Blended wing body

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Computer-generated model of the NASA BWB.

NASA's prototype of a Blended Wing aircraft

Blended Wing Body, or BWB, designates an alternative airframe design which incorporates design features from both a futuristic fuselage and flying wing design. The purported advantages (see Potential advantages below) of the BWB approach are efficient high-lift wings and a wide airfoil-shaped body. This enables the entire craft to contribute to lift generation with the result of potentially increased fuel economy.

Flying wing designs are defined as having two separate bodies and only a single wing, though there may be structures protruding from the wing. Blended wing/body aircraft have a flattened and airfoil shaped body, which produces most of the lift to keep itself aloft, and distinct and separate wing structures, though the wings are smoothly blended in with the body.

[edit] History

An early aircraft exhibiting BWB design principles was the Junkers G.38, which flew in 1929. This "super jumbo" airliner of its day, seated thirty-four passengers, six in each of its two meter thick wings, and the balance in the central fuselage. In comparison, a contemporary passenger aircraft, the Ford Trimotor, carried a total of nine passengers in its more traditional wing and box fuselage design. Another example of similar design is Burnelli CBY-3. It had an airfoil shaped fuselage, producing significant part of the total lift. The CBY-3 had however a fairly conventional twin-boom empennage for added stability.

The Miles M.30 "X Minor" of the early 1940s was an experimental aircraft for research blended wing fuselage designs for a envisaged large airliner.

In some ways, the B-2 Spirit stealth bomber is a design which falls between classic flying wing concepts and the BWB concept. It is usually classified as a flying wing, however, as the protruding body sections are not much larger than the underlying wing shape structure.

Currently, both NASA and Boeing are exploring BWB designs under the designation X-48.^[1] Studies suggest that BWB aircraft, configured for passenger flight, could carry from 450 to 800 passengers and achieve fuel savings of over 20 percent. NASA has been developing, since 2000, a remotely controlled model with a 21 ft (6.4 m) wingspan. This research is focused on establishing the base data concerning the lift, stall and spin characteristics inherent in a Blended Wing Body design.

Progression of aircraft design concepts from conventional airliner (1), blended wing-body (2), hybrid flying wing (3), flying wing (4). Note that the progression does not represent either a chronological or technical progression; the YB-49 (4), representing a true flying wing, actually predates all other depicted aircraft, while the "conventional" Boeing 757 (1) is a relatively new and technologically advanced aircraft.

[edit] Potential advantages

• Significant payload advantages in strategic airlift/air freight^[2] and aerial refueling roles

[edit] See also

• List of flying wings
• Northrop YB-49

[edit] References

[edit] External links

• "The Blended-Wing-Body", NASA Facts
• ‘Blended wing’ craft passes wind-tunnel tests NewScientist.com news service, 14 November 2005
• How design of SAX-40 aircraft reduces noise and improve efficiency
• Progress on the Wingco Atlantica small BWB plane
• Airliners.net photo of the Atlantica prototype aircraft, July 2004
• "Truth Or Fiction" on the rumour of the Boeing 797 blended wing passenger liner
• Blended Wing Body, HAW Hamburg
• Photo-realistic image of blended wing airliner taxiing at airport