CHAPTER:-1 INTRODUCTION

A Wind Turbine is a rotary device that extracts energy from the wind. If the mechanical

energy is used directly by machinery, such as for pumping water, cutting lumber or

grinding stones, the machine is instead converted into electricity. The machine is called a

wind generator, wind turbine, wind power unit (WPC), wind energy converter (WEC), or

aero generator.

1.1 BASIC CONCEPT OF WIND ENERGY CONVERSION

SYSTEAM

There are many ways in which devices to convert he kinetic energy contained in air

stream into mechanical work can be realized and the most bizarre concept have been

proposed .Museums and patent offices are filled to the rafters with more or less

promising invention of this type .In most of the cases, however, the practical

applicability of these “wind power plant” falls far behind the inventor’s expectation.

An attempt to develop an orderly and systematic classification of wind energy convertor

types is certainly an interesting task, but it bring little reward as the number of significant

design is drastically limited by their practical usefulness. When speaking of varying

designs one should be aware of the fact that primary varying design of the wind energy

convertor, the wind rotor meant .but the wind rotor is not the only component of a wind

turbine. other components for the mechanical –electrical energy conversion such as gear

box(pulley),generator ,control system and a variety of auxiliary units and items of

equipment are just as necessary for producing usable electric energy from the wind rotor

‘s rotational motion. Many inventors of novel wind rotors, however do not seem to be

aware of this fact when they are hoping that their invention of a different rotor design

will improve everything.

1.2 HISTRY

Wind machines were used in Persia as early as 200 B.C. The wind wheel of Heron of

Alexandria marks one of the first known instances of wind powering a machine in

history. However, the first practical windmills were built in Siston, a region between

1

Afghanistan and Iran, from the 7th century. These were vertical axle windmills, which

had long vertical driveshaft with rectangle-shaped blades. Made of six to twelve sails

covered in reed matting or cloth material, these windmills were used to grind corn and

draw up water, and were used in the grist milling and sugarcane industries.

Fig:-1.1 The World’s First Automatically Operated Wind Turbine

By the 14th century, Dutch windmills were in use to drain areas of the Rhine River delta.

In Denmark by 1900, there were about 2500 windmills for mechanical loads such as

pumps and mills, producing an estimated combined peak power of about 30 MW. The

first known electricity generating windmill operated, was a battery charging machine

installed in 1887 by James Blyth in Scotland. The first windmill for electricity

production in the United States was built in Cleveland, Ohio by Charles F Brush in 1888,

and in 1908 there were 72 wind-driven electric generators from 5 kW to 25 kW. The

largest machines were on 24 m (79 ft) towers with four-bladed 23 m (75 ft) diameter

rotors. Around the time of World War I, American windmill makers were producing

100,000 farm windmills each year, mostly for water-pumping. By the 1930s, windmills

for electricity were common on farms, mostly in the United States where distribution

systems had not yet been installed. In this period, high-tensile steel was cheap, and

windmills were placed atop prefabricated open steel lattice towers.

A forerunner of modern horizontal-axis wind generators was in service at Yalta, USSR

in 1931. This was a 100 kW generator on a 30 m (100 ft) tower, connected to the local

6.3 kV distribution system. It was reported to have an annual capacity factor of 32 per

2

cent, not much different from current wind machines. In the fall of 1941, the first

megawatt-class wind turbine was synchronized to a utility grid in Vermont. The Smith-

Putnam wind turbine only ran for 1100 hours. Due to war time material shortages the

unit was not repaired.

The first utility grid-connected wind turbine operated in the UK was built by John Brown

& Company in 1954 in the Orkney Islands. It had an 18 meter diameter, three-bladed

rotor and a rated output of 100 kW.

1.3 RESOURCES

Wind turbines in locations with constantly high wind speeds bring best return on

investment. With a wind resource assessment it is possible to estimate the amount of

energy the wind turbine will produce.

A quantitative measure of the wind energy available at any location is called the Wind

Power Density (WPD.) It is a calculation of the mean annual power available per square

meter of swept area of a turbine, and is tabulated for different heights above ground.

Calculation of wind power density includes the effect of wind velocity and air density.

Color-coded maps are prepared for a particular area described, for example, as "Mean

Annual Power Density at 50 Meters." In the United States, the results of the above

calculation are included in an index developed by the National Renewable Energy Lab

and referred to as "NREL CLASS." The larger the WPD calculation, the higher it is rated

by class. Classes range from Class 1 (200 watts/square meter or less at 50 meters

altitude) to Class 7 (800 to 2000 watts/square meter). Commercial wind farms generally

are sited in Class 3 or higher areas, although isolated points in an otherwise Class 1 area

may be practical to exploit.

