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Stroke plane angle controls leading edge vortex in a bat-inspired flapper

Koekkoek, Gide; Muijres, Florian LU ; Johansson, Christoffer LU ; Stuiver, Melanie; van Oudheusden, Bas W. and Hedenström, Anders LU (2012) In Comptes Rendus. Mecanique 340(1-2). p.95-106
Abstract
The present interest in micro air vehicles has given the research on bat flight a new impulse. With the use of high speed cameras and improved PIV techniques, the kinematics and aerodynamics of bats have been studied in great detail. A robotic flapper makes it possible to do measurements by systematically changing only one parameter at a time and investigate the parameter space outside the natural flight envelope of bats without risking animal safety. For this study, a robotic flapper (RoBat), inspired by Leptonycteris yerbabuenae was developed and tested over the speed range 1-7 m/s, with variable maximum angles of attacks (AoA(max) = 55 degrees and 15 degrees, respectively) and constant AoA(max). = 55 degrees. These measurements show the... (More)
The present interest in micro air vehicles has given the research on bat flight a new impulse. With the use of high speed cameras and improved PIV techniques, the kinematics and aerodynamics of bats have been studied in great detail. A robotic flapper makes it possible to do measurements by systematically changing only one parameter at a time and investigate the parameter space outside the natural flight envelope of bats without risking animal safety. For this study, a robotic flapper (RoBat), inspired by Leptonycteris yerbabuenae was developed and tested over the speed range 1-7 m/s, with variable maximum angles of attacks (AoA(max) = 55 degrees and 15 degrees, respectively) and constant AoA(max). = 55 degrees. These measurements show the presence of a leading edge vortex (LEV) for low speeds and a fully attached flow for high speeds at low AoA(max), which is in line with natural bat flight. A LEV occurs for AoA(max) = 55 degrees throughout the complete flight speed range, and throughout which the LEV circulation coefficient remains rather constant. This implies that bats and micro air vehicles could use LEVs for high load maneuvers also at relatively high flight speeds. However, at high flight speeds the LEV bursts, which causes increased drag, most likely due to a decrease in Strouhal number. (C) 2011 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Aerodynamics, Bat flight, Bio-inspired robot, Leading edge vortex, Micro, air vehicle
in
Comptes Rendus. Mecanique
volume
340
issue
1-2
pages
95 - 106
publisher
Editions scientifiques Elsevier
external identifiers
  • wos:000300763400009
  • scopus:84856228355
ISSN
1873-7234
DOI
10.1016/j.crme.2011.11.013
project
CAnMove
language
English
LU publication?
yes
id
b01f4e1c-fab9-4f36-8392-6a4761fc97c1 (old id 2390653)
date added to LUP
2012-04-02 10:45:15
date last changed
2017-01-29 03:15:54
@article{b01f4e1c-fab9-4f36-8392-6a4761fc97c1,
  abstract     = {The present interest in micro air vehicles has given the research on bat flight a new impulse. With the use of high speed cameras and improved PIV techniques, the kinematics and aerodynamics of bats have been studied in great detail. A robotic flapper makes it possible to do measurements by systematically changing only one parameter at a time and investigate the parameter space outside the natural flight envelope of bats without risking animal safety. For this study, a robotic flapper (RoBat), inspired by Leptonycteris yerbabuenae was developed and tested over the speed range 1-7 m/s, with variable maximum angles of attacks (AoA(max) = 55 degrees and 15 degrees, respectively) and constant AoA(max). = 55 degrees. These measurements show the presence of a leading edge vortex (LEV) for low speeds and a fully attached flow for high speeds at low AoA(max), which is in line with natural bat flight. A LEV occurs for AoA(max) = 55 degrees throughout the complete flight speed range, and throughout which the LEV circulation coefficient remains rather constant. This implies that bats and micro air vehicles could use LEVs for high load maneuvers also at relatively high flight speeds. However, at high flight speeds the LEV bursts, which causes increased drag, most likely due to a decrease in Strouhal number. (C) 2011 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.},
  author       = {Koekkoek, Gide and Muijres, Florian and Johansson, Christoffer and Stuiver, Melanie and van Oudheusden, Bas W. and Hedenström, Anders},
  issn         = {1873-7234},
  keyword      = {Aerodynamics,Bat flight,Bio-inspired robot,Leading edge vortex,Micro,air vehicle},
  language     = {eng},
  number       = {1-2},
  pages        = {95--106},
  publisher    = {Editions scientifiques Elsevier},
  series       = {Comptes Rendus. Mecanique},
  title        = {Stroke plane angle controls leading edge vortex in a bat-inspired flapper},
  url          = {http://dx.doi.org/10.1016/j.crme.2011.11.013},
  volume       = {340},
  year         = {2012},
}