Driving mechanism of dragonfly’s wing flapping pattern for liquid circulation inside wing

2020 ◽  
Vol 71 (1) ◽  
pp. 85-101
Author(s):  
Yunjie Wang ◽  
Yajun Yin ◽  
Gangtie Zheng ◽  
Hongxiang Yao
Keyword(s):  
Mathematical Model ◽  
Driving Force ◽  
Theoretical Explanation ◽  
Flapping Wing ◽  
Controlled Experiment ◽  
Flapping Wings ◽  
Driving Mechanism ◽  
Liquid Motion ◽  
Liquid Circulation ◽  
Dragonfly Wings

Abstract Flying animals can inspire practical approaches to a more advanced way of flying. Dragonflies demonstrate a special flapping pattern in which their wings perform torsional movement while flapping, which is different from that of birds. This flapping pattern is referred to as nonsynchronous flapping in this article. We present a hypothesis that nonsynchronous flapping provides a driving force for enhancing the haemolymph circulation inside dragonfly wings. To support this hypothesis, a controlled experiment was designed and conducted with living dragonflies. By observing the liquid motion inside the vein within free flapping wings and restricted wings of living dragonflies, this hypothesis was supported. A mathematical model of the flapping wing was built and numerically studied to further support the function of the nonsynchronous flapping pattern in driving the circulation. With these studies, a theoretical explanation for the mechanism of enhancing the haemolymph circulation by nonsynchronous flapping was provided.

scholarly journals Footprints of a flapping wing

2017 ◽  
Vol 818 ◽  
pp. 1-4 ◽  
Author(s):  
Jun Zhang
Keyword(s):  
Flow Pattern ◽  
External Force ◽  
Thrust Force ◽  
Flow Patterns ◽  
Flapping Wing ◽  
Flapping Wings ◽  
Left Behind ◽  
Full Picture

Birds have to flap their wings to generate the needed thrust force, which powers them through the air. But how exactly do flapping wings create such force, and at what amplitude and frequency should they operate? These questions have been asked by many researchers. It turns out that much of the secret is hidden in the wake left behind the flapping wing. Exemplified by the study of Andersen et al. (J. Fluid Mech., vol. 812, 2017, R4), close examination of the flow pattern behind a flapping wing will inform us whether the wing is towed by an external force or able to generate a net thrust force by itself. Such studies are much like looking at the footprints of terrestrial animals as we infer their size and weight, figuring out their walking and running gaits. A map that displays the collection of flow patterns after a flapping wing, using flapping frequency and amplitude as the coordinates, offers a full picture of its flying ‘gaits’.

Flight Characteristics of Flapping Wing Miniature Air Vehicles With “Figure-8” Spherical Motion

2009 ◽  
Author(s):  
Mohamed B. Trabia ◽  
Woosoon Yim ◽  
Zohaib Rehmat ◽  
Jesse Roll
Keyword(s):  
Mathematical Model ◽  
Wind Tunnel ◽  
Experimental Testing ◽  
Flapping Wing ◽  
Dynamic Stall ◽  
Wind Tunnel Testing ◽  
Servo Motor ◽  
Aerodynamic Forces ◽  
Flapping Motion ◽  
Spherical Motion

Hummingbirds and some insects exhibit “Figure-8” flapping motion that allows them to go through a variety of maneuvers including hovering. Understanding the flight characteristics of Figure-8 flapping motion can potentially yield the foundation of flapping wing UAVs that can experience similar maneuverability. In this paper, a mathematical model of the dynamic and aerodynamic forces associated with Figure-8 motion generated by a spherical four bar mechanism is developed. For validation, a FWMAV prototype with the wing attached to a coupler point and driven by a DC servo motor is created for experimental testing. Wind tunnel testing is conducted to determine the coefficients of flight and the effects of dynamic stall. The wing is driven at speeds up to 12.25 Hz with results compared to that of the model. The results indicate good correlation between mathematical model and experimental prototype.

Recent progress in flapping wings for micro aerial vehicle applications

2020 ◽  
pp. 095440622091742
Author(s):  
Naeem Haider ◽  
Aamer Shahzad ◽  
Muhammad Nafees Mumtaz Qadri ◽  
Syed Irtiza Ali Shah
Keyword(s):  
Leading Edge ◽  
Flapping Wing ◽  
Flapping Wings ◽  
Structural Flexibility ◽  
Micro Aerial Vehicles ◽  
Flexible Wings ◽  
Performance Variables ◽  
Aerial Vehicles ◽  
Wide Range ◽  
Wing Geometry

