How Gas Turbine Engines Work

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  • Topic: Jet engine, Gas turbine, Turbine
  • Pages : 6 (2160 words )
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  • Published : December 15, 2012
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How Gas Turbine Engines Work
Inside this Article
1. Introduction to How Gas Turbine Engines Work
2. Types of Turbines
3. Advantages and Disadvantages of Jet Engines
4. The Gas Turbine Process
5. Combustion Area
6. The Turbine
7. Gas Turbine Variations
8. Thrust Basics
9. Jet Engine Thrust
10. Lots More Information
11. See all Modern articles

1. Introduction to How Gas Turbine Engines Work
When you go to an airport and see the commercial jets there, you can't help but notice the huge engines that power them. Most commercial jets are powered by turbofan engines, and turbofans are one example of a general class of engines called gas turbine engines. You may have never heard of gas turbine engines, but they are used in all kinds of unexpected places. For example, many of the helicopters you see, a lot of smaller power plants and even the M-1 Tank use gas turbines. In this article, we will look at gas turbine engines to see what makes them tick! 2. Types of Turbines

There are many different kinds of turbines:
You have probably heard of a steam turbine. Most power plants use coal, natural gas, oil or a nuclear reactor to create steam. The steam runs through a huge and very carefully designed multi-stage turbine to spin an output shaft that drives the plant's generator. Hydroelectric dams use water turbines in the same way to generate power. The turbines used in a hydroelectric plant look completely different from a steam turbine because water is so much denser (and slower moving) than steam, but it is the same principle. Wind turbines, also known as wind mills, use the wind as their motive force. A wind turbine looks nothing like a steam turbine or a water turbine because wind is slow moving and very light, but again, the principle is the same. A gas turbine is an extension of the same concept. In a gas turbine, a pressurized gas spins the turbine. In all modern gas turbine engines, the engine produces its own pressurized gas, and it does this by burning something like propane, natural gas, kerosene or jet fuel. The heat that comes from burning the fuel expands air, and the high-speed rush of this hot air spins the turbine.

3.Advantages and Disadvantages of Jet Engines

So why does the M-1 tank use a 1,500 horsepower gas turbine engine instead of a diesel engine? It turns out that there are two big advantages of the turbine over the diesel: Gas turbine engines have a great power-to-weight ratio compared to reciprocating engines. That is, the amount of power you get out of the engine compared to the weight of the engine itself is very good. Gas turbine engines are smaller than their reciprocating counterparts of the same power. The main disadvantage of gas turbines is that, compared to a reciprocating engine of the same size, they are expensive. Because they spin at such high speeds and because of the high operating temperatures, designing and manufacturing gas turbines is a tough problem from both the engineering and materials standpoint. Gas turbines also tend to use more fuel when they are idling, and they prefer a constant rather than a fluctuating load. That makes gas turbines great for things like transcontinental jet aircraft and power plants, but explains why you don't have one under the hood of your car.

4.The Gas Turbine Process
Gas turbine engines are, theoretically, extremely simple. They have three parts: Compressor - Compresses the incoming air to high pressure
Combustion area - Burns the fuel and produces high-pressure, high-velocity gas Turbine - Extracts the energy from the high-pressure, high-velocity gas flowing from the combustion chamber The following figure shows the general layout of an axial-flow gas turbine -- the sort of engine you would find driving the rotor of a helicopter, for example:

In this engine, air is sucked in from the right by the compressor. The compressor is basically a cone-shaped cylinder with small fan blades...
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