Advantages of Wind Energy

●One of the greatest advantages of Wind Energy is that it is ample and wind energy is

renewable.

●Wind Energy is that it is widely distributed, cheap, and also reducing toxic gas

emissions.

3

●Wind Energy is also advantageous over traditional methods of creating energy, in the

sense that it is getting cheaper and cheaper to produce wind energy.

●Wind Energy may soon be the cheapest way to produce energy on a large scale.

The cost of producing wind energy has come down by at least eighty percent since the

eighties.

●Wind energy generates no pollution. Wind Energy is also a more permanent type of

energy. The wind will exist till the time the sun exists, which is roughly another four

billion years.

●It is readily available around the globe, and therefore there would be no need of

dependence for energy for any country. Wind energy may be the answer to the globe's

question of energy in the face of the rising petroleum and gas prices.

1.4 WIND POWER GENERATION:

Wind power is the conversion of wind energy into a useful form of energy, such as using

wind turbines to make electricity, wind mills for mechanical power, wind pumps for

pumping water or drainage, or sails to propel ships.

Electricity generation

In a wind farm, individual turbines are interconnected with a medium voltage (often 34.5

kV), power collection system and communications network. At a substation, this

medium-voltage electrical current is increased in voltage with a transformer for

connection to the high voltage electric power transmission system.

The surplus power produced by domestic microgenerators can, in some jurisdictions, be

fed into the network and sold to the utility company, producing a retail credit for the

microgenerators' owners to offset their energy costs.

4

Wind energy conversion systems (WECS)

A wind energy conversion system converts wind energy into some form of electrical

energy. In particular, medium and large scale WECS are designed to operate in parallel

with a public or local ac grid. This is known as grid connected system. A small, isolated

from grid, feeling only to local load is known as autonomous, remote, decentralized,

stand alone or isolated power system. A general block diagram of a grid connected

WECS is shown in fig 3. the turbine shaft speed is stepped up with the help of gears,

with fixed gear ratio, to suit the electrical generator and fine-tuning of speed is

incorporated by pitch control. This block acts as drive for the generator. Use of variable

gear ratio has been considered in the past and was found to add more problems than

benefits. DC, synchronous or induction generator are used for mechanical to electrical

power conversion depending on the design of the system. The interface conditions the

generated power to grid quality power. It may consist of power electronic converter,

transformer and filter, etc. the control unit monitors and controls the interaction among

various blocks. It derives the reference voltage and frequency signals from the grid and

receives the reference voltage and frequency signals from the grid and receives wind

speed, wind direction, wind turbine speed signals, etc. process them and accordingly

controls various blocks optional energy balance.

Main features of various types of generators and their suitability in wind power

generation are discussed below:

(1) DC generator conventional dc generator is no more favored due to their high cost,

weight and maintenance problems due to commutator. However, permanent magnet

(brush less and commutator less) dc machines are considered in small rating ((below

hundred KW) isolated systems.

(2) Synchronous generator synchronous generator produces high quality output and is

universally used for power generation in conventional plants. However, they have very

rigid requirement of maintaining constant shaft speed and any deviation from

synchronous value immediately reflects in the generated frequency. Also precise rotor

speed control is required for synchronization. Due to this reason a synchronous machine

5

is not well suited to wind power generation. Requirement of dc current to excite rotor

field, which needs sliding carbon brushes on the slip rings also poses limitations on its

use. The need of dc field current and brushes can be eliminated by using reluctance rotor.

The reliability is greatly improved while reducing the cost.

(3) Induction generator primary advantages of induction machine are the rugged, brush

less construction, no need of separate dc field power and tolerance of slight variation of

dc and synchronous machine they have low capital cost, low maintenance and better

transient performance. For these reasons induction generators are extensively used in

wind and micro-hydroelectric plants. The machine is available from very low to several

megawatt ratings.

Turbine

u0 v,i

γ

Pitch control vref and fref

Fig:-1.2 General block diagram of a WECS

1.5 SCOPE OF WIND POWER IN INDIA

Wind is the largest segment in India’s renewable energy market and the industry is

growing at 34% per annum since 2004. Comparing installed and maximum potential

capacity, there are tremendous opportunities for investing in this eco-friendly energy

industry.