Micro aerial vehicles using flapping wings are under investigation, as an alternative to fixed-wing and rotary-wing micro aerial vehicles. Such flapping-wing vehicles promise key potential advantages of high thrust, agility, and maneuverability, and have a wide range of applications. These applications include both military and commercial domains such as communication relay, search and rescue, visual reconnaissance, and field search. With the advancement in the computational sciences, developments in flapping-wing micro aerial vehicles have progressed exponentially. Such developments require a careful aerodynamic and aeroelastic design of the flapping wing. Therefore, aerodynamic tools are required to study such designs and configurations. In this paper, the role of several parameters is investigated, including the types of flapping wings, the effect of the kinematics and wing geometry (shape, configuration, and structural flexibility) on performance variables such as lift, drag, thrust, and efficiency in various modes of flight. Kinematic variables have a significant effect on the performance of the flapping wing. For instance, a high flap amplitude and pitch rotation, which supports the generation of the strong leading-edge vortex, generates higher thrust. Likewise, wing shape, configuration, and structural flexibility are shown to have a large impact on the performance of the flapping wing. The wing with optimum flexibility maximizes thrust where highly flexible wings lead to performance degradation due to change in the effective angle of attack. This study shows that the development of the flexible flapping wing with performance capabilities similar to those of natural fliers has not yet been achieved. Finally, opportunities for additional research in this field are recommended.

Induced Strain Actuation for Solid-State Ornithopters: An Aeroelastic Study

2018 ◽  
Author(s):  
Francis Hauris ◽  
Onur Bilgen
Keyword(s):  
Reynolds Number ◽  
Solid State ◽  
Aspect Ratio ◽  
Interaction Model ◽  
Flapping Wing ◽  
Flapping Wings ◽  
Structural Behavior ◽  
Structure Interaction ◽  
Dynamic Motion ◽  
Lift And Drag

This paper investigates the dynamic aeroelastic behavior of strain actuated flapping wings with various geometries and boundary conditions. A fluid-structure interaction model of a plate-like flapping wing is developed. Assuming a chord Reynolds number of 100,000, the wing is harmonically actuated while varying parameters such as aspect ratio and wing root clamped percentage. Characteristic metrics for the dynamic motion, natural frequency, lift and drag are developed. These results are compared with purely structural behavior to understand the aeroelastic effects.

Four-Bar Linkage Mechanism for Insectlike Flapping Wings in Hover: Concept and an Outline of Its Realization

2005 ◽  
Vol 127 (4) ◽  
pp. 817-824 ◽  
Author(s):  
Rafał Z˙bikowski ◽  
Cezary Galin´ski ◽  
Christopher B. Pedersen
Keyword(s):  
Insect Flight ◽  
Micro Air Vehicles ◽  
Flapping Wing ◽  
Flapping Wings ◽  
Test Bed ◽  
Linkage Mechanism ◽  
Actual Design ◽  
Straight Line Mechanism ◽  
Four Bar Linkage ◽  
Air Vehicles

This paper describes the concept of a four-bar linkage mechanism for flapping wing micro air vehicles and outlines its design, implementation, and testing. Micro air vehicles (MAVs) are defined as flying vehicles ca. 150 mm in size (handheld), weighing 50–100 g, and are developed to reconnoiter in confined spaces (inside buildings, tunnels, etc.). For this application, insectlike flapping wings are an attractive solution and, hence, the need to realize the functionality of insect flight by engineering means. Insects fly by oscillating (plunging) and rotating (pitching) their wings through large angles, while sweeping them forward and backward. During this motion, the wing tip approximately traces a figure eight and the wing changes the angle of attack (pitching) significantly. The aim of the work described here was to design and build an insectlike flapping mechanism on a 150 mm scale. The main purpose was not only to construct a test bed for aeromechanical research on hover in this mode of flight, but also to provide a precursor design for a future flapping-wing MAV. The mechanical realization was to be based on a four-bar linkage combined with a spatial articulation. Two instances of idealized figure eights were considered: (i) Bernoulli’s lemniscate and (ii) Watt’s sextic. The former was found theoretically attractive, but impractical, while the latter was both theoretically and practically feasible. This led to a combination of Watt’s straight-line mechanism with a drive train utilizing a Geneva wheel and a spatial articulation. The actual design, implementation, and testing of this concept are briefly described at the end of the paper.

Mechanics of a Graphene Flake Driven by the Stiffness Jump on a Graphene Substrate

2017 ◽  
Vol 84 (8) ◽  
Author(s):  
Hong Gao ◽  
Hongwei Zhang ◽  
Zhengrong Guo ◽  
Tienchong Chang ◽  
Li-Qun Chen
Keyword(s):  
Molecular Dynamics ◽  
Analytical Model ◽  
Driving Force ◽  
Md Simulations ◽  
Driving Mechanism ◽  
Graphene Flake ◽  
Working Temperature ◽  
Directional Motion ◽  
Edge Force ◽  
Motion Behavior

