Ornithopter Flyingwingmecahnismreport 140613045912 Phpapp01

BANSILAL RAMNATH AGARWAL CHARITABLE TRUST`S

VISHWAKARMA INSTITUTE OF TECHNOLOGY

PUNE- 411 037

(An Autonomous Institute Affiliated to University of Pune)

Mini Project

On

Flying Wing Mechanism

Submitted By

Harshal PatilTE T-31

Pooja PatilTE T-33

Vijay PatilTE T-34

Priyanka Salve TE T-43

Under The Guidance of

Prof. G. N. Kotwal

Department of Mechanical Engineering

2013-2014

1 | P a g e

VISHWAKARMA INSTITUTE OF TECHNOLOGY

PUNE-411 037

(An Autonomous Institute Affiliated to University of Pune.)

CERTIFICATE

This is to certify that the Mini Project titled Flying Wing Mechanism has been completed in the academic year 2013 2014, by Harshal Patil (Gr. No. 111675), Pooja Patil (Gr. No. 111229), Vijay Patil (Gr. No. 111355) and Priyanka Salve (Gr. No. 111291) in partial fulfillment of Bachelors Degree in Mechanical Engineering as prescribed by University of Pune.

Prof. G. N. KotwalProf. H. G. Phakatkar

(Guide)(H.O.D. Mechanical Dept.)

Vishwakarma Institute of Technology, PuneVishwakarma Institute of Technology, Pune

Place: PuneDate: 22/04/2014

________________

Examiner

2 | P a g e

ACKNOWLEDGEMENT

Words are inadequate and out of place at times particularly in the context of expressing sincere feelings in the contribution of this work, is no more than a mere ritual. It is our privilege to acknowledge with respect & gratitude, the keen valuable and ever-available guidance rendered to us by Prof. G. N. Kotwal without the wise counsel and able guidance, it would have been impossible to complete the mini project in this manner.

We express gratitude to other faculty members of Mechanical Engineering Department for their intellectual support throughout the course of this work.

Finally, we are indebted to our family and friends and for their ever available help in accomplishing this task successfully. We will be forever grateful to our friend Mayuresh Marhadkar for his precious advice and for letting us do our project in The Robocon Arena.

Above all we are thankful to the almighty god for giving strength to carry out the present work.

3 | P a g e

ABSTRACT

It is no surprise that humanitys first attempts at flight were in the form of birdlike, human-powered ornithopters. The great artist and engineer Leonardo da Vinci is often credited as the first to propose a reasonable flying machine in 1490: a giant bat-shaped craft that uses both the pilots arms and legs to power the wings. Though the aircraft was never built, and we now know that it would not have flown, it was a remarkable achievement considering the knowledge of the day. At the turn of the 20th century, focus shifted both in the method of thrust production, from flapping wings to the propeller, and the method of power generation, from the human body to the internal combustion engine. With the aerodynamic problem greatly simplified, the impossibility of human flight was disproved by the Wright brothers flight in 1903 and the stage was set for the boom of aircraft developments in the decades to come. Though work on human-powered aircraft was still carried on from time to time by several groups in various countries, it would be three-quarters of a century before anyone mastered the art of human-powered flight.

The problem of flapping-wing flight has been tackled by countless engineers and craftsmen, but until recently only moderate success had been achieved. The Subsonic Aerodynamics laboratory under Professor James de Laurier at the University of Toronto has been a prolific contemporary contributor to the body of knowledge concerning flapping-wing flight, with successes in remote-controlled ornithopters, flapping-wing micro air vehicles, and even a full-scale human-piloted engine powered ornithopter. In 1991 the Professor De Laurier and UTIAS were awarded the Diplme dHonneur by the FAI for having flown the worlds first engine-powered remotely-piloted ornithopter. Theoretical and experimental research intensified in subsequent years, culminating in the successful flight of a full-scale piloted ornithopter on July 8th, 2006. A patented wing-twisting mechanism and extensive research in aero elastic tailoring has kept the University of Toronto at the forefront of ornithopter innovation for the last 20 years.

4 | P a g e

Contents

ACKNOWLEDGEMENT3ABSTRACT4INTRODUCTION6Flying on Flapping Wings6Wing Design6LITERATURE REVIEW7Manned flight9Projects Worldwide10DelFly10Robotic Insect11Flapping Wings at ETH12Aerodynamics of Flapping Wings13Lift13PRESENT WORK14ABOUT OUR PROJECT14DIMENSIONS14Components used15Advantages16APPLICATION17Applications for unmanned ornithopters17Ornithopters as a hobby19Conclusion21REFERENCES22

5 | P a g e

INTRODUCTION

Flying on Flapping Wings

What is ornithopter?