The Indian wind industry was placed third in terms of total installed capacity of wind

electricity in the world some years back. It suffered a great setback when this rank shifted

6

Gearing and coupling

Generator

Interface Grid or local load

control

down to fifth after the United States, Germany, Denmark, and Spain in the later years.

The falling profitability of private wind farm operations in the country today has been the

cause of deep concern to many. As a result of the initiatives taken by the government to

promote wind energy, different states have started supporting the wind power companies

and investors with liberal policy initiatives.

WIND ENERGY STATUS AND PROSPECTS IN INDIA

Three years after the formation of the DNES (department of non-conventional energy

sources), in the years 1985. A nation-wind wind energy programme was initiated. One of

the biggest programmes of the present ministry of non-conventional energy sources

(formed in 1992) is the wind resources assessment programme. Nation-wide wind

mapping and wind monitoring activities are undertaken to measure the wind speeds at

potential sites in various states and to assess its seasonal/annual variations. As on 31

December 1992, 251 wind mapping stations were operational in 16 states and in the

union territories of Andaman and Nicobar Islands and Lakshadweep while the total

number is targeted at 470 stations. Similarly, 88 wind monitoring stations are operational

in 10 states/union territories of Andaman and Nicobar Islands and Lakshadweep, while,

the total number is targeted at 136.

7

Table:-1.1 wind monitoring and mapping stations as on 31 December

1992.

SR no. state/union territory wind

monitoring

stations

wind mapping

stations

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

Gujarat

Tamil Nadu

Rajasthan

Karnataka

Maharashtra

Andhra Pradesh

Kerala

Orissa

Madhya Pradesh

Lakshadweep

Andaman and Nicobar

Himachal Pradesh

Meghalaya

Uttar Pradesh

Tripura

West Bengal

Assam

Bihar

16

20

7

8

6

7

9

_

5

5

5

_

_

_

_

_

_

_

30

_

17

_

30

2

30

30

_

_

_

30

7

30

9

6

27

3

Total 88 251

8

Table:-1.2 sites that experience annual average wind speeds over 18

kmph.

SR no. mean annual

wind speed

(kmph)

SR no. station mean annual

wind speed

(kmph)

Tamil Nadu

Sultanpet

19.0

Poolavadi

21.2

Andipatti

19.1

Kayathar

20.3

Muppandal

25.5

Sembagaramanpudar

21.7

Alagiyapandiyapura

m 21.4

Talayathu

20.8

Ayikudy

21.4

Kattadimalai

23.9

Rameswaram

24.3

Kethanur

22.7

Gujarat

Lakshadweep

1. Agatti 18.0

Karnataka

1. Gokak 19.4

2. Malgati 19.2

3. Kanasmsagar 20.1

4. Jogimatti 30.9

5. Bommanahalli 18.7

6. Hanumanhatti 20.4

7. Bb hills 27.1

Andhra Pradesh

1. Tirumala 20.4

2. Payalakuntla 20.5

3. Narasimhakonda 20.2

4. Kakulakonda 24.0

5. Mpr dam 20.0

6. Ramagiri-1 19.7

7. Bhimunipatnam 19.1

8. Ramagiri-2 18.3

Kerala

1. Kangikod 22.3

2. Kottathala 18.4

3. Kottamala 19.7

4. Ponmudi 19.7

5. Ramakalmedu 30.4

9

1. Harshad 20.0

2. Okha 19.4

3. Mudra 19.4

4. Surajbari 19.9

5. Okha madhi 19.0

6. Navi Bandar 19.9

7. Dhank -1 24.2

8. Dhank 2 24.9

9. Dukma 19.2

10. Kalyanpur 21.9

11. Bamanborwe-2 20.5

CHAPTER:-2 CLASSIFICATION OF WIND

TURBINE

Wind energy convertor can be classified firstly in accordance with their

aerodynamics function and secondly, according to their construction al

design. The rotor‘s aerodynamic function is characterized by the fact

of whether the wind energy convertor capture its power exclusively

from the aerodynamic drag of the air stream acting on rotor surfaces,

or whether it is able to utilize the aerodynamic drag of the air stream

acting on rotor surfaces, or whether it is able to utilize the

aerodynamics lift created by the flow against, suitable, shaped

surfaces. Accordingly, there are so called “drag-type rotors” and

“rotors which make use of the aerodynamic lift”. Occasionally, the

aerodynamic “tip-speed ratio” is used to characterize wind rotors and

one speaks of “low-speed and high-speed rotors” in this case. These

characteristics, however, are of little significance to modern wind

turbines. Apart from the American wind turbine, almost all other wind

turbines designs are of the high-speed type.

