Forum: Modern Military Aircraft

[quote="That_Engine_Guy"][quote="johnwill"]TEG, Could you confirm the data above from your May 12 post concerning SFC. It appears that the AL-31F uses less fuel per pound of thrust than does the -229. At least that's how I read it, as pounds per hour of fuel per pound of static thrust. If that's true, it is surprising.

Maybe BPR explains it. Do you have that comparison? Thanks.[/quote]
Yes, you're reading it right, if the public numbers are to be believed.

I do imagine the better MIL SFC has to do with the engines' respective BPR, one also has to consider the OPR. The PW-229 has LOTS more compression.

J@ne'$ has the MAX SFC of the PW-229 a little lower than that of the AL-31F, but still so close it would hardly matter. One has to take these figures with a grain of salt. They are taken from 'public' sources, (J@ne'$, OEM sites, Military FACT sheets, etc) and as such may be subject to propoganda, marketing ploys, or intentional mis-information.

[quote="J@ne'$"]AL-31F Mass Flow 247lbs/s, BPR 0.571, OPR 23.5 MAX SFC 1.96lb/h/lb st

F100-PW-229 - Mass Flow 254lbs/s, BPR 0.36, OPR 32.4, MAX SFC1.94 lb/h/lb st[/quote]
They don't cite the MIL SFC for the PW-229 at J@ne'$, other sources do show the AL-31 has a lower MIL SFC than the PW-229; and I'd have to agree.

[quote="haavarla"]The AL-31F has other specs now.[/quote]
Yes, you're correct, but weren't we talking about the AL-31F? Specifically.

[quote="haavarla"]completly de-militariezed, but with complete set of AL-31F engines and batch of spare parts.[/quote]
[quote="haavarla"]They are rated with more thrust than Mr TEG states here.
With that in mind, they probably gobbles more fuel too..[/quote]
True, but they also have different 'Dash' numbers; -31FP, -31FN-M1, and -31F-M3...
[quote="J@Ne'$"]
MAX thrust: 27,557 lb st
(all production versions prior to AL-31FN-M1)
AL-31FN-M1: 29,760 lb st
AL-31F-M3: 31,970 lb st

Maximum dry:
AL-31F 17,305 lb st
Later versions 17,857 lb st

SFC MAX thrust 1.96 lb/h/lb st
Maximum dry:
AL-31F 0.666 lb/h/lb st
AL-31FP 0.67 lb/h/lb st
AL-31FN 0.705 lb/h/lb st[/quote]
I was strictly talking the AL-31F model and not the more advanced AL-31's installed in NEWER Flanker types; I didn't feel they were worth mentioning as our discussion pertained to the old Flankers in question.

Guess I should mention the F100-PW-232 that was tested up to 37,000lb st? Or that at 32,500lb st it was to have an SFC of 1.91 lb/h/lb st at MAX but an even lower SFC at MIL due to the high-flow fan derived from the F119's technology and an OPR of 35/1!?! Cool

No need, i wasn't aware that the AL-31F had lower fuel consumption over the 229.
That's all.

B.t.w.
I have serious troubble quote tag others post text!
What am i doing wrong?

Thanks

F-16.net Sponsor

@haavarla: Looks like you're missing some closing tags--> [/quote] . For every [quote] there needs to be a close tag. Like this:

[quote]Here is a quote[/quote]

You can use the Preview button to check how your post will look, just go to Post Reply instead of using "Quick Reply."

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Prinz_Eugn wrote:

Do you have disable BBcode or HTML checked when you post?

Testing!!

Ok, i think i got it now.
Thx

Back on the AL-31F Engine, i've heard/read on several forums that the AL-31F have a very high fuel consumption over other engine in the same class..

I have actually never seen any specs/figure before now.
But it seems to be the comon understanding among many people who write a lot on div forums.
So i was thrown off a little here..

Where did u get those data on that fuel consumption TEG?

Do you have any other fuel consumption data on newer AL-31F engine?

Thanks

That_Engine_Guy wrote:

skyhigh wrote:

I wonder if the F100 could power the purchased Su-27s, because the Saturn-Lyulka AL-31F turbofan (Russian equivalent of PW F100) is made in Russia by NPO Saturn and I don't think they'll sell a handful of them to us.

Agreed, support for the F100-PW-229 would be much better than that of the AL-31F. Consider the age of the AL-31F, new build AL-31F engines are no longer produced for the Flanker, and I'm unsure how friendly the Russians will be providing "new" AL-31FNs for a "civil" US customer.

...Considering that company is providing training against their aircraft to anyone willing to pay the $$s? Shrug

Now the bad news... Crying or Very sad

Look at the photos below, the AL-31F has a top mounted gearbox, where the F100 series engines have a bottom mounted gearbox. I figure a MAJOR redesign of the engine bays would be required to run an F100 in place of the AL-31. (Or a very expensive "custom" set of F100s...)

But for comparison sake... (to the best of my resources)

AL-31F (as installed in early SU-27s)
MAX Thrust: 27,557 lbs
MIL Thrust: 17,305 lbs
Length: 194.7"
Max Diameter: 48.82"
Inlet Diameter: 35.8"
Weight: 3,373 lbs
MAX SFC: 1.96 lb/h/lb st
MIL SFC: 0.666 lb/h/lb st

F100-PW-229 (As available today @ $5M each!)
MAX Thrust: 29,100 lbs
MIL Thrust: 17,800 lbs
Length: 191.2"
Max Diameter: 46.5"
Inlet Diameter: 34.8"
Weight: 3,795 lbs
MAX SFC: 2.060 lb/h/lb st
MIL SFC: 0.762 lb/h/lb st

So while a pair of shiny new F100-PW-229s would physically fit into the engine bays of the SU-27 (almost exactly) and the -229 makes about the same power; the differences in gearbox placement would make the procedure cost prohibitive.

Not to mention you'd need $20 Million AND US DoD approval to purchase said F100s from PW. (They can't just sell them on the street without governmental approval)

It was still a cool thought! Cool

Keep 'em flyin' Thumb

TEG

TEG, do you have anything on the 117-S from Jane's?

Thanks

Haavarla wrote:

anything on the 117-S from J@ne's?

Only a little...

J@Ne'$ wrote:

"The 'Product 117S' is an in-depth upgrade of the AL-31F, featuring a 14.5 tonne [31,967 lb -Ed.] thrust, which is 2 tonnes above the baseline"

"The 117 is the thoroughly modernised AL-31F with a new fan of diameter increased from 905 to 932 mm ([36.69 in, -Ed.] and with maximum afterburning thrust increased from 122.58 kN to 137.3 kN [30,866 lb, Ed.] (or 142.2 kN [31,968 lb, Ed.] at special rating)."

" The designer's main objective is to increase service life from 1,500 to 4,000 hours, and to increase TBO from 500 hours to 1,000. After meeting these parameters, expected in 2008-09, the engine will be manufactured in series as the 117S (S for series) or AL-41F1. NPO Saturn's proposal has the advantage that "present AL-31F or FP engines can be upgraded to 117S standard by replacing 25-30 per cent of engine elements".

I wonder if 'special rating' is like the V-MAX was on older F100 engines?
IE - Use it for more than 5 minutes, then tear down the engine for a new high pressure turbine? Doh

Wow a 1000 hour TBO? Laughing

4000 hour engine life? LMAO

The newest F100-PW-229 'EEP' engines are 6000 cycles or about 10 years!

PW wrote:

...extends the amount of time between scheduled depot maintenance from an average of seven to nine years to more than 10 to 14 years, depending on utilization rates. This increase is expected to reduce life cycle costs by 30 percent over the life of the engine.

Keep 'em flyin' Thumb

TEG
(EDIT - Added photo of -117S)

parrothead wrote:

According to what I've read they've got factory support and a good supply of spare parts Wink

The Ukraine has their own manufacturing and maintenance facilities located at Lutsk to support the AL-31F. I would assume that any contract for the sale of the Su-27's to a third party would, of necessity, include a maintenance contract for engine support.

I could add that the Ukraine has also come under some criticism from Moscow, for supplying technical support for the AL-31F and other engines to the Chinese - whom Moscow would like to keep as an exclusively Russian customer (without the technology transfer that China craves and that the Ukraine is apparently willing to provide).

haavarla wrote:

The AL-31F has other specs now.
They are rated with more thrust than Mr TEG states here.

The improved performance versions are being developed in Russia, not the Ukraine. The contract for the supply of these aircraft was exclusively with the Ukraine.

That_Engine_Guy wrote:

Wow a 1000 hour TBO? Laughing

4000 hour engine life? LMAO

The newest F100-PW-229 'EEP' engines are 6000 cycles or about 10 years!

I have to agree with your sentiment. The Russians were able to compete with the West on a performance basis - even though their materials and other manufacturing technology was decades behind - by accepting lower component lives.

For what its worth, the AL-31F reportedly has double the useful service life of the RD-33 that powers the MiG-29. The Indian Air Force was reportedly very unhappy with the reliability that the saw from their MiG-29 squadrons during the Kargil War - as compared to the readiness rates for the Su-27 and Su-30 units. I wouldn't be surprised if the engine was a contributor to that impression.

[quote="tmofarrvl"][quote="parrothead"]

That_Engine_Guy wrote:

Wow a I have to agree with your sentiment. The Russians were able to compete with the West on a performance basis - even though their materials and other manufacturing technology was decades behind - by accepting lower component lives.

For what its worth, the AL-31F reportedly has double the useful service life of the RD-33 that powers the MiG-29. The Indian Air Force was reportedly very unhappy with the reliability that the saw from their MiG-29 squadrons during the Kargil War - as compared to the readiness rates for the Su-27 and Su-30 units. I wouldn't be surprised if the engine was a contributor to that impression.

Yep, in witch case speak highly of both Saturn and MMBPP SALUT. For turning a product into something far better.

http://www.salut.ru/ViewTopic.php?Id=662

AL-31FM1:
Design modular
Maximum thrust, kgf 13500
Minimum specific fuel consumption, kg/kgf*h 0.685
Air consumption, kg/s 118
Inlet diameter, m 0.924
Maximum dimension, mm 1140
Maximum length, m 4.945
Dry weight, kg 1520

Are these data correct TEG?

Forum: Modern Military Aircraft

Two Su-27 Flankers sold and shipped to the U.S.A.