Sukhoi T-50 PAK FA manouverability versus F-22

[chuck4]

chuck4, okay, I see that weapons on F-22 are tucked behind the intakes. Still, the fact that the T-50 splits the fuselage into 3 volumes unlike F-22 which has one large volume indicates better area ruling and thus lower drag. Naturally, this should allow the T-50 to outperform the F-22 aerodynamically (supercruise, sustained turning) when the T-50 gets the second stage engine.

As for lift, what is certainly clear is that the T-50 have a much bigger lifting surface than F-22. Also, the F-14 which has widely spaced engine and tunnel like the T-50 can fly with one wing fully swept and one wing fully extended and even land on a carrier like that, so its fuselage must also produce a lot of lift like F-15.

For consideration of area rule, T50 does not have three volumes. It has one single very lumpy volume, with three of the lumps being particularly prominent. f-22 has one single somewhat less lumpy volume, with one single big lump. It is by no means clear which plane's geometry come closer to the ideal Sears haack cross sectional area distribution. I would guess, if anything, F-22 come closer.

Also, area rule seems to be most important for rapid transit through transonic region. Presumably both f-22 and t-50 are designed to engage each other at well above transonic speeds. So it isn't no means clear area ruling of their respective design says anything about relative agility and maneuverability in the regime where they would likely fight each other.

T-50 definitely has more wetted area, that also translates to drag.

 

[EricChase88]

chuck4, okay, I see that weapons on F-22 are tucked behind the intakes. Still, the fact that the T-50 splits the fuselage into 3 volumes unlike F-22 which has one large volume indicates better area ruling and thus lower drag. Naturally, this should allow the T-50 to outperform the F-22 aerodynamically (supercruise, sustained turning) when the T-50 gets the second stage engine.

As for lift, what is certainly clear is that the T-50 have a much bigger lifting surface than F-22. Also, the F-14 which has widely spaced engine and tunnel like the T-50 can fly with one wing fully swept and one wing fully extended and even land on a carrier like that, so its fuselage must also produce a lot of lift like F-15.

For consideration of area rule, T50 does not have three volumes. It has one single very lumpy volume, with three of the lumps being particularly prominent. f-22 has one single somewhat less lumpy volume, with one single big lump. It is by no means clear which plane's geometry come closer to the ideal Sears haack cross sectional area distribution. I would guess, if anything, F-22 come closer.

Also, area rule seems to be most important for rapid transit through transonic region. Presumably both f-22 and t-50 are designed to engage each other at well above transonic speeds. So it isn't no means clear area ruling of their respective design says anything about relative agility and maneuverability in the regime where they would likely fight each other.

T-50 definitely has more wetted area, that also translates to drag.

Area rule matters in supersonic speeds as well. Like the YF-23, the T-50's fuselage is clearly being distributed mostly among 3 volumes, the forward fuselage, and the two engines, unlike F-22 with one volume that contain everything. This indicates T-50 like the YF-23 likely has better volume distribution, and so lower transsonic and supersonic drag. Wetted area's contribution to drag at higher speed is much smaller than wave drag.

 

[piko1]

but why are you all compare PAK-FA with F-22 and not with YF-22 ???

 

[chuck4]

chuck4, okay, I see that weapons on F-22 are tucked behind the intakes. Still, the fact that the T-50 splits the fuselage into 3 volumes unlike F-22 which has one large volume indicates better area ruling and thus lower drag. Naturally, this should allow the T-50 to outperform the F-22 aerodynamically (supercruise, sustained turning) when the T-50 gets the second stage engine.

As for lift, what is certainly clear is that the T-50 have a much bigger lifting surface than F-22. Also, the F-14 which has widely spaced engine and tunnel like the T-50 can fly with one wing fully swept and one wing fully extended and even land on a carrier like that, so its fuselage must also produce a lot of lift like F-15.

For consideration of area rule, T50 does not have three volumes. It has one single very lumpy volume, with three of the lumps being particularly prominent. f-22 has one single somewhat less lumpy volume, with one single big lump. It is by no means clear which plane's geometry come closer to the ideal Sears haack cross sectional area distribution. I would guess, if anything, F-22 come closer.

Also, area rule seems to be most important for rapid transit through transonic region. Presumably both f-22 and t-50 are designed to engage each other at well above transonic speeds. So it isn't no means clear area ruling of their respective design says anything about relative agility and maneuverability in the regime where they would likely fight each other.

