UNIVERSITY OF PETROLEUM AND ENERGY STUDIES

DESIGN , ANALYSIS AND FABRICATION OF

A UAV FOR AERIAL PHOTOGRAPHY

By

Shivam Kapri-R890213030

Rajat Saklani –R890213022

Prashant Singh-R890213017

Rishabh Kumar-R890213023

Project mentor : Prof. Vijay Kumar Patidar

Department: Aerospace

FOREWORD

We would like to express our deep appreciation and thanks to our project

mentor for allowing us to work in the project “Design and fabrication of

UAV”in his guidance and for all the support we will get for achieving our

project goal.

May 16, 2016

Table of Contents

1.Summary

2.Introduction

3.Purpose of the project

4.Background

5.Methodology

5.1 Structure

5.1.1 Ribs

5.1.2 Spars

5.1.3 Stringers

5.1.4 Bulkhead

5.2 Aerodynamics

6. Operational Plan

6.1 Design

6.2 Fabrication

6.3 Testing

7.The basic design of the airplane

7.1 CAD models of airplane parts

8.Designing of the airplane

8.1 Weight estimation of airplane

8.2 Power and thrust required for level unaccelerated level flight

8.3 Estimating the available thrust and power.

8.4 Stalling calculation

8.5 Gliding flight calculations

8.6 CG moment calculations

9. Aircraft model fluent analysis

10.Some plots

11.Material to be used

12. Conclusion

13. References

List of Figures

Figure 1: Use of UAV in disaster management (source:TED)

Figure 2: Balsa wood

Figure 3:Reference model

Figure4:Main wing

Figure 5:Main wing inner structure

Figure6:Fuselage

Figure 7:Vertical stabilizer

Figure 8: Complete assembly

Figure 9:Available thrust estimation

Figure 10:Distances of ac from CG

Figure 11: Meshed domain

Figure 12:upper pressure contour

Figure 13:lower pressure contour

Figure 14:streamline pattern at 24 deg angle of attack

Figure 15:streamline pattern at 28 deg angle of attack

Figure 16:Lift and Drag plot of wing

Figure 17:Cl-alpha plot for wing

Figure 18:Cl-alpha plot for airfoil

Figure 19:Lift and Drag plot of horizontal stabilizer

Figure 20:Drag polar

Figure 21:L/D-alpha plot

Figure 22:Moment coefficient plot

1.SUMMARY

A model aircraft is a small sized unmanned aircraft or, in the case of a scale

model, a replica of an existing or imaginary aircraft. Model aircraft are divided

into two basic groups: flying and non-flying. Non-flying models are also

termed static, display, or shelf models.

Flying models range from simple toy gliders made of card stock or

foam polystyrene to powered scale models made from materials such as balsa

wood, bamboo, plastic, styrofoam, carbon fiber or fibreglass and are skinned

with tissue paper . Some can be very large, especially when used to research the

flight properties of a proposed full scale design.

Aircraft manufacturers and researchers also make wind tunnel models not

capable of free flight, used for testing and development of new designs.

Sometimes only part of the aircraft is modelled.

The r/c model aircraft fabricated for this project will be radio controlled.

Radio-controlled aircraft have a transmitter operated by the controller, sending

signals to a receiver in the model which in turn actuates servos which

manipulate the model's flight controls in a similar manner to a full sized

aircraft. In traditional aircraft, the radio has directly controlled the servos.

However, modern aircraft often use flight controlling computers to stabilize an

aircraft or even to fly the aircraft autonomously. This is particularly the case

with quadcopters.

2. INTRODUCTION

Aerial photography is the taking of photographs of the ground from an elevated

position. Platforms for aerial photography include fixed-

wing aircraft, helicopters, multirotor Unmanned Aircraft Systems

(UAS), balloons, rockets, pigeons, kites, parachutes. Advances in radio

controlled models have made it possible for model aircraft to conduct low-

altitude aerial photography. Unlike planes and helicopters, where the costs

quickly mount, drones allow to capture aerial shots quickly and inexpensively.

