Jet Engine Temperatures

[TheWanderer]

Does anybody know the maximum temperatures inside modern jet engines?

I mean max temperatures inside the combustion chamber of the engine, not the EGT that pilots can read from their instruments as the EGT is already a somewhat cooler temperature further to the end of the engine.

I have read about temperatures exceeding the range of 1.300 K, as well as temperatures as high as 2.000 K with new modern cooling technics to cool the walls of the combustion chamber.
Are those possible numbers?

Thanks.

[gas path]

For the RB211-524 at take off power:
430psi 1400 deg C :8

[lomapaseo]

Are we talking metal temperatures or stoichrometric gas temperatures?

need background for question

[muduckace]

As I beileve the op understands that EGT is just a sample of a temperature (not the hottest the engine produces) and is different mainly on probe placement on different engines, sorry wanderer I have no resources to answer your question.

[Intruder]

The GE CF6 and others measure EGT -- Exhaust Gas Temp -- which is after the LP turbine. Some other engines measure ITT -- Interstage Turbine Temp, between the HP and LP turbines -- so there is not a completely common standard. The CF6 max of 960C EGT will give you another reference. However, that is more on the order of 650-700C in cruise.

[Bolty McBolt]

Does anybody know the maximum temperatures inside modern jet engines?


Have checked my notes,
the RR RB211-G/H shows fuel nozzel flame temps at approx 1400 Deg C and a Turbine Inlet gas temp prior to the NGVs at above 1350 Deg C

The G.E. CF6-80C/E only give "idle" figures of 540 Deg C gas temp & metal temps of the combustor and 1st Stg turbine

:ok:

[PappyJ]

"Are those possible numbers?" Yes

[muduckace]

Turbine engine manufacturers are probably not keen on sharing temps throughout the engine, the development of alloy's to deal with the higher temperatures modern engines produce by more efficiently taking advantage of the suck bang blow theory.

[lomapaseo]

Turbine engine manufacturers are probably not keen on sharing temps throughout the engine, the development of alloy's to deal with the higher temperatures modern engines produce by more efficiently taking advantage of the suck bang blow theory

Not much secret in this stuff, what with engineers moving around in the industry.

I notice that the original poster never came back to clarify what and why he was interested in.

[barit1]

The GE CF6 and others measure EGT -- Exhaust Gas Temp -- which is after the LP turbine.

Not so, dear friends. DESPITE being labeled "EGT", the thermocouple probes on the CF6 and CFM56 are located BETWEEN the HP and LP turbine stages and should in fact be called ITT. If they were behind the LPT, (a true EGT location), they would read several hundred degrees cooler! :uhoh:

[Pugilistic Animus]

/without the long rigmarole that accompanies:

I'll just say that thermodynamically [2nd law] for any heat engine that the best efficiency is obtained by making the max operating temp as high a possible and the exhaust as cool as possible,..and have every step in the cycle reversible

the problem is that for 100% effeciency you have to either have infinite temperature or an exhaust temperature of Absolute Zero:}

furthermore, if each step were reversible it would take infinite time to complete a cycle :}:}

[Landroger]

Sorry guys, but you are all answering like engineers. Why has a 747 got four engines? Because the engineers haven't figured out where to put a fifth.

Wanderer asked the question - slightly skewed its true, 1300K is way too low, 300K is about room temperature;



Does anybody know the maximum temperatures inside modern jet engines?

I mean max temperatures inside the combustion chamber of the engine, not the EGT that pilots can read from their instruments as the EGT is already a somewhat cooler temperature further to the end of the engine.

I have read about temperatures exceeding the range of 1.300 K, as well as temperatures as high as 2.000 K with new modern cooling technics to cool the walls of the combustion chamber.
Are those possible numbers?

Thanks.



And Gas path answered it;


For the RB211-524 at take off power:
430psi 1400 deg C



And you know why he is asking, cos' its all to do with your volcanics, ain't it? :)

Anyone here know the rule of three?

To a Computer Geek, 3 is 2.9999999999999.

To an Accountant it is 2.843 plus 17.5% VAT

To a Physicist it is 3.00000 +/- 0.00001

And to an Engineer, it is 27 - just to be on the safe side. :)

Roger.

[CONSPICUITY]

Hi
The temperature of the gasses released by the combustion chamber on modern engines can be in the range of between 1800 to 2000 deg C as this is to high to be impinged on the nozzle guide vanes at the turbine section it is progressively cooled by adding air which was not used in combustion process approx 50%. The temperature of the gas flow entering the turbine is between 850 to 1700 deg C