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※twitterでUCニュース配信はじめました。ユーザー名 a77a フォロー自由です

2008/07/15

フロリダ大、キャパシタを搭載し、プラズマを発生して飛行する空飛ぶ円盤を考


WEAV: A cross-section of the Wingless Electromagnetic Air Vehicle, where the yellow dashes outside the craft are electrodes for ionizing surrounding air. The inside of the WEAV would house a camera, control system, battery (or some other power source) and payload.
Courtesy of Ryan Durscher, Computational Plasma Dynamics Laboratory and Test Facility, University of Florida


http://www.sciam.com/article.cfm?id=worlds-first-flying-saucer&sc=rss
The World's First Flying Saucer: Made Right Here on Earth
A University of Florida researcher has plans on the drawing board for a saucer-shaped aircraft that turns the surrounding air into fuel
By Larry Greenemeier
If a professor at the University of Florida (U.F.) has his way, the first flying saucer to grace Planet Earth's skies isn't likely to come from outer space but rather from Gainesville, where the faculty member is drawing up plans to build a circular aircraft that can hover in the air like a helicopter without any moving parts or fuel.In other words, it will look like a UFO, but will actually be more of an IFO—an identified flying object.The saucer will hover and propel itself using electrodes that cover its surface to ionize the surrounding air into plasma. Gases (such as air, which has an equal number of positive and negative charges) become plasma when energy (such as heat or electricity) causes some of the gas's atoms to lose their negatively charged electrons, creating atoms with a positive charge, or positive ions, surrounded by the newly detached electrons. Using an onboard source of energy (such as a battery, ultracapacitor, solar panel or any combination thereof), the electrodes will send an electrical current into the plasma, causing the plasma to push against the neutral (noncharged) air surrounding the craft, theoretically generating enough force for liftoff and movement in different directions (depending on where on the craft's surface you direct the electrical current).The concept sounds far-fetched, but U.F. mechanical and aerospace engineering associate professor Subrata Roy plans to have a mini model ready to demonstrate his theory within the next year.At six inches (15.2 centimeters) in diameter, the device, which Roy calls a "wingless electromagnetic air vehicle" (WEAV), will truly be a flying saucer. Theoretically, Roy says, the flying saucer can be as large as anyone wants to build it, because the design gives the aircraft balance and stability. In other words, this type of aircraft could someday be built large enough to ferry around people. But, Roy says, "we need to walk before we can run, so we're starting small."The biggest hurdle to building a WEAV large enough to carry passengers would be making the craft light, yet powerful enough to lift its cargo and energy source. Roy is not sure what kind of energy source he will use yet. He anticipates that the craft's body will be made from a material that is an insulator such as ceramic, which is light and a good conductor of electricity. "In theory you probably should be able to scale it up," says Anthony Colozza, a researcher with government contractor Analex Corporation who is stationed at NASA's Glenn Research Center in Cleveland and helped Roy draw up the original plans for powering the saucer. The choice of a power source that is powerful, yet lightweight is "probably going to be the thing that makes or breaks it."Roy began designing the WEAV in 2006. The following year, he and Colozza wrote a paper for the now-defunct NASA Institute for Advanced Concepts (NIAC) about the use of electrohydrodynamics, or ionized particles, as an alternative to liquid fuel for powering space vehicles. When NASA shut down NIAC in August 2007, Roy decided to continue his work at U.F.If he's successful, Roy hopes to develop a more stable aircraft and a new form of fuel—air. Other craft that interact with the atmosphere have a problem: moving parts, whether jet engines, propellers or rotors. "My interest started when I saw inherent problems in helicopters and airplanes," Roy says. If these parts stop moving, the aircraft falls from the sky. The flying saucer, on the other hand, has no moving parts.In theory, the WEAV would be more stable than an aircraft—airplanes and helicopters, for example—that rely on aerodynamics to provide lift. Using a plasma field, "you could produce lift in any direction, you could change direction quickly and that power could be turned on or off almost instantly," Colozza says. If the pilot wanted such an aircraft to move to the right, he or she would increase power to electrodes on the left side of the craft and vice versa for moving to the left. Electrodes on the bottom of the craft would power its lift, whereas those on top would bring the craft back down to Earth.Assuming Roy's WEAV prototype gets off the ground next year—and that's a big if—it could prove useful in a number of ways. What makes the WEAV potentially appealing as a way to power spacecraft is that it relies on electricity (from a battery or some other power source) rather than combustion—a process that requires oxygen, which is in short supply outside Earth's atmosphere, Colozza says. Still, the WEAV's biggest fans are likely to be in the U.S. military, who would use the craft as a drone for gathering intelligence, reconnaissance and surveillance information.Roy has been working with the U.S. Air Force Research Laboratory at Wright-Patterson Air Force Base in Dayton, Ohio, since 2001 to study how plasma could be used to control the flow of air—pushing air in different directions—and thereby the vehicle's movements. "If plasma (flow) is turned on the right way, I can blow air any direction I want to blow air," says Doug Blake, deputy director of the Air Force Research Lab's Air Vehicles Directorate, of the craft's ability to push air away from itself. "If I have a jet coming out of the bottom of this, I can create a helicopter with no moving parts. Things that you would use a helicopter for, you could use this for."But this does not mean the Air Force is ready to order a fleet of Roy's flying saucers. "We have worked with (Roy) on plasma studies but there are no concrete plans in place that I'm aware of to explicitly support the development of this device," Blake says.At this early stage, and without a clear decision on how the craft will be powered, Roy says it is unclear how much a WEAV might cost to build and operate. Still, he is optimistic. "All of the materials needed to make this aircraft currently exist," he says, "and plasma is the most abundant form of matter in the universe. If we can somehow tap into that in the future we should be able to fly anywhere."
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WEAV ON THE MOVE: This artist's illustration depicts what a WEAV might look like as it flies in the atmosphere above Mars.
Courtesy of Danielle Zawoy, University of Florida

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PLASMA JET: The strong plasma jet pictured might be useful in the development of the WEAV.
Courtesy of the University of Florida Computational Plasma Dynamics Laboratory and Test facility


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