Ok Guys ,
Here's some pics of the insides of a turbine, completely stripped down

some more pics

Thanks Xantos was waiting for this, with this probably we'll have a jet section dedicated,
For the rest
Jet is a very simple design, problem is dynamic balancing and the metallurgy, IMg 5452 is the turbine, to it's tip the compressor ( this one is centrifugal compressor , another type is an axial multistage compressor) is connected , 5445 is  compressor, 5449 is a 'Can' type combustion chamber, another type is annular and another one is canannular,
The air from centrifugal type compressor exit 90 deg to the entry and the stators 5447 reduces the swirl and the diffuser 5446 converts this kinetic energy to pressure
Constantly burning air fuel mixture in the combustion chamber5449 & 5453 uses this compressed air and burns the fuel, impacts the turbine which in turn rotates the compressor, 60% of the energy is used up by the compressor  rest is the jet velocity which due newtons third law propels the aircraft,

Question to all(don't refer the Internet) which part of the sub parts in a jet engine produces thrust? Tell me the reason too

what a lovly thing

Hi
I think it is the Exhaust that produces the trust as it pushes the air out at more than 1000 km/hr.

Cheers

+1 Asupan.

but there is something to Add. the Special 'conical Shape' of the Exhaust is what produces the thrust, with help of the 'Turbine' which also act as one way 'Valve'. The expanding gas due to the combustion in the chamber tries the escape. This expansion is sustained till the exit at the exhaust, and let the actual expansion occur at the periphery of the Exhaust.

Looks as trivial as the entire engine itself, but the design of the Exhaust is so, so critical that even the best design of other parts (compressor, combustion chamber, fuel injection etc) cannot compensate for its poor implementation. One of my friend did his entire PhD on jet exhaust design and he now works at Goddard  Flight center.

Thanks for sharing this Santosh. This very evening I disassembled my first ever Glow engine. The Jet engine looks comparably simpler than that. But indeed there is a sky of difference in Metallurgy, fabrication and tolerance.

Gusty sir and Santosh, how does it feel to spin a mighty monster like gas turbine engine with your finger tips ? I can trade my music collection for the scream from their exhaust. The sound sets my adrenaline soaring with every AJT/Jag/Bison/LCA test flying over my office and Appt.

Pics and thread, courtesy , nandan, thanks

For larger intestest taking it to the thread below, was wanting to do it for a long time

http://www.rcindia.org/fuel-and-engines/basics-of-jet-engine/msg74736/#msg74736

Hey Nandan,
They are great pictures. Have you open the engine for the interest of fellow aeromodelers? .....

Oh my god , u opened the turbine engine? 
great sir.......
will increase practical knowledge about turbines....
although i read about turbines in course work but never saw a opened these smaller turbine......

obviously , the nozzle part...

the reason being......
it is shaped to accelerate the flow of hot gases....
might be they are using convergent - divergent type nozzle...

Nope not the nozzle or exhaust, let me repeat the question , which part propels the airplane forward.? Let me list the subparts of a jet engine starting from front 1. Compressor 2. Diffuser 3. Combustion chamber 4. Turbine 5. Exhaust nozzle

Your answer has to have a logic as well, don't be shy to shoot

Please use jet engine basics thread for your answers (link above)

Hi Guys,
Sorry my mistake while uploading , I thought i could label/identify parts after uploading.Unfortunately I could not edit.
Any ways Turbine principle very very simply in 4 words is Suck Squeeze Bang and Blow.
The compressor wheel like the name indicates sucks and squeezes(pressurizes) air in the combustion chamber which is then ignited with precisely metered quantities of Fuel (Bang).
Resultant ignition results in massive expansion of gases which are then directed out of the tail cone by the turbine wheel at velocities in excess of 1500kmph thereby providing thrust for flight.
Now the difficult part is how to do this consistently and reliably from idle to max thrust.
This is done by the FADEC ECU which  is connected to the fuel pump commanding it to meter fuel as per the required conditions.
This is a fairly complex algorithm but one of the main parameters that the ECU monitors is the EGT and the RPM which is indicative of the combustion taking place.
Some basic info on this turbine , its a Wren 70 , the 70 indicates that it puts out 70 Newtons of thrust ~ 14.5 lbs. The compressor and turbine wheel are 54mm in Dia. The idle rpm is 55000 and max rpm is 155000 rpm
Maybe Augustine can step in now and take it further

