Project Report of Vwat PDF

8/12/2019 Project Report of Vwat PDF

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By damoddhiran


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ABSTRACT

We know that there is enough wind globally to satisfy much, or even most,

of humanity's energy requirements if it could be harvested effectively and

on a large scale. Vertical axis wind turbines (VW!s", which may be as

efficient as current hori#ontal axis systems, might be $ractical, sim$ler

and significantly chea$er to build maintain than hori#ontal axis wind

turbines (%W!s".!hey also have other inherent advantages, such as they

are always facing the wind, which might make them a significant $layer in

our quest for chea$er, cleaner renewable sources of electricity. VW!s

might even critical in mitigating grid interconnect stability and reliabilityissue currently facing electricity $roducers and su$$liers. dditionally,

chea$ VW!&s may $rovide an alternative to the rain forest destruction for

the growing of biofuel cro$s.

Verticalaxis wind turbines (VW!s) are a ty$e of wind

turbine where the main rotor shaft is set vertically. mong the advantages of

this arrangement are that generators and gearboxes can be $laced close to the

ground, and that VW!s do not need to be $ointed into the wind. a)or

drawbacks for the early designs (*avonius, +arrieus, and cycloturbine"

included the $ulsatory torque that can be $roduced during each revolution

and the huge bending moments on the blades.

n this $ro)ect we attem$t to design and fabricate a

*avonius Vertical xis Wind !urbine.


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Table of Contents

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INTRODUCTION

f the efficiency of a wind turbine is increased, then more $ower can be

generated thus decreasing the need for ex$ensive $ower generators that

cause $ollution. !his would also reduce the cost of $ower for the common

$eo$le. !he wind is literally there for the taking and doesn't cost any money.

4ower can be generated and stored by a wind turbine with little or no

$ollution. f the efficiency of the common wind turbine is im$roved and

wides$read, the common $eo$le can cut back on their $ower costs

immensely.

5ver since the *eventh 1entury $eo$le have been utili#ing the wind to make

their lives easier. !he whole conce$t of windmills originated in 4ersia. !he

4ersians originally used the wind to irrigate farm land, crush grain and

milling. !his is $robably where the term windmill came from.

*ince the wides$read use of windmills in 5uro$e, during the !welfth

1entury, some areas such as the -etherlands have $ros$ered from creating

vast wind farms.

!he first windmills, however, were not very reliable or energy efficient.

/nly half the sail rotation was utili#ed. !hey were usually slow and had a

low ti$ s$eed ratio but were useful for torque.

*ince its creation, man has constantly tried to im$rove the windmill. s a

result, over the years, the number of blades on windmills has decreased.

ost modern windmills have BF blades while $ast windmills have had 3G8

blades. 4ast windmill also had to be manually directed into the wind, while

modern windmills can be automatically turned into the wind. !he sail design

and materials used to create them have also changed over the years.


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n most cases the altitude of the rotor is directly $ro$ortional to its

efficiency. s a matter of fact, a modern wind turbine should be at least

twenty feet above and three hundred feet away from an obstruction, though it

is even more ideal for it to be thirty feet above and five hundred feet away

from any obstruction.

+ifferent locations have various wind s$eeds. *ome $laces, such as the

Aritish sles, have few inhabitants because of high wind s$eeds, yet they are

ideal for wind generation. +id you know that the world's largest wind farm is

located in 1alifornia, and the total wind $ower generated there exceeds

;,3


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have a hori#ontal rotor much like the classic +utch fourarm windmill. !he

hori#ontal axis windmills $rimarily rely on lift from the wind. s stated in

Aernoulli's 4rinci$le, Ia fluid will travel from an area of higher $ressure to

an area of lower $ressure.I t also states, Ias the velocity of a fluid increases,

its density decreases.I Aased u$on this $rinci$le, hori#ontal axis windmill

blades have been designed much like the wings of an air$lane, with a curved

to$. !his design increases the velocity of the air on to$ of the blade thus

decreasing its density and causing the air on the bottom of the blade to go

towards the to$ ... creating lift. !he blades are angled on the axis as to utili#e

the lift in the rotation. !he blades on modern wind turbines are designed for

maximum lift and minimal drag.

Vertical axis windmills, such as the +urries (built in ;:?


