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Project ProposalOn
CONCEPT OF R/C WIG (WING IN GROUND EFFECT) HOVERCRAFT
A report submitted in partial fulfillment of the degree ofBachelor of Technology in Mechanical Engineering with the supervision of
LECT. DEEPANKAR CHANDRA and moderated byLECT. HITENDRA BANKOTI.
SUBMITTED BY
Ajit Pal Singh Gokul Chandra Joshi
Mayank Dhondiyal Yuganter Rawat
Kamal Singh Bisht
SUBMITTED TO
DEPARTMENT OF MECHANICAL ENGINEERING
AMRAPALI INSTIYUTE OF TECHNOLOGY & SCIENCES
YEAR 2013-2014
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DECLARATION
We hereby declare that the project work entitled “Concept of R/C WIG (Wing in ground effect)
hovercraft” is an authentic record of our own work carried out as per requirements of final year
project for the award of degree of Bachelor of Technology in Mechanical Engineering,
Uttarakhand Technical University, under the guidance of Mr.Deepankar Chandra, during 2013-
2014.
Ajit Pal Singh Roll No: 10030104003 Gokul Chandra Joshi Roll No: 10030104015
Kamal Singh Bisht Roll No: 10030104023 Mayank Dhondiyal Roll No: 10030104029
Yuganter Rawat Roll No: 1003010404
It is certified that the above statement made by the student is correct to the best of our knowledge
and belief.
Mr. Deepankar Chandra
Lecturer
Department of Mechanical Engineering
Amrapali Institute of Technology & Sciences
Dr. R.Belwal
H.O.D
Department of Mechanical Engineering
Amrapali Institute of Technology & Sciences
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AcknowledgementCompleting a task is never a one man effort. It is often the result of valuable contribution of a number of individuals in a direct or indirect manner that helps in achieving an objective.
It is difficult to express in words my indebt ness to all intellectuals whose guidance and encouragement, I received in completing the Project Report.I express a deep sense of gratitude to following people :
1) Deepankar Chandra (Lect.)2) Hitendra Bankoti (Lect.)3) Ashis Saxena (Lect.)
Limited for his valuable guidance in giving me a start and his timely advice and active interest in my project. His direction, supervision and constructive criticism were indeed a source of inspiration for me.
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CONTENTS
1. Abstract
2. Introduction
3. Background
3.1. Principle of operation
3.2. Principal of ground effect
3.3. The individual who helped develop the idea of the hovercraft
4. Objective
5. Significance
6. Methodology
6.1. Wing constriction
6.2. Hull constriction
6.3. Skirt constriction
6.4. Lift constriction
6.5. Thrust system
6.6. Steering system
6.7. Electronics assembly
7. Drawing 2D
8. Calculations
9. Original image of components that will be used
10. Budget
11. Time table
12. References
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LIST OF FIGURESFigure 01: Principle of operation
Figure 02: German Dornier DO-X twelve
Figure 03: SR.N1 on sea
Figure 04: SR.N1
Figure 05: The final design
Figure 06: Output plot of XFLR5 on wing analysis
Figure 07: Forces at 18 kmph on entire wingspan
Figure 08: Forces at 28 kmph on entire wingspan
Figure 09: Depron Wing
Figure 10: Joining the individual airfoils
Figure 11: Hull or platform
Figure 12: Bag skirt
Figure 13: Segmented skirt
Figure 14: Jupe skirt
Figure 15: Lift system
Figure 16: Thrust system
Figure 17: Steering system
Figure 18: Block diagram of electronics assembly
Figure 19: Top view
Figure 20: Side view
Figure 21: Original images of all the components
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LIST OF TABLES
Table 1: Wing specifications
Table 2: Output of FoilSim III software after wing analysis
Table 3: Wing specification for weight
Table 4: Weight of components
Table 5: Budget
Table 6: Time Table for project completion
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1. AbstractAn R/C WIG hovercraft is a radio controlled wing in ground effect hovercraft that is capable
of flying without any external aid. It is first of its kind. It is capable to move on land, swim in
water and it can even fly in air. This can be a helping hand to the defense of the nation since it
is capable to reach the places where human approach is a bit dangerous and sometimes
impossible.