Small scale model aircraft offer increased photographic access to these

previously restricted areas. Miniature vehicles do not replace full size aircraft,

as full size aircraft are capable of longer flight times, higher altitudes, and

greater equipment payloads. They are, however, useful in any situation in

which a full-scale aircraft would be dangerous to operate. Examples would

include the inspection of transformers atop power transmission lines and slow,

low-level flight over agricultural fields, both of which can be accomplished by

a large-scale radio controlled helicopter.

Aerial photography using UAV/drones either fixed wing or rotary wing can

also be used for other applications some of which include-fire scene inspection,

monitoring catastrophes, monitoring climate, monitoring volcanic eruptions,

iceberg monitoring ,monitoring of coastal regions, forestry monitoring,

counting animal population, for police operations, for monitoring nuclear

accidents and gas pipeline inspections.

Figure 1 Use of UAV in disaster management (source:TED)

3. PURPOSE OF THE PROJECT

Our purpose in this project is to design and fabricate a small scale model fixed

wing aircraft for general purpose aerial photography.

4. BACKGROUND

The drone seen today started innovation in the early 1900s and was originally

used for target practice to train military personnel. It continued to be developed

during World War I. The first scale remote piloted vehicle was developed by

the film star and model airplane enthusiast Reginald Denny in 1935. More were

made in the technology rush during World War II; these were used both to train

antiaircraft gunners and to fly attack missions. Nazi Germany produced and

used various UAV aircraft during the course of WWII. The use of aerial

photography rapidly matured during the war, as reconnaissance aircraft were

equipped with cameras to record enemy movements and defenses. Later the

aerial photography was done with the drones/UAV and their use for aerial

photography as we see today emerged.

The first U.S. patent for a radio control device was issued to Nikola Tesla in

1898. Tesla demonstrated his invention to a crowd of onlookers at New York’s

Madison Square Garden in the form of a radio controlled boat. The boat seemed

to respond to verbal commands, however, Tesla was using his new invention to

steer the vessel.

In the 1920’s this burgeoning technology was being used by navies across the

word to control boats used for artillery practice. This new technology was

quickly put to use during the First World War. Several countries used radio

control to pilot aircraft as target drones.

5. METHODOLOGY

We are focusing on Structure and Aerodynamics of our UAV.

5.1 STRUCTURE

The basis arrangement of structural components which include the ribs ,skin of

and wing ,bulkhead and skin of fuselage, length of all the components and their

design is the work in the structure of the UAV.As the UAV is a small scale

radio controlled aircraft the design will simple in construction and component

arrangement. Some of the structural components of wing and fuselage are:

5.1.1 RIBS

They are forming elements of the structure of a wing, especially in traditional

construction. Ribs attach to the main spar, and by being repeated at frequent

intervals, form a skeletal shape for the wing. Usually ribs incorporate

the airfoil shape of the wing, and the skin adopts this shape when stretched over

the ribs.

5.1.2 SPARS

In a fixed-wing aircraft, the spar is often the main structural member of the

wing, running spanwise at right angles to the fuselage. The spar carries flight

loads and the weight of the wings while on the ground. Other structural and

forming members such as ribs may be attached to the spar or spars,

with stressed skin construction also sharing the loads where it is used. There

may be more than one spar in a wing or none at all. However, where a single

spar carries the majority of the forces on it, it is known as the main spar.

