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I was doing research about jet engines, and they seem really difficult to fully understand. So, can anyone explain it in a simple way?

Jet Engine Image

How do jet engines work?

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youtube.com/watch?v=eA699AKxT7s I bet my last proton that beast is much closer than you think. –  Jason C Mar 27 at 0:57
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2 Answers 2

up vote 7 down vote accepted

In the simplest of terms:

  • Suck - Air is sucked into the turbine. For efficiency reasons, most aircraft let some of that just pass through the outer part of the fan, rather than through the whole engine.
  • Squeeze - The compressor squeezes that air together to a high pressure. This helps with ignition.
  • Boom - Fuel is injected and ignited. As the air gets hot, it expands.
  • Blow - The hot air drives the low-pressure turbine (driving the whole shaft holding the engine together), sucking new air in, and is itself blown out the back.

jet

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There's a great interactive animated GIF at NASA's K-12 page on jet engines. –  egid Mar 26 at 18:44
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if some of the air bypasses the engine it is called a turbofan engine. but that is semantics –  ratchet freak Mar 26 at 19:05
    
the "suck" part is in effect only at startup/on ground. During cruise is the motion of the aircraft w.r.t. the air that makes the air enter the engine. The fan effectively pushes the air towards the back. –  Federico Mar 27 at 13:43
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A jet engine is an overcomplicated ramjet with extra turbines to let it work at lower speeds.

A ram jet works by igniting compressed incoming by mixing it with fuel and providing a spark.

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hmmm... a ramjet lacks (moving) compressor stages, which are an essential component of a jet engine, and there is no bypass component and most of the time no supersonic flow. So perhaps more distant relatives than siblings? –  yankeekilo Mar 26 at 19:32
    
@yankeekilo that's why I said overcomplicated :) –  ratchet freak Mar 26 at 19:38
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LOL, but then a barrel of fuel and some matches may also claim commen ancestry :D –  yankeekilo Mar 26 at 19:44
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A ramjet is almost totally different from a turbojet (and its derivatives). It lacks a fan/compressor and a turbine, so it would only confuse people to compare them. Once you have a turbojet down, you can look at pulsejets, ramjets, scramjets, and other more esoteric forms. –  Phil Perry Mar 26 at 22:49
    
I don't see why you say it's "overcomplicated" -- it seems that a jet engine is exactly as complicated as it needs to be for its intended operating environment. –  Johnny Mar 26 at 23:43
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