Su-57 Stealth Fighter: News #6

Isos wrote:Fanboy propaganda.

According to this description, f-22 with two external tanks has a ferry range of 1600 nautical miles. It represents 11900kg of fuel.

Internal fuel only is 8200kg.

This means without fuel tanks, it has a ferry range of (8200×1600)÷11900 = 1102 nm = 2040 km.

It gives it a radius of 1000km and even less if it need to fight or go at lower altitudes.

Isos wrote:Pilots are not reliable since they say what the AF tells them to say. Same debat happens with Typhoon supercruise capability with pilots saying total different figures compared to the engineers that made the aircraft and tested it.

I know about the drag but it gives a good estimation.

thegopnik wrote:Guess any real estimates on fuel range without external tanks would be deemed as embarrassing for LM so they have not included it but are reliant on tanks to only post info with the tanks included as their marketing preference Some users here which I cant understand why are hell bent for a little Mach 0.1-0.3 to add on super cruise as more important than having an aircraft that literally already has 75% more range than the other in a internal fuel consumption range(not including drag). Than of course some users here(you know who you are and there is more than 1 stating this) put a lot of emphasis on how much drag greatly effects like if it didn't have those tanks it will still be close to the advertised external fuel tank range  but are not giving any numerical value to calculate the drag but believe it is that bad ? Even if we all pretend that the 12000kg is the internal fuel range which of course it isn't the fuel efficiency is still higher than the afterburner speed efficiency the F-22 has over the Su-57 anyway

I mean they could design a higher thrust engine to begin with on the 1st stage but the fuel efficiency is a no-go to monitor the airspace of a very big country.  But either way we are comparing fruits to vegetables and that is no way to predict a country's engine technology(as some are drawing conclusions based on that, on who is ahead in aircraft engines). For example if the F-22 did not go for high thrust numbers but numbers similar to the Su-57 1st stage or Su-35 engine would it have better internal fuel consumption of those 2 aircrafts? If the Su-57 or Su-35 did prioritize higher thrust similar to the F-22 would it still have a better internal fuel consumption(and lockheed not feeling too embarrassed to disclose the internal fuel range to compare them)?

Please copy and paste this shit to other forums because as meaningless as this 1st stage su-57 vs F-22 engine debate is. I am sure the future argument will be a izdelie 30 vs F-35 ADVENT(which is not going to work for debate anyways). and far future argument will be mig-41 ramjet detonation engines vs whatever the F/A-XX program is doing and it would be a god send if they are nearly the same in some aspects to make more fair comparisons than what this board is currently doing.

are not giving any numerical value to calculate the drag but believe it is that bad

Even if we all pretend that the 12000kg is the internal fuel range which of course it isn't the fuel efficiency is still higher than the afterburner speed efficiency the F-22 has over the Su-57 anyway

I mean they could design a higher thrust engine to begin with on the 1st stage but the fuel efficiency is a no-go to monitor the airspace of a very big country. Not to hit a nerve but I believe there  is a good reason why LM advertises the external tank range over the internal fuel range

But either way we are comparing fruits to vegetables and that is no way to predict a country's engine technology(as some are drawing conclusions based on that, on who is ahead in aircraft engines).

For example if the F-22 did not go for high thrust numbers but numbers similar to the Su-57 1st stage or Su-35 engine would it have better internal fuel consumption of those 2 aircrafts?

If the Su-57 or Su-35 did prioritize higher thrust similar to the F-22 would it still have a better internal fuel consumption(and lockheed not feeling too embarrassed to disclose the internal fuel range to compare them)?

Please copy and paste this shit to other forums because as meaningless as this 1st stage su-57 vs F-22 engine debate is. I am sure the future argument will be a izdelie 30 vs F-35 ADVENT(which is not going to work for debate anyways). and far future argument will be mig-41 ramjet detonation engines vs whatever the F/A-XX program is doing and it would be a god send if they are nearly the same in some aspects to make more fair comparisons than what this board is currently doing.

GarryB wrote:For external tanks to make sense using they would have to extend flight range by a significant value in the subsonic flight regime where the extra drag wont render the extra fuel they carry irrelevant.