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Classification according to constructional design aspects is more

practicable for obvious reasons and thus more common. The

characteristic which most obviously meets the eye is the position of

the axis of rotation of the wind rotor. Thus, it is important to make a

distinction between rotors which have a vertical axis of rotation, and

those with a horizontal axis of rotation.

2.1 HORIZONTAL AXIS WIND TURBINE

Horizontal-axis wind turbines (HAWT) have the main rotor shaft and electrical generator

at the top of a tower, and must be pointed into the wind. Small turbines are pointed by a

simple wind vane, while large turbines generally use a wind sensor coupled with a servo

motor. Most have a gearbox, which turns the slow rotation of the blades into a quicker

rotation that is more suitable to drive an electrical generator.

Since a tower produces turbulence behind it, the turbine is usually pointed upwind of the

tower. Turbine blades are made stiff to prevent the blades from being pushed into the

tower by high winds. Additionally, the blades are placed a considerable distance in front

of the tower and are sometimes tilted forward into the wind a small amount.

Downwind machines have been built, despite the problem of turbulence (mast wake),

because they don't need an additional mechanism for keeping them in line with the wind,

and because in high winds the blades can be allowed to bend which reduces their swept

area and thus their wind resistance. Since cyclic (that is repetitive) turbulence may lead

to fatigue failures most HAWTs are upwind machines.

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Fig:-2.1 Horizontal Axis Wind Turbine

Advantages

Variable blade pitch, which gives the turbine blades the optimum angle of attack.

Allowing the angle of attack to be remotely adjusted gives greater control, so the

turbine collects the maximum amount of wind energy for the time of day and

season.

The tall tower base allows access to stronger wind in sites with wind shear. In

some wind shear sites, the wind speed can increase by 20% and the power output

by 34% for every 10 meters in elevation.

High efficiency, since the blades always move perpendicular to the wind,

receiving power through the whole rotation. In contrast, all vertical axis wind

turbines, and most proposed airborne wind turbine designs, involve various types

of reciprocating actions, requiring airfoil surfaces to backtrack against the wind

for part of the cycle. Backtracking against the wind leads to inherently lower

efficiency.

The face of a horizontal axis blade is struck by the wind at a consistent angle

regardless of the position in its rotation. These results in a consistent lateral wind

loading over the course of a rotation, reducing vibration and audible noise

coupled to the tower or mount.

Disadvantages The tall towers and blades up to 45 meters long are difficult to transport.

Transportation can now amount to 20% of equipment costs.

Tall HAWTs are difficult to install, needing very tall and expensive cranes and

skilled operators.

Massive tower construction is required to support the heavy blades, gearbox, and

generator.

Reflections from tall HAWTs may affect side lobes of radar installations creating

signal clutter, although filtering can suppress it.

Their height makes them obtrusively visible across large areas, disrupting the

appearance of the landscape and sometimes creating local opposition.

12

Downwind variants suffer from fatigue and structural failure caused by

turbulence when a blade passes through the tower's wind shadow (for this reason,

the majority of HAWTs use an upwind design, with the rotor facing the wind in

front of the tower).

HAWTs require an additional yaw control mechanism to turn the blades and

nacelle toward the wind.

In order to minimize fatigue loads due to wake turbulence, wind turbines are

usually sited a distance of 5 rotor diameters away from each other, but the

spacing depends on the manufacturer and the turbine model.

Cyclic stresses and vibration

Cyclic stresses fatigue the blade, axle and bearing resulting in material failures that were

a major cause of turbine failure for many years. Because wind velocity often increases at

higher altitudes, the backward force and torque on a horizontal-axis wind turbine

(HAWT) blade peaks as it turns through the highest point in its circle. The tower hinders

the airflow at the lowest point in the circle, which produces a local dip in force and

torque. These effects produce a cyclic twist on the main bearings of a HAWT. The

combined twist is worst in machines with an even number of blades, where one is

straight up when another is straight down. To improve reliability, teetering hubs have

been used which allow the main shaft to rock through a few degrees, so that the main

bearings do not have to resist the torque peaks.

The rotating blades of a wind turbine act like a gyroscope. As it pivots along its vertical

axis to face the wind, gyroscopic precession tries to twist the turbine disc along its

horizontal axis. For each blade on a wind generator's turbine, recessive force is at a

minimum when the blade is horizontal and at a maximum when the blade is vertical.