This concept can also be implemented on future vehicles to satisfy the upcoming needs of the
peoples as it is all terrain vehicle.One of the thrilling properties of the hovercraft is that it
moves on a cushion of air that means it is not in direct contact with the surface. It can pass
over landmines without detonating them, and it can swim over water without disturbing the
vegetation at even a small depth.
We can implement these hovercrafts at the places which lie in high risk zone. It is a cheap
option even if it is damaged there is not much financial loss.
Moreover a bigger version of this can be used as a target vehicle by army, navy and air force.
Construction of project includes completion of several systems i.e. lift, thrust, body, wing and
skirt. After calculating weight of all the systems and electronic component the total weight
comes out to be 1.12 kg. Analysis on FoilSim III software gives result that this weight of
hovercraft can start take off at a speed of 25 kmph.
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2. INTRODUCTION:R/C WIG hovercraft is a radio controlled wing in ground effect hovercraft. So, it is a radio
controlled (remote controlled) flying hovercraft. It will use ground effect to fly. It is a new
type of ground effect vehicle.
Conventional hovercraft can only hover over the surface but it has the capability to fly up like
airplanes. The design was selected via an iterative design methodology in which many
different designs for the five separate sections; namely, thrust system, lift system, platform &
skirt, wing design and RC control/steering, were considered. The main focus was to find the
best balance between performance, budget, and construction feasibility. The selected design
consists of two motor and propeller (one lift & one thrust), a bag skirt design without holes,
double depronplatform with air duct, a wing for ground effect and rudder assembly for
steering. The hovercraft will be controlled using a 2-Channel remote and receiver which will
control both motor throttles as well as steering of the craft. This report will outline the build
requirements, preliminary budget, list of analysis data & drawings, as well as the
methodology of project construction. We will build and test the designed hovercraft in the 8 th
semester.
3. BACKGROUND:A hovercraft is one of the children of the air cushion vehicle (ACV) family that flies above the
earth's surface on a cushion of air. It is powered by an engine that provides both the lift
cushion and the thrust for forward or reverse movement. The hovercraft is a true multi-terrain,
year-round vehicle that can easily make the transition from land to water because it slides on a
cushion of air with the hovercraft skirt and only slightly brushes the surface.
In its simplest form, a hovercraft is composed of a hull that can float in water and is carried on
a cushion of air retained by a flexible 'skirt'. The air cushion (or bubble), trapped between the
hull and the surface of the earth by the skirt, acts as a lubricant and provides the ability to fly
or slide over a variety of surfaces.
Hovercraft are boat-like vehicles, but they are much more than just a boat, because they can
travel over not only water, but grass, ice, mud, sand, snow and swamp as well.
The R/C WIG hovercraft is capable of flying too, as soon as it reaches an optimum speed it is
capable to take off. In today’s era the army has developed a lot and so has the enemies, there
is a heavy use of many sophisticated weapons like bombs and land mines. It is really a very
high risk in sending a trained army person to overcome the problem. A hovercraft can be
mounted with a robot that can diffuse the weapon. Even in case of failure there is no loss of a
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life and skill. It can easily glide over the land mines. Since the landmines detonate only when
some pressure equivalent to human weight is applied over it The pressure a hovercraft exerts
on its operating surface is conservatively 1/30th that of the human foot! The average human
being standing on ground exerts a pressure of about 3 lb. per square inch (20 KPa), and that
increases to 25 lb. per square inch (172 KPa) when walking. In contrast, the average
hovercraft exerts a pressure of only 0.33 lb. (2.2 KPa) per square inch - even less as speed
increases. This "footprint pressure" is below that of a seagull standing on one leg! Hovercrafts
have literally flown over a pedestrian without inflicting harm.
3.1 Principle of operation:
A Hovercraft is a vehicle which travels over any surface on a cushion of air which is trapped
in a chamber under the vehicle. This chamber is supplied with air under pressure from an axial
3-blade lift fan. The top and bottom of the chamber is formed by the vehicle bottom and the
surface over which the vehicle is traveling respectively. The sides of the chamber are formed
by the flexible skirt. The simplest skirt is the "C" skirt or the straight skirt shown in Fig. 1�
Fig: 1 Principle of operation
3.2 Principle of ground effect:
When an aircraft is flying at an altitude that is approximately at or below the same distance as
the aircraft's wingspan or helicopter's rotor diameter, there is, depending on air foil and
aircraft design, an often noticeable ground effect. This is caused primarily by the ground
interrupting the wingtip vortices and downwash behind the wing. When a wing is flown very
close to the ground, wingtip vortices are unable to form effectively due to the obstruction of
the ground. The result is lower induced drag, which increases the speed and lift of the aircraft.