Isos wrote:So yeah it give a theorical range of around 1000km on internal fuel. Not perfect but it is a good figure.

thegopnik wrote:LMFS why that  attitude? Where am I insulting you?

1.not really have you looked at any f-16s, f-15s or f-35s? They do give max ranges on internal fuels I just cant figure out why they are not doing the same for the f-22.

LMFS wrote:

Mindstorm wrote:
That statement about this parameter is false only assuming that over-ocean CLAIMS about the same paramters was initially true......do you know in the same way of some others: such as an effective area of dispersion in 0,0001 square meters or almost absent IR signature preventing its detection and even lock-on even at reduced ranges....and today guys like М. Толбоев have plenty of hard and coherent data coming from reality confirming how much ridiculous technical disinformation were present in those CLAIMS about F-22

Its assertion is not that Rolls-Royce or Pratt & Whitney ,or any other engine maker at world, had not developed an engine capable to pull a particular airframe over mach 1 at maximum military power regime, but instead that neither of them was capable until now ,matched with any airframe now existing at world, to pull a fighter aircraft at a speed of 1600 km/h in this regime.

That statement is true by any available information outside public domain.

I am limited to open sources, so I have no way of knowing such details, but I know the following:

> Revealing the true capacities of the Su-57 on an interview would normally cause the person in question to be prosecuted. Sometimes data a re purposefully leaked, but Russian official sources have been very secretive regarding that particular parameter and never provided values.
> Given the known / reasonably expected values of izd. 117 based on izd. 117S and older comments from Pogosyan, its military power values should be very inferior to those of the F119. By a 20-30% actually, given the different technologies but specially due to different BPR of both engines. It would require an aerodynamic miracle for the Su-57 to be faster with so much less thrust. I am accounting for the advantages in pressure recovery that the variable intakes provide, but still I see it very difficult
> If the Su-57 was already faster than the F-22 in cruising speed, then there would be no real need for the izd. 30 and the officials and designers talking about it being the engine that really provides the plane with proper supercruising would also make no sense.
> There are planes with lower performance engines and not so optimized overall design like Eurofighter where reliable data informs about 1.4 M cruising speed, very close already to the value reported by Tolboyev as a record and so 1.5 M should perfectly be thinkable for the F-22
> I agree that US information is in general not trustworthy. The supercruising speed of the F-22 has been discussed several times and quotes are abundant for speeds of 1.8 M and even one pilot stating >1.9 M. This is not something that surprises me specially: if you compare the provided uninstalled mil thrust values of the F119 you can see they are actually comparable to AB values of older generation engines used in similarly sized / shaped planes for speeds well above 2M. Granted AB can be more effective at high speed, but still I don't think it is a far fetched claim. Initial flights of the YF-22 and YF-23 already reported supercruising @1.6 M in early program dates, then the YF-22 was actually re-shaped and further optimized for supercruising and became the current F-22. If all is a big lie then at least this time they lied coherently for a change
> Some Russian source spoke (sorry I don't remember the name but he was a military expert) claimed cruising speeds of 2 M and top 2.4 M for the second stage Su-57, now it remains to be seen how much more powerful it would be compared to F119 to understand if the US claims regarding the cruising speed of the F-22 are feasible or not.

So in this case I personally don't think the US claim is that far fetched, but still I can be totally wrong. You would need developer level access to the program to check with real Cl, Cd and installed thrust values to know for sure. Can the Su-57 already supercruise at 1.5M with the izd. 117? It sounds a bit optimistic but maybe it can, I don't know. Pogosyan said in the past that the plane with the first stage engines already fulfilled the requirements, interestingly that 1.5 M is what I am repeating here as the value originally defined for supercruising, so it is actually thinkable that they already tried to achieve exactly that with the first iteration and the second one was in order to surpass F-22.

GarryB wrote:So you accept that the two centrally mounted main weapons bays will have bay doors and actuators that open and close those doors in flight in a range of speeds.

Why do you think they could design actuators and doors over the main weapon bays but not smaller wing mounted bays.

Wouldn't it be logical that a much smaller wing mounted bay door would need less powerful actuators to open and close it?