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blades to avoid the stresses at high wind s$eeds. *ome windmills, like the

cycloturbine, have been equi$$ed with a vane that senses wind direction and

causes the rotor to rotate into the wind. Wind turbine generators have been

equi$$ed with gearboxes to control KshaftL s$eeds. Wind turbines have also

been equi$$ed with generators which convert shaft $ower into electrical

$ower. any of the sails on windmills have also been re$laced with

$ro$ellerlike airfoils. *ome windmills can also stall in the wind to control

wind s$eed. Aut above all of these im$rovements, the most im$ortant

im$rovement to the windmill was made in ;D3B when the fantail was

invented. !he fantail automatically rotates the sails into the wind.

ost wind turbines start to generate $ower at ;; mMs and shut down at

s$eeds near ?EmMs. nother variable of the windmill's efficiency is its swe$t

area. !he swe$t area of a disksha$ed wind wheel is calculated asJ rea

equals $i times diameter squared divided by four ($i equals ?.;3".

nother variable in the $roductivity of a windmill is the wind s$eed. !he

wind s$eed is measured by an anemometer.

nother necessity for a windmill is the tower. !here are many ty$es of

towers. *ome towers have guy wire to su$$ort them and others don't. !he

towers without guy wires are called freestanding towers. *omething to take

into consideration about a tower is that it must su$$ort the weight of the

windmill along with the weight of the tower. !owers are also sub)ect to drag.

*cientists estimate that, by the E;st 1entury, ten $ercent of the world's

electricity will come from windmills.


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SCOPE OF THE PROJECT

!o utili#e the available wind resources and to reduce the usage of non

renewable energy resources. Wind energy is by far the fastestgrowing

renewable energy resource. !he wind energy industry so far has been

su$$orted by market incentives backed by government $olicies fostering

sustainable energy resources.

9argescale wind facilities a$$roaching the out$ut rating of conventional

$ower $lants, control of the $ower quality is required to reduce the adverse

effects on their integration into the network. !hese wind turbines can be used

to $rovide constant lighting. n most cities, bridges are a faster route foreveryday commute and in need of constant lighting makes this an efficient

way to $roduce natural energy.


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LITERATURE REVIEW

POWER & SOURCES

N The Source of Wind

n a macrometeorological sense, winds are movements of air masses in the

atmos$here mainly originated by tem$erature differences. !he tem$erature

gradients are due to uneven solar heating. n fact, the equatorial region is

more irradiated than the $olar ones. 1onsequently, the warmer and lighter air

of the equatorial region rises to the outer layers of the atmos$here and moves

towards the $oles, being re$laced at the lower layers by a return flow of

cooler air coming from the $olar regions. !his air circulation is also affected

by the 1oriolis forces associated with the rotation of the 5arth. n fact, these

forces deflect the u$$er flow towards the east and the lower flow towards the

west. ctually, the effects of differential heating dwindle for latitudes greater

than ?


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N The !o"er in #he Wind

!he $ower in the wind can be com$uted by using the conce$ts of

kinetics. !he wind mill works on the $rinci$le of converting kinetic

energy of the wind to mechanical energy. !he kinetic energy of any

$article is equal to one half its mass times the square of its velocity,

Oinetic 5nergy PQ mvE.

mount of ir $assing is given by

m P R V 2222222..(;"

Where

m P mass of air transversing

Parea swe$t by the rotating blades of wind mill ty$e generator

R P +ensity of air

VP velocity of air*ubstituting this value of the mass in ex$ression of O.5.

P Q R V.VE

watts

P Q R V?

watts 2222222.. (E"

*econd equation tells us that the $ower available is $ro$ortional to air

density (;.EEB kgMm?" S is $ro$ortional to the interce$t area. *ince the

area is normally circular of diameter + in hori#ontal axis aero turbines,

then,

P T+E

(*q. m"

3

4ut this quantity in equation second then

vailable wind $ower 4a P R T +E

V?

watt

8


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CHARACTERISTICS & SPECIFICATIONS OF

WIND TUR$INES

U Wind S!eed

!his is very im$ortant to the $roductivity of a windmill. !he wind turbine

only generates $ower with the wind. !he wind rotates the axis (hori#ontal or

vertical" and causes the shaft on the generator to swee$ $ast the magnetic

coils creating an electric current.