T-50 definitely has more wetted area, that also translates to drag.

Area rule matters in supersonic speeds as well. Like the YF-23, the T-50's fuselage is clearly being distributed mostly among 3 volumes, the forward fuselage, and the two engines, unlike F-22 with one volume that contain everything. This indicates T-50 like the YF-23 likely has better volume distribution, and so lower transsonic and supersonic drag. Wetted area's contribution to drag at higher speed is much smaller than wave drag.

Really? Indicate in what way? Likely for what reason? Let's see some significant consistent correlation between better drag characteristics and "3 pod" layout. Hard data please.

 

[EricChase88]

Area rule matters in supersonic speeds as well. Like the YF-23, the T-50's fuselage is clearly being distributed mostly among 3 volumes, the forward fuselage, and the two engines, unlike F-22 with one volume that contain everything. This indicates T-50 like the YF-23 likely has better volume distribution, and so lower transsonic and supersonic drag. Wetted area's contribution to drag at higher speed is much smaller than wave drag.

Really? Indicate in what way? Likely for what reason? Let's see some significant consistent correlation between better drag characteristics and "3 pod" layout. Hard data please.

Just look at the YF-23. There's no doubt that has better area ruling than the F-22. Someone familiar with the YF-23 will tell you that. Given that the T-50 has very similar layout as the YF-23, its not a stretch to believe the T-50 likely have better area ruling too. For example, at the middle of the fuselage where the end of the forward fuselage volume and the start of the two engine pod volumes overlap, the wings are positioned there to add volume so that the cross section area changes smoothly.

 

[chuck4]

1. It's not important who will tell me f-23 had better area ruling. What is important is the evidence they can bring to prove their point.


2. Even if yf-23 had better area ruling than yf-22, it proves nothing about the overall quality or maneuverability of the aircraft. Area rule is just one criteria whose impact was undoubtedly as clearly understood by the engineers at Lockheed as it was by those at Northrop. So if one made its product better area ruled, the chances are because they other had made some engineering judgment that trading off area rule for some other design goal was worth the cost. Prove the yf-22 trade off was unsound.


3. Even if yf-23 with its three lump layout had better area ruling than yf-22, it doesn't show t-50 with its three lump therefore also had better area ruling. The ideal shape for area rule is in fact one single spindle shaped lump called Sears Haack shape. Every practical plane departs from ideal area ruling. Name a valid reason why three lump shape would come closer to the ideal Sears Haack spindle than a one lump shape.

 

[BioLuminescentLamprey]

Just checked...yep, I'm still on Secret Projects.

Thought I somehow got into a Keypubs thread for a minute....

 

[overscan (PaulMM)]

Agreed - hived off to separate discussion.


Everything here so far is largely supposition on all sides. Given sufficient control authority, T-50 could be more agile than F-22, even with wide engine spacing. Judging from videos of T-50 prototype test flights versus airshow demonstrations of production F-22s is hardly going to get you very far.

 

[piko1]

this thread is going nowhere very fast

1. to compear the T-50 you need to compear it with YF-22 not with a production F-22

2.till the pre production airframe's with the new engine installed no one could even assume that T-50 have worst maneuverability characteristics then F-22A

3. is it only me or on display flights the TVC is hardly even used asuming from other TVC planes as the Su-35/30MKI for instance

 

[EricChase88]

YF-22 was a technology demonstrator and not a true prototype. T-50 is a prototype and production versions will have almost the exact same exterior as what we currently see. Rear fuselage may change slightly to accommodated the planned second stage engine.

chuck4, the YF-23 had higher supercruise performance than the YF-22 using the same engines, and much of that have to do with YF-23's better area ruling. Tradeoff for the YF-23 is less space for weapons, but that was apparently solved in the EMD F-23. Look at this website http://www.yf-23.net/technical.html and this thread http://www.secretprojects.co.uk/forum/index.php?topic=1092.0 and you'll know.

The T-50's configuration being similar to the YF-23 in having three main volumes. Just examine pictures of T-50. The fuselage blends with the wings very well in the transitions and the distribution of volume seem very even, much like YF-23. It's reasonable to assume that like the YF-23, T-50 likely has better area ruling than F-22 which means lower drag. Lower drag is very important in maneuverability, since you bleed less speed and energy in sustained turn. A less draggy plane will outturn a more draggy plane given the same lift. And T-50 has a much larger lifting area than F-22 particularly in the fuselage. These things combined suggest the T-50 will likely outperform F-22 in maneuverability and supercruise when it gets the second stage engine.