A wing generates lift, in part, due to the difference in air pressure gradients between the upper
and lower wing surfaces. During normal flight, the upper wing surface experiences reduced
static air pressure and the lower surface comparatively higher static air pressure. These air
pressure differences also accelerate the mass of air downwards. Flying close to a surface
increases air pressure on the lower wing surface, known as the "ram" or "cushion" effect, and
thereby improves the aircraft lift-to-drag ratio. As the wing gets lower, the ground effect
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becomes more pronounced. While in the ground effect, the wing will require a lower angle of
attack to produce the same amount of lift. If the angle of attack and velocity remain constant,
an increase in the lift coefficient will result, which accounts for the "floating" effect. Ground
effect will also alter thrust versus velocity, in that reducing induced drag will require less
thrust to maintain the same velocity.
3.3 The Individuals Who Helped Develop the Idea of the Hovercraft
The history of the hovercraft spans over three hundred years. At first this may seem very
unlikely due to the fact that today we obviously know that it requires a great deal of energy to
make a craft hover off the ground; yet, in a much more literal sense, the idea of the hovercraft
has had over three hundred years to be perfected and modified. In fact, over eight men have
taken the idea first presented by Emanuel Swedenborg in 1716 and elaborated upon it. I
should also note that the term Hovercraft can also be interchanged with ACV (air-cushion
vehicle) and ground effect machine. Because the ideas that make a hovercraft hover also have
its hands in many other vehicles other than just a hovercraft, the development of the theories
behind hovering has also brought about many other machines which were very important to
the eventual development of the hovercraft. This is very important because the idea that
Emanual first developed branched off into other areas of transportation, and thus I will have
to mention these achievements to fully depict the entire history of the hovercraft.
The Hovercraft is particularly interesting because the idea of the hovercraft came before the
purpose of the hovercraft. To be explained more clearly, an individual by the name of
Emanual Swedenborg first thought of the idea of a hovering craft; he also thought of many
other extreme religious ideals, yet I will not go into detail about his personal history.
Swedenborg had thought up a man powered hovercraft (This is interesting because as I said
earlier, it require a great deal of energy to actually hover).
His plans consisted of the following. It was a circular craft, which resembled aupsidedown
boat with a place for a human to sit in the middle, also known as a cockpit. Inside the upside
down boat looking thing there were very large oars; most likely, we would call it a propeller
today; which would be manually pushed by the human in the cockpit. The air displaced by the
oars would build pressure inside the upside down boat thingy, which would eventually push
the boat off the ground or water so as to let the high pressure created by the oars escape. Thus,
the process would make the up side down boat sit on a cushion of air that the oars would
constantly replenish. Swedenborg never actually made a model of his hovering vehicle, yet he
did get his idea published in the fourth edition of Sweden's first scientific journal called
Daedalus Hyperboreus, which was the first detailed description of any flying machine.
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The idea of Swedenborg's hovering machine rested in the minds of the educated elite until
1865, when a man by the name of William Fronde sent a letter to the chief constructor of the
Royal Netherlands Navy concerning air lubrication. So how is air lubrication similar to the
principle of hovering? Well, the act of hovering, if done properly, will make an almost
frictionless surface between the ground and the craft. To do this, air must be placed between
the ground and the craft. This is the exact same principle that Swedenborg based his
hovercraft on. Due to the lack of technology and a unwilling naval engineer, his idea never
got off the ground. A little while later, a man by the name of Sir John Thornycroft
experimented further with the idea of air lubrication. His idea was that one could use an air
cushion on boats so as to reduce drag that the boat experienced. This was very important
because, during his time period almost everything was transported via water, and his idea
would enable boats to travel significantly faster due to decreased friction. I should note that
water is 815 times denser than air, and thus getting the boat out of the water, would
significantly increase efficiency and speed of all transport craft. However, Thornycroft had
the same problem that everyone else had during his era; they all lacked a sufficient source of
power that could produce such a cushion of air. While he filled couple of patents, the problem
of keeping an air cushion contained under a craft still remained. In 1876 the true design of a
modern day hovercraft was starting to come together. A man by the name of John B. Ward
came up with the idea of a platform made out of aluminium that had blades that pushed air
down for the creation of the air-cushion and another set of blades that would push air
backwards, so as to provide for propulsion. In 1888 James Walker developed a system of
containing the air under the platform and in 1897 Culbertson made the first suggestion for
sidewall air-cushion vehicles.