They don't open like wind brakes, the airflow would be moving down the edge of the doors and most of the actuators will be internal... and new electric actuators are quite powerful... they are replacing heavy hydraulic actuators with electric ones on new planes these days... would you agree that the wind force on those all moving vertical tail surfaces would be pretty damn fierce at high flight speeds... yet it clearly moves the entire vertical tail portion for flight control purposes...

LMFS wrote:I don't quite understand though what you are meaning with "at speed greater than 1500 km/h at different wing's angle of attack, from typical operational maneuvering,", is it related to supersonic meanouvering instead of level flight?

Mindstorm wrote:Partially.

At those speed (obviously at altitudes greater than 15.000 meters) in not afterburner mode also banking of few degrees ,necessary to follow ground based or AWACS commands towards enemy airborne targets, can cause a sensible lowering of the thrust yield , this effect is highly dependent from the glider's aerodynamics design and inlet and air intake's arrangement.

Usually this effect is counterbalanced with transient use of afterburner ,that obviously negate the advantage of supercruise.
Different aircraft with different propulsions  (low bypass turbofan being only a compromise solution) show different speed thresholds for this effect.

In supersonic maneuvring at high altiutudes instead (fundamental to ascertain the anti-missile maneuvering potential of a modern aircraft, particularly against air -to-air ones with limited warhead's potential) another important role play supersonic trim drag, this is one of the reasons both the supersonic optimized F-22 and domestic products have included thrust vectoring solutions.

Mindstorm wrote:
That statement about this parameter is false only assuming that over-ocean CLAIMS about the same paramters was initially true......do you know in the same way of some others: such as an eitney's F119 just in supercruise [/b]capabilities to the point that when matched with most efficient glider for high supersonic flight's regimes among the two - the YF-23 - (lower frontal cross section and flattened cord shape) it managed even to reach a cruise speed in the area of 1.6 Mach.

Is important to remember obviously that both those flying demonstrator models was sensibly lighter, devoid of several drag-generating stealth-related finitures, any kind of RAM and all the self-defense electronic stuffing and consumables and therefore those kind of limit achievements was completely irreproduceable in serial models.

Not a single radar, including OTH, or radar and optical satelitte on this planet has ever recorded an F-22 sustaining speeds even very far from those ridiculous circulating on it; maybe if a modenized GE YF-120 would have produced, by today someone could see a serial F-22 supercruise at speed of 1.5-1.6.

Saw this today on another forum it made me crack up a little.

The tendency of the plane to lower the nose at supersonic speeds is best compensated by forward lift than by rear downforce, maybe this is one further reason for the LEVCONS that can modify the lift profile of the fuselage and therefore contribute more efficiently than the nozzles.

We discussed this not long ago, the time on AB a normal plane has is actually quite reduced, therefore a platform that aims at high persistence should avoid using it as much as possible and in any case reserve it for high energy demand situations where AB is a must. Supercruising allows for tactics that are not possible for other planes and massively reduces the footprint of AD and A2A missiles.

GarryB wrote:I know what you mean but don't agree. On paper using a canard to lift the nose is theoretically better than using a horizontal tail surface to push the rear of the aircraft down to raise the nose because it technically reduces lift. But in this case the body of the aircraft is contributing body lift and directing engine nozzles down applies lift to the rear of the vehicle too.

What TVC engine nozzles lets you do is use the engine nozzles the trim the aircraft into the airflow rather than deflecting tail or canard surfaces... all your control surfaces can be neutral and therefore minimum drag and RCS, while it is your engine nozzles that directs the thrust of the engines to keep the nose and body of the aircraft at the lowest drag angle possible in flight.

But if you think about it you can change the angle of attack of an aircraft... with zero angle of attack meaning cutting straight through the air, while a 20 degree nose high angle would mean high drag from wings and fuselage.

Backman wrote:Apparently Algeria has now officially purchased 14 su 57's + for 2 billion dollars. It was just a coincidence that i mentioned it yesterday

https://twitter.com/brokly990/status/1330075122397540354?s=20

Isos wrote:That's almost 150 million unit price. I doubt it's this much.