Wind Propeller Blade

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WIND PROPELLERS BLADE

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SUBMISSION DATE:
02.01.2012

CONTENTS
1. The Functions and Objectives of Wind Propellers Blade
2. Mechanical and Physical Properties of Wind Propellers Blade 3. Material Properties of Wind Propellers Blade
4. Different Materials for Airplane Wings
5. References

1. The Functions and Objectives of Wind Propellers Blade

FUNCTION OF WIND TURBINE BLADE
Wind flows over a propellers blades it creates lift and makes them turn. But there's more to it than that. Making electricity from wind actually involves a two-step process. A wind turbine converts energy from wind into mechanical energy. This is done as the blades on the turbine turn a drive shaft. The drive shaft is connected to a generator that converts the mechanical energy into electricity, according to the U.S. Environmental Protection Agency. A wind turbine requires maintenance twice a year, advises the EPA. A well-maintained turbine will last about 20 years. Wind energy turbines are broadly classified into two varieties namely, the horizontal-axis type and the vertical-axis type. The classification is based on the orientation of the axis around which the turbine rotates. The horizontal wind turbine rotates around a horizontal axis and is the common variety largely used to generate electricity. A horizontal-axis turbine mainly consists of a rotor shaft, two or three blades and an electric generator. The blades are pointed in the direction of the wind. The movement of the blades moves the shaft mechanically and the generator connected to the shaft uses this mechanical energy into electricity. Thus the electricity produced is directly proportional to the speed of wind, rather the speed of the propeller blades. Some advanced wind energy turbines use a gearbox to turn the slow rotation of the blades into a faster rotation to ensure an efficient driving of the electrical generator. Wind turbines that are mounted on a high tower, say hundred feet capture the most energy as the wind at such a height is less turbulent and much faster. Turbulence is usually produced behind a wind turbine tower and that is why the turbine is normally pointed upwind of the wind tower. To prevent the wind turbine blades from being pushed into the tower by heavy winds, the wind turbine blades are usually made very stiff. Besides, the blades are tilted a little up and placed wide apart in front of the tower to prevent forcing into the wind turbine tower. The downwind type is also built as they do not require the additional mechanics for holding the blades in the direction of the wind. In high wind, however, the wind resistance is reduced due to the fatigue failures thus pulling down its efficiency. The horizontal-axis wind turbines can again be divided into 3 subtypes like the 12th century windmills, the 19th century windmills and the modern wind turbines, the last one being the most evolved and modernized device Vertical-axis wind turbine has the main rotor shaft vertically oriented. Thus this turbine does not require to be pointed in the direction of wind to be effective. This is a big advantage in areas where wind direction is variable and unpredictable too. Wind from different directions is easily and efficiently utilized by the vertical-axis wind turbines. Besides all these advantages the vertical-axis wind turbine has some basic limitations (cannot be installed on high towers due to the huge size) which clearly discourage the large scale usage of this device to generate electricity.

Clean Energy

Wind energy makes use of turbines to produce electricity without producing waste or polluting the environment. With a design based on the traditional windmill, energy-producing wind turbines provide power when the wind turns the blades which, in turn, spin a shaft connected to a generator. Typically, turbines are erected in large numbers, close by and in areas known for consistently high winds to create what are known as...
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