2.2 VERTICAL AXIS WIND TURBINE

Vertical-axis wind turbines (or VAWTs) have the main rotor shaft arranged vertically.

Key advantages of this arrangement are that the turbine does not need to be pointed into

the wind to be effective. This is an advantage on sites where the wind direction is highly

variable. With a vertical axis, the generator and gearbox can be placed near the ground,

so the tower doesn't need to support it, and it is more accessible for maintenance.

13

Drawbacks are that some designs produce pulsating torque. It is difficult to mount

vertical-axis turbines on tower, meaning they are often installed nearer to the base on

which they rest, such as the ground or a building rooftop. The wind speed is slower at a

lower altitude, so less wind energy is available for a given size turbine. Air flow near the

ground and other objects can create turbulent flow, which can introduce issues of

vibration, including noise and bearing wear which may increase the maintenance or

shorten the service life. However, when a turbine is mounted on a rooftop, the building

generally redirects wind over the roof and this cans double the wind speed at the turbine.

SUB TYPES:-

Darrieus Wind Turbine

"Eggbeater" turbines, or Darrieus turbines, were named after the French inventor,

Georges Darrieus. They have good efficiency, but produce large torque ripple and

cyclical stress on the tower, which contributes to poor reliability. They also generally

require some external power source, or an additional Savonius rotor to start turning,

because the starting torque is very low. The torque ripple is reduced by using three or

more blades which results in a higher solidity for the rotor. Solidity is measured by blade

area divided by the rotor area. Newer Darrieus type turbines are not held up by guy-

wires.

Fig:-2.2 Darrieus Wind Turbine Fig:-2.3 Savonius Wind Turbine

Savonius wind turbine 

14

These are drag-type devices with two (or more) scoops that are used in anemometers,

Flatter vents (commonly seen on bus and van roofs), and in some high-reliability low-

efficiency power turbines. They are always self-starting if there are at least three scoops.

They sometimes have long helical scoops to give a smooth torque.

Savonius turbines are used whenever cost or reliability is much more important than

efficiency. For example, most anemometers are Savonius turbines, because efficiency is

completely irrelevant for that application. Much larger Savonius turbines have been used

to generate electric power on deep-water buoys, which need small amounts of power and

get very little maintenance. Design is simplified because, unlike HAWTs, no pointing

mechanism is required to allow for shifting wind direction and the turbine is self-starting.

Savonius and other vertical-axis machines are not usually connected to electric power

grids. They can sometimes have long helical scoops, to give smooth torque.

Advantages

a massive tower structure is less frequently used, as VAWTs are more frequently

mounted with the lower bearing mounted near the ground.

Designs without yaw mechanisms are possible with fixed pitch rotor designs.

the generator of a VAWT can be located nearer the ground, making it easier to

maintain the moving parts.

VAWTs have lower wind startup speeds than HAWTs. Typically, they start creating

electricity at 6 M.P.H. (10 km/h).

VAWTs may be built at locations where taller structures are prohibited.

VAWTs situated close to the ground can take advantage of locations where mesas,

hilltops, ridgelines, and passes funnel the wind and increase wind velocity.

VAWTs may have a lower noise signature.

Disadvantages

15

A VAWT that uses guy-wires to hold it in place puts stress on the bottom bearing as

all the weight of the rotor is on the bearing. Guy wires attached to the top bearing

increase downward thrust in wind gusts. Solving this problem requires a superstructure

to hold a top bearing in place to eliminate the downward thrusts of gust events in guy

wired models.

The stress in each blade due to wind loading changes sign twice during each

revolution as the apparent wind direction moves through 360 degrees. This reversal of

the stress increases the likelihood of blade failure by fatigue.

While VAWTs' components are located on the ground; they are also located under the

weight of the structure above it, which can make changing out parts very difficult

without dismantling the structure, if not designed properly.

CHAPTER:-3 SAVORRIEUS WIND TURBINE

Savorrieus Wind Turbine is the new breed of the Savonius and darrieus wind turbine so

it is called as the Savorrieus wind turbine. Before designing and constructing it we have

to consider how many loads are acting on the wind turbine and how it can sustain

against those types of loads. For sustaining that load which material we have to use that

is very important prospects.

3.1 LOADS ON WIND TURBINE

The causes of all forces acting on the rotor are attributable to the effects of aerodynamic,

gravitational and inertial forces. The different loads and stresses can be classified

according to their effect with time on the rotating rotor.

