Su-57 intakes, supercruise performance and 2nd stage engine

Wil said:
If the Saturn 117 has ~2.5 tnf more thurst than the Al-31, this implies the real thrust of Saturn 117 is 16-17 tnf, similar to the trust of F-119.
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That depends on which Al-31. with the right al-31, that implies 15 tnf

Wil said:
Please look at this picture. Do you really think that this engine is less powerful than the F-119?


http://imageshack.us/a/img89/1340/pakfaatras1.jpg


Best wishes!
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When I develope the superpower needed to divine engine thrust from photographs, I'll let you know.
 
flanker said:
By all accounts i have heard Al-41 was a terribly unreliable bastard, and it never achieved designed trust. I remember "15 tons" at max for some reason, unsure where from or if it is correct.
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Yes, it was a real dog - VABI with FADEC with _full_ hydraulic redundancy that never exceeded 14.4 tons at stand in real life. But I'm sure that given time and money it would become a hot thing.
 
chuck4 said:
When I develope the superpower needed to divine engine thrust from photographs, I'll let you know.
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So where then did you get the following?

Chuck4


..while F-119's fan diameter is over 1000 mm, probably in the region of
1100mm.
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I'm not being difficult, I'm genuinely interested to know the F-119's fan diameter.

Correct on the current PAK FA's engine currently being about 15 000kg thrust, based on the baseline AL-31, going on public statements from the aircraft and engine designers.
They have stated though that there will be development, currently ongoing, to increase this to the levels discussed above in the thread.
 
Don't know if they mentioned it but the last of 507 built was delivered yesterday. :(
 
I predict that the 117 engine will allow supercruise around Mach 1.2 - 1.3, the newer engine allowing Mach 1.5+.


I also note that the F119 could be fitted (with minor mods) in the F-15 engine bay, which mean maximum diameter can't be much larger than F110.
 
PaulMM (Overscan) said:
I also note that the F119 could be fitted (with minor mods) in the F-15 engine bay, which mean maximum diameter can't be much larger than F110.
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Where did you get that info? :eek:
 
http://www.f-16.net/f-16_forum_viewtopic-t-12537.html


As already stated, the F135 is much larger than the F100/F110 engines. It is also larger in diameter than the F119. The airflow requirements for the F135 will be much larger too. Without airflow, the F135's thrust would drop dramatically. On a side note, the F119 would not fit into the Viper, but could fit into the Eagle as it's engine bays (with minor production modifications) as they had extra space in them to begin with. (Space has always been a constraint in the Viper) The Eagle's inlets are also much more capable of handling the additional airflow of an advanced engine.
 
PaulMM (Overscan) said:
http://www.f-16.net/f-16_forum_viewtopic-t-12537.html


As already stated, the F135 is much larger than the F100/F110 engines. It is also larger in diameter than the F119. The airflow requirements for the F135 will be much larger too. Without airflow, the F135's thrust would drop dramatically. On a side note, the F119 would not fit into the Viper, but could fit into the Eagle as it's engine bays (with minor production modifications) as they had extra space in them to begin with. (Space has always been a constraint in the Viper) The Eagle's inlets are also much more capable of handling the additional airflow of an advanced engine.
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Well TEG knows his stuff. :)
 
Interesting figures again, Paul.
So I take it the F-119 fan diameter is not public knowledge?
Quite strange considering the F-135 is.
 
PaulMM (Overscan) said:
F-135 figures from http://www.pw.utc.com/Content/Press_Kits/pdf/me_f135_pCard.pdf

Inlet diameter: 43 inches (1.09m)
Maximum diameter: 46 inches (1.17m)

Maximum afterburning thrust : 43,000lb
Maximum dry thrust: 28,000lb

Even though the F135 produces 20% more thrust and weighs 1,500 pounds more than the F119
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43,000lb / 1.2 = 35,833lb
28,000lb / 1.2 = 23,333lb
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And the F135 has produced 50,000lbs+ according to P&W. Also, I think it would be incorrect to assume the difference between mil/max is going to be the same given their different bypass ratios. The ratio for the F119 is probably more like 26k/35k. One other thing that stands out is I recall reading that in order to make the F135 cheaper they changed materials in the combustor and/or turbine reducing the gas temperature. This means that the F119 is going to get more per pound of airflow than the F135.
 
FWIW, Paul "Max" Moga, the first official F-22 demo pilot said the F119s make 37,000lbs each on the discover channel series he did.
 
