1.
1
ACKNOWLEDGEMENT
Of the many people who have been enormously helpful in the preparation of this
project, we are especially thankful to, Mr. Omar Chafic for his help and support in
guiding us to through to its successful completion.
We would also like to extend our since gratitude to Emirates Aviation College for the
use of their resources, such as online databases and library, without which the
completion of this project would have been extremely difficult.
A very special recognition needs to be given to Ms. Kavita, our librarian, for her
extensive help and support during research and in dealing with online resources.
In addition to this, a special thanks to be given to our friends Cibin, Omar and Yogesh
for their help, consideration and guidance.
Last but not least, we would like to say a special thank you to our parents and family
members for their moral and financial support this semester.
2.
2
INDEX
Content Page no.
Introduction 3
Parametric Design 6
Mission 7
Gantt Chart 8
Cost Analysis 9
Man Power 10
Materials and tools 11
Electrical Parts and
Servos
16
Air Radio 21
Airfoil Selection 22
3D Design(Autocad) 25
Assembly(Construction) 34
Calculations of Area 49
Graphs 58
Calculations 62
Centre of Gravity 74
Formulae 75
Troubleshooting 77
Safety and risk
assessment
81
References
Conclusion
83
84
3.
3
Introduction1
What are aerobatics?
Aerobatics, stunt flying or aeros is the flying of maneuvers that are not used in ‘normal’
flight involving unusual attitudes. Usually an aerobatic sequence is flown comprising of
several figures (maneuvers).
History of aerobatics
Essential to aerobatic technique is the ability to fly an aircraft inverted (upside down),
which was first demonstrated on September 1, 1913, by the Frenchman Adolphe
Pégoud, test pilot for aviator Louis Blériot. Pégoud also flew other advanced maneuvers
as part of a research program. Other aerobatic innovators include the Russian military
pilot Petr Nesterov, who was the first pilot to “loop the loop,” on September 9,1913.
At the outbreak of World War I, military pilots were used mainly for reconnaissance work
and were not expected to possess any knowledge of aerobatics. It was not until the
development of successful fighter aircraft in 1915 that pilots began to engage in serious
aerial combat, discovering in the process that aerobatic skills could give them a
1
http://www.bruceair.com/aerobatics/aerobatics.htm
Fig.1
4.
4
significant advantage in a dogfight. With this realization and with the aid of aircraft
manufactured with enhanced aerobatic capabilities, pilots began to develop a growing
range of aerobatic maneuvers, principally for evading enemy airplanes. Such skills were
entirely self-taught or acquired from comrades in arms, and only late in 1916 were the
first tentative steps taken toward the systematic teaching of aerobatic techniques, which
had hitherto been discouraged (or even prohibited) in military flight training.
After World War I, former combat pilots continued to refine their skills. The United
States saw the evolution of the barnstormers—pilots who toured rural areas performing
stunt-flying exhibitions—while in Europe the most proficient war pilots were employed
by aircraft manufacturers, displaying their skills and the manufacturers’ products at
public air shows. Competitions between pilots ensued, and these led to the
development of rules, notations, and judging criteria. The first and only World Cup of
aerobatics was held in Paris, In June 1934, with nine entries from six countries (all
European). Aerobatic events were also held in conjunction with the 1936 Olympic
Games in Berlin.
Aerobatics Today
Aerobatics has evolved a lot since its beginning. People still fly aerobatics simply for
enjoyment while others compete and display. The FAI, the Federation Aeronautique
Internationale is the world governing body for all air sports and CIVA, Commission
Internationale de Votige Aerienne is responsible for the administration of erobatic
competitions worldwide under auspices of the FAI. In Britain, all aerobatic competition
are run by the BAA, British Aerobatic Association.
Abstract
In this project, we are going to select an aerobatic aircraft as our model. We are mainly
looking to select a fighter aircraft for our model and after doing our research, we will find
the right design that will meet all our requirements. We will construct the aircraft
carefully and make it light so that it can perform the various maneuvers, but also strong
5.
5
enough to support the load. We will test flight the aircraft so see that it meets our
expectations and that it will be able to carry out the various maneuvers.
In the research part, all the maneuvers that the aircraft is supposed to do will be studied
and verified. We will carefully study the dimensions of the aircraft and use it to perform
various calculations that are needed. We will also carefully research the various
materials needed for the aircraft so the plane can fly efficiently. We will do the test flight
and troubleshooting, where all the problems faced will be verified and explained.
6.
6
PARAMETRIC DESIGN
NAMES
F-35 JOINT
STRIKE
FIGHTER
F-16
FIGHTING
FALCON
F-22
RAPTOR
MiG-29
FALCRUM
Wing Area(sq m) 0.18 0.27 0.36 0.36
Wing span(m) 0.7 0.77 0.79 1.13
Weight(kg) 1.1 1.49 1.9 1.99
Length (m) 1.06 1.21 1.09 1.49
Wing Loading(g sq
m)
0.7 5.52 1.08 5.53
Servos 9g light weight
servos
9g high speed
micro servos
8g servos 9g servos
Ducted Fan Wemotec Mini
Fan 480
70mm ducted
fan
64MM Electric
Ducted Fans
70mm*2
electric ducted
fan
Battery 3 cell 1300mAh
Lipo balance
tabs
14.8V 2200mAh
Li-polymer
3S 3000MAH
15C Lithium
Polymer
3 cell 2000MAH
15C Lithium
Polymer
Motor Hecte edf 3w
or 2w-20
3000KV
outrunner
brushless motor
Outrunner
B2040 KV4300
In runner-type
brushless
ESC ESC RBC 60
amp
45A Brushless
speed controller
25A Brushless
speed controller
2*50A ESC
Radio Controller 3 Channel Radio
with delta
mixer
4 CH Radio
Transmitter and
6 CH Micro
Receiver
4 ch receiver &
6 mini ch
transmitter
Transmitter and
Receiver 9CH
2.4G RC
7.