U $%de Len'#h

!his is im$ortant because the length of the blade is directly $ro$ortional to

the swe$t area. 9arger blades have a greater swe$t area and thus catch more

wind with each revolution. Aecause of this, they may also have more torque.

U $e Hei'h#

!he height of the base affects the windmill immensely. !he higher awindmill is, the more $roductive it will be due to the fact that as the altitude

increases so does the winds s$eed.

U $e Dei'n

*ome base is stronger than others. Aase is im$ortant in the construction of

the windmill because not only do they have to su$$ort the windmill, but they

must also be sub)ect to their own weight and the drag of the wind. f a weak

tower is sub)ect to these elements, then it will surely colla$se. !herefore, the

base must be identical so as to insure a fair com$arison.


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$LOC( DIARA* OF WIND POWER

ENERATION

W-+ W-+ !0A-5 W-+

1 9!5-!/

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9/+ 0!9!/-


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N RE+UIRE*ENTS FOR PLACIN

Si#e Se%ec#ion conider#ion

!he $ower available in the wind increases ra$idly with the s$eed hence

wind energy conversion machines should be located $referable in areas

where the winds are strong S $ersistent. !he following $oint should be

considered while selecting site for Wind Ener', Con-erion S,#e.

/WECS)0

U

Hi'h nnu% -er'e "ind !eed!he wind velocity is the critical $arameter. !he $ower in the wind 4w,

through a given @ section area for a uniform wind Velocity is

4w P OV?

(O is constant"

t is evident, because of the cubic de$endence on wind velocity that

small increases in V markedly affect the $ower in the wind

e0'. doubling V, increases 4wby a factor of 8.

U A-i%1i%i#, of "ind V/#) cur-e # #he !ro!oed i#e

!his im$ortant curve determines the maximum energy in the wind and

hence is the $rinci$le initially controlling factor in $redicting the

electrical oM$ and hence revenue return of the W51* machines, it is

desirable to have average wind s$eed V such that

VX;E;F kmMhr i.e. (?.B 3.B mMsec".

U Wind #ruc#ure # #he !ro!oed i#e

Wind es$ecially near the ground is turbulent and gusty, S changes

ra$idly indirection and in velocity. !his de$arture from homogeneous

flow is collectively referred to as Ythe structure of the windZ.


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U A%#i#ude of #he !ro!oed i#e

f affects the air density and thus the $ower in the wind S hence the

useful W51* electric $ower oM$. !he winds tends to have higher

velocities at higher altitudes.

U Loc% Eco%o',

f the surface is bare rock it may mean lower hub heights hence lower

structure cost, if trees or grass or ventation are $resent. ll of which

tends to destructure the wind.

U Nerne of i#e #o %oc% cen#er2uer

!his obvious criterion minimi#es transmission line length S hence losses

S costs.

U N#ure of 'round

>round condition should be such that the foundations for W51s aresecured, ground surface should be stable.

U F-or1%e %nd co#

9and cost should be favorable as this along with other sitting costs,

enters into the total W51* system cost.


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VERTICAL A3IS WIND TUR$INE

Verticalaxis wind tu rbines (or VW!s" have the main rotor shaft arranged

vertically. Oey advantages of this arrangement are that the turbine does notneed to be $ointed into the wind to be effective. !his is an advantage on sites

where the wind direction is highly variable, for exam$le when integrated into

buildings. !he key disadvantages include the low rotational s$eed with the

consequential higher torque and hence higher cost of the drive train, the

inherently lower $ower coefficient, the ?F< degree rotation of the aerofoil

within the wind flow during each cycle and hence the highly dynamic

loading on the blade, the $ulsating torque generated by some rotor designs

on the drive train, and the difficulty of modeling the wind flow accurately

and hence the challenges of analy#ing and designing the rotor $rior to

fabricating a $rototy$e.

