Aerodynamic Characteristics, Power Requirements and Camber Effects of the Pitching-Down Flapping Hovering

Bai, Peng; Cui, Erjie; Zhan, Huiling

doi:10.1016/s1672-6529(08)60109-2

Cited by 10 publications

(4 citation statements)

References 11 publications

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“…The wings are models of Drosophila melanogaster and have a span of R = 0.25 m. The area of each wing is S = 0.0167 m 2 and the average chord is c = 8.79 cm. The wing shape used is similar to the one reproduced in Bai et al (2009). In the experiment of Dickinson et al (1999), one flapping period is composed of two half-strokes and the flapping frequency is f = 0.145 Hz.…”

Section: Code Validationmentioning

confidence: 99%

Dynamic pitching of an elastic rectangular wing in hovering motion

Dai¹,

Luo²,

Doyle³

2012

J. Fluid Mech.

151

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In order to study the role of the passive deformation in the aerodynamics of insect wings, we computationally model the three-dimensional fluid-structure interaction of an elastic rectangular wing at a low aspect ratio during hovering flight. The code couples a viscous incompressible flow solver based on the immersedboundary method and a nonlinear finite-element solver for thin-walled structures. During a flapping stroke, the wing surface is dominated by non-uniform chordwise deformations. The effects of the wing stiffness, mass ratio, phase angle of active pitching, and Reynolds number are investigated. The results show that both the phase and the rate of passive pitching due to the wing flexibility can significantly modify the aerodynamics of the wing. The dynamic pitching depends not only on the specified kinematics at the wing root and the stiffness of the wing, but also sensitively on the mass ratio, which represents the relative importance of the wing inertia and aerodynamic forces in the wing deformation. We use the ratio between the flapping frequency, ω, and natural frequency of the wing, ω n , as the nondimensional stiffness. In general, when ω/ω n 0.3, the deformation significantly enhances the lift and also improves the lift efficiency despite a disadvantageous camber. In particular, when the inertial pitching torque is assisted by an aerodynamic torque of comparable magnitude, the lift efficiency can be markedly improved.

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Section: Code Validationmentioning

confidence: 99%

Dynamic pitching of an elastic rectangular wing in hovering motion

Dai¹,

Luo²,

Doyle³

2012

J. Fluid Mech.

151

View full text Add to dashboard Cite

show abstract

“…The main finding of this study was clarification of the different effects of the handling parameters on generating the pitch, roll, and yaw moments of fourwing flapping mechanisms. In the case of asymmetry, the result showed that the regression coefficient for the yaw moment by FMα had no significant effect, since the asymmetry had little effect on the generation of and/or control of the moments during two-wing flapping [18]. In the case of the tilt angle, the regression coefficient between ∑ 2 siñ and M Y by FMβ was lower as compared to the results of FMα.…”

Section: Discussionmentioning

confidence: 82%

Handling parameters for rotational moment generation with four-wing flapping

2018

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The aim of this study was to clarify the relationships between pitch, roll, and yaw moments during flapping and various handling parameters ((i) wingbeat amplitude, (ii) stroke plane angle, and (iii) asymmetry of the flapping duration). We investigate the effects of the combination of (i) and (ii), or the combination of (i) and (iii) for generating rotational moments. The results demonstrated that flapping amplitudes and asymmetry contributed to generating pitch and roll moments, and flapping amplitude and tilt angle affected the generation of all moments.

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“…The camber and twisting deformations of the whole wing were acquired. In the simulation study of pitching-down flapping, the positive camber can effectively increase C(-) l and C(-) l /C(-) d. As the camber angle increases from 0 to 20%, C(-) l increases nonlinearly, C(-) l /C(-) d reaches the maximum value, and the camber is approximately 10% [46]. These results show that the camber angle of the wing root has a great influence on the aerodynamic performance of the whole wing.…”

Section: Effect Of Camber Anglementioning

confidence: 99%