Quote from: augustinev on August 16, 2011, 09:20:03 AM
which part propels the airplane forward.? Let me list the subparts of a jet engine starting from front 1. Compressor 2. Diffuser 3. Combustion chamber 4. Turbine 5. Exhaust nozzle

If you dont consider the nozzle to increase the EGV, then the propulsion happens due to the Turbine at near the exit, which  become the object on which the'Equal and opposite reaction' acts, due to hot gasses rushing out of the engine, thus the propulsion.

Good explanation, if the exhaust gas velocity increases in a particular part of the engine , will it increase the thrust? Point to ponder

That has been a design challenge for different types of Engines (Turbo Props and Heli engines are Turbines engines, but a different implementation). The optimal dimension according to the engine capacity, Idle/Max RPM etc are the the key constraints and parameter. Make the nozzle too big, you don't get the thrust, make it too narrow, and you would choke the engine.

I am commenting on the design of Jet engine way beyond my qualification. Its all based on the description I got my friend in Jet Engine design.

Quote from: augustinev on August 16, 2011, 09:20:03 AM
Nope not the nozzle or exhaust, let me repeat the question , which part propels the airplane forward.?

i still think , nozzle is the answer. if not , then plz instruct me.
as the exhaust hot gases exert equal force in all directions, providing forward thrust as they escape to the rear. As the gases leave the engine, they pass through a fan-like set of blades turbine . turbine is connected  by a shaft to turn the blades in the compressor and to spin the intake fan at the front. so i think , turbine can not be the correct answer.

Quote from: augustinev on August 16, 2011, 03:59:49 PM
Good explanation, if the exhaust gas velocity increases in a particular part of the engine , will it increase the thrust?

i think no, it will not affect the thrust value.
reason i think is the law of conservation of momentum....
if velocity increases , then mass will decrease and as we know that thrust depends upon mass and velocity of hot gaseous both. so no effect .

"WOOSH"

That was the sound of the discussion going over my head !

Simply may I vote for combustion chember as enthalpy increases here and the chemical energy changes form of other energy (initially heat) and then during exhause from nozzle, adabitic expantion reduces the temp but increases the volume and as the heat value increases, it creates thrust.

Sorry, if I mislead as I have read all those before a decade and not a mech. guy.

Quote from: aditya on August 16, 2011, 06:09:17 PM
i think no, it will not affect the thrust value.
reason i think is the law of conservation of momentum....
if velocity increases , then mass will decrease and as we know that thrust depends upon mass and velocity of hot gaseous both. so no effect .

hi aditya i think u dont need to worry about the mass change (Net Mass is Always constant). coz in fluid dynamics what we really care about is rate of flow of mass.

So keeping that in mind Bernoulli's theorem gives a better explanation. If u consider the sum of pressure head and velocity head is constant. so if inside the engine we have gasses at very high pressure and low velocity. when these gasses are directed through the nozzel. the gasses expands. thus the pressure decrease here and the velocity increases.

P.S.( Head means its unit value to keep it simple)

answer plz.........

Xantos , have you tried a Thrust Augmenter on the engine?

Hi Akshay,
I dont know what you mean by Thrust Augmenter - I think you are referring to Wren's tailpipe design.
It does not augment the thrust but apparent prevents thrust decay due to the tailpipe. The tailpipe as is commonly known, is a steel tube used to direct the hot efflux from the turbine outside the airframe. Upto a 10% decay in thrust is not uncommon in most installations.
Basically it a single wall tailpipe with a varying diameter near the beginning of the pipe . Ive used it on my little Savex L-39.
Wren claims a minimal loss in thrust.
Hope this helps.
Xantos

Impressive !! Just checked the Wren's specs and compared to AMT,, wren gives you more bang for the buck!!
Where do you fly jets in mumbai? Would love to see it!!

-akshay

P.S:- I stay at Bandra.