1+ /+59 /6 V5!19 @* W-+ !0A-5


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With a vertical axis, the generator and gearbox can be $laced near the

ground, hence avoiding the need of a tower and im$roving accessibility for

maintenance. +rawbacks of this configuration include (i" wind s$eeds are

lower close to the ground, so less wind energy is available for a given si#e

turbine, and (ii" wind shear is more severe close to the ground, so the rotor

ex$eriences higher loads. ir flow near the ground and other ob)ects can

create turbulent flow, which can introduce $roblems associated with

vibration, such as noise and bearing wear which may increase the

maintenance or shorten the service life. %owever, when a turbine is mounted

on a roofto$, the building generally redirects wind over the roof and this can

double the wind s$eed at the turbine. f the height of the roofto$ mounted

turbine tower is a$$roximately B


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undisturbed u$stream air velocity, , and the velocity vector of the

advancing blade, .

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ENERAL THEOR4 RELATED TO VERTICAL

A3IS WIND TUR$INE

!he forces and the velocities acting in a +arrieus turbine are de$icted in

figure ;. !he resultant velocity vector, , is the vectorial sum of the

!hus, the oncoming fluid velocity varies, the maximum is found for

and the minimum is found for , where \ is the a#imuthal or orbital

blade $osition. !he angle of attack, ], is the angle between the oncoming air

s$eed, W, and the blade's chord. !he resultant airflow creates a varying,

$ositive angle of attack to the blade in the u$stream #one of the machine,

switching sign in the downstream #one of the machine.

6rom geometrical considerations, the resultant airs$eed flow and the angle of

attack are calculated as followsJ


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Where is the ti$ s$eed ratio $arameter

!he resultant aerodynamic force is decom$osed either in lift (6^9" drag

(+" com$onents or normal (-" tangential (!" com$onents. !he forces are

considered acting at ;M3 chord from the leading edge (by convention", the

$itching moment is determined to resolve the aerodynamic forces. !he

aeronautical terms lift and drag are, strictly s$eaking, forces across and along

the a$$roaching net relative airflow res$ectively. !he tangential force is

acting along the blade's velocity and, thus, $ulling the blade around and the

normal force is acting radially, and, thus, is acting against the bearings. !he

lift and the drag force are useful when dealing with the aerodynamic

behavior around each blade, i.e. dynamic stall, boundary layer, etc while

when dealing with global $erformance, fatigue loads, etc., it is more

convenient to have a normaltangential frame. !he lift and the dragcoefficients are usually normali#ed by the dynamic $ressure of the relative

airflow, while the normal and the tangential coefficients are usually

normali#ed by the dynamic $ressure of undisturbed u$stream fluid velocity.


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where

P *urface rea

RP +ensity of air

+P +rag com$onent of aerodynamic force

-P-ormal com$onent of aerodynamic force

!P!angential com$onent of aerodynamic force

69P9ift com$onent of aerodynamic force

!he amount of $ower, 4 , which can be absorbed by a wind turbine.

Where Cp is the $ower coefficient, R is the density of the air, A is the swe$t

area of the turbine, and _ is the wind s$eed


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T4PES OF VERICAL A3IS WIND TUR$INES

Drrieu "ind #ur1ine

1ommonly described as I5ggbeaterI turbines, or +arrieus turbines, were

named after the 6rench inventor, >eorges +arrieus. !hey have good

efficiency, but $roduce large torque ri$$le and cyclical stress on the tower,

which contributes to $oor reliability. !hey also generally require some

external $ower source, or an additional *avonius rotor to start turning,

because the starting torque is very low. !he torque ri$$le is reduced by using

three or more blades which results in greater solidity of the rotor. *olidity is

measured by blade area divided by the rotor area. -ewer +arrieus ty$e

turbines are not held u$ by guywires but have an external su$erstructure

connected to the to$ bearing.

!he +arrieus design, the aerofoils are arranged so that they are symmetrical

and have #ero rigging angle, that is, the angle that the aerofoils are set

relative to the structure on which they are mounted. !his arrangement is

equally effective no matter which direction the wind is blowing`in contrast

to the conventional ty$e, which must be rotated to face into the wind.

When the +arrieus rotor is s$inning, the aerofoils are moving forward

through the air in a circular $ath. elative to the blade, this oncoming

airflow is added vectorially to the wind, so that the resultant airflow creates a

varying small $ositive angle of attack (o" to the blade. !his generates anet force $ointing obliquely forwards along a certain 'lineofaction'. !his

force can be $ro)ected inwards $ast the turbine axis at a certain distance,

giving a $ositive torque to the shaft, thus hel$ing it to rotate in the direction

it is already travelling in. !he aerodynamic $rinci$les which rotate the rotor

are equivalent to that in autogiros, and normal helico$ters in autorotation.


