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Hovering hummingbird wing aerodynamics during the annual cycle. I. Complete wing

The diverse hummingbird family (Trochilidae) has unique adaptations for nectarivory, among which is the ability to sustain hover-feeding. As hummingbirds mainly feed while hovering, it is crucial to maintain this ability throughout the annual cycle—especially during flight-feather moult, in which wi...

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Detalles Bibliográficos
Autores principales: Achache, Yonathan, Sapir, Nir, Elimelech, Yossef
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The Royal Society Publishing 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5579086/
https://www.ncbi.nlm.nih.gov/pubmed/28878971
http://dx.doi.org/10.1098/rsos.170183
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author Achache, Yonathan
Sapir, Nir
Elimelech, Yossef
author_facet Achache, Yonathan
Sapir, Nir
Elimelech, Yossef
author_sort Achache, Yonathan
collection PubMed
description The diverse hummingbird family (Trochilidae) has unique adaptations for nectarivory, among which is the ability to sustain hover-feeding. As hummingbirds mainly feed while hovering, it is crucial to maintain this ability throughout the annual cycle—especially during flight-feather moult, in which wing area is reduced. To quantify the aerodynamic characteristics and flow mechanisms of a hummingbird wing throughout the annual cycle, time-accurate aerodynamic loads and flow field measurements were correlated over a dynamically scaled wing model of Anna’s hummingbird (Calypte anna). We present measurements recorded over a model of a complete wing to evaluate the baseline aerodynamic characteristics and flow mechanisms. We found that the vorticity concentration that had developed from the wing’s leading-edge differs from the attached vorticity structure that was typically found over insects’ wings; firstly, it is more elongated along the wing chord, and secondly, it encounters high levels of fluctuations rather than a steady vortex. Lift characteristics resemble those of insects; however, a 20% increase in the lift-to-torque ratio was obtained for the hummingbird wing model. Time-accurate aerodynamic loads were also used to evaluate the time-evolution of the specific power required from the flight muscles, and the overall wingbeat power requirements nicely matched previous studies.
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spelling pubmed-55790862017-09-06 Hovering hummingbird wing aerodynamics during the annual cycle. I. Complete wing Achache, Yonathan Sapir, Nir Elimelech, Yossef R Soc Open Sci Biology (Whole Organism) The diverse hummingbird family (Trochilidae) has unique adaptations for nectarivory, among which is the ability to sustain hover-feeding. As hummingbirds mainly feed while hovering, it is crucial to maintain this ability throughout the annual cycle—especially during flight-feather moult, in which wing area is reduced. To quantify the aerodynamic characteristics and flow mechanisms of a hummingbird wing throughout the annual cycle, time-accurate aerodynamic loads and flow field measurements were correlated over a dynamically scaled wing model of Anna’s hummingbird (Calypte anna). We present measurements recorded over a model of a complete wing to evaluate the baseline aerodynamic characteristics and flow mechanisms. We found that the vorticity concentration that had developed from the wing’s leading-edge differs from the attached vorticity structure that was typically found over insects’ wings; firstly, it is more elongated along the wing chord, and secondly, it encounters high levels of fluctuations rather than a steady vortex. Lift characteristics resemble those of insects; however, a 20% increase in the lift-to-torque ratio was obtained for the hummingbird wing model. Time-accurate aerodynamic loads were also used to evaluate the time-evolution of the specific power required from the flight muscles, and the overall wingbeat power requirements nicely matched previous studies. The Royal Society Publishing 2017-08-23 /pmc/articles/PMC5579086/ /pubmed/28878971 http://dx.doi.org/10.1098/rsos.170183 Text en © 2017 The Authors. http://creativecommons.org/licenses/by/4.0/ Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited.
spellingShingle Biology (Whole Organism)
Achache, Yonathan
Sapir, Nir
Elimelech, Yossef
Hovering hummingbird wing aerodynamics during the annual cycle. I. Complete wing
title Hovering hummingbird wing aerodynamics during the annual cycle. I. Complete wing
title_full Hovering hummingbird wing aerodynamics during the annual cycle. I. Complete wing
title_fullStr Hovering hummingbird wing aerodynamics during the annual cycle. I. Complete wing
title_full_unstemmed Hovering hummingbird wing aerodynamics during the annual cycle. I. Complete wing
title_short Hovering hummingbird wing aerodynamics during the annual cycle. I. Complete wing
title_sort hovering hummingbird wing aerodynamics during the annual cycle. i. complete wing
topic Biology (Whole Organism)
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5579086/
https://www.ncbi.nlm.nih.gov/pubmed/28878971
http://dx.doi.org/10.1098/rsos.170183
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