7
MISSION
SPECIFICATIONS
… Wing …
Wing span (A) 0.7m
Root cord (m) 33.8m
Tip cord (k) 8.6m
… Horizontal stabilizer…
Root cord(r) o.167m
Tip cord (q) 0.0029m
…vertical stabilizer…
Height(f) 0.157m
Root cord (c) 0.145m
Tip cord (e) 0.0072m
….Fuselage ….
Nose to wing tip 0.45m
Length(a) 0.95m
Width (s) 0.2m
9.
9
COST ANALYSIS
Items Quantity Cost per
piece(aed)
Total Amount
(aed)
Balsa wood
-‐ 1/16" x 3" x 36" Balsa Sheet
-‐ 1/8" x 3/8" x 36" Balsa Stick
-‐ 3/8" x 3/8" x 36" Balsa Stick
-‐ 1/2" x 1/2" x 36" Balsa Stick
10
1
2
1
10
15
15
15
100
15
30
15
Monokote cover 1 60 60
Super Glue 2 20 40
Sand Paper 4 5 20
Ducted Fan 1 255 255
Electric Speed Control 1 450 450
Cutter 1 15 15
Radio unit 1 1000 1000
Landing Gear unit 1 250 250
Servo pack 5 65 325
Electric Motor 1 345 345
Hinges pack 1 20 20
Transportation --- 400 400
Total 33 2940 3340
10.
10
MAN POWER
Days for the Project 80 days
Days devoted to the project 45 days
Average hours worked per day 4hours/day
Total hours for the days worked 45 x 4 = 180 hours
Average Man power = no. of persons/
hours
4/180
Average hour per person 180/4 = 45
So each person has worked for 45 hours for this project.
11.
11
Materials2
Balsa wood
Balsa wood is the main material that we have used to construct the aircraft. Balsa wood is
lightweight, inexpensive and relatively strong. We have used it to construct the fuselage, wing
and tailplane as well as in the sheeting of the plane.
Ply wood
We used ply wood on our model on the places where we need more strength like the root rips of
the wing, the front side cover of the fuselage, servo plates etc.
2
http://www.moneysmith.net/Soaring/soaring4.html
Fig.2
Fig.3
12.
12
Card board
We used cardboard for the intake and the outtake of the aircraft.
E-poxy Glue
Epoxy is a strong, important modeling glue but one which must be used sparingly because of its
heavy weight.
Epoxy is classified by its strength and working time. Quick cure, or five minute epoxy, is strong
enough for most modeling applications, and is very handy for quick repairs. Slow cure (30
minute or more) epoxy is used when extra strength is required.
We have used epoxy to join the major parts of the airplane. This includes joining the wing
mounts to the fuselage, and attaching the tail to the fuselage. We have also used slow cure
epoxy for bonding the wood skins to the foam wing and stabilizer core.
Fig.4
Fig.5
13.
13
Masking Tape
We used masking tape for minor repairs in the airplane. Masking tape was chosen due
to its convenient size, shape and ease of removal. It was mainly used for fixing small
cracks in the balsa wood.
Tools
Drill tools
We used a small hand drill to drill holes in the balsa wood. A drill press was also used to make
sure that the holes were straight. Our hand drill was able to make holes of 2mm thickness.
Protractor
Fig.6
Fig.7
14.
14
We used a protractor to measure various angles in the model aircraft, which were needed in the
calculations. For example, we used it to measure the sweptback angle and the angle of the tail
planes.
Cutter
We used a normal cutter as it was very useful to cut the balsa wood, it easily cut through the
wood and was simple to handle. We sometimes used it to file the surface of the wood to make it
smooth and even.
Rulers
We used rulers for measuring the dimensions of the aircraft like wingspan, length of the
fuselage etc.
Fig.8
Fig.9
Fig.10
15.
15
Sand paper
Sandpaper is used to remove small quantities of material at a time from the surface of an object.
Sandpaper can be used to remove a specific material from an object (such as a layer of paint)
or to level and/or smooth the surface of the object. Sandpaper comes in many numbered
"grades," with smaller numbers being coarser and removing more surface material with each
pass. Higher numbers are finer and remove less material.
We have mostly used ‘low grade’ sandpaper for polishing and smoothing the aircraft. We have
also used it to shape the ribs and spars of the model aircraft.
Fig.11
16.
16
ELECTRICAL PARTS
The electrical components used were recommended by the manufacturer to suit the
required and desired output, and they were connected in accordance with the
instruction manual.
BL15 Ducted Fan Motor, 3600Kv
Specifications
Recommended Ducted Fan Unit: Delta-V 15 69mm EDF (EFLDF15)
Static Thrust: 1.7 lb on 3S (11.1V)—using recommended Delta-V 15
2.8 lb on 4S (14.8V)—using recommended Delta-V 15
RPM: 31,000 on 3S (11.1V)—using recommended Delta-V 15
40,000 on 4S (14.8V)—using recommended Delta-V 15
Brushless ESC: 50A—60A
Fig.12
17.
