In this study, a model based on potential flow theory is developed to analyze the unsteady nonlinear aerodynamics of a flexible flapping wing at low and high angles of attack. It is assumed that the wing motion is composed of twisting and flapping. The developed unsteady two-dimensional model is applied to the flapping wing using a blade-element-type method. The computational model presented in this study shows better agreement with experimental data especially at a high angle of attack. Analytical results also show that the wings section does not necessarily twist linearly along the wingspan.
DelaurierJD. An aerodynamic model for flapping wing flight. Aeronaut J R Aeronaut Soc1993; 97: 125–130.
2.
Pai PF, Chernovaand DK and Palazotto AN. Nonlinear modeling and vibration characterization of MAV flapping wings. In: 50th AIAA/ASME/ASCE/AHS/ASC structures, structural dynamics and materials conference, California, 1–4 May 2009, pp.1–25.
3.
Zakaria MY, Elshabka AM, Bayoumy AM, et al. Numerical aerodynamic characteristics of flapping wings. In: 13th International conference on aerospace sciences & aviation technology, Cairo, 26–28 May 2009, pp.1–15.
4.
DjojodihardjoHRamliASSWiriadidjajaS. Kinematic and aerodynamic modelling of flapping wing ornithopter. Proced Eng2012; 50: 848–863.
5.
PullinDWangZ. Unsteady forces on an accelerating plate and application to hovering insect flight. J Fluid Mech2004; 509: 1–21.
6.
XiaXMohseniK. Lift evaluation of a two-dimensional pitching flat plate. Phys Fluids2013; 25: 1–26.
7.
SinghBChopraI. Insect-based hover-capable flapping wings for micro air vehicles: experiments and analysis. AIAA J2008; 46: 2115–2135.
8.
Malik MA and Ahmad F. Effect of different design parameters on lift, thrust, and drag of an ornithopter. In: Proceedings of the world congress on engineering, 2010; II. WCE, London, UK.
9.
PourtakdoustSHKarimain AliabadiS. Evaluation of flapping wing propulsion based on a new experimentally validated aeroelastic model. Scientia Iranica B2012; 19: 472–482.
10.
YeungWParkinsonG. On the steady separated flow around and inclined flat plate. J Fluid Mech1997; 333: 403–413.
11.
Milne-ThomsonLM. Theoretical hydrodynamics, New York: MacMillan, 1955.
12.
CreightonD. The Kutta condition in unsteady flow. Annu Rev Fluid Mech1985; 17: 411–445.
13.
AndroJYJacquinL. Frequency effects on the aerodynamic mechanisms of a heaving airfoil in a forward flight configuration. Aerospace Sci Technol2009; 13: 71–80.
14.
HamND. Aerodynamic loading on a two-dimensional airfoil during dynamic stall. AIAA J1968; 6: 1927–1934.
15.
GharaliKJohnsonDA. Dynamic stall simulation of a pitching airfoil under unsteady freestream velocity. J Fluid Struct2013; 42: 228–244.
16.
GopalakrishnanPTaftiD. Effect of wing flexibility on lift and thrust production in flapping flight. AIAA J2010; 48: 865–877.
17.
Kang C and Shyy W. Passive wing rotation in flexible flapping wing. In: 30th AIAA applied aerodynamics conference, New Orleans, 25–28 June 2012, pp.2752–2763.
18.
Shkarayev S and Silin D. Aerodynamics of flapping-wing micro air vehicles. In: 47th AIAA aerospace sciences meeting including the new horizons forum and aerospace exposition, Orlando, Florida, 5–8 January 2009, pp.1–21.
