Preview

Aerodynamics of Hummingbird Flight

Powerful Essays
Open Document
Open Document
2795 Words
Grammar
Grammar
Plagiarism
Plagiarism
Writing
Writing
Score
Score
Aerodynamics of Hummingbird Flight
The Aerodynamics of Hummingbird Flight
Douglas R. Warrick* and Bret W. Tobalske.† Oregon State University, Corvallis Oregon 97331 and University of Portland, Portland OR 97203 Donald R. Powers‡ George Fox University, Newburg, OR 97132 and Michael H. Dickinson§ California Institute of Technology, Pasadena, CA 91125

[Abstract] Hummingbirds fly with their wings almost fully extended during their entire wingbeat. This pattern, associated with having proportionally short humeral bones, long distal wing elements, and assumed to be an adaptation for extended hovering flight, has lead to predictions that the aerodynamic mechanisms exploited by hummingbirds during hovering should be similar to those observed in insects. To test these predictions, we flew rufous hummingbirds (Selasphorus rufus, 3.3 g, n = 6) in a variable–speed wind tunnel (0-12 ms-1) and measured wake structure and dynamics using digital particle image velocimetry (DPIV). Unlike hovering insects, hummingbirds produced 75% of their weight support during downstroke and only 25% during upstroke, an asymmetry due to the inversion of their cambered wings during upstroke. Further, we have found no evidence of sustained, attached leading edge vorticity (LEV) during up or downstroke, as has been seen in similarly-sized insects - although a transient LEV is produced during the rapid change in angle of attack at the end of the downstroke. Finally, although an extended-wing upstroke during forward flight has long been thought to produce lift and negative thrust, we found circulation during downstroke alone to be sufficient to support body weight, and that some positive thrust was produced during upstroke, as evidenced by a vortex pair shed into the wake of all upstrokes at speeds of 4 – 12 m s-1.

I. Introduction
ITH a few exceptional intersections, the evolution of human-engineered flight and the study of the evolution of animal flight have been essentially parallel. Given the results of the earliest such



References: Greenwalt, C. H. “The wings of insects and birds as mechanical oscillators,” Proc. Amer. Phil. Soc. Vol. 104, 1960, pp. 605-611 Norberg, U. M. Vertebrate Flight: Mechanics, Physiology, Morphology, Ecology, And Evolution. Springer-Verlag, Berlin 1990 5 4 Wilmott, A. P. & Ellington, C. P. “The mechanics of flight in the hawkmoth Manduca sexta II. Aerodynamic consequences of kinematic and morphological variation,” J. Exp. Biol. Vol. 200, 1997, pp. 2723-2745 6 Warrick, D. R., , Tobalske, B. W., and Powers, D. R. “Aerodynamics of the hovering hummingbird,” Nature, Vol. 435, 2005, pp.1094-1097. Videler, J. J., Stamhuis, E. J., and Povel, G. D. E. “Leading-edge vortex lifts swifts,” Science, Vol. 306, 2004, pp. 1960-1962. Spedding, G. R., “The wake of a kestrel (Falco tinnunculus) in flapping flight,” J. Exp. Biol., Vol. 127, 1987, pp. 69-78.

You May Also Find These Documents Helpful

  • Good Essays

    Ubt1 Task 1

    • 1382 Words
    • 6 Pages

    duration of flight. “Double Wing” for example did not fly very far but seemed to float down to the…

    • 1382 Words
    • 6 Pages
    Good Essays
  • Powerful Essays

    The Beak of the Finch by Jonathan Weiner explores evolution through the most famous examples in history—the finches of the Galápagos Islands. Charles Darwin’s theory of natural selection and the process of evolution are applied directly to what scientists refer to as Darwin’s Finches. Weiner follows scientists Peter and Rosemary Grant as they study the finches in real time on the Galápagos. Years of previous work, study and data is collected and analyzed. Different species of animals are observed and explained throughout history. The Grants have one goal, and that is to find the origin of the species, how organisms first began. They find that it really is about the “survival of the fittest” and who nature selects to thrive and produce generations far greater than the last.…

    • 3277 Words
    • 14 Pages
    Powerful Essays
  • Good Essays

    Flight

    • 580 Words
    • 3 Pages

    Increasing angle of attack on any airfoil causes the area of the streamtube above the wing to decrease. This produces a greater velocity increase above the wing than below the wing. The greater velocity increases the pressure differential on a cambered airfoil. The greater pressure differential on…

    • 580 Words
    • 3 Pages
    Good Essays
  • Satisfactory Essays

    Beaks of Finches

    • 299 Words
    • 2 Pages

    Results: In this Lab, I learned that you need to be fast and particular with your movements to survive against other “finches.”…

    • 299 Words
    • 2 Pages
    Satisfactory Essays
  • Satisfactory Essays

    Some scientists expressed surprise at the idea that this species could fly at all, given that, at between 22 and 40 kg (48 and 88 lb), it would be considered too heavy by the predominant theory of the mechanism by which birds fly. Dan Ksepka of the National Evolutionary Synthesis Center in Durham, North Carolina, who discovered the new species, thinks it was able to fly in part because of its relatively small body and long wings, and because it, like the albatross, spent much of its time over the ocean, where the bird relied on wind currents rising up from the ocean to keep it aloft.…