17
Product Specifications
Type: 6-pole Inrunner Brushless
Size: 15-size for Ducted Fans
Bearings or Bushings: Two 4 x 10 x 4mm Bearings
Voltage: 11.1–16.8V
RPM/Volt (Kv): 3600
Resistance (Ri): .02 ohms
Idle Current (Io): 2.80A @ 10V
Continuous Current: 46A
Maximum Burst Current: 55A (15 sec)
Cells: 3S–4S LiPo power 10–14 Ni-MH/Ni-Cd battery
Speed Control: 60A brushless
Weight: 106 g (3.7 oz)
Overall Diameter: 28mm (1.10 in)
Shaft Diameter: 4mm (0.16 in)
Overall Length: 40mm (1.56 in)
Delta-V 15 69mm EDF Unit
Specifications:
Rotor Diameter: 69mm (2.7 in)
Shroud Outer Diameter: 73.5mm (2.9 in)
Shroud Length: 58.3mm (2.3 in)
Shroud Length (Including Intake Ring): 72mm (2.8 in)
Center Body Inside Diameter: 28.3mm (1.1 in) – designed for 28mm motor
Overall Weight: 88g (3.1 oz)
Fig.13
18.
18
60-Amp Pro Switch-Mode BEC Brushless ESC
Product Specifications
Brake: Yes - Programmable
Continuous Maximum Current: 60A with reasonable cooling
Input Voltage: 10.8V - 22.2V
Input Connector Types: 13AWG with E-flite EC3 connector
Output Connector Types: 13AWG with 3.5mm Female Gold Bullet Connectors
Momentary Peak Current: 75A (15 sec)
Length: 3.00 in (76mm)
Width: 1.30 in (33mm)
Height: 0.50 in (13mm)
Weight: 2.3 oz (66g)
Wire Gauge: 13AWG
Cells w/BEC: 3-6S Li-Po or 9-18 Ni-MH/Ni-Cd
Fig.14
19.
19
BATTERY
2800mAh 4S 14.8V 30C LiPo, 12 AWG EC3
Product Specifications
Type: LiPo
Capacity: 2800mAh
Voltage: 14.8V
Connector Type: EC3
Wire Gauge: 12 AWG
Weight: 10.9 oz (309g)
Configuration: 4S
Length: 5.25 in (133mm)
Width: 1.70 in (43mm)
Height: 0.96 in (25mm)
Maximum Continuous Discharge : 30C
Maximum Continuous Current : 84A
Fig.15
20.
20
Servos:
Product Specifications
Size Category: Minis and Micros
Type: Digital
Torque: 19.0 oz/in @ 4.8v
Speed: .11 sec/60° @ 4.8v
Length:0.90 in (23mm)
Width: 0.45 in (12mm)
Height: 0.94 in (24mm)
Weight: .26 oz (7.5 g)
Bushing or Bearing: Bushing
Motor Type: Coreless
Connector Type: Universal
Fig.16
21.
21
Gear Type: Nylon
Air Radio:
Product Specifications
No. of Channels = 9
Modulation = DSM2
Band = 2.4GHz
Receiver: = AR6210
Features = Airplane and Heli
Model Memory = 10
Mode = Mode 2
Fig.17
22.
22
AIRFOIL SELECTION
S8035 was selected for the airfoil for RC F-35 Joint Strike Fighter as it was more
suitable than other ones.
So the airfoil was plotted using the software “ Profili “ and hence we got all the
specifications and graphs.
The plotting of the airfoil with its specifications
The main specifications of the airfoil are:
o Max thinkness 14% at 29% of the chord
o Leading edge radius 1.4%
Fig.18
23.
23
This graph is the cl vs cd
These two graphs are the cl vs. alpha and cd vs. alpha
Fig.19
Fig.20
24.
24
These two graphs one is the cl/cd vs. alpha and from it we can get the cl/cd for the
wing is at maximum when alpha is 7.5 degrees.
Fig.21
25.
25
3D DESIGN(AUTOCAD)
After the 2D design is decided , the 3D design was supposed to be made taking the
dimensions and the idea 2D design. So the 3D design of the whole aircraft was made
part by part.
The parts made separately and then assembled together to make 1 whole aircraft.
These parts shown below:
WINGS
The wings were made first being the easiest of them all.
VERTICAL STABILIZER
Being similar to the wings-shape. The 2 horizontal stabilizers were designed then.
Fig.22
Fig.23
26.
26
Horizontal stabilizers
The vertically placed shapes were also almost similar to the wing-shape, so these were
designed then.
Fuselage
The hard part was to be designed , that is the fuselage with all the complicated shapes
and dimension within it. So each dimensions and angles were taken care of and
designed at the best that it could be made.
Ducted fan region
The ducted fan was a cylindrical type of shape so the diameter and length was
measured and fixed along the fuselage.
Fig.24
Fig.25
27.
27
Nose region
The nose region had to be a pointed cone-like structure that extends from the front of
the fuselage. So the base along the fuselage and the length of the nose was taken and
designed in 3D.
Cockpit shield
This shape would an irregular shape so not much detail was given for this part of the
aircraft. It was designed shaping it along the fuselage and the nose.
Finally all the parts were brought together to make a fully single aircraft design.
Fig.26
Fig.27
Fig.28
28.
28
The design of the whole aircraft was done. And since the 3D view of the aircraft in a
continuous orbit cannot be shown in the report, all the possible views of the 2D and 3D
are shown.
2D views
Front view:
Fig.29
Fig.30
29.
29
Rear view:
Side view:
Top view:
Fig.31
Fig.32
31.
31
3D views
Bottom side views:
Bottom rear view:
Fig.35
Fig.36
32.
32
Top rear view:
Top side view:
Fig.37
Fig.38
33.
33
Bottom front view:
This way the 3D design of the F35 aircraft was made giving us the picture of the aircraft
that was about to be constructed mentioned in the next section.
Fig.39
34.
34
Assembly(Construction)3
The Design(plan) gave us a green signal to finally start with the construction of the
aircraft. The component parts that were needed to form an assembled aircraft were
each traced and draw on the balsa wood with the respective dimensions using the
carbon paper. These designs of the parts were traced with the help of a transparent
paper.
And then all the shapes were cut with the help of a normal metal cutter, and then placed
separately.
3
http://www.oakdaleaircraft.com/f35_manual/f35_edf.pdf
Fig.40
35.
