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IJSRD - International Journal for Scientific Research & Development| Vol. 8, Issue 3, 2020 | ISSN (online): 2321-0613
All rights reserved by www.ijsrd.com 217
Design & Analysis of Ornithopter
Gaurav Kumar1 Prakash Kumar2 Shushendra Singh3 Adarsha Reddy B.N4 1,2,3UG Student 4Assistant Professor
1,2,3,4Department of Mechanical Engineering 1,2,3,4NCET, Bengaluru, India
Abstract— This project will present the design of a Flapping
wing UAV which is inspired by various bird mechanisms
and its action during flight. In this project, the real actions
will be tried to convert into a perfect mechanism to get a
stable flight maneuvering. The design will be made CATIA
V5 with all the parameters according to the bird selected.
And then the hexahedral mesh analysis had done and with
the help of ANSYS- Fluent we had done CFD Analysis at a
different angle of attack. To understand the working
principle of ornithopters, various surveys were made on the
natural flyers with flapping wings and their ability to
produce lift and thrust. The crank mechanism is chosen to
make the micro air vehicle (MAV) for spy work without
being identified. This mechanism is one of the most
complex ones, as its flow condition changes along with its
wing motion. The mechanism is analyzed at two different
speeds: 3 & 6 m/s. To analyze the aerodynamic
characteristics, the lift and drag forces are measured at a
different angle of attack using ANSYS software. The results
are compared at various times with different working
conditions to get the most suitable and reliable conditions.
So copying from the flying behavior of it is possible to gain
all the abilities like the bird. And then after the analysis, we
can able to analyze the lift & drag forces over the wings.
Keywords: Ornithopter, CATIA V5, Hexahedral Mesh, CFD
Analysis, ANSYS-Fluent
I. INTRODUCTION
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.
An Ornithopter is a device that imitates the flapping-wing
flight found in nature. Aerodynamics is a branch of
dynamics concerned with studying the motion of air,
particularly when it interacts with a solid object. It is a
subfield of fluid dynamics and gas dynamics, with much
theory shared between them. Aerodynamics is often used
synonymously with gas dynamics, with the difference being
that gas dynamics applied to all gases.
A. Elements of Bird Flight
Among the living animal species, a true flight is confined to
insects, birds, and bats. Man has to use machines to be able
to fly. Necessary elements required for flight are:
1) A lightweight high strength structure.
2) Wings and feathers for generating lift and forward
thrust.
3) Flight muscles to provide power.
4) A fast response flight control and navigation system.
B. Principle of Ornithopter
The flapping wing mechanism works on the conversion of
the rotary motion of the motor into the reciprocating motion
of the ornithopter, which allows it to produce the required
lift and thrust to fly steadily. The looks of an ornithopter are
like a bird, bat, or butterfly which allows it to mix with
nature and makes it difficult for an enemy to identify it. The
flying pattern of ornithopter is unique as compared to other
UAVs that are subjected to one of the most difficult
aerodynamic flow patterns. When compared to other UAVs
ornithopter covers more distances which makes them more
reliable and efficient. The maneuverability and vertical take-
off and landing capabilities of an ornithopter are its main
advantages so that it is used in various operations. The
stability of an ornithopter during the wind gust makes it
more suitable to be used in the windy conditions and safe
due to its unique feature and look.
II. OBJECTIVES
The objectives of the present project work are as follows
1) To study the flying mechanism of a Bird.
2) Analyze the parameters important for the flight of a
Bird.
3) To get the desired specification of the flapping wing
UAV.
4) Design the structure of Ornithopter according to
parameters.
5) Analyze the structure and get the effect of various
parameters on it.
6) Achieve an idea of the overall structure of the
Ornithopter.
7) To study the analysis of Ornithopter and its effect.
III. MATERIALS AND METHODOLOGY
ANSYS is a software, which is used to simulate the
interaction of all disciplines of physical, structural,
vibrational, fluid dynamics, heat transfer, and
electromagnetic for engineers. It can do the simulation test
or working condition, enable to test in a virtual environment
before the manufacturing prototype of the product. ANSYS
can import the Catia data, solid-work, etc. and it also
enables us to build geometry with its ‘pre-processing’
abilities, similar to a finite element model, i.e. mesh which
is required for computation to be generated after defining
the material, boundary condition. Carrying out analyses,
results can be viewed in numerical and graphical forms. It
can also carry out advanced engineering analyses, safely and
practically based on loading features and non-linear material
models.
