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.

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 Circulation in Insect Wings

2020 ◽  
Vol 60 (5) ◽  
pp. 1208-1220 ◽  
Author(s):  
Mary K Salcedo ◽  
John J Socha
Keyword(s):  
Flexible Structures ◽  
Wing Venation ◽  
Living Tissue ◽  
Structural Elements ◽  
Active Sensors ◽  
Wing Membrane ◽  
Insect Wings ◽  
Sensory Hairs ◽  
History Of ◽  
Membrane Wing

Synopsis Insect wings are living, flexible structures composed of tubular veins and thin wing membrane. Wing veins can contain hemolymph (insect blood), tracheae, and nerves. Continuous flow of hemolymph within insect wings ensures that sensory hairs, structural elements such as resilin, and other living tissue within the wings remain functional. While it is well known that hemolymph circulates through insect wings, the extent of wing circulation (e.g., whether flow is present in every vein, and whether it is confined to the veins alone) is not well understood, especially for wings with complex wing venation. Over the last 100 years, scientists have developed experimental methods including microscopy, fluorescence, and thermography to observe flow in the wings. Recognizing and evaluating the importance of hemolymph movement in insect wings is critical in evaluating how the wings function both as flight appendages, as active sensors, and as thermoregulatory organs. In this review, we discuss the history of circulation in wings, past and present experimental techniques for measuring hemolymph, and broad implications for the field of hemodynamics in insect wings.

scholarly journals A Sub-100 mg Electromagnetically Driven Insect-inspired Flapping-wing Micro Robot Capable of Liftoff and Control Torques Modulation

2020 ◽  
Vol 17 (6) ◽  
pp. 1085-1095
Author(s):  
Chenyang Wang ◽  
Weiping Zhang ◽  
Yang Zou ◽  
Ran Meng ◽  
Jiaxin Zhao ◽  
...  
Keyword(s):  
Input Voltage ◽  
Flapping Wing ◽  
Total Weight ◽  
Voltage Amplitude ◽  
Torque Measurement ◽  
Electromagnetic Actuators ◽  
Aerodynamic Model ◽  
Micro Robot ◽  
The Mean ◽  
And Control

AbstractInspired by the unique, agile and efficient flapping flight of insects, we present a novel sub-100 mg, electromagnetically driven, tailless, flapping-wing micro robot. This robot utilizes two optimized electromagnetic actuators placed back to back to drive two wings separately, then kinematics of each wing can be independently controlled, which gives the robot the ability to generate all three control torques of pitch, roll and yaw for steering. To quantify the performance of the robot, a simplified aerodynamic model is used to estimate the generated lift and torques, and two customized test platforms for lift and torque measurement are built for this robot. The mean lift generated by the robot is measured to be proportional to the square of the input voltage amplitude. The three control torques are measured to be respectively proportional to three decoupled parameters of the control voltages, therefore the modulation of three control torques for the robot is independent, which is helpful for the further controlled flight. All these measured results fit well with the calculated results of the aerodynamic model. Furthermore, with a total weight of 96 mg and a wingspan of 3.5 cm, this robot can generate sufficient lift to take off.

FLIPPED VOLTAGE FOLLOWER ANALOG NONLINEAR CIRCUITS

2012 ◽  
Vol 21 (03) ◽  
pp. 1250024 ◽  
Author(s):  
CHAIWAT SAKUL ◽  
KOBCHAI DEJHAN
Keyword(s):  
Relative Error ◽  
Low Voltage ◽  
Harmonic Distortion ◽  
Input Voltage ◽  
Experimental Result ◽  
Voltage Range ◽  
Flipped Voltage Follower ◽  
Voltage Follower ◽  
Power Dispersion ◽  
Four Quadrant

This paper describes squaring and square-rooting circuits operable on low voltage supplies, with their application proposed hereby as vector-summation and four-quadrant multiplier circuits. These circuits make use of a flipped voltage follower (FVF) as fundamental circuit. A detail classification of basic topologies derived from the FVF is given. The proposed circuits have simple structure, wide input range and low power consumption as well as small number of devices. All circuits are also examined and supported by a set of simulations with PSpice program. The circuits can operate at power supply of ±0.7 volts, the input voltage range of the squaring circuit is ±0.8 volts with 1.59% relative error and 1.78 μW power dispersion, the input current of the square-rooting circuit is about 50 μA with 0.55% relative error and 1.4 μW power dispersion and the vector-summation circuit have linearity error of 0.23% and 2.92 μW power dispersion. As in four-quadrant multiplier circuit, the total harmonic distortion of the multiplier is less than 1.2% for 0.8 VP-P input signal at 1 MHz fundamental frequency. Experimental result is carried out to confirm the operation by using commercial CMOS transistor arrays (CD4007). These circuits are highly expected to be effective in further application of the low voltage analog signal processing.