35
So we decided to begin with the wing, which had the following units:
• 8 airfoil shaped ribs for both the sides(Each with decreasing size according to the
chord distance while going from root to tip chord) . 4 for each side.
• 4 joining pieces that would help in supporting the airfoil cross-sections ribs.
• Small size slabs that would keep the joining pieces fixed to the root cross-
sectional airfoil.
• 4 Balsa sheets that are cut into the shape of the covering of the wings.(2 for each
side)
So we first start fixing 2 of the joining pieces to the biggest airfoil rib with the help
of a superglue.
-‐ Leaving holes in the cross-section and later fixing the joining pieces with the help
of the small slabs in such a way that we have a cylindrical space for the wing –
fuselage attachment.
-‐ After having the root airfoil part fixed with the joining pieces we do the same for
the second and the third joining piece.
-‐ Then the second(smaller), third and fourth(smallest) airfoil rib are placed each on
the joining pieces perpendicularly in certain distances till the tip of the joining
pieces. The ribs section of the aircraft is done. It was made sure that the wing
had a strong and rigid support from all sides. So extra balsa pieces were stuck to
the ends.
Fig.41
36.
36
-‐ The balsa sheets are then cut into perfect size of the wing and placed it to shape the
whole part covering all the ribs and the joining pieces inside.
-‐ The ribs and joining pieces were stuck to the balsa sheets with a superglue. No air
was to be left in between the sheet and the ribs so the balsa sheet was pressed and
stuck to the ribs along its shape. These ribs would give support and a perfect airfoil
shape to the entire wing.
Fig.42
Fig.43
Fig.44
37.
37
-‐ After the covering and shaping of the wing in a perfect airfoil shape and when the
construction of the whole wing is made the aileron section is cut at a particular
distance from the trailing edge.
-‐ This cut part of the wing is fixed to the main wing with the help of paper hinges
making it easier for it to move at an angle(later controlled by the servos).
-‐ Now that the construction of the whole wing is done, the servos had to be fitted.
The servo plates are made out of plywood as it can take the heavy loads and
keep the servo rigid on its place. So the servo is fitted at the bottom centre of
both the wings.
Fig.45
38.
38
FUSELAGE
The construction of the fuselage was the most complicated task for our team. All the
components that were traced on the balsa wood after insuring they were in correct
scale, were cut and brought together.
Fuselage consisted the following units:
• Battery holder
• Nose section
• Cockpit shield section
• Intake duct canopy
• Support section for the wing-fuselage attachment.
• Ducted fan holder
• Vertical stabilizer holder
• Horizontal stabilizer holder
The fuselage construction began
-‐ At first, the battery holder is made, making it easier for reference in making any
further parts. Four long pieces of balsa wood with large holes in it(for further
connections through them) are stuck together to make a cuboid-like structure.
-‐ The cockpit shield region is made attached to the top part of battery holder. The
base of the cockpit region resting on top of the battery holder and a certain height
of 3 pieces of semi-circled balsa wood are fixed to each other with superglue.
Fig.46
39.
39
-‐ The nose section is made as an extension to the battery holder, starting from
under the cockpit shield area. The triangular shaped balsa pieces are placed
together making a cone-like shape ending at a point at the front the nose.
The front part of the fuselage is done. Which leaves us with the rear part that consists of
the intake duct path, Ducted fan holder , vertical stabilizer holder and the Horizontal
stabilizer holder.
So the side part of the fuselage,
-‐ Has the wing-fuselage attachment which is supported by the airfoil-like shaped
balsa piece that’s stuck for the purpose of holding the wing and the fuselage
together. These pieces even held the parts that are mentioned in the next point
of this construction.
The rear part of the fuselage,
-‐ The shapes that have multiple purpose(as shown in the figure below); vertical
stabilizer holder and the path that takes in the intake duct chart is cut from the
traced balsa wood. These parts are placed one after the another at a certain
distance and held together by long balsa pieces. These pieces are basically the
ribs of the fuselage.
Fig.47
40.
40
-‐ The making of intact duct canopy is started by covering the inside part of
the path so that it is placed against it and acts as a base for the canopy. 2
pieces of cardboard chart were cut into rectangular shapes and folded into
the shape of the canopy and pushed inside the path so that the chart
takes the shape of the perfect intake duct . From the start of the fuselage
the two charts begin and they end together in a single circle at the rear-
end area.
-‐
(The path of the canopy is created by the balsa pieces accordingly)
Fig.48
Fig.49
41.
41
(The folded chart fit along the path lead by the ribs)
-‐ The ribs are attached with small sections of closed pieces just like the figure, to
support the wing-fuselage attachment rigidly making sure it is tight enough to
hold the fuselage
-‐ .
-‐ The Ducted fan holder is then made with a base that can make the ducted fan
seated at a fixed position. The ducted fan is held by its sides by screwing the
holder to plywood.
Fig.50
Fig.52
Fig.51
42.
42
-‐ The ribs that are at the end have a space that provides a holder to the horizontal
stabilizer.
The horizontal stabilizer is cut exactly according to the design with the
appropriate dimensions.
And both the horizontal stabilizers are placed on provided spaces on the ribs, but
they are a bit angled away.
-‐ The vertical stabilizer is also cut according to the design with the help of the
transparent paper and carbon paper. This part is attached differently, A wooden
rod is used to attach the vertical stabilizer to the two extended fuselage parts that
protrude from the Ducted fan area.
Fig.53
43.
43
-‐ The vertical stabilizers are cut at a distance to make it a movable elevator by
attaching it to the main vertical stabilizer with the help of paper hinges, giving it a
function of moving vertically.
-‐ Servos for the vertical stabilizers are fitted at the bottom of the part ,made out of
plywood, but as light as possible as the load would affect the part as the vertical
stabilizer is a sensitive and small part.