5.1.3 STRINGERS

In aircraft construction, a Longeron, or stringer or stiffener, is a thin strip of

material to which the skin of the aircraft is fastened. In the fuselage, stringers

are attached to formers (also called frames) and run in the longitudinal direction

of the aircraft. They are primarily responsible for transferring the aerodynamic

loads acting on the skin onto the frames and formers

5.1.4 BULKHEAD

A bulkhead is an upright wall within the fuselage of an aeroplane. On an

aircraft, bulkheads divide the cabin into multiple areas.On passenger aircraft a

common application is for physically dividing cabins used for different classes

of service (e.g. economy and business.) On combination cargo/ passenger, or

"combi" aircraft, bulkhead walls are inserted to divide areas intended for

passenger seating and cargo storage.It increases the structural rigidity of the

vessel

5.2 AERODYNAMICS

All the design calculation will be done according to the overall weight of the

aircraft .Proper airfoil shape will be chosen according to the weight of the

aircraft which will give us proper lift for that weight. Understanding the motion

of air around an object (often called a flow field) enables the calculation of

forces and moments acting on the object.The aerodynamic forces like Lift and

Drag can be calculated using aerodynamic experiments. Aerodynamics is

important in a number of applications other than aerospace engineering. It is a

significant factor in any type of vehicle design, including automobiles. It is

important in the prediction of forces and moments in sailing. Structural

engineers also use aerodynamics, and particularly aeroelasticity, to

calculate wind loads in the design of large buildings and bridges.

6. OPERATIONAL PLAN

6.1 DESIGN [Oct-25 to Dec-10]

- The first set of operation going to be executed is the design phase.

- The basic airfoil to be selected will be analyzed through xflr5

software.

- Then the basic calculations required for the design and fabrication of

aircraft such as length of the wing span, configuration of the wing,

length of the fuselage, basic design of the fuselage, tail rudder

length, propeller to be used, landing gears, etc. will be done.

- After making the calculations on paper, the basic design of the

aircraft will be made on the software Catia V5.

- On the same software, testing of the aircraft under different

conditions (with balsa wood selected as the basic material) will be

done.

- After basic design, weight analysis of the aircraft will be done.

- This completes the design phase of the project.

Figure 2 Balsa wood

6.2 FABRICATION [Jan-27 to Feb-20]

- After the design phase, fabrication phase will be started, that is the

implementation of what is done on paper and software.

- Basic material to be used will be Balsa wood.

- Firstly wing will be fabricated. The ribs required by the aircraft will

be cut and filed with precision.

- After wing, fuselage will be made. The fuselage will hold the major

components like ESC, battery, camera, motor, etc.

- After fuselage, other components like tail, landing gears will be

made.

- Electronic components, such as motor, ESC, battery etc will be

installed.

6.3 TESTING [Mar-7]

- After fabrication, testing phase will start.

- The aircraft fabricated will be re-analyzed in software with the

modifications or adjustments introduced during fabrication.

- After final software analysis, the final real time testing and flight

testing will be done before demonstration.

7. THE BASIC DESIGN OF THE AIRPLANE

figure 3 reference model

The dimensioning of the airplane we will fabricate will be based on the model

above. The wing span was decided to be 120cm and all the other dimensions

are according to the ratio of the above design.

Chord of the wing=20cm (NACA 2414 AIRFOIL SECTION).

Span of the wing=120cm.

Horizontal stabilizer span=46cm.

Horizontal stabilizer chord=9cm.

Distance between trailing edge of wing and leading edge of horizontal

stabilizer=39cm.

Distance between engine cowling and leading edge of the wing=22cm.

Distance between engine cowling and leading edge of vertical

stabilizer=74cm.

Root chord of vertical stabilizer=15cm.

Tip chord of vertical stabilizer=9cm.

Height of vertical stabilizer=18.5cm.

Width of fuselage=8cm.

Elevator width=3cm.

Aeiloron width=4.5cm.

Rudder width=4.5cm.

Length of fuselage=88cm.

The wing and the horizontal stabilizer are both rectangular with no taper

and the fuselage will also be made rectangular for the ease of

fabrication. The airfoil chosen for the wing is NACA 2414 and the

airfoil section for horizontal as well as vertical stabilizer is chosen to be

NACA 0010.

