scholarly journals Aerodynamic Performance of the Three-Dimensional Lumped Flexibility Bionic Hovering Wing

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Zhu Jianyang ◽  
Jiang Lin ◽  
Hou Yu
Keyword(s):  
Numerical Analysis ◽  
Three Dimensional ◽  
Aerodynamic Characteristics ◽  
Aerodynamic Performance ◽  
Flapping Wing ◽  
Iterative Coupling ◽  
Insect Wing ◽  
Flexible Wing ◽  
At Resonance ◽  
Systematic Synthesis

Understanding the effect of flexibility on the aerodynamic characteristics of the wing is one of the most important considerations for successfully designing a flapping wing micro aero vehicle (FMAV). This paper aims at providing a systematic synthesis on the flexibility effects on the hovering performance of the bionic wing based on the numerical analysis approach. We construct a novel three-dimensional bionic wing, which has lumped flexibility at the root, and develop an iterative coupling program to simulate the interaction between the flexible wing and fluid. The effects of flexibility on the hovering performance of the three-dimensional flapping wing are investigated, and the results indicate that the best performance of the wing is achieved when the wing flaps at resonance and has the density close to the natural insect wing. The feasibility of using lumped flexibility wings driven by a simple harmonic flapping for designing efficient FMAV is also concluded in this study.

scholarly journals Effect of Wing Corrugation on the Aerodynamic Efficiency of Two-Dimensional Flapping Wings

2020 ◽  
Vol 10 (20) ◽  
pp. 7375
Author(s):  
Thanh Tien Dao ◽  
Thi Kim Loan Au ◽  
Soo Hyung Park ◽  
Hoon Cheol Park
Keyword(s):  
Three Dimensional ◽  
Leading Edge ◽  
Aerodynamic Performance ◽  
Flapping Wing ◽  
Flapping Wings ◽  
Two Dimensional ◽  
Aerodynamic Efficiency ◽  
Insect Wing ◽  
Wing Motion ◽  
Computational Fluid Dynamics Cfd

Many previous studies have shown that wing corrugation of an insect wing is only structurally beneficial in enhancing the wing’s bending stiffness and does not much help to improve the aerodynamic performance of flapping wings. This study uses two-dimensional computational fluid dynamics (CFD) in aiming to identify a proper wing corrugation that can enhance the aerodynamic performance of the KUBeetle, an insect-like flapping-wing micro air vehicle (MAV), which operates at a Reynolds number of less than 13,000. For this purpose, various two-dimensional corrugated wings were numerically investigated. The two-dimensional flapping wing motion was extracted from the measured three-dimensional wing kinematics of the KUBeetle at spanwise locations of r = (0.375 and 0.75)R. The CFD analysis showed that at both spanwise locations, the corrugations placed over the entire wing were not beneficial for improving aerodynamic efficiency. However, for the two-dimensional flapping wing at the spanwise location of r = 0.375R, where the wing experiences relatively high angles of attack, three specially designed wings with leading-edge corrugation showed higher aerodynamic performance than that of the non-corrugated smooth wing. The improvement is closely related to the flow patterns formed around the wings. Therefore, the proposed leading-edge corrugation is suggested for the inboard wing of the KUBeetle to enhance aerodynamic performance. The corrugation in the inboard wing may also be structurally beneficial.

Effect of the Air Duct System of a Simplified Vehicle Model on Aerodynamic Performance

2020 ◽  
Vol 17 (2) ◽  
pp. 7985-7995
Author(s):  
A. W. Huluka ◽  
C. H. Kim
Keyword(s):  
Numerical Study ◽  
Aerodynamic Resistance ◽  
Three Dimensional ◽  
Aerodynamic Characteristics ◽  
Aerodynamic Performance ◽  
Vehicle Model ◽  
Fundamental Study ◽  
Pressure Drag ◽  
Energy Efficiency Improvement ◽  
Simple Body

In this numerical study, ducted Ahmed model is used to study aerodynamic characteristics of ducted models and how ducting would contribute to the energy consumption reduction effort from aerodynamic resistance. Three-dimensional, incompressible, and steady governing equations were solved by commercial software PHOENICS (version 2018) with extended turbulent model proposed by Chen-Kim (1987). The study can be considered as a stepping stone to bring a new approach to design aerodynamically efficient vehicle by ducting target vehicles. To investigate the feasibility of the ducting for aerodynamic energy efficiency improvement, fundamental study has been conducted numerically on a simple body before applying to appropriate vehicle model. It is observed from the study that ducting would reduce over 19% of the pressure drag, to the contrary the increase in skin friction drag is noted although its significance to the total drag is very less compared to pressure drag. Therefore, study of ducting and its effect on aerodynamic performance is expected to contribute to improvement of electric vehicle aerodynamic performance.