- Aerodynamic loads with a uniform, steady wind speed, and centrifugal forces, generate

time-independent, steady-state loads as long as the rotor is running at a constant speed.

16

- An air flow which is steady, but spatially non- uniform over the rotor swept area causes

cyclic load changes on the rotating rotor. This includes, in particular, the uneven flow

towards the rotor due to the increase in wind speed with height, a cross-flow towards the

rotor and interference due to flow around the tower.

-the inertia forces due to the dead weight of the rotor blades also cause loads which are

periodic and thus unsteady. Moreover, the gyroscopic forces produced when the rotor is

yawed must also be included among those which increase or alternate with each

revolution of the rotor.

-in addition to the steady-state and cyclically loads, the rotor is subjected to non-periodic,

stochastic caused by wind turbulence.

3.2 MATERIALS

In the past, the starting point for the consideration of rotor blade design was the question

as to which material is most suitable. Design and manufacturing methods are determined

to a large extent by the properties of the material used and thus sets criteria for the

selection of materials. On other words, the selection of material, the principle of the

conceptual design and the production method cannot be considered independently of

each other in a real situation. Nevertheless makes sense to initially analyse the available

materials with respect to their suitability for wind rotor blades. Judging from experience

gained in aircraft engineering, the following materials are considered as suitable in

principle:

-aluminum,

-titanium,

-steel,

-fiber composite material (glass, carbon and aramide fibers),

17

-wood

The most important material properties by which a first assessment can be made are:

-specific weight (g/cm3)

-strength limit (N/mm2)

-modulus of elasticity (KN/m2)

-breaking strength related to the specific weight, the so-called breaking length (Km)

- Modules of elasticity related to the specific weight (103 Km)

- Allowable fatigue strength after 107 to 108 load cycles (N/mm2).

Cost of the material, manufacturing cost and the cost of the development involved are

also significant. Of course, the last two items cannot be judged solely from the material

point-of-view but must be seen in relation to the selected design concept. Table provides

an overview of the parameters listed above.

The traditional aircraft material aluminium does have suitable material properties, but

The production techniques commonly used in aircraft engineering are too expensive.

Aluminium, therefore, can only be considered if the rotor blades can be assembled from

machine-made semi-finished parts. Titanium is ruled out as a material for reasons of

cost.

Table:-3.1 strength and stiffness parameters of material in principle available for rotor

blades.

parameter

material

Spec.

Weight

γ

g/mm3

strength

limit

σb

N/mm2

modulus of

elasticity

E

KN/mm2

spec.

breaking

strength

σb/γ Km

spec.

modulus

of

elasticity

E/γ

103Km

fatigue

strength

±σa

107N/mm2

steel st 52 7.85 520 210 6.6 2.7 60

Alloyed steel

1.7735.4 7.85 680 210 8.7 2.7 70

Aluminium

ALZnMgCu

2.7 480 70 18 2.6

40

Aluminium

ALMG5 2.7 236 70 8.7 2.6 20

18

(weldable)

Titanium alloy

3.7164.1

4.5 900 110 20 2.4 _

fibre

glass/epoxy*

composite

1.7 420 15 24.7 0.9 35

carbon fibre/

epoxy*composite 1.4 550 44 39 3.1 100

aramide fibre/

epoxy*composite 1.25 450 24 36 1.9 _

wood

(silika spruce) 0.38 appr.65 appr.8 appr.17 appr. 2.1 appr. 20

wood/ epoxy* 0.58 appr.75 appr.11 appr.13 appr. 1.9 appr.35

*Ep-matrix 40 vol. %

3.3 ALL CONSTRUCTIONAL DETAILS AND DESIGN

In the Constructional details the parts of the Savorrius Wind Turbine are as below.

1. Savonius Rotor

2. Darrieus Rotor

3. Shaft

4. Hub

5. Bearing

6. Pulley & Belt

7. Generator

8. Frame

9. Base

1. SAVONIUS ROTOR

19

Fig:-3.1 Design of Savonius Rotor in Pro-e

The Design Prospects of the Savonius Rotor are as below;

- Diameter of the drum = 350 mm

- Total Height of Rotor = 770 mm

The Material used for Savonius Rotor is Galvanized Sheet Metal.

In the Savonius Rotor there are two S-shaped rotors are arranged at a right angle to each

other as shown in fig.

2. DARRIEUS ROTOR

20

Fig:-3.2 Design of Darrieus Rotor in Pro-e

The Design Prospects of the Darrius Rotor are as below;

-Total Height of the Darrius Rotor = 1200 mm

-Total Width of the Darrius Rotor = 1160 mm

The Material used for Darrius Rotor is Galvanized Sheet Metal.