The construction has reached the sheeting part.
-‐ Sheeting is started from the bottom part of the fuselage, 4 thin and long strips of
balsa are placed next to each other that goes along the shape of the bottom,
starts from the cockpit shield section and ends at the Air Duct at the rear end.
Fig.54
Fig.55
44.
44
-‐
-‐ Now the nose part is sheeted covering up the top sides of the structure, filing the
balsa wood along the nose resulting in a good aerodynamic shape.
The bottom section of the Nose is covered by flat balsa sheet taking the shape of
the outline.
-‐ Lengthy sheets of balsa wood are placed at the bottom sides starting from the
opening of the canopy to the rear tip of the fuselage. Two slabs in the 2 sides at
the bottom.
Fig.56
Fig.57
45.
45
-‐ At the top part of the fuselage, 2 lengthy sheets of balsa wood(just like the
bottom covering) are placed on the either sides of the Ducted Fan leaving us with
only the middle part of the top of the fuselage to be covered. This starts from the
start of the middle of the cockpit shield section till the opening of the air duct.
-‐
-‐ The distance of the area that consists of the Ducted fan is covered by small strips
placed next to each other at a flat level along the circular shape. This is the top
part of the fuselage.
Fig.58
Fig.59
46.
46
-‐ The rest of the bottom of the fuselage is covered with balsa wood that is cut
according to the space left uncovered and is fit exactly covering up all the area of
the bottom of the fuselage.
-‐ Now it’s the sides of the fuselage that have to be covered, so the balsa wood is
cut in a shape that fits exactly along the sides of the fuselage as it is the shape is
irregular. So the sides would be covered this way starting from the opening of the
intake duct at the front of the fuselage till the tip of the rear end.
(After covering the whole aircraft and filing them to perfect aerodynamic shape.
We started with the covering the aircraft with monokote)
Fig.60
Fig.61
47.
47
Fixing of landing gears
-‐ After the sheeting of the whole bottom part of the fuselage the area for 3
landing gear wheels and its servos was used. The single front landing
gear was placed at right before the nose section.
-‐ The other 2 landing gears were placed in the fuselage itself on the either
sides rather than on the wing.
Fig.62
Fig.63
48.
48
-‐ And the servos are made of thick plywood with extra pieces fixed so that it does
not leave the support of the landing gear weak making it vulnerable to damage
during landing or while experiencing any other high force.
The main components such as speed control, the battery were wired and placed at their
respective locations.
Fig.64
49.
49
CALCULATIONS:
Wing
Area of A = (18.39 * 25.2)/2 = 231.7 cm2
Area of B = 25.2 * 8.39 = 211.43 cm2
Area of C = 89.46 cm2
Total area = Area of A + Area of B + Area of C
= 231.7 + 211.43 +89.46
= 532.59 cm2
= 0.05326 m2
For both wings = 0.05326 * 2
SREF = 0.1065 m2
Wetted area = 0.21726m2
Fig.65
50.
50
Horizontal tail
Area of A = 9.6 * 15/2 = 72 cm2
Area of B = 2.9*15 = 43.2 cm2
Area of C = (3.9 * 15)/2 = 29.25 cm2
Total Area = Area of A + Area of B + Area of C =
= 72 + 43.2 + 29.25 = 144.45 cm2
= 0.01445 m2 * 2 = 0.0289m2
Wetted Area = 0.0289 * 2.04 = 0.0589m2
Vertical Tail
Area of a Trapezium = [(a +b)/2) * h
= (7.2 + 14.5)/2 *15.7
Fig.66
Fig.67
51.
51
= 166.42 cm2 = 0.01664 m2
= 0.01664 * 2 = 0.03328 m2
Wetted Area = 0.03328 * 2.04 =0.06789 m2
Area of Fuselage
Cylindrical Part
Surface Area = 2πr2
+ 2πrh
= 2*π*(4.9)2 + 2*π*(4.9)*37
= 150.8 + 1139.1
= 1289.9 cm2 = 0.1289 m2
Trapezium Part
Area = (a + b)/2 * h
= (19 +25)/2 * 24
= 528 cm2
= 0.0528 m2
Fig.68
Fig.69
52.
52
Bottom Part
Area = (a + b)/2 * h
= (12.5 +14.5)/2 * 24
= 324 cm2
= 0.0324 m2
Sides
Area = (a +b)/2 * h
= (4.8 + 6.6)/2 * 24
= 136.8 cm2
=0.01368 m2
Area = 0.1368 * 2 = 0.02736 m2
Fig.70
Fig.71
53.
53
Nose
Bottom Triangle
Area = ½ * b * h
= (4.8/2) * 24.8
= 59.52 cm2 = 0.00595 m2
Sides
Area = ½ * b * h
= (6/2) * 25
= 3 * 25
= 75 cm2 = 0.0075 m2
Area = 0.0075 * 2
= 0.015 m2
Fig.72
Fig.73
54.
54
Top
Area = ½ * b * h
= (6.8/2) * 31
= 105.4 cm2
= 0.01054 m2
Cockpit shield
Half Elliptical Cylinder Part
Area = 2πL √(a2
+ b2
)/2 + 2πab
= 2π*11√[(3.4)2 + (6.8)2]/2] + 2π*(3.4)*(6.8)
= 371.55 + 145.26
= 516.81 cm2 = 0.05168 m2
Since it is half
Therefore, 0.05168/2 = 0.02584 m2
Fig.74
Fig.75
55.
55
Half Conical Part
Area = πrs + πr2
=π*6.8*8.3 + π* 6.82
= 177.31 + 145.27
= 322.58 cm2 = 0.03225 m2
Since it is half,
= 0.03225/2
= 0.01612 m2
Top Side Rectangles
Area = a * b
= 35 * 6
= 210 cm2 = 0.021 m2
Fig.76
Fig.77
56.