EDIT: As a side note, has T-50 dimensions ever been released?

 

[TaiidanTomcat]

T-50 is a prototype and production versions will have almost the exact same exterior as what we currently see.

How can you know this?

 

[KoV]

Because there are already 4 prototypes ... maybe ?!

 

[TaiidanTomcat]

They built these prototypes as well.

I would be shocked if there are no design changes between what we are seeing now and actual production.

 

[chuck4]

ItI think it is reasonable to suppose the T-50 prototype is closer to the type's currently intended production configuration than YF-22 was to the F-22 because the T-50 is intended to enter the service in just 4-5 years, around 2016-2017. On F-22's development track 4-5 years before service entry would be 1998-1999, when developmental airframes externally almost indistinguishable from production aircraft have already been flying for 2 years. YF-22 demonstrator predated F-22's service entry by 12 years, not 4.

Much as Lockheed made a fool of itself with its program management of F-35, I still suspect given the resources and industrial base difference between the US and Russia, Russia can't push T-50's pre-production developmental process substantially faster than USAF and lockheed did with F-22 unless T-50 were substantially simpler and further from the edge of technological experience envelope of the aircraft industry involved than F-22 was. So assuming T-50 pushed Russian boundaries as much as F-22 did American boundaries, the limit to the pace of developments means T-50 in serial production in 4 years has to be fairly similarr to current prototypes, about as similar as production F-22A had been from F-22 developmental aircrafts flying in around 1998-1999.

Of course T-50's prototype may yet be revealed to be unsatisfactory, and the service entry delayed by many years from 2016-2017 time frame to allow a major redesign, as was the case with the T-10. But it that were to happen, then T-50 would not be a even a theoretical competitor to F-22 until much further down the line.

 

[aam641]

The T-50's configuration being similar to the YF-23 in having three main volumes. Just examine pictures of T-50. The fuselage blends with the wings very well in the transitions and the distribution of volume seem very even, much like YF-23. It's reasonable to assume that like the YF-23, T-50 likely has better area ruling than F-22 which means lower drag.

In terms of area-ruling, T-50 may actually be closer to F-22 than to YF-23. T-50 fuselage maintains fairly large cross-section all the way to engine nozzles, like F-22, while YF-23 fuselage disappeared near the engine compressor. T-50 intakes are ahead of wing leading edge, like in F-22, but YF-23 intakes were behind the leading edge.
Unlike F-22, both YF-23 and T-50 split the engines into individual nacelles. However, I do not see how this affects cross-sectional area. If anything, separate nacelles will have larger area.

T-50 has a much larger lifting area than F-22 particularly in the fuselage. These things combined suggest the T-50 will likely outperform F-22 in maneuverability and supercruise when it gets the second stage engine.

At supersonic speeds you are flying at very small angle of attack. The induced drag is closely proportional to the lift. Therefore, larger wing only produces larger parasitic drag.
In tight maneuvers, you are flying at a fairly high AoA. The induced drag will increase faster than the lift. Therefore, you want to have a large wing area to generate 9g`s of lift with the smallest AoA possible.

 

[chuck4]

There is no reason why F-22 layout is intrinsically constrained to have less area ruling than either YF-23 or T-50 layout. So saying T-50 (somewhat) resembles YF-23 and therefore probably has better area ruling is complete bullshit on two separate levels.

 

[sferrin]

This thread reminds me of F-22 vs Flanker, F-22 vs Mig 1.42, F-22 vs S-37 threads of ages past. And about as useful.

 

[EricChase88]

The T-50's configuration being similar to the YF-23 in having three main volumes. Just examine pictures of T-50. The fuselage blends with the wings very well in the transitions and the distribution of volume seem very even, much like YF-23. It's reasonable to assume that like the YF-23, T-50 likely has better area ruling than F-22 which means lower drag.

In terms of area-ruling, T-50 may actually be closer to F-22 than to YF-23. T-50 fuselage maintains fairly large cross-section all the way to engine nozzles, like F-22, while YF-23 fuselage disappeared near the engine compressor. T-50 intakes are ahead of wing leading edge, like in F-22, but YF-23 intakes were behind the leading edge.
Unlike F-22, both YF-23 and T-50 split the engines into individual nacelles. However, I do not see how this affects cross-sectional area. If anything, separate nacelles will have larger area.

