change. Then we'll speak with Rebecca Shaw, Lead Scientist at the World Wildlife Fund, about how and why you should get involved with conservation initiatives.