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Wor5in' *ode% of Drrieu Wind #ur1ine

A Drrieu "ind #ur1ine ued #o 'ener#e e%ec#rici#, on #he *'d%en

I%nd


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iro.i%%

subty$e of +arrieus turbine with straight, as o$$osed to curved,

blades. !he cycloturbine variety has variable $itch to reduce the

torque $ulsation and is selfstarting.!he advantages of variable $itch

areJ high starting torque a wide, relatively flat torque curve a lowerblade s$eed ratio a higher coefficient of $erformance more efficient

o$eration in turbulent winds and a lower blade s$eed ratio which

lowers blade bending stresses. *traight, V, or curved blades may be

used.

>iromill VW!s are also selfstarting.

A iro.i%%6#,!e "ind #ur1ine


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S-oniu "ind #ur1ine

*avonius turbines are one of the sim$lest turbines. erodynamically, they

are dragty$e devices, consisting of two or three scoo$s. 9ooking down on

the rotor from above, a twoscoo$ machine would look like an I*I sha$e incross section. Aecause of the curvature, the scoo$s ex$erience less drag

whenmoving against the wind than when moving with the wind. !he

differential drag causes the *avonius turbine to s$in. Aecause they are drag

ty$e devices, *avonius turbines extract much less of the wind's $ower than

other similarlysi#ed liftty$e turbines. uch of the swe$t area of a *avonius

rotor may be near the ground, if it has a small mount without an extended

$ost, making the overall energy extraction less effective due to the lower

wind s$eeds found at lower heights.

Wor5in' *e#hodo%o', of S-oniu Wind Tur1ine


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ADVANTAES OF SAVONIUS TUR$INES

*avonius turbines are used whenever cost or reliability is much more

im$ortant than efficiency. 6or exam$le, most anemometers are *avonius

turbines, because efficiency is com$letely irrelevant for that a$$lication.

uch larger *avonius turbines have been used to generate electric $ower on

dee$water buoys, which need small amounts of $ower and get very little

maintenance. +esign is sim$lified because, unlike with %ori#ontal xis

Wind !urbines (%W!s", no $ointing mechanism is required to allow for

shifting wind direction and the turbine is selfstarting. *avonius and other

verticalaxis machines are good at $um$ing water and other high torque, low

r$m a$$lications and are not usually connected to electric $ower grids. !hey

can sometimes have long helical scoo$s, to give smooth torque.

!he most ubiquitous a$$lication of the *avonius wind turbine is the 6lettner

Ventilator which is commonly seen on the roofs of vans and buses and is

used as a cooling device. !he ventilator was develo$ed by the >erman

aircraft engineer nton 6lettner in the ;:E


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Indi7 *r5e# O-er-ie" of Wind Ener',

O-er-ie"

!he develo$ment of wind $ower in ndia began in the ;::


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*#eri% U'e in Curren# Wind Tur1ine

wide range of materials are used in wind turbines. !here are substantial

differences between small and large machines and there are $ro)ected

changes in designs that will accommodate the introduction of new materialtechnologies and manufacturing methods. !o arrive at a total, the material

usage is weighted by the estimated market share of the various

manufacturers and machines ty$es. n general the materials used for wind

turbines are *teel, luminum, 1o$$er and einforced 4lastic

n this $ro)ect we have used luminum discs and aluminum

sheets. !he following are certain im$ortant $ro$erties $resent in the

materials.

PROPERTIES OF *ATERIALS USED

4oun'7 .odu%u

t is defined as the ratio of stress and strain, where the strain does not have

units. !herefore young&s modulus has the units of stress,-Mmm8, $a , >$a

!he value for luminum is D< >4a

Hoo5e7 L"

!his law states that stress is directly $ro$ortional to strain within the elastic

limit.

4ie%d S#re

"here E9 4oun'7 *odu%u0

t is the value of stress at which the material continues to deform at constant

load conditions. !he value for luminum is E


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Frc#ure S#re

s the reduction in cross sectional area continues, the load bearing ca$acity

of s$ecimen reduces gradually. t a certain stage cross sectional of s$ecimen

is so small that it cannot sustain the load S hence it breaks. !he stress at

which the s$ecimen breaks is known as fracture stress. t is generally lessthan ultimate stress for ductile materials.

