Abstract
The micro Flapping Rotary Wing (FRW) concept inspired by insects was proposed recently. Its aerodynamic performance is highly related to wing pitching and rotational motions. Therefore, the effect of wing pitching kinematics and rotational speed on unsteady aerodynamic forces and power consumption of a FRW in hovering flight is further studied in this paper using computational fluid dynamics method. Considering a fixed pitching amplitude (i.e., 80°), the vertical force of FRW increases with the downstroke angle of attack and is enhanced by high wing rotational speed. However, a high downstroke angle of attack is not beneficial for acquiring high rotational speed, in which peak vertical force at balance status (i.e., average rotational moment equals zero.) is only acquired at a comparatively small negative downstroke angle of attack. The releasing constraint of pitching amplitude, high rotational speed and enhanced balanced vertical force can be acquired by selecting small pitching amplitude despite high power consumption. To confirm which wing layout is more power efficient for a certain vertical force requirement, the power consumed by FRW is compared with the Rotary Wing (RW) and the Flapping Wing (FW) while considering two angle of attack strategies without the Reynolds number (Re) constraint. FRW and RW are the most power efficient layouts when the target vertical force is produced at an angle of attack that corresponds to the maximum vertical force coefficient and power efficiency, respectively. However, RW is the most power efficient layout overall despite its insufficient vertical force production capability under a certain Re.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Shyy W, Aono H, Chimakurthi S K, Trizila P, Kang C-K, Cesnik C E S, Liu H. Recent progress in flapping wing aerodynamics and aeroelasticity. Progress in Aaerospace Ssciences, 2010, 46, 284–327.
Fitchett B. Development and Investigation of a Flapping Rotor for Micro Air Vehicles, Master thesis, University of Maryland, College Park, USA, 2007.
Guo S J, Li D C, Huang Z R. A smart material aeroelastic flapping wing micro rotor craft. Proceeding of International Forum on Aeroelasticity and Structural Dynamics, Seattle, USA, 2009, 21–25.
Guo S J, Li D C, Wu J H. Theoretical and experimental study of a piezoelectric flapping wing rotor for micro aerial vehicle. Aerospace Science and Technology, 2012, 23, 429–438.
Zhou C, Wu J H, Guo S J, Li D C. Experimental study of the lift generated by a flapping rotary wing applied in a micro air vehicle. Proceedings of the Institution of Mechanical Engineers Part G: Journal of Aerospace Engineering, 2014, 228, 2083–2093.
Chen L, Zhang Y L, Wu J H. Study on lift enhancement of a flapping rotary wing by a bore-hole design. Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering, 2017, 0954410016688927.
Wu J H, Wang D, Zhang Y L. Aerodynamic analysis of a flapping rotary wing at a low Reynolds number. AIAA Journal, 2015, 53, 2951–2966.
Wu J H, Zhou C, Zhang Y L. Aerodynamic power efficiency comparison of various micro-air-vehicle layouts in hovering flight. AIAA Journal, 2016, 55, 1–12.
Li H, Guo S J, Zhang Y L, Zhou C, Wu J H. Unsteady aerodynamic and optimal kinematic analysis of a micro flapping wing rotor. Aerospace Science and Technology, 2017, 63, 167–178.
Sun M, Lan S L. A computational study of the aerodynamic forces and power requirements of dragonfly (Aeschna juncea) hovering. Journal of Experimental Biology, 2004, 207, 1887–1901.
Lentink D, Dickinson M H. Rotational accelerations stabilize leading edge vortices on revolving fly wings. Journal of Experimental Biology, 2009, 212, 2705–2719.
Kruyt, J W, Quicazán-Rubio E M, van Heijst G F, Altshuler D L, Lentink D. Hummingbird wing efficacy depends on aspect ratio and compares with helicopter rotors. Journal of the Royal Society Interface, 2009, 11, 20140585.
Wang Z J. The role of drag in insect hovering. Journal of Experimental Biology, 2004, 207, 4147–4155.
Pesavento U, Wang Z J. Flapping wing flight can save aerodynamic power compared to steady flight. Physical Review Letters, 2009, 103, 118102.
Zheng L, Hedrick T, Mittal R. A comparative study of the hovering effciency of flapping and revolving wings. Bioinspiration & Biomimetics, 2013, 8, 036001.
Rogers S E, Kwak D. An upwind differencing scheme for the time-accurate incompressible Navier–Stokes equations. AIAA Journal, 1990, 28, 253–262.
Rogers S E, Kwak D, Kiris C. Steady and unsteady solutions of the incompressible Navier–Stokes equations. AIAA Journal, 1991, 29, 603–610.
Wu J H, Sun M. Unsteady aerodynamic forces of a flapping wing. Journal of Experimental Biology, 2004, 207, 1137–1150.
Gopalakrishnan P, Tafti D K. Effect of wing flexibility on lift and thrust production in flapping flight. AIAA Journal, 2010, 48, 865–877.
Anderson J, Streitlien K, Barrett D, Triantafyllou M. Oscillating foils of high propulsive efficiency. Journal of Fluid Mechanics, 1998, 360, 41–72.
Rozhdestvensky K V, Ryzhov V A. Aerohydrodynamics of flapping-wing propulsors. Progress in Aerospace Sciences, 2003, 39, 585–633.
Ho S, Nassef H, Pornsinsirirak N, Tai Y C, Ho C M. Unsteady aerodynamics and flow control for flapping wing flyers. Progress in Aerospace Sciences, 2003, 39, 635–681.
Ashraf M A, Young J, Lai J C S. Oscillation frequency and amplitude effects on plunging airfoil propulsion and flow periodicity. AIAA Journal, 2012, 50, 2308–2324.
Acknowledgment
This research was primarily supported by the National Natural Science Foundation of China (Grant number: 11672022).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Zhou, C., Zhang, Y. & Wu, J. Unsteady Aerodynamic Forces and Power Consumption of a Micro Flapping Rotary Wing in Hovering Flight. J Bionic Eng 15, 298–312 (2018). https://doi.org/10.1007/s42235-018-0023-y
Published:
Issue Date:
DOI: https://doi.org/10.1007/s42235-018-0023-y