An ornithopter (from Greek ornithos "bird" and pteron "wing") is an aircraft that flies by flapping its wings. Designers seek to imitate the flapping-wing flight of birds, bats, and insects. Though machines may differ in form, they are usually built on the same scale as these flying creatures. Manned ornithopters have also been built, and some have been successful. The machines are of two general types: those with engines and those powered by the muscles of the pilot.The research on Micro Aerial Vehicles (MAV) is comparably young, which has emerged over the past few years. The ongoing miniaturization of electric components such as electric motors and the improvements in microelectronics made it possible to build miniature planes and helicopters at relatively low costs. This development also made it possible to start imitating insect and bird flight, which needs a sophisticated miniaturized actuation chain for their flapping wing motion. The goal of this research is to come up with small aerial vehicles that can operate independently from ground stations, performing certain operations such as surveillance or measurement, especially in environments that are hardly accessible or even dangerous for people.

Wing Design

Ornithopters flapping wings and their motion through the air are designed to maximize the amount of lift generated within limits of weight, material strength, and mechanical complexity. A flexible wing material can increase efficiency while keeping the driving mechanism simple. In wing designs with the spar sufficiently forward of the airfoil that the aerodynamic center is aft of the elastic axis of the wing, aero elastic deformation causes the wing to move in a manner close to its ideal efficiency (in which pitching angles lag plunging displacements by approximately 90 degrees). Flapping wings increase drag and are not as efficient as propeller-powered aircraft. Some designs achieve increased efficiency by applying more power on the down stroke than on the upstroke.

In order to achieve the desired flexibility and minimum weight, engineers and researchers have experimented with wings that require carbon fiber, plywood, fabric and ribs with a stiff strong trailing edge. Any mass located to the aft of the empennage reduces the wing's performance, so lightweight materials and empty spaces are used where possible. In order to minimize drag and maintain the desired shape, choice of a material for the wing surface is also important. In De Laurier's experiments, a smooth aerodynamic surface with a double-surface airfoil is more efficient at producing lift than a single-surface airfoil.

6 | P a g e

LITERATURE REVIEW

The Sanskritepic Ramayana (4thCentury BC) describes an ornithopter,

the PushpakaVimana. The ancientGreek legend of Daedalus (Greek demigod

engineer) and Icarus (Daedalus's son) and The Chinese Book of Han (19 AD) both describe the use of feathers to make wings for a person but these are not actually aircraft. Some early manned flight attempts may have been intended to achieve flapping-wing flight though probably only a glide was actually achieved. These include the flights of the 11th-century monk Eilmer of Malmesbury (recorded in the 12th century) and the 9th-century poet Abbas Ibn Firnas (recorded in the 17th century). Roger Bacon, writing in 1260, was also among the first to consider a technological means of flight. In 1485, Leonardo da Vinci began to study the flight of birds. He grasped that humans are too heavy, and not strong enough, to fly using wings simply attached to the arms. Therefore he sketched a device in which the aviator lies down on a plank and works two large, membranous wings using hand levers, foot pedals, and a system of pulleys.

Some early manned flight attempts may have been intended to achieve flapping-wing flight though probably only a glide was actually achieved. These include the flights of the 11th-century monk Eilmer of Malmesbury (recorded in the 12th century) and the 9th-century poet Abbas Ibn Firnas (recorded in the 17th century). Roger Bacon, writing in 1260, was also among the first to consider a technological means of flight. In 1485, Leonardo da Vinci began to study the flight of birds. He grasped that humans are too heavy, and not strong enough, to fly using wings simply attached to the arms. Therefore he sketched a device in which the aviator lies down on a plank and works two large, membranous wings using hand levers, foot pedals, and a system of pulleys.

