How does a jet engine move an airplane?

Answer 1

It's a four stage process - SUCK...SQUEEZE...BANG...BLOW.

The large inlet fan at the front of the engine compresses the air into a smaller combustion chamber where jet fuel is added and ignited. The resultant hot gassess exit the rear of the engine at high speed producing forward motion by 'pushing' against the air. (Let a balloon go and see the effect of high pressure air pushing against low pressure air)

In military jets an AFTERBURNER can also be used to dump raw fuel into these exhaust gasses just before the final exit nozzle to provide more boost - but this uses around ten times more fuel than full throttle.

Answer 2

Angela, As you know, a jet engine blows a lot of hot air or exhaust out the back. It can do that because of the way it is designed. A jet engine, regardless of the type, sucks a huge amount of air in the front. Fuel is mixed with it and ignited or burned to make the air flow out the back of the engine at a very high speed. The bigger the mass of air and fuel that a jet engine can move, the more thrust or power it can create. The amount of fuel that is being pumped into the engine is also blowing out the back of the engine, although it has been burned. A jet engine is a reaction engine. A little over 400 years ago, a physicist named Newton figured out some interesting properties about objects and their motion. One of the things he found out was that "to every action, there is an equal and opposite reaction". Imagine standing on a skateboard right next to a wall with the front of the skateboard pointing towards the wall. What happens if you put both hands on the wall and push really hard? You and the skateboard roll away from the wall. The harder you push, the further you roll. That movement is a reaction to you pushing on the wall. The wall didn't move, but the force you pushed against it, pushed back against you. And that force moved you away from the wall. A jet engine does the same thing, except it is pushing air and burned fuel out the back. A LOT of it! And it's pushing it out at a very high speed. That action of the exhaust moving out the back 'reacts' against the engine. The engine is attached to the plane with bolts and so the plane moves when there is enough exhaust blowing out the back to create enough force to move the plane. There are many types of jet engines, ramjets, pulsejets, turbojets, turbofans and others, but they all do the same thing. They push air out the back to create thrust, which pushes the airplane forward.

Answer 3

Over the course of the past half a century, jet-powered flight has vastly changed the way we all live. However, the basic principle of jet propulsion is neither new nor complicated.

Centuries ago in 100 A.D., Hero, a Greek philosopher and mathematician, demonstrated jet power in a machine called an "aeolipile." A heated, water filled steel ball with nozzles spun as steam escaped. Why? The principle behind this phenomenon was not fully understood until 1690 A.D. when Sir Isaac Newton in England formulated the principle of Hero's jet propulsion "aeolipile" in scientific terms. His Third Law of Motion stated: "Every action produces a reaction ... equal in force and opposite in direction."

The jet engine of today operates according to this same basic principle. Jet engines contain three common components: the compressor, the combustor, and the turbine. To this basic engine, other components may be added, including:

A nozzle to recover and direct the gas energy and possibly divert the thrust for vertical takeoff and landing as well as changing direction of aircraft flight.

An afterburneror augmentor, a long "tailpipe" behind the turbine into which additional fuel is sprayed and burned to provide additional thrust.

A thrust reverser, which blocks the gas rushing toward the rear of the engine, thus forcing the gases forward to provide additional braking of aircraft.

A fan in front of the compressor to increase thrust and reduce fuel consumption.

An additional turbine that can be utilized to drive a propeller or helicopter rotor.

Answer 4

Let me expand on that a little for you.
Air is drawn into the front of the engine be large fans and be forward movement. The fans compress the air and feed it into the combustion chambers. The are located around the circumference of the engine. Here jet fuel (paraffin basically) is introduce and ignited. This heating of the already compressed air causes it to expand away from the incoming air and out of the back of the engine with great force causing thrust. The expanding air as it exits the engine is made to flow over a turbine causing it to spin. This turbine is on the same axle as the compressor at the front. So it is the escaping exhaust gas that drives the compressor at the front of the engine.

Answer 5

A jet engine is an engine that discharges a fast moving jet of fluid to generate thrust in accordance with Newton's third law of motion. This broad definition of jet engines includes turbojets, turbofans, rockets and ramjets and water jets, but in common usage, the term generally refers to a gas turbine used to produce a jet of high speed exhaust gases for special propulsive purposes. Jet engines are so familiar to the modern world that gas turbines are sometimes mistakenly referred to as a particular application of a jet engine, rather than the other way around.

Answer 6

You forgot one important phase. It goes Suck, Squeeze, Bang, Blow. Think of a jet as a tube with 4 distinct sections. We'll igone the internal parts for a bit and concentrate on the concept of how it actually produces its thrust.

First stage: "Suck" There are turbines (fans) that suck air into the engine. Most of this air is routed around the engine, but about 15% is sent through into the next section

Second Stage: "Squeeze" this is nothing more than a series of turbines (fans) lines up one after another with baffles in between them. The air that was sucked in is squeezed down to a fraction of its original volume.

Third Stage: "Bang" this is where the compressed air is mixed wiuth fuel and ignited. It works much the same as a rocket at this point. Fuel and air are combined and burned. Expansion is the result. Because there is only one hole in the combustion chamber (at the back) all the gasses exit there.

Fourth Stage: "Blow" All those hot gasses expanding out the back gain a LOT of velocity by going through a relatively constricted space (think of putting your finger over the end of a hose) and exit really really fast. As they push out, newton's third law (Which states that for every action there is an equal and opposite reaction) dictated that the aircraft is moved forward with the same amount of force that the engine exhaust shoots backward. This exhaust gas turns a turbine that is attached to the fans at the fron of the engine and spins them, which is how the compression gets its power

Thats a jet in theory. In reality, it gets a bit more complicated. the compressor section is typically divided into two sections with a shaft coming from each and running directly back to the turbines at the back. The first one is typicall referred to as N1 and is the large fan you see when you look at an engine. Most of what it does is ssend air around the outside of the engine. This is called bypass air and is where most of the thrust of the engine actually comes from. The second compressor, known as N2, takes a small amount of the air from the N1 section and compresses it even farther (up to 36 times in some engines) and sends this air to the combustion chamber.

After combustion, the exhaust is routed across the two turbines and spin their respective compressors (N1 and N2). most of the energy from the actual combustion is used up here. It is spent spinning the compressor section up at the fron, both to deliver more air to the combustion chamber and to accelerate the bypass air around the outside of the engine. The aft turbine Spins the N1 compressor so fast that about 80-85% of the engine's thrust is actually produced by the bypass air that is ducted around the outside of the engine.

Answer 7

a pure jet engine pushes out large amounts of hot air produced by burning compressed air-fuel mixture

airliners have bypass engines that suck air through fans as well as push hot air at the exhaust .
displacing the air makes the engine go and push forward.

Answer 8

The same way that air rushing out of a filled balloon moves the balloon throught the air when released from your hand. If that balloon had wings/fins that you could -somehow control- steering the balloon through the air would be possible for the short time that it would have in the air (due to its limited supply of squashed air).

Answer 9

Get Discovery Wings dude. Tuesday night is Jet night, everybody knows that!

Answer 10

combustion, Oxygen is needed to ignite a spark which, when mixed with fuel, makes that spark and all the exhaust is forced out through a chamber at the back of the engine, which causes it to move forward...