Design of a Bio-Inspired Spherical Four-Bar Mechanism for Flapping-Wing Micro Air-Vehicle Applications

2008 ◽  
Author(s):  
Matt McDonald ◽  
Sunil K. Agrawal
Keyword(s):  
Three Dimensional ◽  
Micro Air Vehicles ◽  
Aerodynamic Performance ◽  
Flapping Wing ◽  
Micro Air Vehicle ◽  
Aerodynamic Forces ◽  
Flapping Motion ◽  
Wing Motion ◽  
Air Vehicle ◽  
Flapping Mechanism

Design of flapping-wing micro air-vehicles presents many engineering challenges. As observed by biologists, insects and birds exhibit complex three-dimensional wing motions. It is believed that these unique patterns of wing motion create favorable aerodynamic forces that enable these species to fly forward, hover, and execute complex motions. From the perspective of micro air-vehicle applications, extremely lightweight designs that accomplish these motions of the wing, using just a single, or a few actuators, are preferable. This paper presents a method to design a spherical four-bar flapping mechanism that approximates a given spatial flapping motion of a wing, considered to have favorable aerodynamics. A spherical flapping mechanism was then constructed and its aerodynamic performance was compared to the original spatially moving wing using an instrumented robotic flapper with force sensors.

Aerodynamic analysis and design of Busemann biplane: towards efficient supersonic flight

2011 ◽  
Vol 226 (2) ◽  
pp. 217-238 ◽  
Author(s):  
D Maruyama ◽  
K Kusunose ◽  
K Matsushima ◽  
K Nakahashi
Keyword(s):  
Mach Number ◽  
Design Method ◽  
Three Dimensional ◽  
Aerodynamic Characteristics ◽  
Aerodynamic Performance ◽  
The Body ◽  
Analysis And Design ◽  
Expansion Waves ◽  
Mach Numbers ◽  
Inverse Design Method

Aiming to realize a low-drag supersonic transport, Busemann biplane concept was adopted in this study. Two- and three-dimensional (2D and 3D) biplanes were analysed and designed to improve their aerodynamic performance using computational fluid dynamics. It was confirmed that 3D biplane wings have better aerodynamic-performance areas than 2D biplane airfoils. A winglet is also useful for improvement of their aerodynamic performance. Aerodynamic characteristics of these biplanes at their off-design conditions were also analysed. In 3D wings, a flow choking and its attendant hysteresis as starting problems, which arise when the biplanes accelerate from low Mach numbers, disappear at lower Mach numbers than those in 2D airfoils. It was confirmed that hinged slats and flaps are effective to settle these issues. Finally, interference effects of a body with the biplanes were investigated. When the biplane wings are affected by the expansion waves from the body, their aerodynamic performance at the design Mach number and the starting Mach number are better and lower than those of their isolated wings, respectively. A 3D biplane wing obtained by an inverse-design method was applied to the body. The wing of this wing–body configuration achieves higher aerodynamic performance than the 2D flat-plate airfoil at sufficient lift conditions, which is the almost identical performance of 2D biplane airfoils.

scholarly journals Effect of Wing-Wing Interaction on the Propulsive Performance of Two Flapping Wings at Biplane Configuration

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Jianyang Zhu ◽  
Bin Lei
Keyword(s):  
Numerical Analysis ◽  
Numerical Method ◽  
Phase Angle ◽  
Incompressible Flow ◽  
Underwater Vehicle ◽  
Flapping Wing ◽  
Flapping Wings ◽  
Propulsive Performance ◽  
Wing Interaction ◽  
Systematic Synthesis

The biplane counter-flapping wing is a special type of wing flapping which is inspired from the fish and insect in nature. The propulsive performance is one of the most important considerations for this kind of flapping wing. This paper is aimed at providing a systematic synthesis on the propulsive characteristics of two flapping wings at biplane configuration based on the numerical analysis approach. Firstly, parameters of this special flapping wing are presented. Secondly, the numerical method for simultaneously solving the incompressible flow and counter-flapping motion of the wing is illustrated, and the method is then validated. Thirdly, the effects of phase angle and mean wing spacing on the propulsive characteristics of the biplane counter-flapping wing are analyzed. Finally, the quantification effects of the phase angle and mean wing spacing on the propulsive characteristics of the biplane counter-flapping wing can be obtained. The analysis results in this study will provide useful guidelines to design an effectively propulsive system applying for the flapping micro air or underwater vehicle.

