CFD based determination of aerodynamic effects on birds with extremely large dihedral

Sachs, Gottfried; Moelyadi, Mochammad Agoes

doi:10.1016/s1672-6529(09)60191-8

Cited by 12 publications

(7 citation statements)

References 7 publications

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“…Moelyadi and Sach [2] have simulated flapping motion with a small dihedral angle for calculating dynamic stability derivatives in the yaw for a bird. Also, aerodynamic effects on birds with a large dihedral angle have been studied [3]. Navier-Stokes solutions for the viscous flow around two-dimensional wings have been presented by Isogai [4].…”

Section: Unsteady Aerodynamics Of Flapping Wing Of a Birdmentioning

confidence: 99%

Unsteady Aerodynamics of Flapping Wing of a Bird

2013

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The unsteady flow behavior and time characteristics of the flapping motion of a bird computational method. During wing surfaces and surrounding flow flow changes in the flow of flapping speed on unsteady aerodynamic load, two kinds of computational simulations were carried out, namely To mimic the movement of flapping path accorded dihedral angle and time. The computations of time based on the solution of applying the k-ε turbulen computational domain around the model use provide more accuracy wing and body surfaces research, the seagull bird pointed wing-tips and movement, velocity contours as well as aerodynamic coefficients of motion of the bird at various flapping

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Section: Unsteady Aerodynamics Of Flapping Wing Of a Birdmentioning

confidence: 99%

Unsteady Aerodynamics of Flapping Wing of a Bird

2013

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“…Dihedral (inclining the wings upward from horizontal) is a classic approach to install passive stability in fixed-wing aircrafts [ 19 ]. While most aircraft dihedral angles are less than 10°, we see some very large dihedral angles in gliding animals: 15 ∼ 20° for the pipistrelle bat [ 20 ] and approximately 45° for pigeons [ 21 ]. Dihedral between wings is also present in gliding animals that have little recourse for active control, such as flying fish [ 22 ].…”

Section: Discussionmentioning

confidence: 99%

“…The dragonfly passive dihedral angles are approximately 20° and approximately 35° for fore and hindwings, respectively. These angles should provide very high restoring moments in both roll and yaw axes at the cost of higher drag [ 21 ]. Why then, were the posed dead dragonflies not able to fully recapitulate the aerial righting performance of the anaesthetised dragonflies?…”

Section: Discussionmentioning

confidence: 99%

Dragondrop: a novel passive mechanism for aerial righting in the dragonfly

2021

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Dragonflies perform dramatic aerial manoeuvres when chasing targets but glide for periods during cruising flights. This makes dragonflies a great system to explore the role of passive stabilizing mechanisms that do not compromise manoeuvrability. We challenged dragonflies by dropping them from selected inverted attitudes and collected 6-degrees-of-freedom aerial recovery kinematics via custom motion capture techniques. From these kinematic data, we performed rigid-body inverse dynamics to reconstruct the forces and torques involved in righting behaviour. We found that inverted dragonflies typically recover themselves with the shortest rotation from the initial body inclination. Additionally, they exhibited a strong tendency to pitch-up with their head leading out of the manoeuvre, despite the lower moment of inertia in the roll axis. Surprisingly, anaesthetized dragonflies could also complete aerial righting reliably. Such passive righting disappeared in recently dead dragonflies but could be partially recovered by waxing their wings to the anaesthetised posture. Our kinematics data, inverse dynamics model and wind-tunnel experiments suggest that the dragonfly's long abdomen and wing posture generate a rotational tendency and passive attitude recovery mechanism during falling. This work demonstrates an aerodynamically stable body configuration in a flying insect and raises new questions in sensorimotor control for small flying systems.

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“…Numerical simulations such as computer-aided engineering (CAE) [9][10][11][12] and computational fluid dynamics (CFD) [13][14][15] are used instead of experiments, greatly saving costs of time and money. Scholars have used CFD [16][17][18][19][20][21] and CAE [22][23][24][25] methods in the study of nanofluids [26,27], bionic engineering [28,29], engineering architecture [30], and other fields. Computer-aided simulations enable the observation of many details that cannot be captured by experiments, allowing for more in-depth studies.…”

Section: Introductionmentioning

confidence: 99%

The Nest of Torquigener Albomaculosus: Fluid-Dynamic Aspects and Potential for Bio-Inspired Engineering

Zhao¹,

Wang²,

Tie³

et al. 2023

Fluid Dynamics &Amp; Materials Processing

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Torquigener albomaculosus, also known as the white-spotted pufferfish, is known for creating circular nests in the underwater sand as part of the mating ritual. The nests are built by the males to attract females through the nest's impressive design and related ability to gather fine sand particles. As the fluid-dynamic processes associated with these unique nests are still almost completely unknown, in the present study, an analysis has been conducted to investigate how the geometric parameters related to the nest design influence the fluid velocity in its center. For this reason, a geometric model of the nest consisting of 24 channels, where each unit channel can be described by three strips of broken lines, has been introduced, and a multivariate analysis has been implemented to determine the relative weight of each considered parameter. In particular, the "optimal" combination of parameters has been obtained by means of an orthogonal design approach. We show that these bio-nest structures also display a potential for significant application in marine litter collection, or for use as a buffer against the waves in offshore areas.

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CFD based determination of aerodynamic effects on birds with extremely large dihedral

Cited by 12 publications

References 7 publications

Unsteady Aerodynamics of Flapping Wing of a Bird

Unsteady Aerodynamics of Flapping Wing of a Bird

Dragondrop: a novel passive mechanism for aerial righting in the dragonfly

The Nest of Torquigener Albomaculosus: Fluid-Dynamic Aspects and Potential for Bio-Inspired Engineering

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