Aeroelastic Analysis of Membrane Micro Air Vehicles

2009 ◽  
Author(s):  
Peter J. Attar ◽  
Raymond E. Gordnier ◽  
Jordan W. Johnston ◽  
William A. Romberg ◽  
Ramkumar N. Parthasarathy
Keyword(s):  
Strouhal Number ◽  
Limit Cycle ◽  
Lift Coefficient ◽  
Angle Of Attack ◽  
Micro Air Vehicles ◽  
Element Model ◽  
Wing Membrane ◽  
Reduced Frequency ◽  
Membrane Wing ◽  
Air Vehicles

The fluid and structural response of two different membrane wing Micro Air Vehicles is studied through computation and experiment. A (three) batten-reinforced fixed wing membrane micro air vehicle is used to determine the effect of membrane prestrain and fixed angle of attack on flutter and limit cycle behavior of fixed wing membrane Micro Air Vehicles. For each configuration tested, flutter and subsequent limit cycle oscillations are measured in wind tunnel tests and predicted using an aeroelastic computational model consisting of a nonlinear finite element model coupled to a vortex lattice solution of the Laplace equation and boundary conditions. Correlation between the predicted and measured onset of limit cycle oscillation is good as is the prediction of the amplitude of the limit cycle at the trailing edge of the lower membrane. A direct correlation between levels of strain and the phase of the membranes during the limit cycle is found in the computation and thought to also occur in the experiment. The second membrane wing micro air vehicle configuration is that of a plunging membrane airfoil model. This model is studied computationally using a sixth-order finite difference solution of the Navier-Stokes equations coupled to a nonlinear string finite element model. The effect, on the structural and fluid response, of plunging Strouhal number, reduced frequency and static angle of attack is examined. At two degree angle of attack, and Strouhal number of 0.2, the effect of increasing the plunging reduced frequency is to decrease the sectional lift coefficient and increase the sectional drag coefficient. At this angle of attack, minimal change in the sectional lift coefficient is found when increasing from a Strouhal number of 0.2 to 0.5 at reduced frequencies of 0.5 and 5.903, the lowest and highest values of this parameter which are studied in this work. For this angle of attack the maximum change which occurs when increasing the Strouhal number from 0.2 to 0.5 is at a reduced frequency of 1.5. When the effect of angle of attack is studied, it is found that at a Strouhal number of 0.5 and reduced frequency of 1.5 the plunging flexible model demonstrates improved lift characteristics over the fixed flexible airfoil case. The greatest improvement occurs at an angle of attack of 2 degrees followed by 10 degrees and then 6 degrees. Finally the effect on the flow characteristics of airfoil flexibility is investigated by increasing the membrane pre-strain from a nominal value of 5 percent to that of 20 percent. This increase in pre-strain results in a reduced value of sectional lift coefficient as compared the 5 percent pre-strain case at the same fixed angle of attack, Strouhal number and reduced frequency.

Modeling of Dive Maneuvers for Executing Autonomous Dives With a Flapping Wing Air Vehicle

2017 ◽  
Vol 9 (6) ◽  
Author(s):  
Luke J. Roberts ◽  
Hugh A. Bruck ◽  
S. K. Gupta
Keyword(s):  
Computational Model ◽  
Operation Mode ◽  
Open Loop ◽  
Flapping Wing ◽  
Minimal Amount ◽  
University Of Maryland ◽  
Roll Control ◽  
Wind Speeds ◽  
Air Vehicle ◽  
The University

This paper is focused on design of dive maneuvers that can be performed outdoors on flapping wing air vehicles (FWAVs) with a minimal amount of on-board computing capability. We present a simple computational model that provides accuracy of 5 m in open loop operation mode for outdoor dives under wind speeds of up to 3 m/s. This model is executed using a low power, on-board processor. We have also demonstrated that the platform can independently execute roll control through tail positioning, and dive control through wing positioning to produce safe dive behaviors. These capabilities were used to successfully demonstrate autonomous dive maneuvers on the Robo Raven platform developed at the University of Maryland.

Research on 5V Internal Power Supply Circuit of Switching Power Supply

2014 ◽  
Vol 571-572 ◽  
pp. 950-954
Author(s):  
Zhu Lei Shao
Keyword(s):  
Power Supply ◽  
Input Voltage ◽  
Experimental Result ◽  
Switching Power Supply ◽  
Zener Diode ◽  
Supply Circuit ◽  
Switching Power ◽  
Power Supply Circuit ◽  
Circuit Structure ◽  
The Stability

In order to guarantee the stability working of internal circuit of switching power supply, an internal power supply circuit with stabilization output was designed in this paper. Based on the voltage stabilization principle of zener diode, the internal power supply circuit put the high input voltage into 5v output voltage. Because of using module circuit, the circuit structure is simplified effectively. Based on 0.35um BCD technology, the internal power supply circuit was built in PSPICE. According to the experimental result, the internal power supply circuit can output stably in different input voltage and environmental temperature.

