Sukhoi PAK FA

[MiG-29SMT]

Why no stealthy nozzle for PAK-FA, like the f-22 ? Also, looks like AMCA too will compromise on rearward stealth by having circular nozzle...

The only downside of using rectangular nozzles is thrust loss when compared to a circular nozzle. The loss is expected to be around 5% for a 6:1 aspect ratio (AR) [4], but the loss is sometimes acceptable due to the other advantages offered by rectangular nozzle.

https://www.krishisanskriti.org/vol_image/02Jul20150307299.pdf


The goal of increasing controllability is to increase the envelope of positive control for the pilot, especially at high angles of attack or sideslip. A solution for increased controllability demands is for a thrust vectoring control system (TVCS) to provide the required forces and moments (ref. 6).

In the past, most TVCSs have been developed for pitch vectoring concepts such as the F-15 S/MTD in a trend toward developing short field capability technology and performance optimization. In recent years, the interest in PSM has increased the investigations of pitch and yaw vectoring concepts. Similar in application, pure yaw vectoring concepts are less beneficial in overall aircraft performance than pure pitch vectoring two-dimensional nozzles.

The TVCS have several disadvantages, the primary of which is the reduction of thrust performance and the lost nozzle efficiencies. Losses occur in nozzles because of skin friction, internal flow separation, exhaust flow divergence, under- and overexpansion, and temperature and thrust distortions. Turning the gross thrust from axial direction also causes losses in nozzles. For postexit vanes, additional skin friction and pressure losses are caused by the thrust vectoring hardware (ref. 18).

The structural efficiency of nonaxisymmetric nozzles is less than that of axisymmetric nozzles. Further weight gains can be attributed to the fact that the engine case structure must be strengthened to withstand the vectoring. Takeoff gross weight penalties from 5 to 7 percent occur because of the structural effects and cooling system weights (ref. 18).


https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19920012114.pdf

 

[MiG-29SMT]

Reduction in Vertical Tail Size Aircraft designers have suggested that the installation of TVCS increases the amount of control power and allows a size reduction of the vertical tail. The size reduction of the vertical tail also decreases the lateral-directional stability of the aircraft as well as control power of the rudder thereby changing the dynamics of the aircraft. To estimate the effects of vertical tail size reduction with TVCS control 22 power, the dynamic response for the aircraft was studied with maximum afterburner and deflection thrust vectoring at 100, 75, 50, and 0 percent tail height and compared with the baseline aircraft.

The vertical tail height can be reduced significantly for an aircraft by using thrust vectoring; however, only through careful attention to the tail size, vectoring effectiveness, as well as vane to rudder scheduling will the optimum control and performance be obtained.


https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19920012114.pdf

 

[StealthFlanker]

Today is the same, the americans denied the lose of the F-117 in 1999 but let us remember the Serbs showed the wreckage of the F-117 then they did not have other option that to admit the lose.

Pretty sure they did admit the lost of F-117 before the wreckage is shown

The cruel reality is the USAF will not be able to beat IAF, RuAF or PLAAF simply because these air forces are armed to the teeth, and even their aircraft carriers will not survive attacks by Tu-22Ms or Chinese Tu-16s, further more Indian and Chinese Su-30s are much newer and more advanced than their vintage F-15s, their F-18 while advanced lack range which will increase their vulnerability if Tu-22Ms or Su-30MKIs armed with Brahmos are available, the USAF will not win a conventional war against these air forces, despite their boasting.

In exactly what way Indian and Chinese Su-30 are more advanced than F-15?
From first glance F-15 already get AESA while no Su-30s does

With Amber rack, F-15 can carry over 20 air to air missile, which is obviously not possible for Su-30s

and F-18 E/F isn't exactly short legged with the newly integrated CFT and with support from the up coming XQ-25 support.

 

[StealthFlanker]

In order to understand Su-57 or F-35 we have to see their needs an
For Russia, the ICBMs, SLBM and submarines and hypersonic weapons are priority, it does not matter China or the USA build more weapons, Russia just needs the one that assure these rivals will be highly mauled if they attack Russia.

Hypersonic are also priority for US at the moment, they did't exactly small amount of money on these themselves

Israel also try to make shift with air launched ballistic missile

F-35 is an attack aircraft, but really ill suited for replace the A-10, A-10 is a flying tank, so well it will not really be better it is too delicate, the F-16 is a better dogfighter in general terms and Su-35 is even better same Rafale.

F-35 is a multi role fighter similar to F-16, Rafale and Mig-35. While it indeed intended to replace A-10 in CAS, it wont do it the same way A-10 does, so the armor is irrelevant. The only true attack aircraft that is similar to A-10 is Su-25

 

[Aaj ka hero]

@MiG-29SMT ,I have a question regarding engine of plane.
You know for helicopter we have at the back small rotor to balance counter torque.
What happen then in single engine fighter planes?
Does there this torque do not develop?
How is counteracted?
All esteemed members can also answer this.
I will be very thankfull.