56
Multiplying by 2,
Therefore, 0.021 * 2 = 0.042 m2
Top tail trapezoidal parts
Area = (a+b)/2 * h
= (3.2 + 4.8)/2 * 14.2
= 56.8 cm2 = 0.00568 m2
Since it is two,
0.00568 * 2 = 0.01136 m2
Bottom Rectangular Parts
Area = a * b
= 3.8 * 49
= 186.2 cm2
= 0.01862 m2
Fig.78
Fig.79
57.
57
Since it is two,
0.01862 * 2 = 0.03724 m2
Bottom Trapezoidal Parts
Area = (a * b)/ 2 * h
= (1 + 5.6)/2 * 51.2
= 168.96 cm2 = 0.01689 m2
Since it is two,
0.01689 * 2 = 0.03379 m2
Total Area of Fuselage = 0.1289 + 0.0528 + 0.0324 + 0.02736 + 0.00595 + 0.015
+ 0.01054 + 0.02584 + 0.01612 +0.042 + 0.01136 +0.03724
+ 0.03379 = 0.439 m2
Wetted area = 0.439 * 2.04 = 0.8955 m2
Fig.80
58.
58
Airplane components
GRAPHS4
The graphs that we are going to use are the following
The aerodynamic form factor graph
4
Fundamentals
of
Flight
by
Richard
S
Shevell
Fig.81
61.
61
6
6
Fundamentals
of
Flight
by
Richard
S
Shevell
Fig.86
62.
62
Wing
Wetted area = 0.21726/ Platform area or SREF = 0.1065 m2
Root Chord: 0.338
Taper ratio = CT/CR = 0.086/0.338 = 0.25
Tip Chord : 0.086m
MAC = 2/3 * CR(1 + σ - σ/1+σ) = 2/3 * 0.338(1 + 0.25 - 0.25/1+0.25)
= 0.225m
Weight = 1.21kg = 1.21*10= 12.1N
Wing Loading = Weight/Wing Area = 12.1/0.1065 = 113.61 N/m2
Thickness ratio = 10% = 0.1
Sweptback angle: 400
Tracing from the graph at 40o
Swept angle [Put Graph 11.3 page 182]
Form Factor ‘k’ = 1.16
Aspect Ratio (AR) = b2
/SREF = 0.72
/0.1065 = 4.6
63.
63
Wing
Fuselage
Area 0.439 m2
Wetted Area 0.8955 m2
Length 0.955m
Diameter 0.2m
Finesse ratio 4.7
Body form factor ‘k’ 1.31
Fuselage diameter/Wingspan 0.28
Induced drag factor ‘S’ 0.84
Horizontal Tail
Reference Area = 0.0289 m2
wetted area = 0.0589 m2
Root Chord = 0.16m
Tip Chord = 0.029m
Taper ratio = CT/CR = 0.029/0.16 = 0.18
Planform Area 0.1065 m2
wetted area 0.21726m2
Root Chord 0.338m
Taper Ratio 0.25
Tip Chord 0.086m
MAC 0.225m
Weight 12N
Wing Loading 113.61 N/m2
Thickness ratio 0.1
Swept back angle 400
Form factor ‘k’ 1.16
Aspect ratio 4.6
64.
64
M.A.C = 2/3CR(1 + σ – σ/1+σ) = 2/3 * 0.16(1 + 0.18 - 0.18/1+0.18) = 0.109 m
t/c = 9% = 0.09
From graph 11.3, page 182, Richard Shevell
K = 1.31
Vertical Tail
Reference area = 0.03329 m2
= wetted area = 0.06789 m2
Root chord (CR) = 0.145m
Tip Chord (CT) = 0.072 m
Taper ratio = σ = CT/CR = 0.072/0.145 = 0.496
M.A.C = 2/3CR (1 + σ – σ/1 +σ)
= 2/3CR (1 + 0.496 - 0.496/1 + 0.496)
= 0.112 m
t/c = 9% = 0.09
k = 1.31
Reference area 0.03329 m2
Wetted area 0.06789 m2
Root chord 0.145m
Tip Chord 0.072m
Taper ratio 0.496
M.A.C 0.112 m
t/c 0.09
K 1.31
Reference area 0.0289 m2
Wetted Area 0.0589 m2
Root Chord 0.16 m
Tip Chord 0.029 m
Taper ratio 0.18
M.A.C 0.109 m
t/c 0.09
K 1.31
65.
65
At Cruise condition
CL Calculation
Lift (L) = ½ ρV2
SCL
At Cruise Condition, L = W
Thrust = Drag
Therefore, CL = 2W/ρV2
S
Vcruise = 15 m/s
ρ= 1.2250 kg/m3
S = 0.1065 m2
L = W = 12.1 N
Therefore, CL = 2 * 12.1/1.2250 * 152
* 0.1065
CLcruise = 0.8312
Condition Value
Weight 12.1 N
Height 100 m
Temperature 288.16 K
Pressure 101325 N/m2
Density 1.2250 Kg/m3
Kinematic Viscosity 1.4607 * 10-5
m2
/s
Speed 15 m/s
CL 0.8312
t/c 0.1
K (Fuselage) 1.31
K (wing) 1.16
Aspect Ratio (AR) 4.6
66.
