Turbine, TUR bihn or TUR byn, is a device with a rotor turned by a moving fluid, such as water, steam, gas, or wind. A turbine changes kinetic energy (energy of movement) into mechanical energy (energy in the form of mechanical power). Such energy can be used to run machinery. Mechanical energy is transmitted by a turbine through the spinning motion of the rotor's axle.
Turbines provide power for a variety of machines. Generators driven by turbines produce most of the electric power used to light homes and run factories. Turbines that power water pumps play an important role in irrigation projects throughout the world. Turbines are also used to turn the propellers of ships, and they are an essential part of jet-airplane engines.
The earliest known turbines date back to simple water wheels used by the ancient Greeks about 2,000 years ago. Today, turbines vary greatly in size and power, depending on their use. For example, a huge turbine that turns an electric generator can deliver nearly 750 million watts of power. But some turbines used to run shop machinery measure less than 1 inch (2.5 centimeters) in diameter and deliver under 750 watts. Turbines less than 1/5 inch (5 millimeters) in diameter may someday power microengines designed to output 20 to 100 watts.
