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

1

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

2

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.

3

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

4

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

5

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

6

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.

7

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

8

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

9

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.

10

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

11

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

12

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.

13

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.

14

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

15

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

16

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

17

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.

18

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

19

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

20

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.

21

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

22

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.

23

Rudder

Servo motor

7. DRAWINGS: 2D

Fig.19: Top view

Fig.20: Side view

24

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.

26

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

27

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.

28

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.

29

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

30