Journal ArticleDOI
Flight Mechanics of a Dragonfly
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The results of calculations show that the dragonfly performs low speed flight with ordinary airfoil characteristics, instead of adopting an abnormally large lift coefficient.Abstract:
SUMMARY The steady slow climbing flight of a dragonfly, Sympetrum frequens, was filmed and analysed. By using the observed data, the mechanical characteristics of the beating wings were carefully analysed by a simple method based on the momentum theory and the blade element theory, and with a numerical method modified from the local circulation method (LCM), which has been developed for analysing the aerodynamic characteristics of rotary wings. The results of calculations based on the observed data show that the dragonfly performs low speed flight with ordinary airfoil characteristics, instead of adopting an abnormally large lift coefficient. The observed phase advance of the hindwing, Adi — 80° can be fully explained by the present theoretical calculation. Similarly, the spanwise variation of the airloading and the time variations of the horizontal force, vertical force, pitching moment and torque or power can be definitely estimated within a reasonable range of accuracy in comparison with the flight data. The distribution of loading between the fore and hind pairs of wings is also clarified by the calculations.read more
Citations
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Journal ArticleDOI
The aerodynamics of insect flight
TL;DR: The basic physical principles underlying flapping flight in insects, results of recent experiments concerning the aerodynamics of insect flight, as well as the different approaches used to model these phenomena are reviewed.
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Dissecting insect flight
TL;DR: The results obtained by “taking the insects apart” helped to resolve previous puzzles about the force estimates in hovering insects, to ellucidate basic mechanisms essential to flapping flight, and to gain insights about the efficieny of flight.
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Unsteady aerodynamics and flow control for flapping wing flyers
TL;DR: In this paper, the scaling laws and unsteady flow regime constraining both biological and man-made fliers have been reviewed and an explanation for aerodynamic gains seen in flexible versus rigid membrane wings, derived from a three-dimensional computational fluid dynamics model with an integrated distributed control algorithm, is presented.
Journal ArticleDOI
Dragonfly flight: free-flight and tethered flow visualizations reveal a diverse array of unsteady lift-generating mechanisms, controlled primarily via angle of attack.
TL;DR: It appears that stability of the LEV is achieved by a general mechanism whereby flapping kinematics are configured so that a LEV would be expected to form naturally over the wing and remain attached for the duration of the stroke, however, the actual formation and shed is controlled by wing angle of attack.
Journal ArticleDOI
Dragonfly flight. II. Velocities, accelerations and kinematics of flapping flight
TL;DR: The free flapping flight of the dragonfly Sympetrum sanguineum and the damselfly Calopteryx splendens was filmed in a large flight enclosure at 3000 frames s-1.
References
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Book
Aerodynamics of the Helicopter
Alfred Gessow,Garry C Myers +1 more
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