The various steps to be carried out in the
performance of finite element analyses using ANSYS are:
1) Defining the problem
Design & Analysis of Ornithopter (IJSRD/Vol. 8/Issue 3/2020/058)
All rights reserved by www.ijsrd.com 218
2) Specifying the type of analysis,i.e., 2D Fluid Flow
Fluent
3) Designing the Geometry or model
4) Creating the model in CATIA
5) Importing the Geometry
6) Boundary Condition
7) Solving the problem
8) Plot contour
9) Result
A. FIRST, decide the various parameters for designing the
flapping wing UAV
1) Design Parameters- Length, Mass, WingSpan, Aspect
ratio, etc.
2) Flight Parameters- Wingbeat Frequency, Flight Speed,
Flapping Angle, etc.
3) Velocity Parameters- Vertical, Horizontal, and Relative
Velocity.
4) Angle of Attack(AOA)
5) Force Parameters- Horizontal, Verticle, and Normal
Force.
6) Lift along Span
7) Thrust Parameters
8) Drag Force.
B. SECOND, design the model
1) Wings:
2) Base/Body:
3) Crank:
4) Slider:
5) Tail:
C. THIRD, Wing Structure
D. FORTH, Drive Mechanism
In this model, we have used the slider-crank mechanism.
Design & Analysis of Ornithopter (IJSRD/Vol. 8/Issue 3/2020/058)
All rights reserved by www.ijsrd.com 219
E. FIFTH, Assembled Model
F. SIXTH, Analysis
Here in our project, we use ANSYS-FLUENT software
using the CFD method (FVM). Finite Volume Method is the
method we are used in the project.
In the CFD FVM method, 3 steps are involved:
1) Pre-processor-
It is used to define the computational domain and generate
the mesh (Hexahedral) also apply boundary conditions.
1) Computational Domain of Interest:
2) Hexahedral Mesh of Wings:
3) Boundary Conditions:
For the analysis, we are having two types of
boundary conditions i.e., inlet BC & outlet BC.
Inlet BC includes – Inlet Velocity, Ambient
Temperature, and Turbulence Parameters. The
velocity of the air at the inlet BC is set in FLUENT
with a value of 3 m/s & 6m/s. The outlet BC is set
to pressure outlet with the gauge pressure of 1 atm.
The model contour, the left and the right of the
virtual wind tunnel are set as symmetry. The
density of air is set as 1.225 kg/m3 and the
viscosity of air is 1.7894 x 10-5 kg/ms.
2) Solver-
The software solves the problem by iterative methods and
for this, the flow will be transient.
3) Post-processor-
It provides for visualization of the results and includes the
capability to display the geometry/mesh, create a vector,
contour, and 2D and 3D surface plots.
IV. RESULTS AND DISCUSSIONS
Using the analytical approach, to get the analysis of airflow
over the wing of an ornithopter to show which orientation
produces the maximum possible lift along with the various
other parameters, which lead us to get the best design. Both
the steady and unsteady flows are demonstrated so that the
flow over the wings of the ornithopter is stable in all
possible conditions. To begin with, we will show the steady
flow simulations of the ornithopter wing.
Imported model at 0º angle of attack-
Imported model at +ve angle of attack-
Imported model at -ve angle of attack-
The below results show the pressure over the wing
surface under the steady flow of the air over the wing area at
a different angle of attack before the analysis. And to study
the unsteady flow, we will divide the wing section into
various sections to get the precise value of the parameters
under different conditions. The wing is divided into two
halves to get the flow analysis on screen, during the process
the wing was divided into various sections. We will discuss
the unsteady flow over the wing at different conditions. The
figures allow us to understand the difference between flow
velocity and pressure in different regions of the wing.
A. Flow Velocity at 3m/s
1) 0º Angle of Attack
Design & Analysis of Ornithopter (IJSRD/Vol. 8/Issue 3/2020/058)
All rights reserved by www.ijsrd.com 220
The pressure & velocity distribution over the wings surface
at 0º angle of attack as shown below.
2) Upward 6º Angle of Attack
Top View
Bottom View
The pressure & velocity distribution over the wings surface
at 6º upward angle of attack as shown below.
3) Upward 12º Angle of Attack
Top View
Design & Analysis of Ornithopter (IJSRD/Vol. 8/Issue 3/2020/058)
All rights reserved by www.ijsrd.com 221
Bottom View
The pressure & velocity distribution over the wings surface
at 12º upward angle of attack as shown below.
