Wind Turbines-Blade Element Theory
16 June 2009 | Wind Power | 1 Comment
Growing energy demand and environmental consciousness have revoked human interest in wind energy.As a result, wind is the fastest growing energy source in the world today.Policy frame works and action plans have already been formulated at various corners for meeting at least 20 per cent of the global energy demand with new-renewables by 2010, among which wind is going to be the major player.
Since the inception of the wind energy technology, machines of several types and shapes were designed and developed around different parts of the world.Some of these are innovative designs which are not commercially accepted.Although there are several ways to categorize wind turbines, they are broadly classified into horizontal axis wind turbines and vertical axis wind turbines, based on their axis of rotation.
What I want to present, especially in this post, is the blade element theory.Blade element theory was initially proposed by Froude and Taylor.In this approach it is considered that the blades are made up of a number of strips arranged in the span wise direction.The strips have infinitesimal thickness.These strips are aerodynamically independent and do not have any interference between them.Under this analysis, the lift and drag forces acting over the strip are estimated and integrated over the total blade span incorporating the velocity terms, to obtain the torque and power developed by the blade.This is further multiplied by the number of blades to get the total rotor torque and power.The blade element theory gives us more understanding on the relationship between the airfoil properties, thrust experienced by the rotor and the power produced by it.
Tags: airfoil properties, Blade element theory, environmental consciousness, fastest growing energy source, global energy demand, horizontal axis wind turbines, new-renewables, total rotor torque, vertical axis wind turbines, wind power, Wind Powered, wind turbines
useful info, thx