Leonardo da Vinci's ornithopter design

The first ornithopters capable of flight were constructed in France. Jobert in 1871 used a rubber band to power a small model bird. Alphonse Pnaud,

HYPERLINK "http://en.wikipedia.org/wiki/Abel_Hureau_de_Villeneuve" Abel Hureau de Villeneuve, and Victor Tatin, also made rubber-powered ornithopters during the

7 | P a g e

1870s. Tatin's ornithopter (now in the US Air & Space Museum) was perhaps the first to use active torsion of the wings, and apparently it served as the basis for a commercial toy offered by Pichancourt c. 1889. Gustave Trouv was the first to use internal combustion and his 1890 model flew a distance of 70 meters in a demonstration for the French Academy of Sciences. The wings were flapped by gunpowder charges activating a bourdon tube.From 1884 on, Lawrence Hargrave built scores of ornithopters powered by rubber bands, springs, steam, or compressed air. He introduced the use of small flapping wings providing the thrust for a larger fixed wing. This eliminated the need for gear reduction, thereby simplifying the construction.

E.P. Frost's 1902 ornithopter

E.P. Frost made ornithopters starting in the 1870s; first models power by steam engines then in the 1900s an internal combustion one large enough for a person but which did not fly.

In the 1930s, Alexander Lippisch and the NSFK in Germany constructed and successfully flew a series of internal combustion powered ornithopters, using Hargrave's concept of small flapping wings, but with aerodynamic improvements resulting from methodical study.

Erich von Holst also working in the 1930s achieved great efficiency and realism in his work with ornithopters powered by rubber band. This includes perhaps the first success of an ornithopter with a bending wing, intended to more closely imitate the folding wing action of birds although it was not a true variable span wing like birds have.

Around 1960, Percival Spencer successfully flew a series of unmanned ornithopters using internal combustion engines ranging from 0.020-to-0.80-cubic-inch (0.33 to 13.11 cm3) displacement, and having wingspans up to 8 feet (2.4 m). In 1961, Percival Spencer and Jack Stephenson flew the first successful engine-powered, remotely piloted ornithopter, known as the Spencer Orniplane. The Orniplane had a 90.7 inches (2,300 mm) wingspan, weighed 7.5 pounds (3.4 kg), and was powered

8 | P a g e

by a 0.35-cubic-inch (5.7 cm3) displacement 2-stroke engine. It has a biplane configuration, to reduce oscillation of the fuselage.

Manned flight

Otto Lilienthal on August 16, 1894 with his kleiner Schlagflgelapparat

Schmid 1942 Ornithopter

Manned ornithopters fall into two general categories: Those powered by the muscular effort of the pilot (human-powered ornithopters), and those powered by an engine.

Around 1894, Otto Lilienthal, an aviation pioneer, became famous in Germany for his widely publicized and successful glider flights. Lilienthal also studied bird flight and conducted some related experiments. He constructed an ornithopter, although its complete development was prevented by his untimely death on the 9th of August 1896 in a glider accident.

In 1929, a man-powered ornithopter designed by Alexander Lippisch (designer of the Me163 Komet) flew a distance of 250 to 300 meters after tow launch. Since a tow launch was used, some have questioned whether the aircraft was capable of flying on its own. Lippisch asserted that the aircraft was actually flying, not making an extended glide. (Precise measurement of altitude and velocity over time would be necessary to resolve this question.) Most of the subsequent human-powered ornithopters likewise used a tow launch, and flights were brief simply because human muscle power diminishes rapidly over time.

In 1942, Adalbert Schmid made a much longer flight of a human-powered ornithopter at Munich-Laim. It travelled a distance of 900 meters, maintaining a height of 20 meters throughout most of the flight. Later this same aircraft was fitted with a

9 | P a g e

3 hp (2.2 kW) Sachs motorcycle engine. With the engine, it made flights up to 15 minutes in duration. Schmid later constructed a 10 hp (7.5 kW) ornithopter based on the Grunau-Baby IIa sailplane, which was flown in 1947. The second aircraft had flapping outer wing panels.

In 2005, Yves Rousseau was given the Paul Tissandier Diploma, awarded by the FAI for contributions to the field of aviation. Rousseau attempted his first human-muscle-powered flight with flapping wings in 1995. On 20 April 2006, at his 212th attempt, he succeeded in flying a distance of 64 meters, observed by officials of the Aero Club de France. Unfortunately, on his 213th flight attempt, a gust of wind led to a wing breaking up, causing the pilot to be gravely injured and rendered paraplegic.A team at the University of Toronto Institute for Aerospace Studies, headed by Professor

HYPERLINK "http://en.wikipedia.org/wiki/James_DeLaurier" James De Laurier, worked for several years on an engine-powered, piloted ornithopter. In July 2006, at the Bombardier Airfield at Downsview Park in Toronto, Professor De Laurier's machine, the UTIAS Ornithopter No.1 made a jet-assisted takeoff and 14-second flight. According to De Laurier, the jet was necessary for sustained flight, but the flapping wings did most of the work.

