Blended wing body
Blended Wing Body (BWB or Hybrid Wing Body, HWB) aircraft have a flattened and airfoil shaped body, which produces most of the lift, the wings contributing the balance. The body form is composed of distinct and separate wing structures, though the wings are smoothly blended into the body. By way of contrast, flying wing designs are defined as a tailless fixed-wing aircraft which has no definite fuselage, with most of the crew, payload and equipment being housed inside the main wing structure.
A blended wing body has lift-to-drag ratio 50% greater than a conventional airplane. Thus BWB incorporates design features from both a futuristic fuselage and flying wing design. Thepurported advantages 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 and range.
Blended Wing Bodies
| Year | Model | Description |
|---|---|---|
| 1944 | Burnelli CBY-3 | |
| 1996 | Lockheed Martin/Boeing RQ-3 DarkStar | |
| 2002 | Boeing X-45C | unmanned aircraft |
| 2003 | Northrop Grumman X-47 Pegasus | unmanned aircraft |
| 2003 | Silent Aircraft Initiative | |
| 2007 | Boeing X-48 |
Popular Science concept
A concept photo of a blended wing body commercial aircraft appeared in the October 2003 issue of Popular Sciencemagazine. Artists Neill Blomkamp and Simon van de Lagemaat from The Embassy Visual Effects created the photo for the magazine using computer graphics software, to depict the future of aviation and air travel. It is likely the photo was inspired by models of BWB-450, a pre-X-48 concept designed in the late 1990s or the X-48A concept designed around 2001.
Boeing 797 hoax Emails and articles using the concept photo from the Popular Science magazine have been circulating since 2006 or earlier. These claim Boeing has developed a "1000 passenger Jet Liner" with a "radical Blended Wing design" in cooperation with NASA Langley Research Center, in direct competition to the Airbus A380. The email also claims this aircraft is called the Boeing 797 and it "can comfortably fly 10,000 miles" at a speed of "Mach 0.88 or 654 mph". The photos are claimed to have been shot by an amateur photographer.
Boeing has reportedly responded to inquiries, stating the information about the blended wing body commercial aircraft is a hoax. Randy Baseler, Vice President of Marketing for Boeing Commercial Airplanes until 2007, also stated in his blog that the claims are false and that "someone was having a bit of fun with Photoshop perhaps." The hoax email has remained in circulation and some websites still report this as truth.
Oblique wing
An oblique wing (also called a slew wing) is a variable geometry wing concept. On an aircraft so equipped, the wing is designed to rotate on center pivot, so that one tip is swept forward while the opposite tip is swept aft. By changing its sweep angle in this way, drag can be reduced at high speed (with the wing swept) without sacrificing low speed performance (with the wing perpendicular)
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DARPA Oblique Flying-Wing (OFW) Project
The United States Defence Advanced Research Projects Agency (DARPA) has awarded Northrop Grumman a $10.3 million (USD) contract for risk reduction and preliminary planning for an X-plane OFW demonstrator.,known as the Switchblade.
The program aims at producing a technology demonstrator aircraft to explore the various challenges which the radical design entails. The proposed aircraft would be a pure flying wing (an aircraft with no other auxiliary surfaces such as tails, canards or a fuselage) where the wing is swept with one side of the aircraft forward, and one backwards in an asymmetric fashion. This aircraft configuration is believed to give it a combination of high speed, long range and long endurance. The program entails two phases. Phase I will explore the theory and result in a conceptual design, while Phase II will result in the design, manufacture and flight test of an aircraft. The outcome of the program will result in a dataset that can then be used when considering future military aircraft designs.
Wind tunnel tests for the aircraft design has been completed. The design was noted to be "workable and robust."
Closed wing
- A closed wing is a non-planar wing planform concept. The term closed wing encompasses a number of designs, including the annular wing(commonly known as the cylindrical or ring wing), the joined wing, and the box wing. A closed wing can be thought of as the maximum expression of a wingtip device, which has the aim of eliminating the influence of the wingtip vortices which occur at the tips of conventional wings. These vortices form a major component of wake turbulence and are associated with induced drag, which negatively affects aerodynamic performance in most regimes. A closed wing surface has no wingtips whatsoever, and thus is capable of greatly reducing or eliminating wingtip drag, which has great implications for the improvement of fuel efficiency in the airline industry.
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