4) Downward 6º Angle of Attack
Top View
Bottom View
The pressure & velocity distribution over the wings surface
at 6º downward angle of attack as shown below.
Design & Analysis of Ornithopter (IJSRD/Vol. 8/Issue 3/2020/058)
All rights reserved by www.ijsrd.com 222
5) Downward 12º Angle of Attack
Top View
Bottom View
The pressure & velocity distribution over the wings
surfaceat 12º downward angle of attack as shown below.
B. Flow Velocity at 6m/s
1) 0º Angle of Attack
The pressure & velocity distribution over the wings surface
at 0º angle of attack as shown below.
2) Upward 6º Angle of Attack
Top View
Design & Analysis of Ornithopter (IJSRD/Vol. 8/Issue 3/2020/058)
All rights reserved by www.ijsrd.com 223
Bottom View
The pressure & velocity distribution over the wings surface
at 6º upward angle of attack as shown below.
3) Upward 12º Angle of Attack
Top View
Bottom View
The pressure & velocity distribution over the wings surface
at 12º upward angle of attack as shown below.
Design & Analysis of Ornithopter (IJSRD/Vol. 8/Issue 3/2020/058)
All rights reserved by www.ijsrd.com 224
4) Downward 6º Angle of Attack
Top View
Bottom View
The pressure & velocity distribution over the wings surface
at 6º downward angle of attack as shown below.
5) Downward 12º Angle of Attack
Top View
Bottom View
The pressure & velocity distribution over the wings surface
at 12º downward angle of attack as shown below.
Design & Analysis of Ornithopter (IJSRD/Vol. 8/Issue 3/2020/058)
All rights reserved by www.ijsrd.com 225
The below tables shows the lift and drag forces on
the wing area at a different angle of attack at a flow velocity
of 3m/s & 6m/s.
Flow Velocity 3m/s 3m/s
Angle of Attack Lift (N) Drag (N)
Upward 12º 1.62e-01 0.042927
Upward 6 º 1.09e-01 0.022827
Flat 0 º 1.54e-04 0.016563
Downward 6 º -1.09e-01 0.024195
Downward 12 º -1.82e-01 0.054787
Angle of Attack Lift (N) Drag (N)
Upward 12º 6.67e-01 0.200693
Upward 6 º 4.44e-01 0.084941
Flat 0 º 9.04e-04 0.061639
Downward 6 º -4.43e-01 0.090302
Downward 12 º -7.16e-01 0.216809
Table 1: Lift & Drag force
V. CONCLUSIONS
The main aim of this project is to study the flying
parameters of a bird and to design and analyze the structure
of ornithopter. From this work, we will get the desired
profile for the flapping wings and to compare the
performance of it to the existing ones. This will give an idea
to achieve the profile of the overall structure of the
ornithopter that is efficient under optimum resources and
energy consumption with minimal overall weight. So to
achieve this, we had decided the parameters for the structure
of flapping wing UAV i.e., ornithopter for better efficiency
in terms of resource.
According to our project work, we calculated the
lift and drag forces at two different angles of attack i.e., 6º &
12º both upward and downward (+ve & -ve) with two
different flow velocity of air at 3m/s & 6m/s. When the +ve
angle of attack is given, then the bottom side of the wings is
in direct contact with the flow which results in the high-
pressure region on the bottom side and low-pressure region
at the top side. And this will produce a force from the higher
to lower pressure region area and help the bird to fly or
takeoff and vice-versa with the –ve angle of attack. But
when the velocity is increased the forces also increase of
both lift as well as of drag with the increase in the angle of
attack either in +ve or –ve the forces increases. Hence as per
our project works, we can conclude that as long as the angle
of attack increases until the critical angle of attack reached
the lift and drag forces increases and the same results will
come with the flow velocity. So, in our project the
maximum lift force is with 6m/s flow velocity at flat 0º
angle of attack and minimum drag is with 3m/s flow
velocity at flat 0º angle if attack.
VI. ACKNOWLEDGMENTS
The satisfaction and euphoria that accompany the successful
completion of any task would be incomplete without the
mention of people who made it possible, whose consistent
guidance and encouragement crowned our effort with
success. We consider it is our privilege and duty to express
our gratitude and respect to all those who guide us in the
completion of this project work. We would like to thank our
parents, friends, teaching and non-teaching staff of the
Department of Mechanical Engineering, NCET.
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