Once the combustion engine was created, it gave engineers a suitable power source to try to
create a working ground effect vehicle. The realization that man can fly in 1903 by the Wright
Brothers, further supported the controversial idea of the funnel effect (note, the funnel effect
is also known as a cushion of air, which later became known as the ground effect). Once the
combustion engine was suitable for use, naval engineers began experimenting with the idea of
air lubrication once again. Shortly thereafter, many different types of air lubrication vehicles
were created. In fact, the first working model was displayed in 1916. However, as far as
practical applications, Dagobert Mullerdeveloped a torpedo boat for the Austrian navy using
the same ideas expressed by Swedenborg's first model thought up in 1716. As the technology
developed, the ground effect was more widely used. For example, throughout World War II
ground effect vehicles were used on reconnaissance missions. Keep in mind that while ground
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effect craft are similar to air planes, there only difference is that ground effect craft fly closer
to the ground and thus use less fuel because of the air cushion produced under the hull of the
plane/boat. One of the most important ground effect craft is the German Dornier DO-X twelve
(see below).
Fig. 2: German Dornier DO-X twelve
In 1929 the Dornier crossed entirely in ground effect. Furthermore, even Charles Lindbergh
flew in ground effect so as to conserve fuel. It wasn't until the 1950's that the hovercraft
thatwe know today was developed by Christopher Cockerell. He created the idea of peripheral
jets, which aided in the balancing of the hovercraft while it is hovering, thus increasing
stability. On the 25th of July 1959, Cockerell's invention, the SR.N1 crossed the English
Channel from Calais, France to Dover, England. The SR.N1 is seen below.
Fig. 3: SR.N1 on Sea
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Later, another British inventor C.H.Latimer-Needhah developed the rubber skirt that is now
present on all modern hovercrafts. The skirt enables hovercraft to be hit by waves yet not be
slowed down by them. When the skirt is hit by a wave it becomes depressed, and after the
hovercraft has cleared the wave, the skirt reforms it shape. This made it much easier for
hovercraft to travel over water. It was Christopher Cockerell's design that has eventually
created the hovercraft that we see today. His intelligence and cunning enabled the world to be
changed by the hovercraft and it's seeming ability to defy friction.
The SR.N1 Hovercraft
To many the SR.N1 was considered the first real hovercraft due to the fact that most of the
other ground effect vehicles were very similar to planes. When it was originally manufactured
it had a skirt that was 6 inches long, so as to act as a cushion so the craft itself does not hit any
hard objects. At first the skirt was not intended to create a better air cushion, and it was only
after the SR.N1 flew over the English Channel that Cockerell began to experiment with longer
skirts. The change in performance in the SR.N1 was amazing. With the six inch long skirt the
craft travelled 25 knots, however, when the engine was changed to a gas turbine engine and
the skirt was extended to 4.5 feet, then craft then travelled at 50 knots. For lift the SR.N1 uses
peripheral jets of air located on the outside corners on the bottom of the hull. They all point
toward the centreof the bottom of the hovercraft, which helps maintain an even and steady air
cushion. After creating his hovercraft, he started Hovercraft Ltd. Below you can see the
SR.N1.
Fig. 4: SR.N1.
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4. OBJECTIVE:The purpose of making this project is to give a concept how a RC flying hovercraft can be
built that will simply use ground effect like ground effect vehicle to fly.
5. SIGNIFICANCE Exploring the vast number of shallow and narrow waterways that cannot be reached by boat
Help in rescue work on swift water, ice, snow, mud flats, and deserts, in wetlands, shallow
water, swamps, bogs, marshes and floodwaters by giving continuous live videos.
Wildlife conservation and research
Big model can be used as a target vehicle or plane for both army and air force.
Military services: Assault vehicles and transporting troops
Dive recovery teams
Retrieving birds from tailings ponds at mining sites
Border Patrol and Homeland Security
Hover over the land mines and can give necessary data by reaching the enemy’s location
Entertainment at Disney World water shows
Agricultural spraying; cranberry, rice and pecan farming.
Survey work
Carrying bomb diffusing robot to the place of more height like building’s roof etc.