It still appears to me that the T-50 offers better area ruling compared to F-22. The canopy ends as the LEVCONs begin. Also, unlike the F-22's single volume body, the T-50's fuselage shrinks as it begins overlapping the nacelles length-wise. In addition, small short range missile bays start right after the LEVCONs to make the transition to the wings smoother.

T-50 has a much larger lifting area than F-22 particularly in the fuselage. These things combined suggest the T-50 will likely outperform F-22 in maneuverability and supercruise when it gets the second stage engine.

At supersonic speeds you are flying at very small angle of attack. The induced drag is closely proportional to the lift. Therefore, larger wing only produces larger parasitic drag.
In tight maneuvers, you are flying at a fairly high AoA. The induced drag will increase faster than the lift. Therefore, you want to have a large wing area to generate 9g`s of lift with the smallest AoA possible.

So shouldn't T-50 should hold an advantage at subsonic speeds because of bigger lifting surface and LEVCONs to lower AOA?

 

[chuck4]

Is this going to remain at the level of "the brochure of my favorite plane has more jargon words"?

 

[kcran567]

My question is does the Pakfa have to have levcons, more volume, and more wetted area, to be able to match the performance of the f-22? for example its a less efficient design (engines, aerodynamics) so it needs to hold more fuel just to match the f-22? Not criticizing, just asking the question about the Pakfa. How could being a larger design be an advantage? it certainly doesn't help stealth. Lets not forget that the Pakfa is supposed to be a stealth fighter. Are there any solid numbers for weight vs the f-22?

 

[EricChase88]

The T-50 should not be less efficient. Wetted area is only a part of the drag. T-50 has wings that swept back more, and has area ruling at least as good if not better than F-22. Larger design can carry more fuel and allow more supercruising time. It may also carry more weapons.

 

[aam641]

EDIT: Why interrupt uniformed speculations, they are too entertaining. PAK-FA performance will depend on its weight, aerodynamics and engine. We are plain guessing about all three. You are welcome to prove me wrong!

PS: There are at least two very good-looking 3D models of T-50 up for sale. Is anybody here interested & qualified for some CFD simulation? I would gladly pitch in a little cash.

PPS: I highly recommend RAND's 1997 paper on JSF. It is extremely informative on the trade-offs involved in aircraft design (link).

 

[BioLuminescentLamprey]

Yes. It will remain on that level. Got some trolls in here!

 

[piko1]

U NO SAY

 

[BioLuminescentLamprey]

Haha! Nice!

 

[saintkatanalegacy]

I've seen some CFD's of PAK-FA a few years ago and been telling that LEVCON's =/= canards.

 

[EricChase88]

I've seen some CFD's of PAK-FA a few years ago and been telling that LEVCON's =/= canards.

LEVCON as a leading edge device should make the required AOA lower for a given amount of lift than without such devices.

 

[chuck4]

How?


If they function like leading edge flaps for the fuselage, or if they function by creating vortices, then they will increase the AOA at which the plane stalls. Prior to stalling, they won't do much to reduce the AOA at which a given amount of lift is achieved in maneuvering.

 

[EricChase88]

According to this diagram, leading edge devices reduces AOA required for given amount of lift.

 

[chuck4]

Not much.

In addition, just how much would probably depends on how large the leading edge flaps are compared to the chord of the airfoil. If the LEVCONS act as leading edge flaps for the fuselage, they would seem to be fairly small compare to the chord of the fuselage, furthermore, LEVCON only works on a portion of the fuselage, and that portion is nowhere near an ideal lifting shape, with engine nacelles hanging under it.

 

[piko1]

let's face like this F-22 preforms like F-15 PAK FA preforms more or less like Su-27

in close combat pak-fa can easy gain advantage over the 22 i just watched the Dogfights Of The Future from History channel
there is one dogfight f-22 vs Dassault Rafale the F-22 preformed cobra ( huh ye F-22 preforming cobra nice joke ) to gain advantage over the Rafale in this moment i was like OK you will do cobra i have gun you are siting duck fully exposed i will just pull the trigger and the F-22 will burst in to flames no offence but enough of the US everthing is better cr**

 

