Deformable wing kinematics in the desert locust: how and why do camber, twist and topography vary through the stroke?
TLDR
A detailed analysis of the wing kinematics and wing deformations of desert locusts flying tethered in a wind tunnel implies tuning of the structural, morphological and kinematic parameters of the hindwing for efficient aerodynamic force production.Abstract:
Here, we present a detailed analysis of the wing kinematics and wing deformations of desert locusts (Schistocerca gregaria, Forskal) flying tethered in a wind tunnel. We filmed them using four high-speed digital video cameras, and used photogrammetry to reconstruct the motion of more than 100 identified points. Whereas the hindwing motions were highly stereotyped, the forewing motions showed considerable variation, consistent with a role in flight control. Both wings were positively cambered on the downstroke. The hindwing was cambered through an 'umbrella effect' whereby the trailing edge tension compressed the radial veins during the downstroke. Hindwing camber was reversed on the upstroke as the wing fan corrugated, reducing the projected area by 30 per cent, and releasing the tension in the trailing edge. Both the wings were strongly twisted from the root to the tip. The linear decrease in incidence along the hindwing on the downstroke precisely counteracts the linear increase in the angle of attack that would otherwise occur in root flapping for an untwisted wing. The consequent near-constant angle of attack is reminiscent of the optimum for a propeller of constant aerofoil section, wherein a linear twist distribution allows each section to operate at the unique angle of attack maximizing the lift to drag ratio. This implies tuning of the structural, morphological and kinematic parameters of the hindwing for efficient aerodynamic force production.read more
Citations
More filters
Journal ArticleDOI
Recent progress in flapping wing aerodynamics and aeroelasticity
Wei Shyy,Hikaru Aono,Satish Kumar Chimakurthi,Pat Trizila,Chang-Kwon Kang,Carlos E. S. Cesnik,Hao Liu +6 more
TL;DR: In this article, a review of the recent progress in flapping wing aerodynamics and aeroelasticity is presented, where it is realized that a variation of the Reynolds number (wing sizing, flapping frequency, etc.) leads to a change in the leading edge vortex (LEV) and spanwise flow structures, which impacts the aerodynamic force generation.
Journal ArticleDOI
Details of Insect Wing Design and Deformation Enhance Aerodynamic Function and Flight Efficiency
TL;DR: The full-fidelity model achieved greater power economy than the uncambered model, which performed better than the untwisted model, showing that the details of insect wing topography and deformation are important aerodynamically.
Book
An Introduction to Flapping Wing Aerodynamics
TL;DR: In this article, the authors present an ideal book for graduate students and researchers interested in the aerodynamics, structural dynamics and flight dynamics of small birds, bats and insects, as well as of micro air vehicles (MAVs).
Journal ArticleDOI
Deformable wing kinematics in free-flying hoverflies
TL;DR: A detailed analysis of the deforming wing kinematics of free-flying hoverflies (Eristalis tenax, Linnaeus) during hovering flight is presented, finding that the alula, a hinged flap near the base of the wing, operates in two discrete states: either in plane with theWing, or flipped approximately normal to it.
Journal ArticleDOI
A fluid-structure interaction model of insect flight with flexible wings
Toshiyuki Nakata,Hao Liu +1 more
TL;DR: The results demonstrate the feasibility of the present FSI model in accurately modeling and quantitatively evaluating flexible-wing aerodynamics of insect flapping flight in terms of the aerodynamic forces, the power consumption and the efficiency.
References
More filters
Journal ArticleDOI
A Computational Approach to Edge Detection
TL;DR: There is a natural uncertainty principle between detection and localization performance, which are the two main goals, and with this principle a single operator shape is derived which is optimal at any scale.
Journal ArticleDOI
Robust Tests for the Equality of Variances
Morton B. Brown,Alan B. Forsythe +1 more
TL;DR: In this paper, alternative formulations of Levene's test statistic for equality of variances are found to be robust under nonnormality, using more robust estimators of central location in place of the mean.
Book
Algorithms for image processing and computer vision
TL;DR: Algorithms for Image Processing and Computer Vision, 2nd Edition provides the tools to speed development of image processing applications.
Journal ArticleDOI
The Aerodynamics of Hovering Insect Flight. III. Kinematics
TL;DR: In this paper, a projection analysis technique is described that solves for the orientation of the animal with respect to a cam era-based coordinate system, giving full kinematic details for the longitudinal wing and body axes from single-view films.