Repository logo

Infoscience

  • English
  • French
Log In
Logo EPFL, École polytechnique fédérale de Lausanne

Infoscience

  • English
  • French
Log In
  1. Home
  2. Academic and Research Output
  3. Journal articles
  4. To tread or not to tread: comparison between water treading and conventional flapping wing kinematics
 
research article

To tread or not to tread: comparison between water treading and conventional flapping wing kinematics

Krishna, Swathi  
•
Gehrke, Alexander  
•
Mulleners, Karen  
November 1, 2022
Bioinspiration & Biomimetics

Hovering insects are limited by their physiology and need to rotate their wings at the end of each back-and-forth motion to keep the wing's leading edge ahead of its trailing edge. The wing rotation at the end of each half-stroke pushes the leading edge vortex away from the wing which leads to a loss in the lift. Unlike biological fliers, human-engineered flapping wing micro air vehicles have different design limitations. They can be designed to avoid the end of stroke wing rotation and use so-called water-treading flapping kinematics. Flapping wings using conventional flapping kinematics have a designated leading and trailing edge. In the water-treading mode, the role of the leading and trailing edges are continuously alternated throughout the stroke. Here, we compare velocity field and force measurements for a rectangular flapping wing conducting normal hovering and water-treading kinematics to study the difference in fluid dynamic performance between the two types of flapping kinematics. We show that for similar power consumption, the water-treading mode produces more lift than the conventional hovering mode and is 50% more efficient for symmetric pitching kinematics. In the water-treading mode, the leading edge vortex from the previous stroke is not pushed away but is captured and keeps the newly formed leading edge vortex closer to the wing, leading to a more rapid increase of the lift coefficient which is sustained for longer. This makes the water-treading mode a promising alternative for human-engineered flapping wing vehicles.

  • Details
  • Metrics
Type
research article
DOI
10.1088/1748-3190/ac9a1b
Web of Science ID

WOS:000878377200001

Author(s)
Krishna, Swathi  
Gehrke, Alexander  
Mulleners, Karen  
Date Issued

2022-11-01

Publisher

IOP Publishing Ltd

Published in
Bioinspiration & Biomimetics
Volume

17

Issue

6

Article Number

066018

Subjects

Engineering, Multidisciplinary

•

Materials Science, Biomaterials

•

Robotics

•

Engineering

•

Materials Science

•

bio-inspired propulsion

•

flapping wings

•

hovering

•

water-treading

•

motion

•

flight

•

aerodynamics

•

optimization

•

takeoff

•

driven

Editorial or Peer reviewed

REVIEWED

Written at

EPFL

EPFL units
UNFOLD  
Available on Infoscience
November 21, 2022
Use this identifier to reference this record
https://infoscience.epfl.ch/handle/20.500.14299/192371
Logo EPFL, École polytechnique fédérale de Lausanne
  • Contact
  • infoscience@epfl.ch

  • Follow us on Facebook
  • Follow us on Instagram
  • Follow us on LinkedIn
  • Follow us on X
  • Follow us on Youtube
AccessibilityLegal noticePrivacy policyCookie settingsEnd User AgreementGet helpFeedback

Infoscience is a service managed and provided by the Library and IT Services of EPFL. © EPFL, tous droits réservés