scholarly journals Dipteran wing motor-inspired flapping flight versatility and effectiveness enhancement

2015 ◽  
Vol 12 (104) ◽  
pp. 20141367 ◽  
Author(s):  
R. L. Harne ◽  
K. W. Wang
Keyword(s):  
Structural Model ◽  
Aerodynamic Force ◽  
Flapping Wing ◽  
Flapping Flight ◽  
Axial Stiffness ◽  
Small Scale ◽  
Aerodynamic Efficiency ◽  
Linear Motors ◽  
Air Vehicle ◽  
Compression Characteristics

Insects are a prime source of inspiration towards the development of small-scale, engineered, flapping wing flight systems. To help interpret the possible energy transformation strategies observed in Diptera as inspiration for mechanical flapping flight systems, we revisit the perspective of the dipteran wing motor as a bistable click mechanism and take a new, and more flexible, outlook to the architectural composition previously considered. Using a representative structural model alongside biological insights and cues from nonlinear dynamics, our analyses and experimental results reveal that a flight mechanism able to adjust motor axial support stiffness and compression characteristics may dramatically modulate the amplitude range and type of wing stroke dynamics achievable. This corresponds to significantly more versatile aerodynamic force generation without otherwise changing flapping frequency or driving force amplitude. Whether monostable or bistable, the axial stiffness is key to enhance compressed motor load bearing ability and aerodynamic efficiency, particularly compared with uncompressed linear motors. These findings provide new foundation to guide future development of bioinspired, flapping wing mechanisms for micro air vehicle applications, and may be used to provide insight to the dipteran muscle-to-wing interface.

scholarly journals Towards Bio-Inspiration, Development, and Manufacturing of a Flapping-Wing Micro Air Vehicle

Drones ◽  
2020 ◽  
Vol 4 (3) ◽  
pp. 39
Author(s):  
P. Lane ◽  
G. Throneberry ◽  
I. Fernandez ◽  
M. Hassanalian ◽  
R. Vasconcellos ◽  
...  
Keyword(s):  
Aerodynamic Force ◽  
Force Production ◽  
Flight Test ◽  
Flapping Wing ◽  
Micro Air Vehicle ◽  
Air Vehicle ◽  
Successful Design ◽  
The Stability ◽  
And Control ◽  
The Impact

Throughout the last decade, there has been an increased demand for intricate flapping-wing drones with different capabilities than larger drones. The design of flapping-wing drones is focused on endurance and stability, as these are two of the main challenges of these systems. Researchers have recently been turning towards bioinspiration as a way to enhance aerodynamic performance. In this work, the propulsion system of a flapping-wing micro air vehicle is investigated to identify the limitations and drawbacks of specific designs. Each system has a tandem wing configuration inspired by a dragonfly, with wing shapes inspired by a bumblebee. For the design of this flapping-wing, a sizing process is carried out. A number of actuation mechanisms are considered, and two different mechanisms are designed and integrated into a flapping-wing system and compared to one another. The second system is tested using a thrust stand to investigate the impact of wing configurations on aerodynamic force production and the trend of force production from varying flapping frequency. Results present the optimal wing configuration of those tested and that an angle of attack of two degrees yields the greatest force production. A tethered flight test is conducted to examine the stability and aerodynamic capabilities of the drone, and challenges of flapping-wing systems and solutions that can lead to successful flight are presented. Key challenges to the successful design of these systems are weight management, force production, and stability and control.

scholarly journals Characterizing and modeling the enhancement of lift and payload capacity resulting from thrust augmentation in a propeller-assisted flapping wing air vehicle

2017 ◽  
Vol 10 (1) ◽  
pp. 50-69 ◽  
Author(s):  
Alex E Holness ◽  
Hugh A Bruck ◽  
Satyandra K Gupta
Keyword(s):  
Mixed Mode ◽  
Aerodynamic Force ◽  
Force Production ◽  
Flight Time ◽  
Flapping Wing ◽  
Operating Conditions ◽  
Biologically Inspired ◽  
Air Vehicle ◽  
Payload Capacity ◽  
Aerodynamic Lift