[sferrin]

let's face like this F-22 preforms like F-15 PAK FA preforms more or less like Su-27

in close combat pak-fa can easy gain advantage over the 22 i just watched the Dogfights Of The Future from History channel
there is one dogfight f-22 vs Dassault Rafale the F-22 preformed cobra ( huh ye F-22 preforming cobra nice joke ) to gain advantage over the Rafale in this moment i was like OK you will do cobra i have gun you are siting duck fully exposed i will just pull the trigger and the F-22 will burst in to flames no offence but enough of the US everthing is better cr**

/fanboy

 

[lastdingo]

Does it really bear mentioning that the T-50 almost certainly used nowhere near its full potential during the displays flown so far? Its first public display was some 18 months after it first flew for crying out loud! How far do you think the envelope was cleared by then, bearing in mind that for 12 of those 18 months there was only one airframe available and even that one was grounded for some time during the 2010 wild fires. I seem to recall displays up to now did not exceed 5g, representing less than 60% of the aircraft's full turning potential.
And if it comes to that, what if one were to judge the F-35 on its only air show performance so far, fully 5 years after its first flight - a flyby at what, 1g? Compared to THAT, the T-50 is doing shockingly well.
Come on, you cannot be serious.

This.

Judging the T-50 based on its published flight demos is ridiculous.


Demos for audiences are never truly indicative anyway, for most air combat happens at much greater altitudes where the air is thinner.

 

[piko1]

/fanboy

try this in a flight sim you will see that im correct the super manouverability is punishable im nether fan of both airframes
in theory F-16c/d should easy come out winner against MiG-21Bis but in practice F-16 lose :

 

[Kryptid]

It is very, very unlikely that the F-22 or even the Su-35 would actually perform cobras during real combat.

Aside from an aircraft's basic performance figures, you can expect that rules of engagement, strategy, pilot training and chance will play massively into determining which fighter will come out on top.

 

[lantinian]

I've read that for the SU-27 to perform Cobra, it should be at 25% fuel, have no weapons and fly at a very specific speed. I've yet to see a flight demo of even a single weapon being attached to the fighter performing the Cobra. The safest version of the Cobra is also performed in a level flight and it requires the pursuing aircraft to be quite close (within the missile minimum safe envelope) to overshoot and not turn up and perform a Lag displacement roll or other maneuver designed to reduce the traveled distance while conceving energy

Given modern helmet mounted sights and off bore sight missiles, I just can't imagine a situation where a F-22 would fly close behing T-50 and not shoot a missile long enough for the T-50 to execute this maneuver to a practical effect.... Except if the F-22 has exhausted its missiles and was going for a gun kill.

 

[Trident]

There is a video on youtube of the Su-35 (or rather Su-27M) flying an essentially unrestricted display - including Tail-Slide and Cobra - with a full load of air-to-air weapons at a 1990s Farnborough airshow. As in "full Flanker air-to-air load" (10+ missiles), not "full F-35 air-to-air load" (4 MRAAMs for the time being), too - a point worth bearing in mind when LM waxes lyrical about F-35 performance vs. 4th generation fighters "with a full weapons load". You can also find pictures on airliners.net of Irkut's Su-30KN performing somewhere in the UK at around the same time with a load that included several heavy air-to-ground munitions - I've never seen a video of the full display, but the take-off is shown in a recent Su-27 documentary on YT and it wasn't particularly gentle! Same for the Su-34 display with almost 3 tons of weapons that I saw at MAKS 2007 - the added weight and drag didn't seem to hurt its handling very much, such as that is when you bear in mind that the Fullback is no Su-27 or Su-35 any more.
I'd agree that the Cobra isn't particularly useful during actual combat, but the ability to perform the manoeuvre is indicative of handling qualities which most certainly are!

 

[EricChase88]

Although airshow performances does not entirely reflect the plane's aerodynamics in actual combat, the Su-35's demonstrations are a lot more aggressive and shows tighter turns and maneuvers than F-22 demo.

 

[chuck4]

Although airshow performances does not entirely reflect the plane's aerodynamics in actual combat, the Su-35's demonstrations are a lot more aggressive and shows tighter turns and maneuvers than F-22 demo.

F-22 was never intended for sale to impressionable audiences easily overawed by sight of plane being thrown around willy nilly like a stunt toy, accompanied by daunting sounding jargons in brochures.

 

[sferrin]

Although airshow performances does not entirely reflect the plane's aerodynamics in actual combat, the Su-35's demonstrations are a lot more aggressive and shows tighter turns and maneuvers than F-22 demo.

The F-15's 104 to 0 record speaks louder than any airshow.