What is a Turbine?

Michael Anissimov
Michael Anissimov

A turbine is a type of engine that can extract energy from a fluid, such as water, steam, air, or combustion gases. It has a series of blades, typically made of steel but sometimes ceramic, that can withstand higher temperatures. The fluid goes in one end, pushing the blades and causing them to spin, then gets ejected out the other end. The fluid leaves the engine with less energy than it had going in — a portion of the difference is captured by the turbine.

Turbines have been used to generate electricty from working fluids in power plants for over a century.
Turbines have been used to generate electricty from working fluids in power plants for over a century.

Turbines are at the core of civilization, since practically every form of electric power is generated by them. When people say coal power, nuclear power, hydrothermal power, etc., they are referring to using some energy source to agitate a gas that then drives the blades and generates power. It is one of the most common types of engines, where an engine is defined simply as something that takes an input and generates an output. Along with heat engines and motors, turbines make up the vast majority of dynamic machinery.

Aircraft jet engines compress air and mix it with fuel to power combustion and create thrust.
Aircraft jet engines compress air and mix it with fuel to power combustion and create thrust.

Gas turbines are one of the most flexible type, and they are used to power a variety of mobile machines above a certain size, jets being the most famous application. Even the Space Shuttle uses one to combine fuel at tremendous rates. Because they can spin at extreme rates, gas turbines allow a huge amount of power to be packed in a relatively tiny space. A typical engine of this type operates between 3,000 and 10,000 rpm, and smaller variants can climb above 100,000 rpm. A recently constructed matchbox-sized one spins at 500,000 rpm and generates 100 watts. Scientists want to push them to operate at a million rpm or above, but making this possible without melting the assembly can be tricky.

The axis of a turbine is lined with rotating blades that either compress fluids or are turned by them.
The axis of a turbine is lined with rotating blades that either compress fluids or are turned by them.

To extract the greatest efficiency from turbines, they are often chained together. This can lead to efficiency levels of 60% or higher, quite amazing in the world of thermodynamics. Understanding the operation of these engines in detail is the province of mechanical engineers, though anyone who works with machines is probably familiar with the basics.

Wind turbines depend on the speed of the wind to produce energy.
Wind turbines depend on the speed of the wind to produce energy.
Michael Anissimov
Michael Anissimov

Michael is a longtime wiseGEEK contributor who specializes in topics relating to paleontology, physics, biology, astronomy, chemistry, and futurism. In addition to being an avid blogger, Michael is particularly passionate about stem cell research, regenerative medicine, and life extension therapies. He has also worked for the Methuselah Foundation, the Singularity Institute for Artificial Intelligence, and the Lifeboat Foundation.

You might also Like

Readers Also Love

Discussion Comments

anon312326

What are the parameters that help in increasing the efficiency of a turbine?

anon162654

How can the efficiency increase if we chain the turbines together? And what are the different kinds of turbines?

- weezy

Em4ce

Efficiency can be increased by "chaining" turbines together because it increases the rotational power, thus you can spin a larger generator and supply a larger load (which is really your resistance to rotation).

Of course, there are many other things involved such as the steam loses its power as it goes further on spinning the rows of turbine blades - so the blades have to get longer and eventually the steam needs to be "re-energized" and is sent back to a reheating source (boiler) before it goes on to the next turbine.

Em4ce

Different kinds of turbines are steam, gas (and jet engines), and wind and water. They are all similar and designed to best use their "fuel" medium.

To produce electrical power they must turn a generator (which is like a opposite of a motor). The rotating element must be a magnet, either permanent or electromagnet. The slower the medium spins the turbine the more magnets are needed.

Typical is a large steam turbine that turns at 3600 RPM, and the rotating electromagnetic has two poles (or a north and south magnet).

Em4ce

A generator can be used to spin a motor (electrically) which in turn could be shifted to replace the initial "prime mover," but due to natural loses it would shortly stop if no other outside additional power is applied, i.e., there is no perpetual motion machine.

Even if this were possible all you would get is a spinning machine and as soon as you tried to use the spinning to produce power to siphon off, you would be in the hole and it would stop.

anon56202

can an electrical generator run another without a power source once it has been started up, therefore creating continuous power without a source?

anon47394

there is a wind turbine but what does it exaclty do?

vijaya

How can the efficiency increase if we chain the turbines together?And what are the different kinds of turbines?

Post your comments
Login:
Forgot password?
Register: