Turbine

[hasri]

Can anyone help me out here.... do any of u guys know what is the common name for the turbine area of a jet engine? and also..what is a reverse flow combustion area?...

[gas path]

Turbine section would do as a description could also be broken down into high pressure and/or low pressure (or indeed intermediate pressure in the case of the RB211).
A reverse flow combustion chamber is used primarily to reduce the overall length of the engine used mostly on the smaller gas turbines a good picture and description HERE (http://www.chinook-helicopter.com/standards/areas/engine.html)

[Milt]

"The Hot End" will do for most purposes !!

Just loved the piano accompanying the sectionised engine in the last post.

[hasri]

thanks for the information...im sorry, but its kinda hard for me 2 understand that one..hha i juz started gettin into these kinda stuff and the qs i saw in a book that i couldnt answer was that one..what is a reverse flow combustion chamber..haha...hmm..is it the Whittle combustion chamber?..i understand that had the reverse flow combustion chamber..hmmm...help me!!!..its killing me!!! BTW,im new here, and i reckon this is the most AWESOME- MOST website...hv learnt alot here...cherios guys!!!!!!!

[Bally Heck]

Canon in D by Pachelbel. Nice innit.

[coolape]

The turbine is basically a rotating fan that extracts the energy from the hot gas flow which are expanding rapidly to rotate the compressors and sometimes other accessories.

The basic engine must have 4 elements:
Suck -> Squeeze -> Bang -> Blow.

meaning

Air Intake -> Compression -> Ignition / Combustion -> Exhaust

the Turbine operates within the combustion chamber section.

Hope this helps.

*EDITED*

There are different types of turbines,
-Single Stage
-Tripple Stage
-Free power contra-rotating turbine,

but they all operate in the same principle.

[egsc_h17]

To clarify, in a reverse flow combustion chamber the fuel and compressed air enter and combust in the opposite direction to the compressor intake. The hot gases then change direction once again to drive the turbines and exit out the back.

As another poster explained, this has the advantage of packing the combustion path into a smaller space (length wise) and also accelerates the hot gases before they reach the turbine stages. The disadvantage is the extreme heat to which the gas flow diverter is subjected.

Rob

[lomapaseo]

Disadvantage is also diameter if anyone was thinking of applying this concept to a fan/reverser engine.

[barit1]

There are different types of turbines,
-Single Stage
-Tripple Stage
-Free power contra-rotating turbine,

but they all operate in the same principle.

These are but a few of the many types I've encountered.

First - identify how many independent spools there are in the engine:

e.g. Single spool - J85, J79, TPE331, T56 etc.
Twin spool - J57/JT3D/JT8D/JT9D, CF6, T58, T64, CT7, PT6, PW120 etc.
Three spool - RB211, Trent etc.

Each spool rotates mechanically separate from other spools in the engine, therefore each spool needs a turbine section to drive it. A twin spool engine has 2 sections - High Pressure and Low Pressure. A three-spool engine adds an Intermediate pressure section.

Each turbine may have from 1 to 6 or 7 stages of blades.

And they may all rotate the same direction, or counter-rotate.

So just the basic type definition must consider all these factors.

[hekokimushi]

hi guys.

can anyone confirm the various stages of a Jet turbine's gas velocity and pressure are correct in the following statements??
V = velocity, P = pressure
Suck: Low V Low P
Squeeze: Low V High P
Bang : High V High P
Blow: High V Low P (with bypass) << ??

thanks.

nelson