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Soaring Birds as “Maxwell Demons”

  • Ferdinand Hendriks

Abstract

The suggestion implied in the title of this theoretical article was made by Samuel Langley (1893) in his treatise “The Internal Work of the Wind”. He, like a number of other scientists of his time, during which there was great curiosity about bird flight and, as a consequence, about the nature of the wind, was particularly fascinated by the question if birds might in some sense rectify the turbulent fluctuations of the wind as a means to offset their drag, and thereby stay aloft. Until it was discovered by Idrac (1931) that thermal updraughts must in most cases be considered the true source of energy in soaring, there was lively debate over the ways in which turbulence might be exploitable in flight. The work of Klemperer (1926) and Breguet (1925) is typical in this respect.

Keywords

Aerodynamic Force Turbulent Fluctuation Inertial Subrange Lively Debate Black Kite 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. Batchelor, G. K. 1953 The Theory of Homogeneous Turbulence. Cambridge University Press.Google Scholar
  2. Bréguet, L., 1925 Le Vol à Voile Dynamique des Oiseaux. Gauthiers-Villars, Paris.Google Scholar
  3. Hendriks, F. 1972 Dynamic Soaring. Ph. D. thesis, UCLA.Google Scholar
  4. Idrac, P. 1931 Études Éxpérimentales sur le Vol à Voile. Vivien, Paris.Google Scholar
  5. Klemperer, W. B. 1926 Theorie des Segelfluges. Abh. aus. dem Aerod. Inst. an der Techn. Hochschule Aachen, Heft 5.Google Scholar
  6. Langley, S. P. 1893 The internal work of the wind. Smithsonian Contributions to Knowledge, No. 884.Google Scholar
  7. Pennycuick, C. J. 1972 Soaring behaviour and performance of some East African birds, observed from a motor glider. Ibis, 114, 178–218.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1975

Authors and Affiliations

  • Ferdinand Hendriks
    • 1
  1. 1.IBM Thomas J. Watson Research CenterYorktown HeightsUSA

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