 

[StealthFlanker]

@MiG-29SMT ,I have a question regarding engine of plane.
You know for helicopter we have at the back small rotor to balance counter torque.
What happen then in single engine fighter planes?
Does there this torque do not develop?
How is counteracted?
All esteemed members can also answer this.
I will be very thankfull.

On piston engine aircraft, the torque is countered by rudder input.
On jet engine aircraft:
1- The torque is negligible, due to the length and mass of the rotating component versus the mass of the aircraft
2- In a jet engine, behind the rotating blades of the fan and each compressor and turbines stage, there are stator vanes that will redirect the swirling gases towards the rear. This neutralizes the torque from the rotating blades.

 

[Armand2REP]

With Amber rack, F-15 can carry over 20 air to air missile, which is obviously not possible for Su-30s

The US might be able to afford to pull $20 million worth of missiles out of storage but once you do that their operational life is reduced by a factor of 10. Keeping a fully stocked inventory requires careful management of stores during peacetime or you won't be able to afford to keep it at the ready in case of war.

 

[MiG-29SMT]

@MiG-29SMT ,I have a question regarding engine of plane.
You know for helicopter we have at the back small rotor to balance counter torque.
What happen then in single engine fighter planes?
Does there this torque do not develop?
How is counteracted?
All esteemed members can also answer this.
I will be very thankfull.

in jets you have wings, the aircraft has different axis lines, the engines pushes along the longitudinal axis lines, on a twin engine the engines can be located under the wing giving a pitch up component, remember each axis is controlled with rudders, vertical tails or horizontal tails

on a MiG-29 you have 2 engines. they can create troubles in yaw and pitch, in yaw because they are located parallel to the longitudinal axis, and in pitch because the engines are bellow the wings and bellow longitudinal axis , on an A-300, is the same but the engines in pods bellow the wing also give a pitch up force so for aircraft like A-320 well that it is good so most airlines have engines bellow the wing.

On aircraft like LCA or Mirage 2000, the engine longitudinal axis coincides with the aircraft fuselage longitudinal axis, but still you have the normal axis this is usually the fulcrum of pitch so you can adapt TV C nozzles or use pitch control devices.

PAKFA Su-57 has better TVC nozzles because the engines are offset from the longitudinal axis so their yaw effect is better than on F-22, reducing the need for higher deflections

F-22 only has pitch thrust vectoring so the engines can be close to the longitudinal axis, but on the Su-57, they have yaw too, so being away and flanking the longitudinal axis makes it better than the F-22 in yaw control

 

[asianobserve]

@MiG-29SMT ,I have a question regarding engine of plane.
You know for helicopter we have at the back small rotor to balance counter torque.
What happen then in single engine fighter planes?
Does there this torque do not develop?
How is counteracted?
All esteemed members can also answer this.
I will be very thankfull.

Animation of jet engine operation


Notice contra rotating compressors and turbines.

 

[death.by.chocolate]

The US might be able to afford to pull $20 million worth of missiles out of storage but once you do that their operational life is reduced by a factor of 10. Keeping a fully stocked inventory requires careful management of stores during peacetime or you won't be able to afford to keep it at the ready in case of war.

Those are not real AIM 120’s they are CATM 120’s.

http://marvineng.com/wp-content/uploads/sites/5/2018/01/CATM-Final-Draft2.pdf

 

[MiG-29SMT]

F-35 is a multi role fighter similar to F-16, Rafale and Mig-35. While it indeed intended to replace A-10 in CAS, it wont do it the same way A-10 does, so the armor is irrelevant. The only true attack aircraft that is similar to A-10 is Su-25

you have admitted F-35 is too delicate for replacing A-10

 

[MiG-29SMT]

Pretty sure they did admit the lost of F-117 before the wreckage is shown

In exactly what way Indian and Chinese Su-30 are more advanced than F-15?
From first glance F-15 already get AESA while no Su-30s does

With Amber rack, F-15 can carry over 20 air to air missile, which is obviously not possible for Su-30s

and F-18 E/F isn't exactly short legged with the newly integrated CFT and with support from the up coming XQ-25 support.

Su-27 aerodynamically speaking is much more advanced.
Su-30MKI has al the refinements that F-15 never got, originally they wanted to make it like this

Plus remember the USAF still operates old airframes built before the year 2000, while India and China operate Flankers built in the 2000 onwards.



For an old fuselage like F-15, Su-35 with Irbis still is a target, electromagnetic waves work the same wave in radars of WWII or in a modern PESA or AESA, the only thing that has changed is the number or transmitters or receivers and the digital processing power.


Irbis will burn through most jammers, since it is so powerful jamming it will be very hard and still a conventional fuselage like F-15 has a RCS very big, armed with 14 missiles and it is more observable, in fact it increases its RCS many times.


