"Wind technology" for "Non-wind technical" people (2)

This series is for people who are interested to know about wind technology, but they don't actually need a deep knowledge in this topic. or this series can be your start into the wind technology.
you can find the first article of this series here.

now lets talk about the secret behind the wind turbine blade movement. this secret is called "Aerodynamic Forces".

Aerodynamic forces and Basics:

Aerodynamic forces refers to the forces and moments existed on any object that subjected to air flow (did you put your hand out of a moving car window before?!!, then you met aerodynamic forces).

These forces magnitude and direction depends on the body shape, and surface material of the subjected body, and air characteristics (like: speed, direction, density,....etc).

the best shape that develops a good forces to be used is called an Airfoil, you find airfoil in the cross section of an airplane wing, birds wing, sailing boats sails, and of course most of wind turbines blades

YES, you got it, we actually us this forces to rotate wind turbine blades.

Wind turbines classifications:

Wind turbines can be classified by a lot of factors.At first we can define a wind turbine by its size (rated power); their is a micro wind turbine which has a power of few watts, then their is a small wind turbine (house hold) with a power lower than 50 Kw, then a medium size wind turbine with no more than 800 Kw, Large wind turbine with a higher rated power, and finally a mega scalewind turbines.

Wind turbines can also be classified by its rotation axis; Some wind turbines rotate around a vertical axis, and others rotate around a horizontal axis

you can call a wind turbine by its number of blades; like a single-bladedwind turbine, double-bladed wind turbine, three-bladed wind turbine, andmulti-bladed wind turbine.

Their are a lot of other classifications like; Up-wind vs Down-wind, Geared vs Gearless (direct drive), and stall vs pitch controlled wind turbines.

The most common type nowadays for large wind turbines is:
Horizontal axis, three bladed, up-wind wind turbines (HAWT)

I hope you enjoyed it, if so please follow me for more alike articles.

If their is any question or you want to add some interesting info about wind turbines, feel free to reply to this post.

Renewable regards,
Abdelhalim Osama

[photo#1: http://www.aerospaceweb.org/question/aerodynamics/q0194.shtml ]
[photo#2: http://www.windturbine-performance.com/www/types%20of%20wind%20turbines.htm ]
[photo#3: http://www.esru.strath.ac.uk/EandE/Web_sites/01-02/RE_info/wind.htm ]

you can read the original post on linked in here