Abstract
A numerical study on the effects of the asymmetry in flapping motions on the aerodynamic performance of a 2-D inclined hovering wing is carried out through the solution of the two-dimensional unsteady Navier-Stokes equations. Asymmetric flapping motions with different flapping durations as well as different angles of attack during downstroke and upstroke are considered, correspondingly the aerodynamic forces, the energy consumption and the flow structures of the wing are examined for the purpose. The results show that the asymmetry either in flapping duration or in angle of attack can effectively alter the aerodynamic characteristics of the wing. It is found that much larger vertical force is generated in the downstroke with smaller duration. As for the angle of attack, an increase in the angle during the downstroke gives rise to a larger vertical force and lifting efficiency while for the upstroke the increase in the angle results in a larger thrust force. Furthermore, a combined model with asymmetry in both flapping duration and angles of attack is also studied and the results show that a combined flapping motion with a faster downstroke and a higher downstroke angle of attack can produce much larger vertical force than a motion with asymmetry simply in stroke duration or angle of attack. The present results provide physical insight into a better understanding of the asymmetric stroke mechanisms in the flapping motion of insects.
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Chao Wang received his B.S. and M.S. degrees in Harbin Institute of Technology, People’s Republic of China. He is currently a Ph.D. candidate in Harbin Institute of Technology Shenzhen Graduate School, People’s Republic of China. His research interests include fluid structure interaction, flapping flight aerodynamics and wind turbine aerodynamic design and optimization.
Chaoying Zhou received her Ph.D. in Imperial College, University of London. Professor Zhou is currently an Associate Dean of Harbin Institute of Technology Shenzhen Graduate School, People’s Republic of China. Her research interests include flow induced vibrations and control, fluid structure interaction, flapping micro aerial vehicle design and supersonic/hypersonic flow.
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Wang, C., Zhou, C. & Xie, P. Numerical investigation on aerodynamic performance of a 2-D inclined hovering wing in asymmetric strokes. J Mech Sci Technol 30, 199–210 (2016). https://doi.org/10.1007/s12206-015-1223-6
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DOI: https://doi.org/10.1007/s12206-015-1223-6