6. METHODOLOGY
Fig.5: The final design.
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The project shall be made in following phases:
Wing construction
Hull construction
Skirt construction
Lift system
Thrust system
Steering system
Electronics assembly
6.1 Wing construction:
This is the additional feature that we are including in the hovercraft.It will provide the
capability of flying to hovercraft. So, we have given more attention to wing design. We have
used two software XFLR5 &Nasa’s FOILSIM III Student Version for determining wing
specifications and for the analysis of wing.Various tables and figures regarding research are
given below.
Wing specifications:
Aspect ratio (constant factor) 9.456
Chord-m 0.140208
Span-m 1.32558
Area-sq. m 0.18589899
Angle-degree 8.28
Camber-% chord 18.6
Thick-% chord 19.506
Table 1: Wing specifications
Outputs of wing on FOILSIM III Student Version. Constant factors are:
Pressure = 101.261 KPa.
Temperature = 15 Centigrade
Density = 1.224 kg/m^3
Viscosity = 1.7326E-5 Kg/m-s
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Sr. No.Speed-
km/hr.Altitude-m Lift-N Drag-N Reynolds#
L/D
ratio
1. 20 0 11 2.453 55028 4.733
2. 25.2 0 19 4.599 76850 4.733
3. 30 0 26 5.52 82543 4.733
4. 35.2 0 35 7.599 96850 4.733
5. 40 0 46 9.813 110057 4.733
6. 50 0 72 15 137571 4.733
7. 60 0 104 22 165086 4.733
8. 70 0 142 30 192600 4.733
9. 80 0 185 39 220115 4.733
10. 90 0 235 49 247629 4.733
11. 100 0 290 61 275143 4.733
Table 2: Output of FoilSim III software after wing analysis
Fig. 6: Output plot of XFLR5 on wing analysis
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Analysis of forces on wing: Software used for analysis is XFLR5
At 18 kmph.
Fig. 7: Forces at 18kmph on entire wingspan
At 28 kmph.
Fig. 8: Forces at 28 kmph on entire wingspan
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Constructing the Wing:
There are two available methods for the construction of R/C wing.
6.1. a: Using Depron:
Fig. 9: Depron Wing
Depron is a light weight material like a thermocol but it is much more strong and flexible. It
can be simply bent to form a wing of required wingspan and cord. Its top and bottom surface
must be covered with tap in order to minimize the skin friction drag. For camber and angle of
attack rectangular shaped depron can be inserted in wing as shown in figure above. The wing
will be attached to body with carbon rod.
5.1.b: Joining the individual airfoils:
Fig. 10: Joining the individual airfoils
In this method different airfoils of required specifications are first made then assembled
together by putting them between two straight carbon rods at uniform gap.
Then finally the whole arrangement is enveloped by a poly composite nylon cloth and
required wing is constructed.
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We have chosen the first method as depron is light weight and more uniform wing can be
made by using this.
6.2 Hull construction:
Fig. 11: Hull or platform.
The hull can be considered as the chassis of a hovercraft.it has all the mountings over it. It
should be light weighted to make a hovercraft fly. It will be made of depron.The platform of
the hovercraft is important as it will house all of the components and must take all of the
respective loads. “Depron” was selected due to its light weight and strength properties. For
giving more strength two depron sheet will be joined together. This will also increase the
buoyancy of the hovercraft and the chances of shrinkage of craft in water will be negligible.
The overall size of the hovercraft has been selected as 550 mm in length, 350 mm in width
and 10 mm in height. For efficient lift a ducting system will also be attached to bottom of hull
at a gap for proper air flow. The dimensions of air duct are 500mm x 300mm x 5 mm. The
final design of the platform can be seen in Fig.11.
6.3 Skirt construction
Skirt does not allow the pressure created inside the chamber (the top and bottom of the
chamber is formed by the vehicle bottom and the surface over which the vehicle is traveling
respectively) to escape from it. The sides of the chamber are formed by the flexible skirt. The
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550 mm
350 mm
500 mm
300 mm
Dia. 275 mm
500 mm
550 mm
bottom of the skirt is opened the little pressure escapes from there and in reaction to that it
provides lift to the hovercraft. Skirt shall be made up of poly urethrine or vinyl coated nylon.
