scholarly journals Experimental Investigation of Aerodynamics of Feather-Covered Flapping Wing

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Wenqing Yang ◽  
Bifeng Song
Keyword(s):  
Experimental Investigation ◽  
Carbon Fiber ◽  
Power Consumption ◽  
Flapping Wing ◽  
Flapping Wings ◽  
Avian Flight ◽  
Aerodynamic Performances ◽  
New Type ◽  
Lift Curve ◽  
Membrane Wing

Avian flight has an outstanding performance than the manmade flapping wing MAVs. Considering that the feather is light and strong, a new type of the flapping wing was designed and made, whose skeleton is carbon fiber rods and covered by goose feathers as the skin. Its aerodynamics is tested by experiments and can be compared with conventional artificial flapping wings made of carbon fiber rods as the skeleton and polyester membrane as the skin. The results showed that the feathered wing could generate more lift than the membrane wing in the same flapping kinematics because the feathered wing can have slots between feathers in an upstroke process, which can mainly reduce the negative lift. At the same time, the power consumption also decreased significantly, due to the decrease in the fluctuating range of the periodic lift curve, which reduced the offset consumption of lift. At the same time, the thrusts generated by the feather wing and the membrane wing are similar with each other, which increases with the increase of flapping frequency. In general, the aerodynamic performances of the feather wing are superior to that of the membrane wings.

scholarly journals Experimental investigation of wing flexibility on force generation of a hovering flapping wing micro air vehicle with double wing clap-and-fling effects

2017 ◽  
Vol 9 (3) ◽  
pp. 187-197 ◽  
Author(s):  
Quoc V Nguyen ◽  
Woei L Chan ◽  
Marco Debiasi
Keyword(s):  
Experimental Investigation ◽  
Power Consumption ◽  
High Speed ◽  
Electrical Power ◽  
Leading Edge ◽  
Flapping Wing ◽  
Micro Air Vehicle ◽  
Custom Made ◽  
Air Vehicle ◽  
Set Up

Experimental investigation of wing flexibility on vertical thrust generation and power consumption in hovering condition for a hovering Flapping-Wing Micro Air Vehicle, namely FlowerFly, weighing 14.5 g with a 3 g onboard battery and having four wings with double wing clap-and-fling effects, was conducted for several wing configurations with the same shape, area, and weight. A data acquisition system was set up to simultaneously record aerodynamic forces, electrical power consumption, and wing motions at various flapping frequencies. The forces and power consumption were measured with a loadcell and a custom-made shunt circuit, respectively, and the wing motion was captured by high-speed cameras. The results show a phase delay of the wing tip displacement observed for wings with high flexible leading edge at high frequency, resulting in less vertical thrust produced when compared with the wings with less leading edge flexibility at the same flapping frequency. Positive wing camber was observed during wing flapping motion by arranging the wing supporting ribs. Comparison of thrust-to-power ratios between the wing configurations was undertaken to figure out a wing configuration for high vertical thrust production but less power consumption.

scholarly journals Check-Valve Design in Enhancing Aerodynamic Performance of Flapping Wings

2021 ◽  
Vol 11 (8) ◽  
pp. 3416
Author(s):  
Lung-Jieh Yang ◽  
Reshmi Waikhom ◽  
Wei-Chen Wang ◽  
Vivek Jabaraj Joseph ◽  
Balasubramanian Esakki ◽  
...  
Keyword(s):  
Check Valve ◽  
Input Voltage ◽  
Flapping Wing ◽  
Experimental Result ◽  
Wing Membrane ◽  
Wind Speeds ◽  
Thrust Generation ◽  
Aerodynamic Performances ◽  
Membrane Wing ◽  
Inclined Angle

A flapping wing micro air vehicle (FWMAV) demands high lift and thrust generation for a desired payload. In view of this, the present work focuses on a novel way of enhancing the lift characteristics through integrating check-valves in the flapping wing membrane. Modal analysis and static analysis are performed to determine the natural frequency and deformation of the check-valve. Based on the inference, the check-valve opens and closes during the upstroke flapping and downstroke flapping, respectively. Wind tunnel experiments were conducted by considering the two cases of wing design, i.e., with and without a check-valve for various driving voltages, wind speeds and different inclined angles. A 20 cm-wingspan polyethylene terephthalate (PET) membrane wing with two check-valves, composed of central disc-cap with radius of 7.43 mm, supported by three S-beams, actuated by Evans mechanism to have 90° stroke angle, is considered for the 10 gf (gram force) FWMAV study. The aerodynamic performances, such as lift and net thrust for these two cases, are evaluated. The experimental result demonstrates that an average lift of 17 gf is generated for the case where check-valves are attached on the wing membrane to operate at 3.7 V input voltage, 30° inclined angle and 1.5 m/s wind speed. It is inferred that sufficient aerodynamic benefit with 68% of higher lift is attained for the wing membrane incorporated with check-valve.

NUMERICAL AND EXPERIMENTAL INVESTIGATION ON A NEW TYPE ELECTRICAL HEAT STORAGE BASED ON FLAT MICRO HEAT PIPE

2018 ◽  
Author(s):  
Zeyu Wang ◽  
Yanhua Diao ◽  
Yaohua Zhao ◽  
Chuanqi Chen ◽  
Lin Liang ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Heat Pipe ◽  
Heat Storage ◽  
Micro Heat Pipe ◽  
New Type

scholarly journals The research on precise forming technology of “λ” type composite skin

2021 ◽  
Vol 30 ◽  
pp. 263498332199474
Author(s):  
Qiang Guo ◽  
Kai He ◽  
Hengyuan Xu ◽  
Youyi Wen
Keyword(s):  
Carbon Fiber ◽  
Middle Layer ◽  
Fiber Reinforced ◽  
Process Verification ◽  
Forming Technology ◽  
Fiber Reinforced Materials ◽  
New Type ◽  
Carbon Fiber Reinforced ◽  
Type Composite ◽  
Reinforced Materials

With the application of “ λ” type composite skin becoming more and more extensive and diversified, its precise forming technology is also widely concerned. This article mainly solves the quality problems of “ λ” type corner area, such as delamination dispersion and surface wrinkle, which exist in reality commonly in the manufacturing process. The prepreg is heated along the corner area of the tooling to solve the problem that prepreg is difficult to be compacted due to the large modulus of carbon fiber in “ λ” type corner area. Furthermore, two precompaction tests are creatively increased at 16 layers (middle layer) and 32 layers (last layer) for the thick structure, respectively, to ensure the compaction effect of the blank. In addition, combined with the characteristics of highly elastic rubber and carbon fiber-reinforced materials, a new type of soft mold structure with proper flexibility and good stiffness is proposed innovatively through the reasonable placement of carbon fiber-reinforced materials and the setting of exhaust holes according to the structure characteristics of “ λ” type root skin. Through further process verification, it is shown that the improved process has effectively solved the problems of wrinkles and internal delamination at the sharp corners of parts and realized zero-defect manufacturing of “ λ” type root skin for the first time.

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’.

Experimental investigation of shell-and-tube heat exchanger with a new type of baffles

2011 ◽  
Vol 47 (7) ◽  
pp. 833-839 ◽  
Author(s):  
Yingshuang Wang ◽  
Zhichun Liu ◽  
Suyi Huang ◽  
Wei Liu ◽  
Weiwei Li
Keyword(s):  
Experimental Investigation ◽  
Heat Exchanger ◽  
Tube Heat Exchanger ◽  
New Type ◽  
Shell And Tube
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