Topical Problems of Fluid Mechanics


Institute of Thermomechanics AS CR, v.v.i.	CTU in Prague Faculty of Mech. Engineering Dept. Tech. Mathematics	MIO Université du Sud Toulon Var - AMU - CNRS - IRD	Czech Pilot centre ERCOFTAC

Unsteady CFD Analysis of an Oscillating Aerofoil Inspired by Dragonfly Wings
W.H. Ho, T.H. New, E. Matare
Abstract:
An unsteady two-dimensional CFD analysis of an oscillating (dynamically pitching) aerofoil inspired by dragonfly wings was conducted to investigate its aerodynamic and flow characteristics. The aerofoil morphology was an idealised geometry based on the crosssection near the mid-span of a dragonfly wing. The aerofoil was made to oscillate at 2Hz with amplitude of 10° with an upstream flow such that the chord Reynolds number was 14,000. The methodology mirrored a previous study but with slight differences due to the difference in geometry. Complex flow structures near to the aerofoil surface revealed significant effect on lift and drag characteristics. Lift and drag hysteresis indicate that there is net lift generated but no net thrust. Instantaneous lift and drag shows there is a difference in both the negative and positive peak lift and drag values between when the aerofoil is pitching up and when it is pitching down. This is consistent with previous studies. Comparisons with previous studies on oscillating smooth aerofoils do not indicate that such corrugated aerofoils exhibit any advantages. It is possible that any performance enhancements will only manifest itself when operating in tandem with other aerofoils in close proximity such as between the fore and hind-wing of a dragonfly.
Keywords:
computational fluid dynamics, particle image velocimetry, oscillating airfoil, bioinspired airfoil

Fulltext: PDF DOI: https://doi.org/10.14311/TPFM.2017.021

In Proceedings Topical Problems of Fluid Mechanics 2017, Prague, 2017 Edited by David Šimurda and Tomáš Bodnár, pp. 159-166 ISBN 978-80-87012-61-1 (Print) ISSN 2336-5781 (Print)