Rotor Blades Used In Wind Turbines

Rotor Blades Used In Wind Turbines

INTRODUCTION:

The energy of the wind airflow is efficiently converted into a rotating motion by the sophisticated shape of the rotor blades. The rotor blades are fixed to the rotor hub, which are placed directly on the main shaft causing it to rotate. This rotating motion is accelerated in a gearbox to drive a high-speed generator producing electricity.

The rotors thus convert rotational motion of the rotor blades into electrical energy. Thus rotors have a great importance in the design and working of a windmill. . On a modern 1000 kW wind turbine each rotor blade measures about 27 metres (80 ft.) in length and is designed much like a wing of an aeroplane.

Working of a Rotor Blades, attached to the turbine rotor, convert power (kinetic energy of the wind) from the air flowing through the turbine and make the rotor turn. This rotational energy passes on to the energy converter--typically an electrical generator.
The energy production of a turbine depends on the diameter of the rotor and the wind strength. Hence it can be seen that larger the diameter of the rotor blades more the energy that can be harnessed. Here another consideration is the size of the generator used, a large blade diameter is used with a large generator so as to produce more energy, if a small generator were to be placed there would be unnecessary wastage of power. Modern wind turbines use high efficiency airfoil shaped blades that extract energy from the wind by generating aerodynamic lift. Air flowing over the airfoil generates two forces: lift, perpendicular to the airflow; and drag, in the direction of the airflow. Air flowing over the top of the airfoil creates a lift force, which causes a slight decrease in pressure that forces the airfoil 'upward'.

The amount of upward force depends on the length of the airfoil, velocity of the air, and the angle at which the air meets the airfoil or the angle of attack.

for more info visit.
http://www.enjineer.com/forum