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A gas turbine engine uses a pressurized gas to spin a turbine and compressor. Inside the engine, fuel is ignited to increase the gas’s temperature and pressure. This causes the gas to act on the turbine at a higher velocity. Gas turbine engines are used to power many aircraft and boats and have recently been used in some battle tanks.
A turbine uses the energy of a flowing fluid to rotate a wheel. The concept of a turbine has existed for many years; windmills and water wheels are simple examples. Moving air passes over a windmill’s slanted blades, causing the wheel to spin. Turbines can also be used with steam, as in the case of many power plants. The turbine in a gas turbine engine, however, uses highly pressurized air to rotate.
Norwegian engineer Aegidius Elling was granted a patent for a gas turbine in 1884. His first turbine model that produced more power than it consumed was unveiled in 1903. Elling’s design locked a spinning air compressor to the turbine, a feature widely used today. He believed that if more heat-resistant materials could be found, the gas turbine engine could be used to power airplanes.
The main parts of a gas turbine engine are the compressor, the combustion area and the turbine. Air enters the compressor at normal pressure and then gets compressed. In the combustion area, some type of fuel is burned to increase the temperature and energy content of the air. The high-temperature, high-pressure gas is then forced to exit the engine, turning the turbine on its way out. A solid shaft connects the compressor and turbine—the rotation of the turbine is used to spin the compressor, which makes the engine as a whole more efficient.
The shaft that connects the compressor to the turbine may or may not be used to power additional devices. In a jet engine, the method of obtaining thrust is expelling the exhaust gas at a high velocity, which causes the aircraft to be pushed forward. In vehicles that are not powered by thrust, the spinning shaft can be used to do mechanical work. The M1 Abrams tank of the United States Army uses a gas turbine engine for this purpose. In this case, the flow of gas is used to rotate a shaft that powers the tank’s treads.
A gas turbine engine has several advantages over the type of engine found in most automobiles. First of all, it has a better power-to-weight ratio. Gas turbine engines are also smaller than their automobile counterparts for a given amount of power. These reasons explain why many helicopters and airplanes use this type of engine.
@Logicfest -- engineers have worked on that goose strike problem for a long time with limited degrees of success. The most successful method has been to use multiple engines.
Here's the thing. A goose strike is a rare thing. Let's say you have a plane with four jet engines. It is very unlikely that a goose will show up and disable even one of those engines. But if that happens, the plane can still fly just fine on three engines.
So, one goose strike in a plane is very rare and it is almost impossible for two or more engines to be disabled by suicidal geese.
The performance boost that comes with using these in airplanes is quite obvious. Jet powered planes would be impossible without them and the speed those can achieve made prop powered fighters and bombers obsolete.
But there is one disadvantage that has lingered over the years -- in order to get enough air to compress for thrust, a jet engine has a huge turbine housed at the front of a tube. A goose or something getting sucked into that tube can destroy an engine. The "goose strike" problem is something that engineers haven't eliminated yet and more than a few airplanes have been brought down by junk getting sucked into an engine and destroying it.
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