TYPES OF SKIRT:
There are three basic kinds of skirts that can go on a hovercraft
1. BAG SKIRT
2. SEGMENTED SKIRT
3. JUPE SKIRT
The three designs are all very different and have their own sets of advantages and
disadvantages
6.3.a Bag skirt:
Fig.12: Bag skirt
Advantages:Disadvantages:
Cheaper costsHigher drag
Lower weight Poor taking of performance
Better stability
6.3.bSegmented or finger skirt:
Fig.13: Segmented skirt
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Advantages:Disadvantages:
Easier to repair Higher cost
Easier to balance Bouncy ride
Better climbing capability
6.3.c.: Jupe skirt:
Fig.14: Jupe skirt
The jupe skirt is the next type. It is rarely seen now. It is one of the original types of skirts that
were used. The jupe skirt is similar to a bag, but it does not bubble on the outside, but is
angled inward under the craft. It is no longer used because of its instability. In order for it to
maintain stability, a series of about four jupe skirts underneath the craft are needed. Similar to
the bag skirt, it is also difficult to repair.
SKIRT SELECTION:
The bag skirt was chosen because
Better stability
It weighs less
It is much cheaper.
In this design the lift air is ducted directly into the skirt which then inflates. The skirt allows
the air to exit under the craft using specified holes or a cut section in the skirt. This air flow
under the craft creates the high pressure which will lift the hovercraft. The skirt is constructed
using a Polyurethane-Coated Nylon Fabric which is attached directly to the platform at two
separate locations sealed off air tight. Skirt total length will be 180 cm, 4cm wide and .2 cm
thick.
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6.4 Lift System
Fig.15: Lift system
The hovercraft relies on a stable cushion of air to maintain sufficient lift. The air ejected from
the propeller is allowed to flow downwards that will make the required cushion of air. The
weight distribution on top of the deck is arranged so that the air is distributed throughout the
cushion volume in an approximately even fashion to provide the necessary support.A air duct
will be made for proper air flow under the body. The skirt extending below the deck provides
containment, improves balance, and allows the craft to traverse more varied terrain. For
producing enough lift a high rpm brushless motor will be attached to a 3-blade propeller of
dimension 10 x 4.7(Inches).A separate battery and ESC (Electronic speed controller) will be
attached to the motor. The motor will be mounted on a 100 mm tall specially designed stand
in downward direction. This mount will enclose the hole of dia. 275 mm through which air
will flow downwards.
6.5 Thrust System
Fig.16: Thrust system
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100 mm
Motor Stand
ESC
A 3-blade propeller of 10 x 4.7 (inches) connected directly to a brushless dc motor that is
capable of producing 1.2 kg of thrust will be used for the thrust system. A separate battery and
ESC will be connected to the motor. The size of the propeller (diameter), pitch of propeller
and rpm are the determining parameters for the thrust force. A thrust duct channeling the air
into the propeller can provide up to a 15% increase in efficiency. The motor will mount on a
stand that will be made up of strong foam.
6.6 Steering System
Fig.17: Steering system
The steering will be remote controlled. The leftward and rightward movement of hovercraft
will be controlled by the rudder. The two rudders will be connected together by a thin plastic
connector. The one of the rudder will be governed by a servo motor. The servo motor shall be
further controlled with an ESC (electronic speed controller) and will take power from battery
that will be used for lift system. A receiver will be mounted on the motor stand of thrust
system while the transmitter will be with the operator.
6.7 Electronics assembly
The final stage will be adding of all the electronic components like receiver & transmitter for
radio control, assembling the lift motor, thrust motor and servo motor with the rudder.
Fig.18: Block diagram of electronics assembly.
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Rudder
Servo motor
7. DRAWINGS: 2D
Fig.19: Top view
Fig.20: Side view
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8. CALCULATIONS:WEIGHT CALCULATION
Wing specifications:
Span 132 cm
Chord 14 cm
Area 1848 cm2
Thickness 5 mm or .5 cm
Table 3: Wing specification for weight calculation
For chamber and required angle of attack:
One Wing:
2.6 cm depron (width) will be used. Length will be 66.
