Advances in Aerospace Science and Applications.
ISSN 2277-3223 Volume 3, Number 3 (2013), pp. 227-234
© Research India Publications
http://www.ripublication.com/aasa.htm
On the Aerodynamic Performance of Dragonfly Wing
Section in Gliding Mode
Syed Fahad Anwer
1
, Intesaaf Ashraf
2
, Hussain Mehdi
1
,
Akhlaq Ahmad
1
and Grafi H
3
1
Department of Mechanical Engg, ZHCET, AMU Aligarh-202002.
2
Graduate student, Department of Mechanical Engg, IIT Bombay, Powai, Mumbai.
3
Department of Mechanical Engg, Taibah University, P.O. Box. 344,
Al Madina Al Munawara, Kingdom of Saudi Arabia.
Abstract
A comprehensive numerical of fluid dynamic study of a pleated wing
section based on the wing of Aeshna Cyanea has been performed at
ultra low Reynolds numbers corresponding to the gliding flight of
these dragon flies. The simulations employ an unstructured triangular
mesh based on finite volume discritization. A critical assessment of the
computed results was performed. In this work, we investigate the
aerodynamic characteristics and spatio-temporal dynamics of a cut
section of Aeshna Cyanea's wing. Numerical simulations were
performed at ultra low Reynolds numbers (100 to 1000) at different
angle of attacks ranging from 0
o
to 15
o
. The results give a satisfactory
measure of confidence in the fidelity of the simulation. The effect of
the Reynolds number on the gliding ratio is that at Re 1000 and at
angle of attack (here after, AOA) 15
o
. The largest gliding ratios are
obtained. Flow invariably for all Reynolds number, minimum Drag
coefficient is obtained at AOA 15
o
.
Keywords: Gliding flight; pleated airfoil; Aeshna Cyanea; Gliding
Airfoil; Ultra Low Reynolds number.
1. Introduction
There are two modes of flight in insects. First and the more dominating mode is the
flapping mode while the second mode is the gliding flight. In a dragon fly, both modes