turbine

A turbine is a machine that extracts energy from a flowing fluid and converts it into rotary motion. In most turbines, moving fluid exerts forces on blades mounted on a rotor, creating torque that can drive a generator, a compressor, or other machinery. Turbines are used across power generation, propulsion, and mechanical drives, and they can be driven by steam, gas, water, or wind.

Steam turbines use high-pressure steam produced in a boiler to impart momentum to turbine blades, causing the rotor to turn as steam expands and cools through several stages. Gas turbines compress air, mix it with fuel, burn it to produce high-temperature high-pressure gas, which expands through turbine stages to produce shaft power. Hydroelectric or water turbines use the energy of flowing or falling water to turn the turbine; common types include Pelton (impulse, high head), Francis (mixed-flow, widely used), and Kaplan (axial, adjustable blades). Wind turbines convert the kinetic energy of wind into rotational energy via large rotor blades, connected to a generator through a gearbox or direct drive.

Turbines may be classified by flow type (axial, radial) and by operating principle (impulse vs reaction). Impulse turbines rely on the jet to impart momentum with minimal pressure change on the blade, while reaction turbines develop lifting forces from pressure changes along the blades. Material and cooling requirements limit turbine temperatures and performance, influencing efficiency and lifetime. The modern steam turbine was developed in the 1880s by Sir Charles Parsons; gas turbines followed in the 20th century, enabling modern aviation and power plants.