BDF said:
FWIW, Paul "Max" Moga, the first official F-22 demo pilot said the F119s make 37,000lbs each on the discover channel series he did.
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And Paul Metz said the F-22 will do better than 1600 mph. Good luck getting anybody to believe the words of a pilot though. ;)
 
sferrin said:
BDF said:
FWIW, Paul "Max" Moga, the first official F-22 demo pilot said the F119s make 37,000lbs each on the discover channel series he did.
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And Paul Metz said the F-22 will do better than 1600 mph. Good luck getting anybody to believe the words of a pilot though. ;)
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With the invention of the internet and its associated experts, you no longer need pilot opinion. ;D
 
Not true! If the pilot has been flying a Eurofighter and getting gun kills willy-nilly against F22s.....then you are allowed to believe. Otherwise, all pilots are shills for Lockheed. :D
 
chuck4 said:
Wil said:
If the Saturn 117 has ~2.5 tnf more thurst than the Al-31, this implies the real thrust of Saturn 117 is 16-17 tnf, similar to the trust of F-119.
Click to expand...

That depends on which Al-31. with the right al-31, that implies 15 tnf
Click to expand...


Official data from Sukhoi:


http://img10.imageshack.us/img10/6738/saturn117s.jpg


The engine of PAK FA, the Saturn 117 is more powerful than Saturn 117S (of Su-35).

A little math:


Thrust of Saturn 117 = Thrust of Saturn 117S + 2.5 tnf = 14 tnf + 2.5 tnf = 16.5 tnf


Bingo!! B)


The F-119 engine has technology created 20 years ago... Russia has no problems in creating something similar, is only a matter of $$$...
 
Wil, I think you are mistaken about the thrust increase over which AL-31 variant.

It seems that the additional thrust was measured against the standard AL-31 baseline engine, as fitted to the Su-27.

This ties in very neatly to the officially released thrust of the PAK FA's engines of 33 000lb.

We should take this figure as this is what was officially released.

Also of interest:

It seems that these current engines of the PAK FA, giving 33 000, are known as the AL-41F1 (117).

Having a little dig around, the 117 designation seems to be the inhouse designation for the engine based on the AL-31 core.

Ilya Fedorov, Managing Director of Saturn has stated that the "product 117" is the first stage engine. This is the engine currently in PAK FA at 147kN.
The second stage engine is called "product 129".
This engine is described as being new, with inferences being drawn that this will include a new core.
The thrust for this second stage "product 129" engine is mooted to be around 107kN dry and 176kN maximum afterburning.


It is difficult to sift through the information, particularly the confusing designations.
Looking at the above, some things do perhaps make sense.
The 117 appears to be a referral to the 2 upgraded engines using the AL-31 engine core.
These are the AL-41F1 (117) as used in the PAK FA currently.
AL-41F1A (117S) as used in the Su-35BM. From descriptions, this appears to be perhaps a downspec'd version of the PAK FA's engines. It would certainly make sense from a designation point of view.

Then, we have the aircraft designer, and the engine designer both stating that the PAK FA's engines are totally new, and that it will be a true 5th generation engine. The engine manufacturer is talking about these engines being tested or fitted to the PAK FA in 2014-2015.
This makes sense if we assume this to be the more powerful "product 129".

Excuse the speculation, but the engine story and trying to figure it out from the various statements is proving to be torturous, but intrigueing.

Opinions?
Or have I got my tail before my nose? :p
 
sferrin said:
And the F135 has produced 50,000lbs+ according to P&W.
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On a bench test it did, they also said the exhaust nozzle on the production engine can only take 43,000lb so the extra thrust is not usable in service. Doubtful that running the engine at utter max thrust does good things to its service lifespan, any jet engine can be tuned for higher thrust if you ignore that issue.
 
Sea Skimmer said:
sferrin said:
And the F135 has produced 50,000lbs+ according to P&W.
Click to expand...


On a bench test it did, they also said the exhaust nozzle on the production engine can only take 43,000lb so the extra thrust is not usable in service. Doubtful that running the engine at utter max thrust does good things to its service lifespan, any jet engine can be tuned for higher thrust if you ignore that issue.
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What in the world would be the point of running an engine ten seconds from explosion and then announcing it to the world? ::)
 
kaiserbill said:
Wil, I think you are mistaken about the thrust increase over which AL-31 variant.

It seems that the additional thrust was measured against the standard AL-31 baseline engine, as fitted to the Su-27.

This ties in very neatly to the officially released thrust of the PAK FA's engines of 33 000lb.

