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Dolphins get a lift from delta wing technology
June 26, 2009We can only marvel at the way that dolphins, whales and porpoises scythe through water. Their finlike flippers seem perfectly adapted for maximum aquatic agility. However, no one had ever analysed how the animals' flippers interact with water; the hydrodynamic lift that they generate, the drag that they experience or their hydrodynamic efficiency. Laurens Howle and Paul Weber from Duke University teamed up with Mark Murray from the United States Naval Academy and Frank Fish from West Chester University, to find out more about the hydrodynamics of whale and dolphin flippers. They publish their finding that some dolphins' fins generate lift in the same way as delta wing aircraft on 26 June 2009 in The Journal of Experimental Biology at http://jeb.biologists.org
Using Computer tomography scanning of the fins of seven different species ranging from the slow swimming Amazon River dolphin and pygmy sperm whale to the super-fast striped dolphin, the team made scaled models of the flippers of each species. Then they measured the lift and drag experienced by the flipper at inclinations ranging from -45deg. to +45deg. in a flow tunnel running at a speed that would have been the equivalent of 2m/s for the full scale fin.
Comparing the lift and drag coefficients that the team calculated for each flipper at different inclination angles, they found that the flippers behave like modern engineered aerofoils. Defining the flippers' shapes as triangular, swept pointed or swept rounded, the team used computer simulations of the fluid flows around the flippers and found that sweptback flippers generate lift like modern delta wing aircraft. Calculating the flippers' efficiencies, the team found that the bottle nose dolphin's triangular flippers are the most efficient while the harbour porpoise and Atlantic white-sided dolphin's fins were the least efficient.
Commenting that environmental and performance factors probably play a significant role in the evolution of dolphin and whale flipper shapes and their hydrodynamics, Howle and his colleagues are keen to find out more about the link between the flippers' performances and the environment that whales and dolphins negotiate on a daily basis.
The Company of Biologists
Commenting that environmental and performance factors probably play a significant role in the evolution of dolphin and whale flipper shapes and their hydrodynamics, Howle and his colleagues are keen to find out more about the link between the flippers' performances and the environment that whales and dolphins negotiate on a daily basis.
The Company of Biologists
Dolphins Current Events and Dolphins News RSSFish vision discovery makes waves in natural selection
Emory University researchers have identified the first fish known to have switched from ultraviolet vision to violet vision, or the ability to see blue light. The discovery is also the first example of an animal deleting a molecule to change its visual spectrum.
Getting a leg up on whale and dolphin evolution
When the ancestors of living cetaceans-whales, dolphins and porpoises-first dipped their toes into water, a series of evolutionary changes were sparked that ultimately nestled these swimming mammals into the larger hoofed animal group.
Evidence Points to Conscious 'Metacognition' in Some Nonhuman Animals
J. David Smith, Ph.D., a comparative psychologist at the University at Buffalo who has conducted extensive studies in animal cognition, says there is growing evidence that animals share functional parallels with human conscious metacognition -- that is, they may share humans' ability to reflect upon, monitor or regulate their states of mind.
Hundreds of New Species Discovered in Fragile Eastern Himalayas
Over 350 new species including the world's smallest deer, a "flying frog" and a 100 million-year old gecko have been discovered in the Eastern Himalayas, a biological treasure trove now threatened by climate change.
Human language and dolphin movement patterns show similarities in brevity
Two researchers from the Polytechnic University of Catalonia (UPC) and the University of Aberdeen in the United Kingdom have shown for the first time that the law of brevity in human language, according to which the most frequently-used words tend to be the shortest, also extends to other animal species.
Spanish scientists develop echo-location in humans
A team of researchers from the University of Alcalá de Henares (UAH) has shown scientifically that human beings can develop echolocation, the system of acoustic signals used by dolphins and bats to explore their surroundings.
NOAA, USFWS study finds potential disease threats to Washington sea otters
Many of Washington State's sea otters are exposed to the same pathogens responsible for causing disease in marine mammal populations in other parts of the country.
