Computational aerodynamics of low Reynolds number plunging, pitching and flexible wings for MAV applications

Shyy, Wei; Lian, Yongsheng; Tang, Jian; Líu, Hao; Trizila, Patrick Clark; Stanford, Bret; Bernal, Luis P.; Cesnik, Carlos E. S.; Friedmann, Peretz P.; Ifju, Peter

doi:10.1007/s10409-008-0164-z

Cited by 128 publications

(52 citation statements)

References 37 publications

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“…The aerodynamics of flapping wings is a combination of several complex phenomena, including Wagner effects, wake capture, leading edge vortex, near fling, and added mass. Results of recent experimental and theoretical investigations of flapping flight have been covered in reviews underlying fluid mechanics and aerodynamics [1][2][3], flapping flight controls [4], and theoretical and numerical modeling of unsteady flowfields in the near and far wakes of oscillating wings [5,6].…”

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confidence: 99%

Applications of Actuator Disk Theory to Membrane Flapping Wings

Shkarayev

Silin

2010

AIAA Journal

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This study addresses the aerodynamics of elastic membrane flapping wings. Several applications of the actuator disk theory to the flapping wings of insects and birds are reviewed. In previous studies, to account for spatial and temporal variance in the wake behind the flapping wings, empirical corrections were proposed for the induced velocity and power. In the present paper, a new procedure for determination of the correction factor is proposed, using membrane-type flapping-wing devices. Wind-tunnel experiments were conducted and the stroke-averaged propulsive thrust was measured on 25-cm-wingspan (flat and 9% camber) and 74-cm-wingspan flapping-wing models. Either flapping frequency or input power was held constant during the tests. Obtained thrust forces were compared to theoretical values predicted by the actuator disk theory. Empirical correction factors to the actuator disk theory were determined, providing a best fit to the experimental data when the flapping axis aligned with freestream velocity. It is noteworthy that the numerical value for the correction factor for the 25 cm cambered wing agrees with the results obtained on large insects. The theoretical corrections for angle of attack of the flapping wing give satisfactory agreements with the experimental data only for relatively low forward speeds.

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confidence: 99%

Applications of Actuator Disk Theory to Membrane Flapping Wings

Shkarayev

Silin

2010

AIAA Journal

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“…The time history and power spectrum of the lift on a flat plate undergoing the same trigonometric motion are plotted in Figures 3(a) and 3(b), respectively. These oscillations of the same frequency for x-translation and rotation are considered to mimic the motion of insects and birds' wings, 3,13 i.e., ω x = ω θ . From Figure 3(b), we observe that the lift spectrum exhibits a peak at twice the frequency of flapping motion as well as smaller peaks at the first and third harmonics of that frequency.…”

Section: Resultsmentioning

confidence: 99%

Deterministic Global Optimization of Flapping Wing Motion for Micro Air Vehicles

Ghommem¹,

Hajj²,

Watson³

et al. 2010

13th AIAA/ISSMO Multidisciplinary Analysis Optimization Conference

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The kinematics of a flapping plate is optimized by combining the unsteady vortex lattice method with a deterministic global optimization algorithm. The design parameters are the amplitudes, the mean values, the frequencies, and the phase angles of the flapping motion. The results suggest that imposing a delay between the different oscillatory motions and controlling the way through which the wing rotates at the end of each half stroke would enhance the lift generation. The use of a general unsteady numerical aerodynamic model (UVLM) and the implementation of a deterministic global optimization algorithm provide guidance and a baseline for future efforts to identify optimal stroke trajectories for micro air vehicles with higher fidelity models. updates the indices of the wake vortices at each time step L 8 represents the impact of the freestream velocity on each on each wake vortex location Nomenclature

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“…(1) and (2). At every time step, the governing equation for the discrete stream function is then discretized and solved numerically.…”

Section: Immersed-boundary Flow Solvermentioning

confidence: 99%

“…Although (passive) flexibility of wing/fin has long been recognized as an important factor in the aerodynamic (hydrodynamic) performance of insect flight or fish swimming, it has received little attention until recently (see [1,2] for a comprehensive review). By using a combination of computational and analytic methods, Daniel and Combes [3] have shown that the deformation in flapping wings was dominated less by aerodynamic loading than by inertial and elastic forces.…”

Section: Introductionmentioning

confidence: 99%