    • 329 Words
    • 1 Page
    Satisfactory Essays
  • Satisfactory Essays

    They are about 2-5 inches long, and have poorly developed feet, which makes them unable to walk. Hummingbirds fly at about 30mph, but the males can fly up to 60mph during their mating dives. During this dive, their tail creates a 'song', which is used to attract a female. A hummingbird's brain is 4.2% of their body weight, the largest proportion in the bird kingdom. They are very smart, and can remember every flower they've been to, and how long it will take a flower to refill. Hummingbirds can see further and hear better than humans. A hummingbird's heart beats 250-1,260 times per minute. The female hummingbirds are usually larger than the males, but not in a few species. The average sized hummingbird has 940 feathers, and some hummingbirds migrate 500 miles over the Gulf of Mexico in about 20…

    • 464 Words
    • 2 Pages
    Satisfactory Essays
  • Good Essays

    References: Arce, I. (2003). Flying high. NEA Today, 21 (4), 38–39. Retrieved January 21, 2003 from the Proquest database.…

    • 889 Words
    • 4 Pages
    Good Essays
  • Good Essays

    References: clarisse. (2011, 02 8). The difference between Hawk and Falcon. Retrieved 09 22, 2011, from http://www.difference between.com…

    • 893 Words
    • 4 Pages
    Good Essays
  • Good Essays

    The Importance of Bees

    • 649 Words
    • 3 Pages

    Cited: Stipp, David. Flight of the honeybee. 156th ed. New York: time inc., 1992. Web. 13 Nov. 2010.…

    • 649 Words
    • 3 Pages
    Good Essays
  • Powerful Essays

    Most birds flap their wings up and down to fly, but the hummingbird moves its wings forward and backward very rapidly in a figure eight pattern.…

    • 987 Words
    • 4 Pages
    Powerful Essays
  • Powerful Essays

    Drosophila Melanogaster

    • 2009 Words
    • 6 Pages

    2. Elland, Carol; NASA Official: Navarro, BJ. Last Updated: September 2006. Accessed November 14, 2008 at http://quest.nasa.gov/projects/flies/lifeCycle.html…

    • 2009 Words
    • 6 Pages
    Powerful Essays
  • Good Essays

    Hummingbirds

    • 2893 Words
    • 12 Pages

    Hummingbirds are amazing to watch. They are able to fly up, down, forward, backward, sideways, and even upside down. In hovering flight, the wings move forward and backward--not up and down--and trace a figure-8, with lift being produced by both the forward AND backward strokes. Normal wing beat rate is about 80 times per second, up to 200 times per second in courtship flight. Hummingbirds are famous for their aerial display. Some displays are courtship displays; other displays are aggressive. They are able to perch and will do so at feeders regularly, but because they fly so much, their feet are poorly developed. They can barely walk at all. The…

    • 2893 Words
    • 12 Pages
    Good Essays
  • Good Essays

    The Habitat of Bats

    • 1060 Words
    • 5 Pages

    Bats are flying mammals in the order Chiroptera (pronounced /kaɪˈrɒptərə/). The forelimbs of bats are webbed and developed as wings, making them the only mammals naturally capable of true and sustained flight. By contrast, other mammals said to fly, such as flying squirrels, gliding possums and colugos, glide rather than fly, and can only glide for short distances. Bats do not flap their entire forelimbs, as birds do, but instead flap their spread out digits,[2] which are very long and covered with a thin membrane or patagium. Chiroptera comes from two Greek words, cheir (χείρ) "hand" and pteron (πτερόν) "wing."…

    • 1060 Words
    • 5 Pages
    Good Essays
  • Good Essays

    Hummingbirds

    • 784 Words
    • 4 Pages

    Miflin 2005. 161-180. The air passing over the top of the wing must travel further than the air going under the wing. As the hummingbird moves forward, the velocity of the fluid increases over the wing and the pressure above the wing is reduced. The higher end under the hummingbird 's wing provides lift for the bird. Hummingbirds have unusually strong muscles that enable them to raise and lower their wings with great power. As the hummingbirds thrust their wings up and down, they fly into the air with amazing agility and speed. The sleek outline of the bird and smooth feathers create little drag as the bird darts through the air. Thus, it will be to no surprise if we ever saw Hummingbirds flying upside down.…

    • 784 Words
    • 4 Pages
    Good Essays
  • Powerful Essays

    Boxfish Case Study

    • 1300 Words
    • 6 Pages

    The boxfish, living in chaotic, turbulent reefs, has over a long period of time, developed an ideal aerodynamic rectangular shape, which allows it to maintain stability naturally (no energy required), and allows for excellent manoeuvrability. In addition to this, the skeletal structure of a boxfish needed in an environment such as this, must be rigid, to prevent damage from collisions, yet light-weight, in order to manoeuvre around the reef. To achieve rigidness, but maintain its light-weightiness, boxfish’ have developed skeletons that emphasize reinforcement of skeletal tissue on areas with greater amount of stress, whereas have softer tissue on areas under less stress. This, in combination with the hexagonal-shaped structure of the skin and the ideal aerodynamic shape, provides optimum protection and manoeuvrability without sacrificing its lightness. The boxfish is an ideal model-organism to be emulated to improve sustainability in the motor…

    • 1300 Words
    • 6 Pages
    Powerful Essays