Intrinsic driving mechanism is of particular significance to nanoscale mass delivery and device design. Stiffness gradient-driven directional motion, i.e., nanodurotaxis, provides an intrinsic driving mechanism, but an in-depth understanding of the driving force is still required. Based on molecular dynamics (MD) simulations, here we investigate the motion behavior of a graphene flake on a graphene substrate with a stiffness jump. The effects of the temperature and the stiffness configuration on the driving force are discussed in detail. We show that the driving force is almost totally contributed by the unbalanced edge force and increases with the temperature and the stiffness difference but decreases with the stiffness level. We demonstrate in particular that the shuttle behavior of the flake between two stiffness jumps on the substrate can be controlled by the working temperature and stiffness configuration of the system, and the shuttle frequency can be well predicted by an analytical model. These findings may have general implications for the design of nanodevices driven by stiffness jumps.

Numerical Investigation of Unsteady Flows Past Flapping Wings with Immersed Boundary-Lattice Boltzmann Method

2017 ◽  
Vol 34 (2) ◽  
pp. 193-207 ◽  
Author(s):  
C. L. Gong ◽  
Z. J. Yuan ◽  
Q. Zhou ◽  
G. Chen ◽  
Z. Fang
Keyword(s):  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Flapping Wing ◽  
Flapping Wings ◽  
Immersed Boundary ◽  
Thrust Coefficient ◽  
Single Plate ◽  
The Mean ◽  
The One ◽  
Boltzmann Method

AbstractBiomimetic motions are helpful to underwater vehicles and new conception airplanes design. The lattice Boltzmann method with an immersed boundary method technique is used to reveal the propulsion and lift enhancement mechanism of biomimetic motions. The flow past a sphere and an ellipsoidal flapping wing were validated respectively by comparing with other numerical methods. Then a single flapping wing and three flapping wings in a tandem arrangement are accomplished respectively. It founds that the mean thrust coefficient of three plate wings is bigger than the one of the single plate wing. Three ellipsoidal wings and single ellipsoidal wing are compared. It shows that the single ellipsoidal wing has larger thrust coefficients than the three ellipsoidal wings. Ellipsoidal flapping wing and plate wing were further compared to investigate the influence of wing shape. It indicates the mean thrust coefficient of the ellipsoidal wing is bigger than the plate wing.

Superhydrophobicity-Enabled Interfacial Microfluidics on Textile

2013 ◽  
Vol 1569 ◽  
pp. 115-120
Author(s):  
Siyuan Xing ◽  
Jia Jiang ◽  
Tingrui Pan
Keyword(s):  
Surface Tension ◽  
Capillary Force ◽  
Three Dimensional ◽  
Liquid Volume ◽  
Driving Mechanism ◽  
Chemical Analyses ◽  
Skin Model ◽  
Liquid Motion ◽  
Liquid Flows ◽  
Hydrophilic Materials

ABSTRACTCapillary-driven microfluidics, utilizes the capillary force generated by fibrous hydrophilic materials (e.g., paper and cotton) to drive biological reagents, has been extended to various biological and chemical analyses recently. However, the restricted capillary-driving mechanism persists to be a major challenge for continuous and facilitated biofluidic transport. In this abstract, we have first introduced a new interfacial microfluidic transport principle to automatically and continuously drive three-dimensional liquid flows on a micropatterned superhydrophobic textile (MST). Specifically, the MST platform utilizes the surface tension-induced Laplace pressure to facilitate the liquid motion along the fibers, in addition to the capillary force existing in the fibrous structure. The surface tension-induced pressure can be highly controllable by the sizes of the stitching patterns of hydrophilic yarns and the confined liquid volume. Moreover, the fluidic resistances of various configurations of connecting fibers are quantitatively investigated. Furthermore, a demonstration of the liquid collection ability of MST has been demonstrated on an artificial skin model. The MST can be potentially applied to large volume and continuous biofluidic collection and removal.

A Design of Innovative Experiment Platform Based on the Research of Flapping-Wing Aircraft

2014 ◽  
Vol 651-653 ◽  
pp. 587-592
Author(s):  
Bing Hao Zhu ◽  
Xiao Yi Jin ◽  
Li Li Zhao ◽  
Jing Yuan Zhang ◽  
Hua Cheng Tao
Keyword(s):  
Mechanism Design ◽  
Flapping Wing ◽  
Driving Mechanism ◽  
Experimental Platform ◽  
Experiment Platform ◽  
Design And Implementation ◽  
Design Scheme ◽  
Development Processes ◽  
Motion Parameters ◽  
Platform System

According to the fact that it need several tests to determine the size and motion parameters of the flapping-wing aircraft in the development processes, the paper proposed a design scheme of flapping wing system experimental platform. Separately from the scheme, the system platform, driving mechanism design, motion parameters change, described in detail the design and implementation of this innovation experiment platform. Users can simulate and debug the platform system to determine the performance of the flapping-wing mechanism.

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