The Darrius Rotor is mounted on the Shaft with the help of Hub. Darrius rotor

Cover the area of the Savonius Rotor.

3. SHAFT

Fig:-3.3 Design of Shaft in Pro-e

- Diameter of the Shaft = 15 mm

- Length of the Shaft = 1780 mm

The material used for Shaft is Galvanised Steel.

4. HUB(ARMS)

21

Darrieus Rotor

Fig:-3.4 Design of Hub in Pro-e

There are two hub (arms) used in the savorrius Wind Turbine.The Arms are used

for connecting the Darrius Rotor with the Shaft.

- Diameter of the Hub = 220 mm

5. BEARING

The Bearing used in Savorrius Wind Turbine is of 40 mm.

Fig:-3.5 Ball Bearing

6.PULLEY & BELT

22

Fig:-3.6 Design of Wooden Pulley in Pro-e

- Pulley Diameter = 300 mm

- Thickness of the Pulley = 15 mm

Material:- Wood

7.GENERATER

In the Savorrius Wind Turbine the DC Motor used as Generator.The Motor used as

generator has very low rpm So that for small revolution of wind rotor it generate the

more voltage,and it gives high power.

Fig:-3.7 Generator

8.FRAME

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FRAME

Fig:-3.8 Design of Frame in Pro-e

The Frame is as shown in fig. It is used for Supporting the Structure and Reduces the

Vibration induced in the Structure.

The Dimension of the frame is about 150 mm × 150 mm.

The Frame Structure made of the Cast Iron.

8.BASE

The Structure of the Base is shown in fig.It is seen like a table.

-Height of the Base = 700 mm

-The Dimension of the Base = 350 mm × 350 mm.

The Base Mainly used for Supporting the Frame.

Fig:-3.9 Design of Base In Pro-e

3.4 CIRCUIT DIAGRAM

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Fig:-3.10 Circuit Diagram of Savorrieus Wind Turbine

3.5 THE COMPLATE ROTOR ARRANGEMENT

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DARRIEUS ROTOR

SAVONIUS ROTOR

GENERATOR

BASE

PULLEY

BEARING

FRAME

Fig:-3.11 Assembly of Savorrieus Wind Turbine in Pro-e

3.6 COMPLATE PHOTOGRAPH OF TESTING

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Fig:-3.12 Photograph of Testing

3.7 WORKING OF TESTING

On 21st April, 2010 the Testing was done at the terrace of our collage. At that time the

wind velocity was around 5 km/hr. so the turbine was not rotating as high as our

expectation. But when the wind velocity is going as high as 7km/hr, the turbine rotates at

very good speed which is very much encouraging for us. Due to some generator problem

we could not get power that we were expecting. But at the time of second test at the same

place on 30th April,2010 the wind velocity is around 6km/hr our turbine rotates at around

42 rpm and by applying new generator we can get Voltages up to the 20V.

During Working of the Savorrius Wind Turbine it rotates at a around 35 rpm at a 5

km/hr, and as the wind speed going to increase it rotates at a higher speed. At the Speed

of 6 km/hr the Savorrius rotates at a around 42 rpm. At Wind speed of 7 km/hr it rotates

at a 48 rpm and at 8 km/hr it reaches the speed of 54 rpm. At the end we are going to

success to lighting the Strip of LCIT made by 40 LEDS.

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CHAPTER:-4 PERFORMANCE ANALYSIS OF

SAVORRIUS WIND TURBINE

During the testing time the Savorrieus Wind Turbine shows the following Readings.

The Reading that we get it is of the prototype Savorrieus Wind Turbine. It can be

increased by using higher capacity generator and some modification in rotor Design.

Table:-4.1 Practical Observation of Prototype Savorrius Wind Turbine

Wind Velocity

(km/hr)

Rotor Speed

(RPM)

Voltage

(V)

Current

(A)

5 35 13.4 0.43

6 42 18.1 0.58

7 48 23.2 0.77

8 54 26.5 0.97

4.1 THEORATICAL CALCULATION

For calculating the power available by the Wind Turbine we have the Following

Equation.

Pavailable = ½ ×ρ×A2×V3

Where ρ = Air Density = 1.177 J/kg.K/m3

A = Area Swept by the Rotor Blade in m2

V = Velocity of the Wind in km/hr.

For Wind Speed of 5 Km/hr.