7.1 CAD MODEL OF AIPRPLANE PARTS

figure 4 main wing

figure 5 main wing inner structure

figure 6 fuselage

figure 7 vertical stabilizer

figure 8 complete assembly

8. DESIGNING OF THE AIRPLANE

8.1 WEIGHT ESTIMATION OF PLANE

Component Number of

components

Weight (grams)

Electronic speed controller(ESC) 1 30

Battery 1 200

Servo 4 9x4=36

Receiver 1 40

Motor 1 80

Total weight of electrical components=30+200+36+40+80=386 grams.

Total weight of aircraft is= 1000grams.

8.2 POWER AND THRUST REQUIRED FOR LEVEL,UNACCELERATED

FLIGHT

The airfoil shape we chosen for the wing is NACA 2414 airfoil and as takeoff

should be done at nearly zero degree angle of attack so is the further calculation

according to it.

The velocity during the level flight is taken as 10m/s.

Thrust required(Tr)=(Weight of airplane)/(Cl/Cd).

Maximum thrust required during level,unaccelerated flight can be calculated by

taking the Cl/Cd at 00

angle of attack,which is=0.9789.

Thus Tr=10.21N

Power required Pr=Tr×V∞=100.16N-m/s

8.3 ESTIMATING THE AVAILABLE THRUST AND POWER

Using the formula for knowing the rpm of a brushless motor

RPM=0.8×3.5V×(Series cell count)×(Motor kv rating)

For our project we have selected a 820kv brushless motor and a 3 cell lipo

battery.

So RPM of the used motor=(0.8×3.5×3×820)=6880 rotations per minute.

For the RPM we have from the above calculation and choosing a 10×7

propeller, 10 being the diameter and 7 being the pitch of the propeller in

inches(in), gives the estimated thrust the propeller and motor combination can

give us. It is shown in the below graph.

figure 9 Available thrust estimation

So the estimated available thrust we have is Ta=1.158×9.81=11.35 N.

And also the estimated power available Pa=11.35×10=113.5 W.

Thus the above calculations tell us that that the available thrust and power are

well above the required thrust and power for level and unaccelerated flight.

8.4 STALLING CALCULATION

Vstall=(2W/(Density of air×Surface area of wing×Cl max)1/2

The maximum Cl given by the wing during flight is Cl max=1.2077. Put this

value in the above equation gives the stalling speed Vstall=7.43m/s

8.5 GLIDING FLIGHT CALCULATIONS

Range(R)=h/tan(α) where tan(α)=1/(L/D).

For maximum range at the time of glide the lift to drag ratio should be

maximum.

Thus put it in the above relation considering the glide from a height of 50 m we

get R=60.38m.

8.6 CG MOMENT CALCULATION

The CG position of the model as shown in figure 8 is shown in the above

figure. The position of CG as shown above is given by CATIA V5.The

moments at this CG position is calculated for the model. The moment

contribution of wing and the horizontal stabilizer have been considered in the

following calculations.

The vertical and horizontal distances of aerodynamic centers of wing and

horizontal stabilizer from the CG position is summarized in the figure below.

The vertical stabilizer has been removed for ease of understanding. The lift and

drag forces of wing and horizontal stabilizer have been assumed to act at

0.25mac where mac(mean aerodynamic chord)=20cm.

Figure 10 distance of ac from CG

Lift and drag table of wing

Angle of attack(degrees) Drag(N) Lift(N)

0 0.9723 0.9517

4 1.1331 4.7129

8 1.5709 7.6805

12 2.3094 11.3263

16 3.5220 14.8014

20 4.6776 16.6923

24 6.00521 17.7533

28 7.4222 16.9493

32 8.68375 15.3978

36 10.293 15.3978

40 11.7312 14.7701

44 13.5573 14.718

Lift and drag table of horizontal stabilizer

Angle of attack(degrees) Drag(N) Lift(N)

0 0.1559 0

3 0.1734 0.4404

6 0.232 0.9239

9 0.3298 1.3977

12 0.4656 1.8796

The lift and drag forces as tabulated are always perpendicular to the free stream

velocity direction as shown in the above figure whatever be the angle of attack

of the plane and acting at the respective aerodynamic centers. The effect of

angle of attack on distances between different points have been neglected.