On August 2, 2010, Todd Reichert of the University of Toronto Institute for Aerospace Studies piloted a human-powered ornithopter named Snowbird. The 32-metre (105 ft 0 in) wingspan, 42-kilogram (93 lb) aircraft was constructed from carbon fiber, balsa, and foam. The pilot sat in a small cockpit suspended below the wings and pumped a bar with his feet to operate a system of wires that flapped the wings up and down. Towed by a car until airborne, it then sustained flight for almost 20 seconds. It flew 145 meters with an average speed of 25.6 km/h (7.1 m/s) Similar tow-launched flights were made in the past, but improved data collection verified that the ornithopter was capable of self-powered flight once aloft.

Projects Worldwide

With the ongoing miniaturization in robotics during the past years it became possible to remarkably downsize aerial vehicles. Recently, several research groups have been trying to build aerial vehicles that are based on the principle of flapping the wings such as insects do. Two of these projects are the DelFly and from TU Delft and the Robotic Insect from Harvard University.

DelFly

DelFly is a MAV developed at TU Delft in the Netherlands. It has four wings, which are actuated by one electric motor. The wings are arranged in pairs, 3State of the Art 4 with the right upper wing connected to the left lower wing and vice versa. Via a small gear train the wing pairs are connected to the electric motor so that the upper and the lower wing approach towards each other. In forward flight, the course can be controlled with rudders installed at the tail of the vehicle. DelFly also carries a

10 | P a g e

camera onboard that sends images to a ground computer from where the vehicle is controlled.

Figure 1: DelFly.

Robotic Insect

Another interesting project is the so called Robotic Insect, being developed at the Harvard Micro robotics Laboratory. The underlying concept is the applying motion of small insects such as flies. For the actuation of the wings of this very small scale MAV a piezoelectric cantilever is used, inducing an oscillation of the wings at their resonance frequency, in order to produce high amplitude. The joints are integrated in the structure as exible parts. The power supply however is not included in this vehicle, which means that despite of already producing remarkably high lift it is not yet able to actually y.

Figure 2: Robotic Insect.

11 | P a g e

Flapping Wings at ETH

The ASL at ETH also aims to develop a MAV of bird size that is based on the aerodynamic principles used in insect flight and by small birds. Unlike other developments in this area, the intended MAV at ETH shall be able to hover like insects or Humming birds, and so it is supposed to become an interesting alternative to Flapping Wings at ETH helicopters as currently being developed at ASL. Furthermore, such an aerial vehicle should be large enough to carry some payload such as a camera, but still small enough to have high agility. Hovering is closely connected to unsteady aerodynamic effects at small Reynolds numbers used in nature by insects and small birds. With a wingspan of 280mm and a weight of about 20g the Giant Hummingbird is one of the largest species in nature that can hover, and therefore had been selected as natural ante type [2]. The goal, however, is not to copy nature but to adopt the basic principles.

Figure 3: Female black-chinned Hummingbird in hover. (fromhttp://en.wikipedia.org)

12 | P a g e

Aerodynamics of Flapping Wings

When flapping the wings, the airflow is highly turbulent and producing more lift compared to wing flight. These are a consequence of the permanently changing wing position during flapping, and are connected to the Reynolds number. In this section the most important aerodynamic are described, however only as a short introduction because this has already been subject to previous work by S. Gisler and O. Breitenstein, where fairly detailed explanations can be found.

Lift

The lift that is produced by applying the wings is characterized by highly un-stationary aerodynamic effects which make it difficult to predict the resulting lift force for a given wing. In order to get a rough idea about what could be expected as lift, and therefore have a boundary for the total weight of the MAV, some simplifications are necessary, which allow applying the 2-dimensional airfoil theory with the formula for lift (L)

L = (CL..v2.A)/2

With the air density

Airspeed v

Platform area A

And,

The lift coefficient CL, for a specific angle of attack.