Biologically-inspired flapping wing flight is attractive at low Reynolds numbers and at high angles of attack, where fixed wing flight performance declines precipitously. While the merits of flapping propulsion have been intensely investigated, enhancing flapping propulsion has proven challenging because of hardware constraints and the complexity of the design space. For example, increasing the size of wings generates aerodynamic forces that exceed the limits of actuators used to drive the wings, reducing flapping amplitude at higher frequencies and causing thrust to taper off. Therefore, augmentation of aerodynamic force production from alternative propulsion modes can potentially enhance biologically-inspired flight. In this paper, we explore the use of auxiliary propellers on Robo Raven, an existing flapping wing air vehicle (FWAV), to augment thrust without altering wing design or flapping mechanics. Designing such a platform poses two major challenges. First, potential for negative interaction between the flapping and propeller airflow reducing thrust generation. Second, adding propellers to an existing platform increases platform weight and requires additional power from heavier energy sources for comparable flight time. In this paper, three major findings are reported addressing these challenges. First, locating the propellers behind the flapping wings (i.e. in the wake) exhibits minimal coupling without positional sensitivity for the propeller placement at or below the platform centerline. Second, the additional thrust generated by the platform does increase aerodynamic lift. Third, the increase in aerodynamic lift offsets the higher weight of the platform, significantly improving payload capacity. The effect of varying operational payload and flight time for different mixed mode operating conditions was predicted, and the trade-off between the operational payload and operating conditions for mixed mode propulsion was characterized. Flight tests revealed the improved agility of the platform when used with static placement of the wings for various aerobatic maneuvers, such as gliding, diving, or loops.

scholarly journals Development of a novel flapping wing micro aerial vehicle with elliptical wingtip trajectory

2019 ◽  
Vol 10 (2) ◽  
pp. 355-362
Author(s):  
Qiang Liu ◽  
Qiang Li ◽  
Xiaoqin Zhou ◽  
Pengzi Xu ◽  
Luquan Ren ◽  
...  
Keyword(s):  
Aerodynamic Force ◽  
Aerodynamic Performance ◽  
Flapping Wing ◽  
Micro Air Vehicle ◽  
Degree Of Freedom ◽  
Motion Trajectory ◽  
Micro Aerial Vehicle ◽  
Air Vehicle ◽  
Aerial Vehicle ◽  
Flapping Mechanism

Abstract. This paper describes a novel flapping wing micro air vehicle (FWMAV),which can achieve two active degree of freedom (DOF) movements of flapping and swing, as well as twisting passively. This aircraft has a special “0” figure wingtip motion trajectory with the 140∘ flapping stroke angle. With these characteristics integrated into the simple flapping mechanism, the aerodynamic force is somewhat improved. The model made a balance between the improved aerodynamic performance induced by complicated movements and the increased weight of the extra components in aircraft. In the driven design, Only one micro-motor is employed to drive the wing flapping and swing motion simultaneously forming the prescribed trajectory. The 23 g aircraft could reach the maximum flapping frequency of 11 Hz with the tip-to-tip wingspan of 29 cm.

The influence of wing morphology on the three-dimensional flow patterns of a flapping wing at bird scale

2015 ◽  
Vol 768 ◽  
pp. 240-260 ◽  
Author(s):  
William Thielicke ◽  
Eize J. Stamhuis
Keyword(s):  
Aerodynamic Force ◽  
Translational Motion ◽  
Three Dimensional ◽  
Flapping Wing ◽  
Flapping Flight ◽  
Design Parameters ◽  
Wing Morphology ◽  
Slow Speed ◽  
Three Dimensional Flow ◽  
Dimensional Flow