We should take this figure as this is what was officially released.
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From NPO Saturn:

"The max thrust (of "117") has been increased by a couple of tons compared to it´s predecessor "117S" for the Su-35 fighter"...

See 4:43 of this video:

http://www.youtube.com/watch?v=JVJny6UL6V8


Max thrust of Saturn 117S: 14.5 tnf

Source:

http://npo-saturn.ru/?sat=64&slang=1

This implies the Max thrust of Saturn 117: ~16.5 tnf

Best wishes!
 
sferrin said:
Sea Skimmer said:
sferrin said:
And the F135 has produced 50,000lbs+ according to P&W.
Click to expand...


On a bench test it did, they also said the exhaust nozzle on the production engine can only take 43,000lb so the extra thrust is not usable in service. Doubtful that running the engine at utter max thrust does good things to its service lifespan, any jet engine can be tuned for higher thrust if you ignore that issue.
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What in the world would be the point of running an engine ten seconds from explosion and then announcing it to the world? ::)
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As Sea Skimmer alludes, the "point" would likely have been a "triple red line" stress test and why NOT announce the result - the implications will be lost on the vast majority of people. It's the same with any rating beyond 34000 pounds (which is already severely life limited) for the F100/F110 or the 100000 pound maximum quoted for the current Trent XWB during bench testing - they are NOT in any way, shape or form indicative of useful operational performance.
 
Sea Skimmer said:
About the same points all destructive testing and corporate propaganda have.
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This sounds like tinfoil hat territory. They don't publicize destructive testing results.
 
If the F135 can generate 50,000 lbst, why has P&W not proudly offered this as a no-risk upgrade?

Several likely reasons. The rating may not be compatible with design lifetime. It may involve a huge degree of A/B boost (beyond the normal 70 per cent realm for turbofans). It may be available only at static, with installed thrust and temperature limits cutting in at higher speeds, where the thrust is useful.

Also ISTR that P&W was dismissive of the utility of extra thrust for the B, because it would mean redesigning the lift system.

Otherwise, comparing the F119 with the F135 is difficult because the F119 has a lower bypass ratio. For the same size core, this reduces static intermediate thrust somewhat, and A/B thrust considerably, because there is not enough oxygen at the back of the engine to achieve a 70 per cent augmentation ratio. But it's better for specific thrust (lbst per lb of air) in intermediate, which is what is needed for supercruise.
 
LowObservable said:
Several likely reasons. The rating may not be compatible with design lifetime. It may involve a huge degree of A/B boost (beyond the normal 70 per cent realm for turbofans). It may be available only at static, with installed thrust and temperature limits cutting in at higher speeds, where the thrust is useful.
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Or maybe the JPO hasn't asked them to or it has been discussed informally but decided against - remember that even proposals cost money to prepare.
 
Well, I read somewhere that izd 20 has already variable bypass (like YF-120).
But it was heavy - for large plane, and using old technology.
So I assume also izd 30 will have such. There are such information :
https://www.aviaport.ru/digest/2020/03/20/631483.html

"Важной особенностью конструкции, обеспечивающей получение новых возможностей, является изменение степени двухконтурности."
"An important design feature that provides new opportunities is the change in the degree of bypass."
 
LukaszK said:
Well, I read somewhere that izd 20 has already variable bypass (like YF-120).
But it was heavy - for large plane, and using old technology.
So I assume also izd 30 will have such. There are such information :
https://www.aviaport.ru/digest/2020/03/20/631483.html

"Важной особенностью конструкции, обеспечивающей получение новых возможностей, является изменение степени двухконтурности."
"An important design feature that provides new opportunities is the change in the degree of bypass."
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It can also means simple bypass ratio change. e.g from 0.7 to 0.8. As larger engine means larger diameter and that allows for increasing bypass ratio.
 
«… У АЛ-41Ф был регулируемый смеситель. Этого недостаточно для эффективного управления двухконтурностью, это был первый шаг. Кстати, в процессе испытаний до него не добрались, он на всех 28 машинах стоял на упоре (не работал).

А недостаточно этого было вот почему. Просто грубо затыкать дырку на выходе второго контура не требует перераспределения работы газогенератора между турбиной вентилятора и турбиной компрессора. Этим и занимаются регулируемые НА ТНД (Направляющий Аппарат Турбины Низкого Давления). Поворачиваясь на закрытие, они увеличивают перепад давления на ТНД, а соответственно и работу на ней. Увеличение располагаемой работы приводит к увеличению расхода воздуха. При этом желательно ещё регулировать и входные сечения обоих контуров после вентилятора. В общем, нужна развитая механизация проточной части, а это вес, надёжность, да и электроника в те времена хреновая (плохая) ещё была. Вкратце так. »
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paralay said:
«… У АЛ-41Ф был регулируемый смеситель. Этого недостаточно для эффективного управления двухконтурностью, это был первый шаг. Кстати, в процессе испытаний до него не добрались, он на всех 28 машинах стоял на упоре (не работал).