66
Parasitic Drag Coefficient
Wing
K = 1.16
CDP = (Cf * k * Swet)/Sref
RN = ( Vo * L)/v
= (Vo * M.A.C)/v
RN = 15 * 0.225/1.4607 * 10 -5
= 231,053.60
For RN > 200,000, the flow is turbulent
Hence, calculations for turbulent flow is adopted
CF = 0.455/(Log RN)2.54
= 0.455/ (Log 231053.00)2.58
= 5.970 * 10-3
C DP = 5.970 * 10-3
* 1.16 * 0.21726/0.1065 = 0.0141
Fuselage
RN = ( Vo * L)/v = (15 * 0.955)/1.4607 * 10-3
= 980,694.18
K = 1.31
Cf = 0.455/(Log 980694.18)2.58
CDP = (4.4871 * 10-3
* 1.31 * 0.8955)/0.1065 = 0.0494
Horizontal Tail
RN = (Vo * M.A.C)/v = (15 * 0.109)/1.4607 * 10-5
= 111,932.63
For RN < 200,000, we use laminar flow calculation
C f = 1.328/√RN = 1.328/√111932.63 = 3.9693 *10-3
K = 1.31
CDP = (3.9693 *10-3
* 1.31 * 0.0589)/0.0289 = 0.0105
67.
67
Vertical tail
RN = (Vo * M.A.C)/v = 15 * 0.112/1.4607 * 10-5
= 115,013.34
C f = 1.328/√RN = 1.328/√115013.34 = 3.9158 * 10-3
K = 1.31
CDP = (3.9158 * 0678910-3
* 1.31 *0.)/0.03329 = 0.0104
Total CDP = 0.0141 + 0.0494 +0.0105 + 0.0104 = 0.0844
Induced Drag
CDi = CLcruise
2
/πARe
e = 1/[πARK + 1/(u * s)]
AR = 4.6, u = 0.99, s = 0.84 , k = 0.45 CDp for 350
Swept wings
e = 1/[π*4.6*0.45+(1/(0.99*0.84)]
e = 0.1297
CLcruise = 0.8312
CDi = (0.8312)2
/π*4.6*0.1297 = 0.03686
CD = CDp + CDi = 0.0844 +0.03686 = 0.1297
D = ρ * V2
* CD * S/2 = (1.2250 * 152
* 0.1297 * 0.1065)/2
D = 1.9036 N
(L/D)cruise = CL/CD = 0.8312/0.1297 = 6.408
70.
70
CDp = 0.0030 * 1.31 * 0.21726/0.1065 = 0.0080
Total CDp = 0.0124 + 0.0108 + 0.0081 + 0.0080 = 0.0393
Induced drag
CDi = C L to climb
2
/πARe
e= 0.1297
C L to climb = 0.2783
C Di = (0.2783)2
/π* 4.6 * 0.297 = 0.0413
There is an increase in CDi which could be corrected by ‘ground effect’
Height from ground to wing m.a.c , h = 29cm = 0.29m
Wing span = 4.6
Therefore, h/b =0.29/4.6 = 0.1
Using Graph figure 9.10 on page 152, Richard Shevell “Fundamentals of Flight” (K L)
K L = 0.5
0.5 * C Di = 0.5 * 0.0413 = 0.0206
CD = CDp + CDi = 0.0393 + 0.0206 = 0.0599
D = p* V2
* CD * S/2 = 1.2250 * 152
* 0.0599 * 0.1065/2 = 0.879 N
(L/D)LO = CL/C D = 0.2783/0.0599 = 4.64
72.
72
CDp = 0.0061 * 1.31 * 0.21726/0.1065 = 0.0163
Total CDp = 0.0123 + 0.0109 + 0.0163 + 0.0163 = 0.0558
Induced Drag
CDi = CL/πARe
e= 0.1297
C L =0.8312
CDi =(0.8312)2/π* 4.6 * 0.1297 = 0.0368
CD = CDp + C Di = 0.0558 + 0.0368 = 0.0923
D = pV2
CD S/2 = 1.2250 * 152
* 0.0923*0.1065/2 = 1.3546
(L/D) = CL/CD = 0.8312/0.0923 = 9.00
Maneuvers
Turning Performance
V = 15 m/s
θ = 60o
g = 10 m/s 2
n = 1/Cosθ = 1/Cos60 = 2
Level Turn
73.
73
Radius of turn (r)
r = V2
/g√n2
– 1) = 152
/10√(22
-1) = 152
/10√3 = 12.9m
Angular Velocity (ω)
ω= g√n 2
– 1/v = 10 * √3/15 = 1.15 m/s
Vertical Turn Pull up
Radius of turn (r)
r = r 2
/g(n-1) = 15 2
/10(2-1) = 22.5 m
Angular velocity
ω= g(n-1)/v = 10(2-1)/15 = 10/15 = 0.66 m/s
VERTICAL TURN PULL DOWN
Radius of turn (r)
r= v 2/
g(n+1) = 152
/10(2+1) = 7.5m
Angular velocity
ω = g(n +1)/v = 10* 3/15 = 2 m/sθ
Vertical turn
Radius of turn r
r = v2
/gn = 152
/10*2 = 11.25 m
Angular velocity (ω)
ω= gn/v = 10 * 2/15 = 1.33 m/s
74.
74
Centre of Gravity:
The reference is taken as 10cm from the Ducted fan.
The weight and distance of each component is mentioned in the table.
Object Weight(kg) Arm + Reference(m) moment
Tail 0.095 0.03 + 10 0.95285
Fuselage 0.343 0.55 + 10 3.61865
Wings 0.250 0.33 + 10 2.5825
Landing gear 0.117 0.15 + 10 1.18755
Servo box 0.040 0.34 + 10 0.4136
Speed Control 0.066 0.17 + 10 0.67122
Ducted fan 0.088 0 + 10 0.88
e-poxy 0.100 0.001 + 10 1.0001
Motor 0.106 0.05 + 10 1.0653
Total 1.205 91.61 12.37177
To find the center of gravity the moment is divided by the weight.
