Pterodactyl-inspired flying robots
According to Sankar Chatterjee, a professor of paleontology at the Texas Tech University in Lubbock (TTU), a 225-million-year-old pterodactyl might soon be reborn as a flying robot. The Tapejara wellnhoferi, which lived in Brazil, was a big flying lizard with an unusual 'accessory,' an 8-inch-high fleshy crest stuck straight up from its head. This crest probably acted like a rudder. Chatterjee is now teaming with engineers to mimic this pterosaur crest for designing a cutting-edge robotic aircraft. Read more...
According to this page at Wikipedia, "Tapejara (from a Tupi word meaning 'the old being') is a genus of Brazilian pterosaur from the Cretaceous Period. Several species existed including the Tapejara wellnhoferi studied at TTU and the Tapejara navigans shown above (Credit: Dmitry Bogdanov, link to a WikiMedia Commons larger version) TTU adds that "this illustration shows an artist's conception of a Tapejara pterosaur. Noting the ancient creature's agile flying design, researchers are planning to build an autonomous aircraft with a crest on its head."
This research work has been led by Dr. Sankar Chatterjee, Curator of Paleontology and Paul Whitfield Horn Professor in Geosciences and Museum Science at Texas Tech University. Now, he's working with aerospace engineer Richard Lind, an associate professor at the University of Florida.
Here are some explanations from Lind. "On most aircraft the vertical tail fin is at the back, where it functions as a stabilizer. Slight shifts in its position act like a rudder to push a plane into smooth, banking turns. The pterosaur's head crest is like having the tail at the front of the plane, Lind said. As the animal turned its head, it could execute drastic, sharp turns, making it incredibly agile. 'It's really good for turn radius and tracking prey while it flies,' he said. 'But it's inherently unstable. The tradeoff is it probably had to move its wings a lot more to fly.' Later this year, Lind plans to affix a metal fin to the head of a conventional remote-controlled flying vehicle to test how well the design works. If it's airworthy, he plans to move on to a model that steers using its head."
So we'll have to wait before seeing flying robots inspired by pterosaurs. In the mean time, for more information about Chatterjee's latest work, you can read "Prehistoric Monsters Take Flight" (John Davis, Texas Tech Today, July 25, 2008). But it's not the first time that Chatterjee has studied how other dinosaurs were flying.
For example, you can take a look at how he discovered how 'big birds' flew" (John Davis, Texas Tech University, July 2, 2007). Here is a short quote. "At the size of a Cessna 152 light aircraft, the world’s largest bird couldn't take off entirely by flapping its wings. It just wasn't strong enough. But when it came to flying, Argentavis maginicens glided lazily on updrafts and thermals as it searched for prey and soared over the Andes Mountains just as modern condors would do 6 million years later, said Sankar Chatterjee, Horn professor of museum sciences and curator of paleontology at the Museum of Texas Tech University. Once airborne, the bird could take 200-mile trips across the sky with ease."
Here is a second excerpt. "'Think about a super-sized bald eagle with a 21-foot wingspan,' Chatterjee said. 'It would darken the sky. It's almost like a tale from the 'Arabian Nights.' It was a very aggressive bird that flew over the pampas of Argentina to sweep down from the sky and seize large prey with a formidable beak.' Chatterjee said he and other scientists estimated the flight parameters of fossilized Argentavis bones and put that data into two computer algorithms commonly used in flight simulation. Based on the power that would have been available from its pectoral muscles, the authors concluded that Argentavis would have been incapable of flight powered entirely by wing flapping, but could soar efficiently."
This research work has been published in the Proceedings of the National Academy of Sciences (PNAS) under the title "The aerodynamics of Argentavis, the world's largest flying bird from the Miocene of Argentina" (Volume 104, Number 30, Pages 12398-12403, July 24, 2007). Here are several links to the abstract, the full text and a PDF version (6 pages, 715 KB).
Earlier in 2007, Chatterjee published another paper about a feathered dinosaur named Microraptor gui, and "his discovery ignited discussion around the world, according to TTU (Gretchen Pressley, Texas Tech University, January 23, 2007). Here is the introduction. "After a careful re-examination of fossil remains from one of the earliest-known flying dinosaurs, a Texas Tech researcher along with a retired aeronautical engineer from Ottawa, Canada, have discovered that this feathered dinosaur used two sets of wings, much like the design of a biplane. The flying dinosaur, called Microraptor gui, inhabited the earth during the Cretaceous period in northeastern China 125 million years ago, says Sankar Chatterjee. [...] According to his research, the dinosaur may have used its double sets of feathers as upper and lower sets of wings, much like the biplanes of the Wright Brothers."
This research work has also been published in PNAS under the title "Biplane wing planform and flight performance of the feathered dinosaur Microraptor gui" (Volume 104, Number 5, Pages 1576-1580, January 22, 2007). Here are several links to the abstract, the full text and a PDF version (5 pages, 967 KB).
Sources: Michael Reilly, Discovery News, September 29, 2008; and various websites
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