I found this video to be informative on how a jet engine works. This guy does a great job of explaining the path of the air intake and fuel and combustion.

This is how a Jet Turbine works:

Suck squeeze bang blow.

I wrote a thesis once for when I got my A&P a few years back. Not all turbine engines are alike.

What's an A&P?

Ofcourse, there's different turbine engines, like turbojets, turbofans, turboshafts, turboprops, but the basics are the same. You need lots of air (suck), you compress it (squeeze), you ignite it (bang) and you force it out (blow).

And same principle of all internal combustion engines: suck-queeze-bang-blow




you can bypass the 1st min.

A&P = Airframe and powerplant mechanic. Its an FAA certification authorizing work on aircraft.

And yes, the basics are the same, but the physics arent. In turbojets and turbofans, the compression/combustion is converted to thrust energy, while in turboprops/turboshafts, the compression/combustion is converted to torque energy. Turboshafts and turboprops have more in common with turbos than they do with turbofans and turbojets.

Take my word...don't argue with an A&P about A&P issues...it's always a losing proposition... 

Im only an A&P by certification only. I just work at Lockheed building the next gereration of whoopass.

oh no... an another word to learn...    ok somebody can tell me what means whoopass?

LOL...KICKING ASS...it's a red neck way of saying he's doing something that's bad ass

Its been a while since anybody choked me, so my neck isnt that red...

Actually, its just a fancy word I give it for machines that are designed to dominate. They "whoop ass". For example: F-22 whoops ass, AC-130U whoops ass, F-14...self explodes and does not whoop ass in any way, AH-6 Loach whoops ass, Robinson R22 does not whoop ass.

LOL 

Hitman, more in common with turbo's? I don't understand, turbo is just forced induction, which is one of the basic operating principles for turbine engines, so how come a turboshaft/prop could have more in common with the basics than the basics of a turbojet/fan. It's exactly the same, right? Turbo is just a stage in every turbine engine.

Let me guess...even basics are same, the main difference would be propulsion?

Turbos in naturally aspirated engines use the same mechanics as turboprops to get more work out of the engine. The end results are different, but the physics are the same. The impeller in a turbo pushes more air charge into the cylinders to create a higher manifold pressure (in aircraft, they just help maintain atmospheric pressure above 14,000 feet in civilian aircraft). It uses the thrust of the hot exhaust gases to drive the impeller, which compresses more cold air into the cylinders. Not many people know or realize that a turbo is just a very crude jet engine.

In turbos, the impeller is exhaust driven that does all the work. Same thing with turboshaft engines: the exhaust thrust drives the shaft, which in turn drives the propellers and blades, which propels the vehicle forwards. In turbojets and turbofans, the exhaust is what propels the vehicle forward.

Think of it like this: you are blowing wind on a fan, and the fan blades turn as a result. Its the exhaust thrust that provides the torque to the shaft by blowing highly compressed air at high velocity that turns the fan. This is essentially what a turboshaft and turboprop engine does. Its not that simple, but thats just the best, easiest way I can think of to describe how they actually function.

In turbofans and turbojets, the compressor section provides cool, highly compressed air at low velocity to the ignition chamber. The ignition chamber creates thrust by superheating that cold air instantly, which creates extremely low pressure, extremely high velocity thrust.

Little known fact: its the shape of the exhaust nozzle that determines the velocity of the air flow in a jet engine. If you have ever wondered why fighter aircraft nozzles are closed shut at max military speed before they go supersonic, its because the convergent shape of the nozzle (fully closed) has the maximum thrust/minimum pressure required. Bernoulli's principals get flipped backwards after supersonic speeds. A divergent shaped nozzle (fully open) at supersonic speeds do the exact same thing. Same thing goes for the intake ducts. The airflow has to be subsonic to produce thrust at supersonic velocity to get supersonic speeds. After it reaches supersonic, I get kind of lost because its been a while since I last did research on this.

 Hey thanks Hitman. Very interesting!  Ok let me revise... ...manifold...above 14k ft...hum..low pressure high velocity......convergent nozzle, Bernoulli flipped backwards....be subsonic at supersonic thrust...  

Ok let me revise again... ...manif...abo...

 gotcha

Ok, hitmans revised edit of how turboshaft is different than turbojets:
Tubroshaft blows hot air onto fan. Fan spins. Helicopter goes up.
Turbojets blow hot air. Plane goes forward.

(A/229) Hitman wrote:Ok, hitmans revised edit of how turboshaft is different than turbojets:
Tubroshaft blows hot air onto fan. Fan spins. Helicopter goes up.  
Turbojets blow hot air. Plane goes forward.

  I was just jocking. Thanks to take care.  

Nicely put Hitman...I take back my "red neck" comment...that is whoop ass

I know exactly how turbines work Hitman, but I didn't know how a car's turbo works. Didn't realize a turbo's impeller was driven by exhaust gasses. Makes sense now.

But still, basicly in turbojets and turbofans the 'turbo' (compressor stage) is also driven by those same exhaust gasses?

They are, but they arent either. The sole purpose of the combustion rotors are to force the escaping exhaust at a higher velocity, with the exception of the R1. The R1 rotor turns the N1 fan on high bypass turbofan engines. The compressor is driven mostly by the N1 fan intake...basically the engine just huffs itself to life. The APU supplies this force of air at startup in turbofans and turbojets until combustion. Correction - the R1 and R2 rotors turn the N1 fan. In some Rolls Royce engines, R3 drives it as well. The stators in the combustion turbine wheels in turofans are solely for increasing the velocity of the escaping gases.

Like I said, I know how turbines work, but aren't stator vanes there to streamline the airflow? How do they increase velocity?

And I might've forgotten, cuz it's been like 7 years since I've gotten the classes on turbines, but what are the R1, R2, R3 stages? I'm only familiar with the Nx-stages.

Stator vanes do straighten out the air flow, but you also have to remember that stator vanes are airfoil shaped to increase lift. Stator vanes are also mechanically linked to each other, and their pitch can be controlled mechanically to increase the amount of lift. Lift is basically a low pressure zone above the airfoil and a high pressure zone below the airfoil. The bottom of the vanes are pointing towards the compressor section, while the top of the vanes are pointing aft. Just like a propeller on a prop job, you can increase velocity by changing the pitch of the stator vanes.

R1, R2, and in some engines, R3, are the rotor vane turbine wheels in the hot section.

(A/229) flyer wrote:Nicely put Hitman...I take back my "red neck" comment...that is whoop ass

I choke myself all the time! I take it back...I do live in GA, after all!  

As any aviator worth their salt would (or should) know, its what exactly keeps your aircraft in the air. On the upper suface of the control surface, is a low pressure zone. Below that control surface is a high pressure zone. Which force is greater?

A) Low pressure above the wing
or
B) High pressure below the wing