Hrdne

t is the measure of resistance to $enetration Sabrasion, which is a function

of stress required to $roduce some s$ecified ty$e of failure. t is generally

ex$ressed as a number.

Tou'hne

!he ability of material to absorb energy in the $lastic range is known as

toughness. !oughness $er unit volume of the material is known as modulus

of toughness.

Poion7 r#io

!he ratio between lateral strain and longitudinal strain is known as 4oisson&s

ratio. !he value for luminum is


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Princi!%e of D,n.o O!er#ion

!he dynamo uses rotating coils of wire and magnetic fields to convert

mechanical rotation into a $ulsing direct electric current through 6araday's

law of induction. dynamo machine consists of a stationary structure, called

the stator, which $rovides a constant magnetic field, and a set of rotating

windings called the armature which turn within that field. !he motion of the

wire within the magnetic field causes the field to $ush on the electrons in the

metal, creating an electric current in the wire. /n small machines the

constant magnetic field may be $rovided by one or more $ermanent

magnets larger machines have the constant magnetic field $rovided by oneor more electromagnets, which are usually called field coils.

!he commutator was needed to $roduce direct current. When a loo$ of wire

rotates in a magnetic field, the $otential induced in it reverses with each half

turn, generating an alternating current. %owever, in the early days of electric

ex$erimentation, alternating current generally had no known use. !he few

uses for electricity, such as electro$lating, used direct current $rovided by

messy liquid batteries. +ynamos were invented as a re$lacement for

batteries. !he commutator is essentially a rotary switch. t consists of a set of

contacts mounted on the machine's shaft, combined with gra$hiteblock

stationary contacts, called IbrushesI, because the earliest such fixed contacts

were metal brushes. !he commutator reverses the connection of the

windings to the external circuit when the $otential reverses, so instead of

alternating current, a $ulsing direct current is $roduced


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DESIN OF WIND TUR$INE

30


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DESININ OF VERTICAL A3IS WIND TUR$INE

wind mill is machine for wind energy conversion. wind turbine

converts the kinetic energy of the wind&s motion to mechanical energy

transmitted by the shaft. generator further converts it to electrical

energy. *o it is necessary to kee$ in mind, while designing the

windmill&s structural $art.

Dei'n of 1%de

Wind turbine blades have on aerofoil ty$e cross section and a variable

$itch. While designing the si#e of blade it is must to know the weight

and cost of blades. n the $ro)ect three blade with vertical shaft are used,

it has a height S width of D?cm S ;EEcm res$ectively. !he angle

between two blades is F

E. %elium

Ad-n#'e of #he Cu##in'0

U 5nvironment friendly (reducing the emission of 1/E"

U %igh quality of cut surface

U eduction of manhours for finishing after cutting

U %igh $roductivity by high s$eed cutting.


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ARC WELDIN

rc welding uses a welding $ower su$$ly to create an electric arc between

an electrode and the base material to melt the metals at the welding $oint.

!hey can use either direct (+1" or alternating (1" current, and consumable

or nonconsumable electrodes. !he welding region is sometimes $rotected

by some ty$e of inert or semiinert ga s ,known as a shielding ga s ,andMor an

eva$orating filler material. !he $rocess of arc welding is widely used

because of its low ca$ital and running costs

!he following gauge lengths of electrodes are used in this $rocess 8,

;


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RIVETIN

rivet is a $ermanent mechanical fastener. Aefore being installed a rivet

consists of a smooth cylindrical shaft with a head on one end. !he end

o$$osite the head is called the bucktail. /n installation the rivet is $laced in

a $unched or $redrilled hole, and the tail is u$set, or bucked (i.e. deformed",

so that it ex$ands to about ;.B times the original shaft diameter, holding the

rivet in $lace. !o distinguish between the two ends of the rivet, the original

head is called the factory head and the deformed end is called the sho$ head

or bucktail.

Aecause there is effectively a head on each end of an installed rivet, it can

su$$ort tension loads (loads $arallel to the axis of the shaft" however, it is

much more ca$able of su$$orting shear loads (loads $er$endicular to the

axis of the shaft". Aolts and screws are better suited for tension a$$lications.