А недостаточно этого было вот почему. Просто грубо затыкать дырку на выходе второго контура не требует перераспределения работы газогенератора между турбиной вентилятора и турбиной компрессора. Этим и занимаются регулируемые НА ТНД (Направляющий Аппарат Турбины Низкого Давления). Поворачиваясь на закрытие, они увеличивают перепад давления на ТНД, а соответственно и работу на ней. Увеличение располагаемой работы приводит к увеличению расхода воздуха. При этом желательно ещё регулировать и входные сечения обоих контуров после вентилятора. В общем, нужна развитая механизация проточной части, а это вес, надёжность, да и электроника в те времена хреновая (плохая) ещё была. Вкратце так. »
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So, the izd. 20 was intended as a VCE but it never got the variable BPR feature actually working? How true are the values reported in an article above about BPR being variable between 0.2 and 0.4?

Ideally the max BPR value for izd. 30 should be a bit higher for optimal subsonic flight and given the engine manages to at least maintain the TSFC of the AL-31F, probably a BPR of at least 0.5 looks realistic in my perfectly ignorant opinion...
 
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From what i have read, not much of anything worked on Izd.20...

Attached just a nice pic. The first, and the last prototype. (although technically T-50-10 flew after -11)
 

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icyplanetnhc said:
It appears that the AL-41F1 (izdeliye 117) is not quite as "interim" as many have believed; while I think there was always a longer term goal of equipping the aircraft with new engines, it appears that the plan has always been for the PAK FA to enter production and serve in combat units with the AL-41F1, and this was decided as far back as 2004. In fact, it appears that Sukhoi's T-50 submission for the PAK FA had the AL-41F1 from the very beginning. This is an interesting contrast with the Su-27, where the T-10 prototypes used the AL-21, but the revised T-10S and the production aircraft were equipped with the AL-31 from the beginning.
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I mean, yeah? That was well known for anyone who has followed the program decently and knows about Al-41F1 beyond the meme of iT iS jUsT a SoUpEd uP Al-31F. It has supposedly very different characteristics at altitude (aka for "supercruise") for example and 80% of the parts are all new. Back when T-50-1 first flew and RuAF higher ups were so optimistic they claimed there would be 50 serial T-50's by 2020, all powered by Al-41F1.

Also, the capital U in the title of that book annoys me to no end. It is Su-57 goddamit. It is always Su.
 
In spite of the limitations of the F-22, I’m rather amused by those touting the superiority of the Su-57 as 5.5 generation or even better. The premise of arguing that the Su-57 is a half generation over the F-22 assumes many of the Su-57’s attributes from the “Megalopolis” upgrade program, which represents the planned Su-57M variant that hasn’t even finished development. The izdeliye 30 engines being an example. Some of the claims put forth are also purely speculative. No source has ever stated that the izdeliye 30 engine is variable cycle. The airframe design of the Su-57 represent a different set of requirements, with range and payload being higher priority compared to the F-22.

Some of the points listed also seem like advertising talking points. Fixed inlet? “Advanced lift augmentation devices?” So what? I frankly don’t even see a tangible benefit of the former; the latter is pretty marginal.

EDIT: What is "oversizing airflow" supposed to mean? Have you considered spillage especially at supersonic speeds?

In any case, the debate over a comprehensive MLU of the F-22 within USAF stems more from economy of scale rather than the physical limitation of the airframe itself. Perhaps the F-22’s airframe doesn’t have the potential to reach what USAF is looking for in the NGAD, but it’s quite presumptuous to somehow equate this as an example of the Su-57’s superiority; whose to say the Su-57 can meet NGAD requirements any better?

Before simply handwaving away the differences in stealth between the two aircraft, industry sources that I’ve spoken with have alluded to the Su-57’s LO design lacking features for the S-band, in contrast to the F-22. Certainly this would be a limitation for maritime strike.
 
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Pretty sure the Idz-30 will NOT be a variable cycle engine. I have not seen anything that suggest it.
But that does mean it won't be an advanced and high performance jet engine.
 
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