The Fabrication and Test of a Phase-Change Micropump

2001 ◽  
Author(s):  
Hyeun Joong Yoon ◽  
Woo Young Sim ◽  
Sang Sik Yang
Keyword(s):  
Phase Change ◽  
Flow Rate ◽  
Flow Characteristics ◽  
Check Valve ◽  
Maximum Flow ◽  
Input Voltage ◽  
Working Fluid ◽  
Duty Ratio ◽  
Boron Diffusion ◽  
Change Type

Abstract This paper presents the fabrication and test of a phase-change type micropump with two aluminum flap valves. This micropump consists of a pair of Al flap valves and a phase-change type actuator. The actuator is composed of a heater, a silicone rubber diaphragm and a working fluid chamber. The diaphragm is actuated by the vaporization and the condensation of the working fluid. The micropump is fabricated by the anisotropic etching, the boron diffusion and the metal evaporation. The dimension of the micropump is 8.5 mm × 5 mm × 1.7 mm. The forward and the backward flow characteristics of the flap valve illustrate the appropriateness as a check valve. Also, the flow rate of the micropump is measured. When the square wave input voltage of 10 V is applied to the heater, the maximum flow rate of the micropump is 6.1 μl/min at 0.5 Hz and the duty ratio of 60% for zero pressure difference.

Optimal Compliant Flapping Mechanism Topologies With Multiple Load Cases

2012 ◽  
Vol 134 (5) ◽  
Author(s):  
Bret Stanford ◽  
Philip Beran
Keyword(s):  
Aerodynamic Force ◽  
Compliant Mechanism ◽  
Micro Air Vehicles ◽  
Flapping Wing ◽  
Gradual Transition ◽  
Multiple Load Cases ◽  
Thrust Generation ◽  
Force Moment ◽  
Turning Maneuver ◽  
Multiple Load

The conceptual design of effective actuation mechanisms for flapping wing micro air vehicles presents considerable challenges, with competing weight, power, authority, and life cycle requirements. This work utilizes topology optimization to obtain compliant flapping mechanisms; this is a well-known tool, but the method is rarely extended to incorporate unsteady nonlinear aeroelastic physics, which must be accounted for in the design of flapping wing vehicles. Compliant mechanism topologies are specifically desired to perform two tasks: (1) propulsive thrust generation (symmetric motions of a left and a right wing) and (2) lateral roll moment generation (asymmetric motions). From an optimization standpoint, these two tasks are considered multiple load cases, implemented by scheduling the actuation applied to the mechanism’s design domain. Mechanism topologies obtained with various actuation-scheduling assumptions are provided, along with the resulting flapping wing motions and aerodynamic force/moment generation. Furthermore, it is demonstrated that both load cases may be used simultaneously for future vehicle control studies: gradual transition from forward flight into a turning maneuver, for example.

scholarly journals Wing Design, Fabrication, and Analysis for an X-Wing Flapping-Wing Micro Air Vehicle

Drones ◽  
2019 ◽  
Vol 3 (3) ◽  
pp. 65 ◽  
Author(s):  
Boon Hong Cheaw ◽  
Hann Woei Ho ◽  
Elmi Abu Bakar
Keyword(s):  
Insect Flight ◽  
Micro Air Vehicles ◽  
Flapping Wing ◽  
Indoor Environments ◽  
Wing Design ◽  
Thrust Generation ◽  
Thrust Measurement ◽  
Glue Method ◽  
Controller Board ◽  
Full Throttle

Flapping-wing Micro Air Vehicles (FW-MAVs), inspired by small insects, have limitless potential to be capable of performing tasks in urban and indoor environments. Through the process of mimicking insect flight, however, there are a lot of challenges for successful flight of these vehicles, which include their design, fabrication, control, and propulsion. To this end, this paper investigates the wing design and fabrication of an X-wing FW-MAV and analyzes its performance in terms of thrust generation. It was designed and developed using a systematic approach. Two pairs of wings were fabricated with a traditional cut-and-glue method and an advanced vacuum mold method. The FW-MAV is equipped with inexpensive and tiny avionics, such as the smallest Arduino controller board, a remote-control receiver, standard sensors, servos, a motor, and a 1-cell battery. Thrust measurement was conducted to compare the performance of different wings at full throttle. Overall, this FW-MAV produces maximum vertical thrust at a pitch angle of 10 degrees. The wing having stiffeners and manufactured using the vacuum mold produces the highest thrust among the tested wings.

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