The effect of airfoil design parameters, such as airfoil thickness and camber, are well understood in steady-state aerodynamics. But this knowledge cannot be readily applied to the flapping flight in insects and birds: flow visualizations and computational analyses of flapping flight have identified that in many cases, a leading-edge vortex (LEV) contributes substantially to the generation of aerodynamic force. In flapping flight, very high angles of attack and partly separated flow are common features. Therefore, it is expected that airfoil design parameters affect flapping wing aerodynamics differently. Existing studies have focused on force measurements, which do not provide sufficient insight into the dominant flow features. To analyse the influence of wing morphology in slow-speed bird flight, the time-resolved three-dimensional flow field around different flapping wing models in translational motion at a Reynolds number of $22\,000<\mathit{Re}<26\,000$ was studied. The effect of several Strouhal numbers ($0.2<\mathit{St}<0.4$), camber and thickness on the flow morphology and on the circulation was analysed. A strong LEV was found on all wing types at high $\mathit{St}$. The vortex is stronger on thin wings and enhances the total circulation. Airfoil camber decreases the strength of the LEV, but increases the total bound circulation at the same time, due to an increase of the ‘conventional’ bound circulation at the inner half of the wing. The results provide new insights into the influence of airfoil shape on the LEV and force generation at low $\mathit{Re}$. They contribute to a better understanding of the geometry of vertebrate wings, which seem to be optimized to benefit from LEVs in slow-speed flight.

scholarly journals State-space aerodynamic model reveals high force control authority and predictability in flapping flight

2021 ◽  
Vol 18 (181) ◽  
pp. 20210222
Author(s):  
Yagiz E. Bayiz ◽  
Bo Cheng
Keyword(s):  
State Space ◽  
Force Control ◽  
Aerodynamic Force ◽  
State Space Model ◽  
Three Dimensional ◽  
Large Degree ◽  
Flapping Wing ◽  
Flapping Flight ◽  
Aerodynamic Forces ◽  
Control Authority

Flying animals resort to fast, large-degree-of-freedom motion of flapping wings, a key feature that distinguishes them from rotary or fixed-winged robotic fliers with limited motion of aerodynamic surfaces. However, flapping-wing aerodynamics are characterized by highly unsteady and three-dimensional flows difficult to model or control, and accurate aerodynamic force predictions often rely on expensive computational or experimental methods. Here, we developed a computationally efficient and data-driven state-space model to dynamically map wing kinematics to aerodynamic forces/moments. This model was trained and tested with a total of 548 different flapping-wing motions and surpassed the accuracy and generality of the existing quasi-steady models. This model used 12 states to capture the unsteady and nonlinear fluid effects pertinent to force generation without explicit information of fluid flows. We also provided a comprehensive assessment of the control authority of key wing kinematic variables and found that instantaneous aerodynamic forces/moments were largely predictable by the wing motion history within a half-stroke cycle. Furthermore, the angle of attack, normal acceleration and pitching motion had the strongest effects on the aerodynamic force/moment generation. Our results show that flapping flight inherently offers high force control authority and predictability, which can be key to developing agile and stable aerial fliers.

Nonlinear Aeroelastic Analysis for Highly Flexible Flapping Wing in Hover

2022 ◽  
Author(s):  
Xuan Yang ◽  
Aswathi Sudhir ◽  
Atanu Halder ◽  
Moble Benedict
Keyword(s):  
Structural Model ◽  
Flapping Wing ◽  
Image Correlation ◽  
Elastic Response ◽  
Flapping Wings ◽  
Aerodynamic Model ◽  
Aeroelastic Analysis ◽  
Air Vehicle ◽  
Aeroelastic Simulations ◽  
Nonlinear Fluid

