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ISSN Online: 2379-1748

ISBN Flash Drive: 978-1-56700-517-2

5-6th Thermal and Fluids Engineering Conference (TFEC)
May, 26–28, 2021 , Virtual

INVESTIGATING DRAGONFLY FLIGHT DYNAMICS AT VARIOUS HEAVING AMPLITUDES OF ITS WING

Get access (open in a dialog) pages 85-91
DOI: 10.1615/TFEC2021.bbe.036714

摘要

The dragonfly wing has a corrugated cross-section that significantly affects its flight dynamics. Therefore, inspired from a dragonfly wing, the corrugated foil performing heaving motion at various heaving amplitude, is being studied through numerical simulations. The objective is to understand the effect of heaving amplitude on the bioinspired corrugated foil, thereby unravelling the secret of dragonfly flight at various heaving amplitude of its wing. Two-dimensional numerical simulations are performed over a wide range of heaving amplitude (normalized by the chord length), H = 0.15 − 0.75. The chord-based Reynolds number is 10,000 and reduced frequency is 0.87. Further, to explore the effect of corrugations found in dragonfly wing, the results are compared with a smooth heaving NACA (National Advisory Committee for Aeronautics)0012 foil. Over the studied heaving amplitude range for the corrugated foil, at H = 0.15 net drag on the corrugated foil is observed which transits into a net thrust at H = 0.3, however the time-averaged thrust is less than that for NACA0012 foil at all H. At any studied H, corrugated foil out-performs the NACA0012 foil in terms of time averaged lift generation. Therefore, corrugations found in dragonfly wings are for enhancement of lift rather than thrust. The present study helps understand the influence of corrugations of dragonfly wing in the enhanced lift generation mechanisms of dragonflies.
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