Centre of Gravity = Moment/Weight = 12.37177 / 1.205
= 10.267
So the center of gravity for our aircraft is 10.267 from our ducted fan.
75.
75
FORMULAE USED in calculations throughout the report
• Area of triangle = (b*h)/2
• Area of Trapezium = [(a+b)/2]h
• Area of rectangle = (length x breadth)
• Surface Area of cylinder = 2πr2
+ 2πrh
• Surface area of elliptical cylinder = 2πL √(a2
+ b2
)/2 + 2πab
• Surface Area of cone = πrs + πr2
• Taper ratio = CT/CR
• MAC = 2/3 * CR(1 + σ - σ/1+σ)
• Wing Loading = Weight/Wing Area
• Aspect Ratio (AR) = b2
/SREF
• Lift (L) = ½ ρV2
SCL
• CL = 2W/ρV2
S
• CDP = (Cf * k * Swet)/Sref
• RN = ( Vo * L)/v
•
CF = 0.455/(Log RN)2.54
e = 1/[πARK + 1/(u * s)]
CDi = CLcruise
2
/πARe
• D = ρ * V2
* CD * S/2
• (L/D)cruise = CL/CD
• CL(L/D)max = √CDp *π*AR*e
76.
76
• (L/D)max = √π/2 * b√e/√ CDps
• V stall = √2w/ ρ*s*CLmax
• D = pV2
CD S/2
• Centre of Gravity = Moment/Weight
77.
77
Troubleshooting
After testing the plane we had a problem with the following things:
Landing Gear
We were told that the landing gear was too high and needed to be made lower
otherwise the aircraft won’t move straight. We decided to try it out anyway, but as
expected the plane didn’t move straight and turned over.
Battery
The battery was fine, except that it needed to be charged on the day of the test flight.
Fig.87
Fig.88
78.
78
Speed controller
The speed controller was not working, due to an internal problem
Remote Control and receiver
The remote control that we used wasn’t working as it had an old system and had a
glitch, so it was difficult to configure. Hence there was interference between the receiver
and remote control.
Fig.89
Fig.90
79.
79
Engine
The engine was working perfectly and gave us no problems
Fixing the problems:
We managed to fix all the problems within 3 days:
Landing Gear
We removed the existing landing gear and put lower ones instead. After testing it the
plane moved properly and was able to take off.
Speed controller
We had to replace the current speed controller and buy another one. Though it was
expensive we had no other choice.
Remote control
80.
80
We had to also get another remote control and receiver for the aircraft
Overall, the problems were not many and were easily fixed as there was no major
damage on the aircraft. This is because the plane did not crash or anything and we
were not able to fly it during the test flight, now that the problems have been rectified the
aircraft is ready to fly.
Fig.91
81.
81
Safety and Risk Assessment7
• When working with glue, accelerator or acetone, remember that they are toxic
and hazardous materials. Follow all guidelines and precautions accompanying
these materials. It is easy to become complacent, as the hazard is not
immediately obvious.
• Always wash hands after working with glue materials. Keep glue, accelerator and
acetone away from the eyes. Safety glasses are recommended. Avoid rubbing
the eyes, and keep the hands away from the face when working with these
materials
• If power tools are used, eye protection, instruction in the safe use of the tools and
proper supervision should all be considered prerequisites.
• If not flying at a club field, make sure the site you choose is adequate and
appropriate ,not too small an area and not too close to people, animals, trees,
power lines, buildings, roads, etc. Also find out if there are any local ordinances
that prohibit flying RC airplanes in public spaces.
• When working with a hand cutter make sure not to apply big forces as it might
lead to hurting your hand.
• Unless your radio system is 2.4GHz, use a frequency checker or some other
method of frequency control before turning on your transmitter. Having two or
more people flying RC airplanes on the same frequency does not work; if you
interfere with another pilot’s frequency, you will cause an accident.
• Never ever keep your hands close to the engine propeller blade it can cut
anything with the speed of 17,000 rpm.
7
http://www.rcplanesandcopters.com/flying-‐rc-‐airplanes-‐safety-‐tips/
82.
82
• Don’t try flying RC airplanes in “adverse” wind conditions. Depending on your
model, that could be anything over 10-15 mph. Know your plane’s limitations and
if unsure about wind speed, wait for another day.
83.
83
REFERENCES
1.
http://www.bruceair.com/aerobatics/aerobatics.htm
2.
http://www.moneysmith.net/Soaring/soaring4.html
3. Fundamentals
of
Flight
by
Richard
S
Shevell
4. http://www.oakdaleaircraft.com/f35_manual/f35_edf.pdf
5.
http://www.rcplanesandcopters.com/flying-‐rc-‐airplanes-‐safety-‐tips/
84.
84
Conclusion
We have learned a lot of things from this project, the most important thing that we have
learned is how to construct an RC aerobatic aircraft. We have also learned the basics of
flying a RC aerobatic aircraft and have a better understanding of the different designs of
airplanes.
In this report we have described the assembly and construction of the aircraft in great
detail. We have also included pictures of the different stages of the construction to give
you a better understanding on how we made the aircraft. We have also included the
parametric design of the aircraft, Gantt chart and mission. In addition, we have included
the cost analysis as well as the manpower hours of each member in the group. We
have mentioned the different materials and tools used during the project and the
product specifications as well.
AutoCAD was used to help us with the design of the model, the 3D design of the model
gave us a proper idea of how to construct the aircraft, the AutoCAD designs have been
included in this report.
The second part of this assignment contains all the calculations of the aircraft, this
includes all the maneuvers calculations etc. Lastly, we described the troubleshooting of
the aircraft that talks about the problems faced during the test flight and how to rectify it.
The report ended with a few points about safety and risk assessment.
Overall we learned a lot from this project, it took a lot of hard work and commitment, but
in the end our hard paid off and our project was successful.