Aeromechanics of highly flexible flapping wings is a complex nonlinear fluid–structure interaction problem and, therefore, cannot be analyzed using conventional linear aeroelasticity methods. This paper presents a standalone coupled aeroelastic framework for highly flexible flapping wings in hover for micro air vehicle (MAV) applications. The MAV-scale flapping wing structure is modeled using fully nonlinear beam and shell finite elements. A potential-flow-based unsteady aerodynamic model is then coupled with the structural model to generate the coupled aeroelastic framework. Both the structural and aerodynamic models are validated independently before coupling. Instantaneous lift force and wing deflection predictions from the coupled aeroelastic simulations are compared with the force and deflection measurements (using digital image correlation) obtained from in-house flapping wing experiments at both moderate (13 Hz) and high (20 Hz) flapping frequencies. Coupled trim analysis is then performed by simultaneously solving wing response equations and vehicle trim equations until trim controls, wing elastic response, inflow and circulation converge all together. The dependence of control inputs on weight and center of gravity (cg) location of the vehicle is studied for the hovering flight case.

Implementation of initial passive stability in insect-mimicking flapping-wing micro air vehicle

2015 ◽  
Vol 3 (1) ◽  
pp. 18-38 ◽  
Author(s):  
Hoang Vu Phan ◽  
Quang-Tri Truong ◽  
Hoon-Cheol Park
Keyword(s):  
Aerodynamic Force ◽  
Three Dimensional ◽  
Flapping Wing ◽  
Micro Air Vehicle ◽  
Content Type ◽  
Wing Kinematics ◽  
Blade Element Theory ◽  
Air Vehicle ◽  
The Mean ◽  
Vertical Takeoff

Purpose – The purpose of this paper is to demonstrate the uncontrolled vertical takeoff of an insect-mimicking flapping-wing micro air vehicle (FW-MAV) of 12.5 cm wing span with a body weight of 7.36 g after installing batteries and power control. Design/methodology/approach – The forces were measured using a load cell and estimated by the unsteady blade element theory (UBET), which is based on full three-dimensional wing kinematics. In addition, the mean aerodynamic force center (AC) was determined based on the UBET calculations using the measured wing kinematics. Findings – The wing flapping frequency can reach to 43 Hz at the flapping angle of 150°. By flapping wings at a frequency of 34 Hz, the FW-MAV can produce enough thrust to over its own weight. For this condition, the difference between the estimated and average measured vertical forces was about 7.3 percent with respect to the estimated force. All parts for the FW-MAV were integrated such that the distance between the mean AC and the center of gravity is close to zero. In this manner, pitching moment generation was prevented to facilitate stable vertical takeoff. An uncontrolled takeoff test successfully demonstrated that the FW-MAV possesses initial pitching stability for takeoff. Originality/value – This work has successfully demonstrated an insect-mimicking flapping-wing MAV that can stably takeoff with initial stability.

Aerodynamic Simulation and Analysis for Biomimetic Flapping-Wing Robot

2010 ◽  
Vol 29-32 ◽  
pp. 1301-1306
Author(s):  
Jin Xu ◽  
Liang Chen ◽  
Wei Sun
Keyword(s):  
Aerodynamic Force ◽  
Unsteady Aerodynamics ◽  
Flapping Wing ◽  
Micro Air Vehicle ◽  
Geometric Similarity ◽  
Aerodynamic Model ◽  
Air Vehicle ◽  
Flight Parameters ◽  
Rotary Wing ◽  
Aerodynamic Simulation

As a new conceptual micro air vehicle, biomimetic flapping-wing robots have the advantages of small sizes, light weights, high maneuverability, and perfect aerodynamic performance. Flapping-wing robot can produce more effective aerodynamic force than traditional fixed-wing or rotary-wing aircrafts. Unsteady aerodynamics at low Reynolds number is the main theory applied to micro air vehicle analysis. In this paper, the flight parameters for a flapping-wing robot are designed with geometric similarity firstly. Then an improved aerodynamic model with optimized parameters is established. Lastly, some simulation and analysis are presented to illustrate and verify the feasibility and effectiveness of the models.

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