The lift coefficient (CL, Ca or Cz) is a dimensionless coefficient that relates the lift generated by a lifting body to the density of the fluid around the body, its velocity and an associated reference area. A lifting body is a foil or a complete foil-bearing body such as a fixed-wing aircraft. CL is a function of the angle of the body to the flow, its Reynolds number and its Mach number. The lift coefficient CL is refers to the dynamic lift characteristics of a two-dimensional foil section, with the reference area replaced by the foil chord.The lift coefficient CL is defined by

,

where is the lift force, is fluid

HYPERLINK "http://en.wikipedia.org/wiki/Density" density, is true airspeed, is platform area and is the fluid dynamic pressure.Applying equation for the Flapping wings requires the following assumptions:

1. Non stationary lifts that occur only when the wings are flapping are neglected, with the result that the resulting lift will likely be higher in reality.

2. The lift coefficient CL is independent of time and location on the wing.

3. Induced inflow is disregarded.

13 | P a g e

PRESENT WORK

ABOUT OUR PROJECT

In our model there is one crank and connecting rods. Wings are attached to connecting rods and the wings are hinged to two different slots. When we rotate the crank, the second connecting rod oscillates. The oscillatory motion of connecting rod leads to flapping of wings. Quick Return Mechanism is used here. The wings travel faster during the downward stroke as compared to the upward stroke. This gives more power during the downward stroke and hence gives lift.

DIMENSIONS

Crank radius= 4.5 cm

Length of connecting rod 1= 20 cm

Length of wing rod= 28 cm

Length of Wings= 30 cm

14 | P a g e

Components used

Aluminum Linkages Nut and bolts.

Lock nuts.

Vinyl Sheet (Wings) Wooden Plank (Base)

15 | P a g e

Advantages

Flapping wings offer potential advantages in maneuverability and energy savings compared with fixed-wing aircraft, as well as potentially vertical take-off and landing. It has been suggested that these advantages are greatest at small sizes and low flying speeds.

Unlike airplanes and helicopters, the driving airfoils of the ornithopter have a flapping or oscillating motion, instead of rotary. As with helicopters, the wings usually have a combined function of providing both lift and thrust. Theoretically, the flapping wing can be set to zero angle of attack on the upstroke, so it passes easily through the air. Since typically the flapping airfoils produce both lift and thrust, drag-inducing structures are minimized. These two advantages potentially allow a high degree of efficiency.

16 | P a g e

APPLICATION

Because ornithopters can be made to resemble birds or insects, they could be used for military applications, such as aerial reconnaissance without alerting the enemies that they are under surveillance. Several ornithopters have been flown with video cameras on board, some of which can hover and maneuver in small spaces. In 2011, AeroVironment, Inc. announced a remotely piloted ornithopter resembling a large hummingbird for possible spy missions.

Practical applications capitalize on theresemblance to birds or insects.

The Colorado Division of Wildlife has usedthese machines to help save

the endangered Gunnison Sage Grouse. An artificial hawk under the control of an operator causes the grouse to remain on the ground so they can be captured for study.

Applications for unmanned ornithopters

Practical applications capitalize on theresemblance to birdsor insects.

The Colorado Division of Wildlife has usedthese machines tohelp save

the endangered Gunnison Sage Grouse. An artificial hawk under the control of an operator causes the grouse to remain on the ground so they can be captured for study.

Because ornithopters can be made to resemble birds or insects, they could be used for military applications, such as aerial reconnaissance without alerting the enemies that they are under surveillance. Several ornithopters have been flown with video cameras on board, some of which can hover and maneuver in small spaces. In 2011, AeroVironment, Inc. announced a remotely piloted ornithopter resembling a large hummingbird for possible spy missions.

AeroVironment Humming bird

17 | P a g e

AeroVironment, Inc., then led by Paul B. MacCready

HYPERLINK "http://en.wikipedia.org/wiki/Gossamer_Albatross" (Gossamer Albatross) developed in the mid-1980s, for the Smithsonian Institution, a half-scale radio controlled replica of the giant pterosaur,

HYPERLINK "http://en.wikipedia.org/wiki/Quetzalcoatlus_northropi" Quetzalcoatlus northropi. It was built to star in the IMAX movie On the Wing. The model had a wingspan of 5.5 meters (18 feet) and featured a complex, computerized autopilot control system, just as the full-size pterosaur relied on its neuromuscular system to make constant adjustments in flight.