RIVETIN E+UIP*ENT


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CALCULATIONS

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40

THEORTICAL CALCULATIONS

!he wind mill works on the $rinci$le of converting kinetic energy of the

wind to mechanical energy. !he kinetic energy of any $article is equal

to one half its mass times the square of its velocity, or Q mvE.

(0E 9 kinetic energy

. 9 mass

- 9 velocity,

(0E9; .-80 2222222.. (;"

is equal to its Volume multi$lied by its density R of air

* 9 R AV 2222222.. (E"

*ubstituting eqn(E" in eqn(;"

We get,

( E 9 ; R AV0V8

( E 9 ; R AV< "##

R P density of air (;.EEB kgMm?"

A 9 T D8

2= (*q.m"

D P diameter of the blade

A 9 T>/?088)8

2=

A 9 ?0?@S:0.

vailable wind $ower 4a 9 /; R T D8

V


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TRAIL ?

6/ V59/1!C 3.BmMs

P 9 /; R T D8

V?088B>T>?0888 >=0BT>?0888 >0B


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APPLICATIONS OF WIND ENER4

Windturbine generators have been built a wide range of $ower out$uts

from kilowatt or so to a few thousand kilowatts, machine of low $ower

can generate sufficient electricity for s$ace heating S cooling S for

o$erating domestic a$$liances.

9ow $ower W51 generators have been used for many years for the

corrosion $rotection of buried metal $i$e lines.

$$lication of more $owerful turbines u$ to about B


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D. *im$ler installation and maintenance besides the traditional

installation site, it can be mounted directly on a roofto$, doing

away with the tower and associated guy lines.

8. -ot affected by orientation variation`no matter the wind blow

from any orientation, VW! can work without regard to its

face.

:. 5conomical and $racticallthough onetime investment

ex$enses are larger, but you don&t have to $ay higher tariffs

forever.

Ad-n # 'e

a" t is a renewable source of energy.

b" Wind $ower systems are non$olluting so it has no adverse

influence on the environment.

c" Wind energy systems avoid fuel $rovision and trans$ort.

d" /n a small scale u$ to a few kilowatt system is less costly.

e" /n a large scale costs can be com$etitive conventional

electricity and lower costs could be achieved by mass

$roduction.

f" !hey are always facing the wind no need for steering into the

wind.

g" %ave greater surface area for energy ca$ture can be many

times greater.

h" re more efficient in gusty winds already facing the gust.

i" 1an be installed in more locations on roofs, along highways,

in $arking lots.

)" 1an be scaled more easily from mill watts to megawatts.


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CONCLUSION & FUTUREDEVELOP*ENTS


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CONCLUSION

/ur work and the results obtained so far are very encouraging and reinforce

the conviction that vertical axis wind energy conversion systems are

$ractical and $otentially very contributive to the $roduction of clean

renewable electricity from the wind even under less than ideal sitting

conditions. t is ho$ed that they may be constructed used highstrength, low

weight materials for de$loyment in more develo$ed nations and settings or

with very low tech local materials and local skills in less develo$ed

countries. !he *avonius wind turbine designed is ideal to be located on to$

of a bridge or bridges to generate electricity, $owered by wind. !he elevated

altitude gives it an advantage for more wind o$$ortunity. With the idea on

to$ of a bridge, it will $ower u$ street lights and or commercial use. n most

cities, bridges are a faster route for everyday commute and in need of

constant lighting makes this an efficient way to $roduce natural energy

FUTURE DEVELOP*ENTS

!he develo$ment of effective alternators and dynamos can be used to

harness wind energy from relatively small winds. !he use of materials

like crylic 4lastic *heets can be used to develo$ low cost VW!


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$I$LIORAPH4

5ggleston, +avid . Wind Turbine Engineering Design. Van -ostrand

einhold, ;:8D.

%unt, +aniel V. Wind power: A Handbook on Wind Energy ConversionSystems. Van -ostrand einhold, ;:8;.

Oovarik, !om, 1harles 4u$her, and 7ohn %urst. Wind Energy. +omusAooks, ;:D:.

4ark, 7ack. The Wind ower !ook. 1heshire Aooks, ;:8;.

4utnam, 4almer 1osslett.ower "rom the Wind. Van -ostrand 1om$any,


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PHOTOS

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1C195 +C-/

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