Dolphins maintain round-the-clock visual vigilance
Dolphins have a clever trick for overcoming sleep deprivation. Sam Ridgway from the US Navy Marine Mammal Program explains that they are able to send half of their brains to sleep while the other half remains conscious.
The numerate honey bee
The remarkable honey bee can tell the difference between different numbers at a glance. A fresh, astonishing revelation about the 'numeracy' of insects has emerged from new research by an international team of scientists from The Vision Centre, in Australia, published January 28 in the online, open-access, peer-reviewed journal PLoS ONE.
"Gray's Paradox" Solved: Researchers Discover Secret of Speedy Dolphins
There was something peculiar about dolphins that stumped prolific British zoologist Sir James Gray in 1936.
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Light up Dolphins Animal Sculpture Led Lamp Lighting by Jed Mart A crystal reef glows with a hauntingly beautiful light, adding undersea magic to a long, dark night! Clear pink "coral" and three dancing dolphins are bathed in a soothing blue glow from a hidden LED light. A fanciful decoration sure to delight the most ardent dolphin admirer! Polyresin with wood base. Uses three cell batteries (included). 5 1/4" x 4 1/2" x 6 1/2" high. |
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DOLPHIN Crystal Necklace in Blue Dolphin Gift Box by Abernook Gorgeous Pendant with genuine European Crystals in a matching Velour Hinged Gift Box! Our entire series of these cute animal necklaces makes wonderful gifts! Each pendant hands on an 18" chain, genuine European crystals and 18 kt gold finish. Get one of each style! |
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Everything Dolphin: What Kids Really Want to Know about Dolphins (Kids' Faqs) by Marty Crisp (Author) Everything Dolphin... What Kids Really Want to Know About Dolphins. Dolphins captivate us with their intelligence, their chattering and their amazing jumping! These truly cool animals are the latest focus in the popular Kids' FAQs(tm) series, based on real questions from real kids. In addition to providing basic information like habitat, diet, species distinction, and life cycle, this book delves into the more unusual--but equally important--questions, like "Why are dolphins always smiling?" Everything Dolphin is packed full of useful information and fun trivia. Parents and teachers agree, the Kids' FAQs(tm) series is perfect for budding scientists or simply curious kids. Also available in hardcover. |
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Sterling Silver Diamond Cut Kissing Dolphin Pendant With Entwined Tails by JewelryWeb Sterling Silver Diamond Cut Kissing Dolphin Pendant With Entwined Tails - in Sterling Silver - Ships Without a Chain - - JewelryWeb Style: ISC21295NC - FREE gift-ready jewelry box |
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Lekue Silicone Ice Cube Tray, Dolphin by Lekue Lekue Fancy Shapes trays are made out of FDA approved recycleable rubber. They are ideal for making cool shaped ice cubes and also for molding gelatin for fun snacks. Non-stick and bendable, ice cubes pop right out and Lekue ice cube trays never lose their shape, whatever shapes you choose. Try using colored punch, food coloring, juices or lemonade in the tray to make awesome cubes! |
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Uncle Milton Zen Dolphin by Uncle Milton This is the Zen Dolphin Swimming from Uncle Milton / Suitable for Ages 10 & Older / / FEATURES: Smooth swimming dolphin movement / Brilliant blue LED illumination / Natural ocean and dolphin sounds / Volume, light and auto timer controls / Detailed user guide / / INCLUDES: One Zen Dolphin Swimming Illuminated Swimming Dolphin / / REQUIRES: (3) C Batteries (SANP3503) / AC adapter (not included) 120V AC, 60Hz 6V DC output. Available at / most home electronics retail stores / / tlw 10/4/07 / ir/jxs |
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Color glass carousel dolphins - Style 30308 by Gift Warehouse Frosted dolphins frolic around this spun glass carousel with its pink, mirrored base. A touch sends the carousel spinning, shimmering with gold plated highlights. 3 3/8'' diameter x 6 1/4'' high. |
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