Area = 2x2.6x66 cm=343.2 cm2+343.2 cm2 (covering carbon rod)
= 686.4cm2 +carbon rod weight
So, additional area due to chamber =2x686.4=1372.8 cm2
Total wing volume = (Total area of wing span (top & bottom surface) + Additional area
due to chamber) x depron thickness
= (2x1848+1372.8) cm2x 0.5 cm
= 2534.4 cm3
Weight of wing=2534.4 cm^3x0.03616 g/cm^3 = 91.64 g
Weight of two carbon =10 g
Total weight of entire wing s = (91.64+10)g = 101.64 g
Weight of the components
Receiver 5 g
Battery 188 g
ECS x2 2x23 g
Motorx2 2x76g (1.2 kg thrust THS 3628)
Servo 38 g
Battery for receiver 118 g
Propeller 5g
Rudder 10 g
Total 562g
Table 4: Weight of components
Body:
25
Dimensions = (55 x 35x.5) cm
Area = 962.5 cm2
Weight =(962.5 x0.03616) g
= 34.804 g
Total weightof body or hull = 2x34.804 = 69.60g (two layer of depron)
Skirt
Length = 2(55+35) = 180 cm
Area = 180 x4 cm (height is 10% - 15% of breadth of hull)
= 720 cm2
Total Surface area= 35 x 55 + 720-15x50=1895 cm2
Thickness = 0.2 cm
Skirt weight = 379 g
Total weight of craft =weight of wing + weight of all components + weight of body + weight
of skirt material
= (101.64 + 562 + 69.60 + 379) g
= 1.12 kg
Therefore, total weight to be lifted = 1.12 kg
= 10.99 N
Speed required:
From the table No.2 the speed at which minimum effective 10.99 N lift generated is 25 kmph
(actually 14N).So, by calculation we came to a conclusion that the hovercraft will start to
takeoff at a speed of about 25 kmph.
There is no need to calculate effective thrust produced by motor because we will be using a
combination of motor and propeller that are capable of producing 1.2 kg thrust with pre-
defined configurations.
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9. Original image of components that will be used:
BrushlessMotor ESC (Electronic speed controller)
Propeller Battery
Servo motor Transmitter & Receiver
Fig. 21: Original images of all the components
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10. BUDGET
Item Quantity Price
(Rs.)
Receiver and transmitter for RC 1 3000
Battery(3S 2200 mah lipo) 1 1850
40W hot glue trigger gun 1 430
motor + 25 Amp ESC + 10 * 4.7 props + standard servo + 3.5mm
Gold connector+ XT 60 male connector
3+2+4+1+6
+15300
3 mm prop saver with 0 ring 1 160
25.33 LIPO charger 1 980
Battery for receiver 1 750
Skirt 1 700
Miscellaneous cost 1 2000
TOTAL COST * 15170
Table 5: Budget
Note: - * shows that there is an approximation in the above details; the real characteristics
may be vary from the tabular sheets.
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11. TIME TABLE
Sr.No Aim Activity Target date Duration
1 Research Wing and body analysis 21-09-2013 30 hours
2 Research Lift and thrust system analysis 3-09-2013 10 hours
3 Research Skirt and steering system analysis 5-09-2013 7 hours
4 Modification Modification after guide’s comment 18-10-2013 10 hour
5 Purchasing Order online 06-01-2014 3-4 days
6 Purchasing Purchasing from market. 10-01-2014 1 day
7 Construction Hull, skirt and wing 18-02-2014 20 hours
8 Construction Lift, thrust & steering system 22-02-2014 20 hours
9 Construction Electronics assembly 25-02-2014 2 hours
10 Testing On ground, grass & water 27-01-2014 2 hours
11 Modification In any system 10-03-2014 20 hours
12 Testing Final testing 18-03-2014 4 hours
Table 6: Time Table for project completion
Total time required: 10 days and 5 hours
Note: * shows that total time required might increase due some unavoidable situation or
delays.
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12. References:1. http://www.model-hovercraft.com/trouble/troublegallery1.html
2. http://www.rcgroups.com/forums/showthread.php?t=1437391
3. http://www.rcfoam.com/depron-and-epp-foam-density-a-depron_epp_density.html
4. http://www.john-tom.com/html/RCHover.html
5. http://icarushoverwing.wordpress.com/design/research/skirt-design/
6. http://thehobbyshop.in/
7. http://www.instructables.com/id/Very-Fast-RC-Hovercraft/
8. http://www.fpvflying.com/categories/Wireless-audio-video-transmitter-for-FPV/
9. http://www.youtube.com
10. http://www.universalhovercraft.com
11. http://www.wikipedia.com
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