LIFT PERFORMANCE OF A CAMBERED WING FOR AERODYNAMIC PERFORMANCE ENHANCEMENT OF THE FLAPPING WING

2015 ◽  
Vol 75 (8) ◽  
Author(s):  
H. Yusoff ◽  
N. Iswadi ◽  
A.H. Zulkifly ◽  
Sh. Mohd Firdaus ◽  
M.Z. Abdullah ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Performance Enhancement ◽  
Wind Tunnel Test ◽  
Micro Air Vehicles ◽  
Aerodynamic Characteristics ◽  
Aerodynamic Performance ◽  
Open Circuit ◽  
Flapping Wing ◽  
Flapping Flight ◽  
Advance Ratio

Flapping-Wing Micro Air Vehicles (FW-MAVs) are small hand-held flying vehicles that can maneuver in constrained space owing to its lightweight, low aspect ratio and the ability to fly in low Reynolds number environment. In this study, the aerodynamic characteristics such as time-averaged lift of camber wings with different five wind tunnel test models with 6, 9, 12, and 15 percent camber were developed and the results were compared with time-averaged lift of a flat wing in order to assess the effects of camber wing on the aerodynamic performance for flapping flight applications. The experiments were performed in an open circuit wind tunnel with of non-return airflow with a test section of (0.3 x 0.3) m and capable of speeds from 0.5 to 30 m/s. The time-averaged lift as functions of advance ratio of the flapping motions with respect to the incoming flows are measured by using a strain gauge balance and KYOWA PCD-300A sensor interface data acquisition system. It is found that camber would bring significant aerodynamic benefits when the flapping flight is in unsteady state regime, with advance ratio less than 1.0. The aerodynamic benefits of camber are found to decay exponentially with the increasing advance ratio. Cambered wing shows significantly higher lift in comparison to the flat wing.

Experimental Studies on Aerodynamic Performance and Unsteady Flow Behaviors of a Single Turbine Stage With Variable Rotor-Stator Axial Gap: Comparisons With Time-Accurate Numerical Simulation

2007 ◽  
Author(s):  
Ken-Ichi Funazaki ◽  
Kazutoyo Yamada ◽  
Mamoru Kikuchi ◽  
Hideaki Sato
Keyword(s):  
Experimental Studies ◽  
Three Dimensional ◽  
Aerodynamic Characteristics ◽  
Aerodynamic Performance ◽  
Rotor Blades ◽  
Turbine Stage ◽  
Flow Angle ◽  
Count Ratio ◽  
Stator Vane ◽  
Flow Information

This paper describes experimental results from detailed measurements of aerodynamic performance of a single stage in the turbine test rig of Iwate University, focusing on effects of the rotor-stator axial gap in the turbine stage. The measurements using a 5-hole Pitot tube provide time-averaged flow information such as stagnation pressure distributions and velocity vectors behind the stator as well as the rotor. Time-accurate three-dimensional flow analyses are also made in this study using an in-house N-S code. Realistic flow analyses are achieved in terms of blade-count ratio only by adding one stator vane, resulting in 3:4 blade-count ratio for the present simulation. Aerodynamic characteristics at the exits of the stator as well as the rotor for three axial gap cases are examined in detail through the experimental data and the numerical results. It follows that the increase in the axial gap gives rise to small increment in exit flow angle from the stator, seemingly affecting the flow structure near the hub as well as tip regions around the rotor blades. Furthermore, the turbine stage efficiency slightly decreases with the axial gap enlargement.

Airfoil Section Characteristics at a Low Reynolds Number

1997 ◽  
Vol 119 (1) ◽  
pp. 129-135 ◽  
Author(s):  
Shigeru Sunada ◽  
Akitoshi Sakaguchi ◽  
Keiji Kawachi
Keyword(s):  
Reynolds Number ◽  
Three Dimensional ◽  
Leading Edge ◽  
Reynolds Numbers ◽  
Aerodynamic Characteristics ◽  
Aerodynamic Performance ◽  
Flight Performance ◽  
High Reynolds ◽  
Shape Characteristics ◽  
Sharp Leading Edge

The aerodynamic characteristics of airfoils operating at Re = 4 × 103 were examined, varying the parameters related to the airfoil shape such as thickness, camber, and roughness. Airfoils with good aerodynamic performance at this Re have the following shape characteristics: (1) they are thinner than airfoils for higher Re numbers, (2) they have a sharp leading edge, and (3) they have a camber of about five percent with its maximum camber at about mid-chord. The characteristics of airfoils are strongly affected by leading edge vortices. The measured two-dimensional airfoil characteristics indicate that the planform, which greatly affects the flight performance of the three-dimensional wing at high Reynolds numbers, has little effect on the flight performance at this Reynolds number.

scholarly journals Unsteady aerodynamic characteristics of a bionic flapping wing in three-dimensional composite motion

AIP Advances ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 015109
Author(s):  
Lun Li ◽  
Jiulong Xu ◽  
Yuan Gao ◽  
Jinghong Yang ◽  
Fan Bai ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Aerodynamic Characteristics ◽  
Flapping Wing ◽  
Unsteady Aerodynamic
Sign in / Sign up

Export Citation Format

Share Document