Forward Acting Thrust

[donnlass]

In How Airliners Fly it shows the workings of a jet engine and states:

"The fan, which is encased in a cowling, forces the compressed air backwards in the form of a jet, much in the form of a domestic electric fan. The engine itself experiences an equal and opposite force and this is the forward acting thrust which propels the aircraft".


If the thrust is coming out forward from the engine, how come the aircraft still flies forwards?:confused:

[TURIN]

Newtons 3rd (I think) law of motion.

For every action there is an equal and opposite reaction.

Propel a mass of air rearwards and the resultant force (thrust) is forward.

Simples. :ok:

[wiggy]

If the thrust is coming out forward from the engine, how come the aircraft still flies forwards?

Read "How Airliners Fly" again. What they are saying is the air expelled from the engine is going backwards, but the thrust (i.e. the force) produced by the engine is acting in a forwards direction, i.e. it's pushing the aircraft forwards.

[WASALOADIE]

By pushing all that air through the engine rearwards, the engine sucks it way forwards

[donnlass]

I will do:ok:

Thanks all for your patience and replies, I get it now:ok:

[Lord Spandex Masher]

Although the action of producing thrust does produce a rearward force in the engine!

[Load Toad]

Isn't there a bloody big vacuum in front of the engine...?

[Lightning Mate]

Although the action of producing thrust does produce a rearward force in the
engine!

Not so I'm afraid.

The compressors and the diffuser section, amongst others, produce forward thrust. The turbine section produces a rearwards force. :)

[Lightning Mate]

This should help your understanding.......

http://i636.photobucket.com/albums/uu82/Lightning_29/jetthrustConverted.jpg

[donnlass]

Should have a Reply With Quote Button on here but anyway:p


So the total forward gas load less the rearward gas load produces total forward thrust?

[Lord Spandex Masher]

Although the action of producing thrust does produce a rearward force in the
engine!


Not so I'm afraid.

The compressors and the diffuser section, amongst others, produce forward thrust. The turbine section produces a rearwards force. :)

So it does then...Unless I missed the bit where my turbine isn't in my engine;)

[Lightning Mate]

So the total forward gas load less the rearward gas load produces total forward
thrust?

Well, if you think I am incorrect, check the Rolls Royce book, upon which my diagram above is based.

If you think it's wrong, then please feel free to put Rolls Royce on the right track!!!!

[donnlass]

No I dont think you're wrong at all, am not qualified to think that:)