Pavailable = 1/2×1.177× (1.16×1.20)2× (5)3

= 142.5 W

For Wind Speed of 6 Km/hr.

Pavailable = 1/2×1.177× (1.16×1.20)2× (6)3

= 246.3 W

For Wind Speed of 7 Km/hr.

Pavailable = 1/2×1.177× (1.16×1.20)2× (7)3

= 391.1 W

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For Wind Speed of 8 Km/hr.

Pavailable = 1/2×1.177× (1.16×1.20)2× (7)3

= 583.8 W

4.2 ANALYSIS

From the Practical Observation the Following Graphs can be made. This observation are

taken from the Savorrieus Prototype Wind Turbine. There are so many chances that it

going to very much increase up to its 50% effiency in actual Turbine.

Graph:-4.1 Voltage Vs RPM

Graph:-4.2 Current Vs RPM

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Graph:-4.3 Voltage Vs Velocity

Graph:-4.4 Current Vs Velocity

4.3 COST

The most expensive parts of this design, in terms of material cost, were the base and

frame. Labour cost is also somewhat high due to it need high technical skill.

The cast iron which is required for base & frame fabrication cost approximately 2000 Rs.

Bearing cost is approximately 150 Rs. The Material used for blades, its approximately

cost is around 700 Rs. The other Fasteners cost is around 200 Rs. the cost of pulley and

generator is around 500 Rs. (approxy).

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CONCLUSION

The initial goal of this project was to come up with a self-starting mechanism for a

typical Darrieus wind turbine and get higher effiency of Savonius Wind turbine.

However, the solution attempted was anything but typical, resulting in a totally new

breed of Darrieus and Savonius turbine which is the Savorrius Wind Turbine.

This new breed that was developed probably has more potential.

This potential has not yet been completely realized, but the concept has been proven to

function as a self starter and get higher effiency. This design fills the functions required

of a starting mechanism; it is mainly the inaccuracy of the blade profiles that led to less

than desirable results during testing.

Most of the tough design problems have been resolved, so another group could easily

concentrate on fabricating quality blades and improving the overall design. With a

sufficient time, this design could easily be developed to capitalize on the potential which

has been discovered. The concept that has been proposed has much room for future

development.

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CHAPTER:-6 FUTURE WORK

Design Improvements

While the prototype did not perform as well as initially hoped, with a few changes to the

design this should improve greatly. The most important area of improvement is the blade

construction. Currently the profile is not exact. Having the precise Airfoil shape is

essential to generate sufficient lift. Also try to for reducing some weight of rotor blade.

This could be accomplished by using some lighter Material of the Blade.

Another change that would improve the performance is altering the design of the arms.

They are creating a large drag force, hindering the rotation of the blades. By making

them an aerodynamic shape as opposed to simply flat plates, it would greatly reduce the

overall drag on the device.

By done some modification on the transmission system that is the making good belt-

pulley arrangement or by putting gear box instead of belt-pulley some effiency may be

increased

There are several simple improvements that could be made on this design.. Some of

these improvements would be to purchase better bearings, install better stops. A better

bearing (possibly a linear bearing) would enable the turbine to turn more freely, reducing

the starting torque and making everything work much more smoothly

Additional Considerations

In order for this design to be most useful there are several additional items that must be

considered. These items were deemed to be out of the scope of the project given the time

and monetary constraints; however, they must be addressed if this project is to prove its

true value. Once the arms have been redesigned and the blades have been fabricated to

the exact specifications, this turbine will be capable of spinning at extremely high

rotational speeds. As a result, the centrifugal forces will be very high, and the turbine

Could be damaged. To keep the turbine from reaching these dangerous speeds a braking

mechanism should be designed. This mechanism should not require human intervention;

rather, it should engage only when the speeds are high, and disengage automatically

when these speeds decrease.

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REFERREENCES

1. Wind Turbines, Application and Economics 2ed edition By Erich Hau.

Springer.

2. Renewable Energy Sources and Emerging Technologies by D.P.Kothari,

K.C. Singal, Rakesh Ranjan

3. Non Conventional Energy Sources by B.H.Khan.

4. Non-Conventional Energy Resources by D.S. Chauhan, S.K. Shrivastava.

5. Renewable Energy Sources and Their Environmental Impact by S.A.

Abbasi, Naseema Abbasi

6. Non Conventional Energy Sources by G.D.Rai.

7. Wikipedia of Wind Turbine, Savonius Wind Turbine, Darrius Wind

Turbine, Wind Power.

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