1. (MCG)α=0=(0.9517× 0.06)+(0.9723 ×0.03)+(0.1559×0.03)=0.0909Nm so

(CmCG)α=0=0.0309.

Now after the angle of attack crosses 1.20

,the aerodynamic center of

horizontal tail will come below CG hence the drag force acting on it

will contribute negative moment at CG i.e anticlockwise moment unlike

the clockwise moment it contributed when it was above CG.

2. (MCG)α=4=(4.7129×0.06)+(1.1331×0.03)-(0.6×0.5025)-

(0.20×.03)=0.00926Nm

(CmCG)α=2=0.00314.

3. (MCG)α=8=(7.6805× 0.06)+(1.5709× 0.03)-(1.2× 0.5025)-(0.3× 0.03)=

-0.104Nm

(CmCG)α=8= -0.03537.

4. (MCG)α=12=(11.3263×0.06)+(2.3894×0.03)-(1.8796×0.5025)-

(0.4656×0.03)= -0.2072Nm

(CmCG)α=12= -0.07048.

9.AIRCRAFT MODEL FLUENT ANALYSIS

Figure 11 Meshed domain

Figure 12 upper pressure contour

Figure13 lower pressure contour

Figure14 streamline pattern at 24 deg angle of attack

Figure 15 streamline pattern at 28 deg angle of attack

10.Some Plots

Figure16 Lift and drag plot of wing

Figure 17 Cl-alpha plot for wing

Figure 18 Cl-alpha plot for airfoil

Figure 19 Lift and Drag plot of horizontal stabilizer

Figure 20 Drag polar

Figure 21 L/D-alpha plot

Figure 22 CG moment coefficient plot

11 MATERIAL TO BE USED

- Ribs: Light medium grade balsa wood (6.0 lb density; 3mm thick)

- Bulkheads: Plywood (5mm thick)

- Spacers: Medium grade balsa wood (6.0 lb density; 5mm thick)

- Spar: Medium hard grade balsa wood (9.6 lb density; 5mm thick)

- Skin: Heat shrink sheet

The basic material to be used is balsa wood.The secret to balsa wood's lightness

can only be seen with a microscope. The cells are big and very thinned walled,

so that the ratio of solid matter to open space is as small as possible. To give a

balsa

tree the strength it needs to stand in the jungle, nature pumps each cell in the

wood full of water until they become rigid like a car tire full of air. Green balsa

wood must therefore be carefully kiln dried to remove most of the water before

it can be sold.

Most people are surprised to learn that compared to other woods, balsa is only

about the third or fourth lightest wood in the world. It is not until balsa is

reached in that line that there is any sign of real strength combined with

lightness. In fact, balsa wood is often considered the strongest wood for its

weight in the world. Pound for pound it is stronger in some respects than pine,

hickory, or even oak.

Apart from the major components, the basic material to be used in skin would

be heat shrink sheet.

They are special type of sheets which shrink and stick to the surface on

application of heat, hence they form the best material for the skin of our aircraft

as it will be a major weight saver.

12. CONCLUSION

UAVs have their use in wide range of areas and they are helping in reducing the

cost and risk associated with any field they are used in. They need not be a

large in size and can be very easy to fabricate and install with their small size

and weight. The UAV we will design and fabricate will fulfill its purpose and

will have all the advantages of a UAV .

13. REFERENCES

Raymer,D.P. Aircraft Design:Aconceptual approach.

Lenon,A.Basics of R/C model aircraft design.

Horgen,John.Modified UAVs.

Aerial photography.wikipedia.org(retrieved October 15, 2015).

Anderson,J.D.Introduction to flight