Introduction

Hydropower is called the energy of the water which, through waterfalls drives turbines for electricity generation.The utilization of water power was taking place from antiquity through watermills for grinding cereals and cutting timber.

1.1 Definition of the Water Turbine

A water turbine is a rotary engine that takes energy from moving water,as simple as that. Water turbines are used to extract energy from moving water, typically for production of hydroelectricity. They operate by forcing water past slanted blades, which spin the turbines. Water turbines can be mechanically attached to machinery or to an electric generator.

dietrick_clip_image004.jpg

Figure 2:Kaplan turbine and electrical generator cut-away view.

1.1.1 History of water turbines

Water wheels have been used for hundreds of years for industrial power. Their main shortcoming is size, which limits the flow rate and head that can be harnessed. The migration from water wheels to modern turbines took about one hundred years. Development occurred during the Industrial revolution, using scientific principles and methods. They also made extensive use of new materials and manufacturing methods developed at the time. The word turbine was introduced by the French engineer Claude Burdin in the early 19th century and is derived from the Latin word for "whirling" or a "vortex". The main difference between early water turbines and water wheels is a swirl component of the water which passes energy to a spinning rotor. This additional component of motion allowed the turbine to be smaller than a water wheel of the same power. They could process more water by spinning faster and could harness much greater heads. (Later, impulse turbines were developed which didn't use swirl). The earliest known water turbines date to the Roman Empire. Two helix-turbine mill sites of almost identical design were found at Chemtou and Testour, modern-day Tunisia, dating to the late 3rd or early 4th century AD. Johann Segner developed a reactive water turbine (Segner wheel) in the mid-18th century in Kingdom of Hungary. It had a horizontal axis and was a precursor to modern water turbines. It is a very simple machine that is still produced today for use in small hydro sites.

1.2 Purposes and Objectives

The purpose of this paper is the reader to obtain as much as possible knowledge of water turbines.So our goal is to find information,as best as possible, and put them in this site so that any reader can understand and learn about water turbines.An important objective also is the accessibility of this work for anyone interested. So is written in English and it is available and open for all people.