Researchers hope to eliminate the motors and gears of current designs by more closely imitating animal flight muscles. Georgia Tech Research Institute's

HYPERLINK "http://en.wikipedia.org/wiki/Robert_C._Michelson" Robert C. Michelson is developing a Reciprocating Chemical Muscle for use in micro-scale flapping-wing aircraft. Michelson uses the term "entomopter" for this type of ornithopter. SRI International is developing polymer artificial muscles which may also be used for flapping-wing flight.

In 2002, Krister Wolff and Peter Nordin of Chalmers University of Technology in Sweden built a flapping wing robot that learned flight techniques. The balsa

HYPERLINK "http://en.wikipedia.org/wiki/Wood" wood design was driven by machine learning

HYPERLINK "http://en.wikipedia.org/wiki/Software" software technology known as a steady state linear evolutionary algorithm. Inspired by natural evolution, the software "evolves" in response to feedback on how well it performs a given task. Although confined to a laboratory apparatus, their ornithopter evolved behavior for maximum sustained lift force and horizontal movement.

Since 2002, Prof. Theo van Holten has been working on an ornithopter which is constructed like a helicopter. The device is called the ornicopter and was made by constructing the main rotor so that it would have no reaction torque at all.

In 2008, Schiphol Airport started using a real looking mechanical hawk designed by falconer Robert Musters. The radio controlled robot bird is used to scare away birds that could damage the engines of airplanes.

In March 2011, scientists and engineers at the Festo Bionic Learning Network introduced a robotic SmartBird, based on the motion of a seagull. The Smart Bird weighs only 450 grams and is controlled by a radio handset. On video, its flight appears remarkably realistic.

18 | P a g e

Ornithopters as a hobby

The Dragonfly is a toy made by Wow-Wee.

Hobbyists can build and fly their own ornithopters. These range from light-weight models powered by rubber band, to larger models with radio control.

The rubber-band-powered model can be fairly simple in design and construction. Hobbyists compete for the longest flight times with these models. An introductory model can be fairly simple in design and construction, but the advanced competition designs are extremely delicate and challenging to build. Roy White holds the United States national record for indoor rubber-powered, with his flight time of 21 minutes, 44 seconds.

Commercial free-flight rubber-band powered toy ornithopters have long been available. The first of these was sold under the name Tim Bird in Paris in 1879. Later models were also sold as Tim Bird (made by G de Ruymbeke, France, since 1969).

Commercial radio controlled designs stem from Percival Spencer's engine-powered Seagulls, developed circa 1958, and Sean Kinkade's work in the late 1990s to present day. The wings are usually driven by an electric motor. Many hobbyists enjoy experimenting with their own new wing designs and mechanisms. The opportunity to interact with real birds in their own domain also adds great enjoyment to this hobby. Birds are often curious and will follow or investigate the model while it is flying. In a few cases, RC birds have been attacked by birds of prey,

HYPERLINK "http://en.wikipedia.org/wiki/Crow" crows, and even cats. More recent cheaper models such as the Dragonfly from WowWee have extended the market from dedicated hobbyists to the general toy market.

Some helpful resources for hobbyists include The Ornithopter Design Manual, book written by Nathan Chronister, and The Ornithopter Zone web site, which includes a large amount of information about building and flying these models. To see video examples of a remote control Ornithopter visits the Birds You Fly website.Ornithopters are also of interest as the subject of one of the events in the nationwide Science Olympiad event list. The event ("Flying Bird") entails building a self-propelled ornithopter to exacting specifications, with points awarded for high

19 | P a g e

flight time and low weight. Bonus points are also awarded if the ornithopter happens to look like a real bird.

20 | P a g e

Conclusion

Sooner or later, maybe - in the nearest future, manned motor ornithopters will cease to be "exotic", imaginary, unreal aircraft and start to service for humans as a junior member of aircraft family. Necessary high aviation technology already exists. Designers and engineers will be forced to solve not only, for example, wing design problem, but all problems peculiar to any safe and reliable aircraft of any type. Parts of them, such as stability, controllability, durability etc. are inherent to all aircraft with no exemption. The second part - specific ornithopter new problems, unknown before, which will appear at the first time; flapping wing design problem is only one of them.

21 | P a g e

REFERENCES

1. "Flying on Flapping Wings Ankit Bhardwaj- IIT Patna. (2012).

2. "An Ornithopter Wing Design" De Laurier, James D. (1994), 1018.

3. Winged robot learns to fly New Scientist, August 2002.

22 | P a g e