[Intoxicating Boy]

1.1 WHY WIND ENERGY:
The world has been facing huge amount of energy crisis from past few years. The developments of technology and a continuous increase in population lead to the huge amount of fossil fuel. Our earth has limited reserves of fossil fuels which are getting less day by day, this bitter fact has diverted the attention of whole world towards renewable energy resources.
The following are the renewable energy resources:
• Solar energy
• Wind energy
• Geothermal Energy
• Hydroelectric Energy
• Biomass
• Biofuels
• Wave Energy
These sources cannot be replenished from our Earth. They produce clean energy and have zero pollution. Each type has its own characteristics, benefits and some limitations, for example solar energy produces electricity by absorbing sunlight through solar panels, solar energy can also generate electricity through the production of steam by huge reflective mirrors concentrating sunlight on a tank producing high temperatures. The main limitation of solar energy is that it can only work during day time when sunlight is there. Wave energy cannot be used for large production of energy, this is because it is only limited to seashore areas and depends upon the strength of wind. Similarly geothermal, biomass and others have some limitations but the most important and easily available energy is wind energy.
Land has low specific heat capacity than sea which means faster increase in temperature so during day time land is warmer than sea so air above land gets heated up and rises and cooler air having high pressure , from the sea comes to fill the low pressure heated air as shown in figure below:

During night time land gets cooler while sea is warmer so reverse process occurs and cooler air from land moves towards the hot air above sea as shown in figure below:

So in this way this cycle continues and air keeps blowing no matter whether its day or night. This is the main advantage of wind energy over solar energy. Wind energy can be produced whether its day or night whenever there is wind.
So from these comparisons of renewable energy types with each other we come to know that wind energy is the best choice for producing energy.

1.2 WIND TURBINE:
As the name it selves tell that a turbine which works by extracting energy from moving air is called wind turbine. A wind turbine converts kinetic energy in the air to mechanical energy and this mechanical energy is then converted to electrical energy by a generator. If this mechanical energy is used to pump water or do any other work then it is known as windmill. If it is being used to produce electricity, then it is known as the wind charger or wind generator.

1.3 AIRBORNE WIND TURBINE:
Imaginative concepts for flying wind machines have been introduced to take advantage of the larger magnitude and more constant wind speeds with low intermittence at higher elevations in the atmosphere. They also would avoid the near surface turbulence.
The word Airborne means transported by air or flying so Airborne Wind Turbine is an innovative lighter-than-air tethered turbine that rotates about a horizontal axis in response to wind, efficiently generating clean renewable electrical energy at a lower cost than all competing systems. This electrical energy is transferred down the tether to a transformer of ground station and then transferred to electricity powered grid. Helium (an inert non-reactive lighter than air gas) sustains the air rotor which ascends to an attitude for best winds and its rotation also causes the Magnus effect. This provides additional lift, keeps the device stabilized, keeps it positioned within a very controlled and restricted location, and causes it to pull up overhead rather than drift downwind on its tether.
The above figure shows the air rotor concept of airborne wind turbine mentioning all the parts of the turbine.
1.4 WORKING PRINCIPLE OF OUR WIND TURBINE:
The working principle of our project is very easy. The following are the steps which our wind turbine will follow to work:
• Helium would lift the air rotor into air.
• Turbine absorbs energy from the air.
• Convert the wind energy into mechanical energy (torque).
• The shaft of the wind turbine is attached to a gear.
• The gear attached to a generator
• Tether attached to a generator transfer electricity to ground.
By following these steps, the airborne wind turbine will be able to run the generator and thus producing clean electrical energy.

1.5 TYPESOF WIND TURBINES:
Traditional turbines have two basic tpes which are as follow:
• Horizontal Axis Wind Turbine (HAWT)
• Vertical Axis Wind Turbine (VAWT)
1.5.1 HORIZONTALAXIS WINDTURBINE (HAWT):
A turbine in which the axis of rotation is parallel to the free stream wind velocity and the ground. This is the most common wind turbine design. HAWT works on the lift phenomenon, drag is the unwanted force in this design. The blades are designed in such a way that the blade get more lift component till the tip of the blade. These turbines are more efficient in stormy seasons. As the wind moves faster, more lift is generated on the blade. This rotates the blade faster. The following are the advantages and the disadvantages of the HAWT.
Advantages:
• Blades are to the side of the turbine’s center of gravity, helping stability.
• Allowing the angle of attack to be remotely adjusted gives greater control, so the turbine collects the maximum amount of wind energy.
• The ability to pitch the rotor blades in a storm so that damage is minimized.
• Tall tower allows access to stronger wind in sites with wind shear and placement on uneven land or in offshore locations.
• Most of them are self-starting.
Figure 1.4 horizontal wind turbine.


Disadvantage:
• Has difficulties operating near the ground and with turbulent winds because the yaw and bladebearing need smoother, more laminar wind flows.
• The tall towers and long blades are difficult to construct, transport and need a special installation procedure.
• When placed offshore, they can cause navigation problem.
• Noise factor of turbine huge blades during operating.
• They are not birds friendly.

1.5.2 VERTICALAXISWINDTURBINE (VAWT):
A turbine in which the axis of rotation is perpendicular to the free stream velocity and the ground. The vertical axis wind turbine can work on both principles, the lift based VAWT (Darrieus) and the drag based VAWT (Savionus). The Darrieus design has blades which are shape of airfoils, on which lift is generated and rotates in the opposite direction of the free stream velocity. The Savionus turbine has cup or semi cylindrical shape blades on which wind may apply pressure and rotates the turbine. The following are the advantages and disadvantages.

 

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Kabi Kisi ka Dil Mat Dukaio Kion Kh Dilon Me Khudaa Basa Kerta Hay. Be Happy Always.

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Last edited by Intoxicating Boy; 12-01-2013 at 01:08 AM..

[Golden Tears]

itna kon parhy ab

 

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[SIGPIC][/SIGPIC]

[nehastar1]

nice sharing

 

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[Intoxicating Boy]

Originally Posted by nehastar1

nice sharing

thanks

 

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Kabi Kisi ka Dil Mat Dukaio Kion Kh Dilon Me Khudaa Basa Kerta Hay. Be Happy Always.

[pakeeza]

goooooooood

 

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Be Positive... Everything Gonna be Alright

[(‘“*JiĢäR*”’)]

Very Nice Sharing

 

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დ∫დ→◄●♥●►↔ǺήĐằŽ~◊Ệ◊~ßάΫǻЙ↔◄●♥●►←დ∫დ

[Intoxicating Boy]

Originally Posted by pakeeza

goooooooood

thanks

 

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Kabi Kisi ka Dil Mat Dukaio Kion Kh Dilon Me Khudaa Basa Kerta Hay. Be Happy Always.

[Intoxicating Boy]

Originally Posted by JiGaR

Very Nice Sharing

thanks

 

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Kabi Kisi ka Dil Mat Dukaio Kion Kh Dilon Me Khudaa Basa Kerta Hay. Be Happy Always.

[Hassan Raza88]

Hmmmmmmmmmmmmmmmmm