A Ducted Horizontal Wind Turbine for Efficient Generation

Abstract

This chapter investigates ducted turbines for the use of wind power generation. The interest for this grew from the ever increasing demand for energy. After investigating the nature of the three bladed wind turbines, it became apparent that the machines were not very efficient, expensive and have a limited fatigue life. The ducted twin turbine wind power generator is proposed in this chapter and a comparison in performance has been carried out between the ducted turbine and the conventional turbine. The ducted turbine has the ability to accelerate the air flow through a converging intake thereby increasing the power that can be extracted from the air flow. As the wind passes through a converging duct the velocity increases while the pressure decreases. The power extracted has a cubic relationship to wind velocity where as the relation to pressure is linear. The need for energy consumes our society. As technology has advanced in certain areas the ability to produce power has had to keep pace with the ever increasing demands. There always seems to be an energy-crisis weather contrived or real, and society allows the pollution of our environment in the name of power production. Power production with traditional means has polluted our planet. Hydro power dams release carbon that was locked up in the trees and plants that were drowned during the filling of the dam. Any sort of fossil fuel powered plant releases carbon into the environment during the combustion process. Nuclear plants are generally unpopular and will not be accepted in New Zealand for a very long time. Renewable, environmentally friendly, clean, safe, even wholesome, are the types of adjectives we should be using to describe power production. Wind energy is the closest we may have at present that may be considered to fit into those criteria. Certain aspects such as noise and blade flash are a concern. The ducted twin turbine is proposed in this report as an environmentally friendly, safe alternative method of power production from renewable sources. The ducted twin turbine wind power generator is proposed in this chapter and a comparison in performance has been carried out between the ducted turbine and the conventional turbine. The ducted turbine has the ability to accelerate the air flow through a converging intake thereby increasing the power that can be extracted from the air flow. As the wind passes through a converging duct the velocity increases while the pressure decreases. The power extracted has a cubic relationship to wind velocity where as the