Today the Su-35 has only one real counterpart and it is Eurofighter and to a lesser extend Rafale, F-15 has inferior agility, and not real true improvements, the USAF made the mistake of building few F-22, not upgrading the F15 or F-16 and making a striker with low agility and speed its main air superiority.

the USAF needs a dedicated new air superiority in the form of a 6th generation aircraft

 

[asianobserve]

you have admitted F-35 is too delicate for replacing A-10

CAS is not a matter of being delicate or tank-like anymore. A-10 needs to be heavily armored as it needs to dive down low to attack Soviet tanks with GAU-8 30mm gatling gun. So it is expected to recieve flacks thus the armor.

But the F-35 can do the same job from high altitude using SDBs and smart bombs. The same weapons can be employed against terrorists.

 

[asianobserve]

Su-27 aerodynamically speaking is much more advanced.
Su-30MKI has al the refinements that F-15 never got, originally they wanted to make it like this

Plus remember the USAF still operates old airframes built before the year 2000, while India and China operate Flankers built in the 2000 onwards.



For an old fuselage like F-15, Su-35 with Irbis still is a target, electromagnetic waves work the same wave in radars of WWII or in a modern PESA or AESA, the only thing that has changed is the number or transmitters or receivers and the digital processing power.


Irbis will burn through most jammers, since it is so powerful jamming it will be very hard and still a conventional fuselage like F-15 has a RCS very big, armed with 14 missiles and it is more observable, in fact it increases its RCS many times.


Today the Su-35 has only one real counterpart and it is Eurofighter and to a lesser extend Rafale, F-15 has inferior agility, and not real true improvements, the USAF made the mistake of building few F-22, not upgrading the F15 or F-16 and making a striker with low agility and speed its main air superiority.

the USAF needs a dedicated new air superiority in the form of a 6th generation aircraft

TVC is overhyped. Softfare has supplanted the need for heavy mechanical TVC to vastly improve fighter agility.


And look at how even oldet gen F-18 maneuvers like it has TVC...


More importantly, TVC is no use against an enemy that can see you and thus cannot shoot you down first. TVC cannot also cannot negate human body's G-limitation versus 40+Gs A2A missiles.

 

[MiG-29SMT]

CAS is not a matter of being delicate or tank-like anymore. A-10 needs to be heavily armored as it needs to dive down low to attack Soviet tanks with GAU-8 30mm gatling gun. So it is expected to recieve flacks thus the armor.

But the F-35 can do the same job from high altitude using SDBs and smart bombs. The same weapons can be employed against terrorists.

A-10 has an advantage F-35 has not, when an aircraft will target a position it needs to know if the target is friend or foe, visual identification is necessary, because number one today anti aircraft weapons are developing anti drone capability, either downing them or jamming them, furthermore if the target its close to friendly lines and position mistakes can happen. A-10 is a WWII style aircraft, so it needs armour.

F-35 can not replace A-10 basically it is a joke, is like saying Tu-22M can replace Su-25, a funny joke, but A-10 can not be replaced with a machine that a rifle can down it, F-35 it is very delicate, a few bullets or damages will render its stealth useless

 

[MiG-29SMT]

TVC is overhyped. Softfare has supplanted the need for heavy mechanical TVC to vastly improve fighter agility.

More importantly, TVC is no use against an enemy that can see you and thus cannot shoot you down first. TVC cannot also cannot negate human body's G-limitation versus 40+Gs A2A missiles.

TVC nozzles are also used for RCS and air drag reduction, so yes F-22 has better stealth and less drag that F-35; PAKFA Su-57 will deflect much less its feathers than F-35, so yes TVC nozzles can also extend range

 

[asianobserve]

A-10 has an advantage F-35 has not, when an aircraft will target a position it needs to know if the target is friend or foe, visual identification in is necessary, because number one today anti aircraft weapons are developing anti drone capability, either downing them or jamming them, furthermore if the target its close to friendly lines and position mistakes can happen. A-10 is a WWII style aircraft, so it needs armour.

F-35 can not replace A-10 basically it is a joke, is like saying Tu-22M can replace Su-25, a funny joke, but A-10 can not be replace with a machine that a rifle can down it, F-35 it is very delicate, a few bullets or damages will render its still useless

New targeting techs negate the need for pilots to visually identify their targets. That's the job of JTACs. Plus with God's view, and F-35 pilot has better and more stable visibility of ground targets than A-10 barreling down to the ground on a steep dive.

 

[MiG-29SMT]

New targeting techs negate the need for pilots to visually identify their targets. That's the job of JTACs. Plus with God's view, and F-35 pilot has better and more stable visibility of ground targets than A-10 barreling down to the ground on a steep dive.

that is only theory, a high intensity conflict, where the other side has similar level of technology shows that is fantasy, the americans launched their cruise missiles at the Russians and Drones in Syria and the Russians downed most of the cruise missiles, and all the time they are downing drones, when F-35 launches its weapons from farther distances it gives more time to down them, simple like that.
In low intensity wars like in jungles, drones do not have range, you need troops with drones as recce, if they send long range drones SAMs can work too, so at the end of the day a well armed adversary will destroy the weapons and drones and keep the F-35 away

 

[asianobserve]

TVC nozzles are also used for RCS and air drag reduction, so yes F-22 has better stealth and less drag that F-35; PAKFA Su-57 will deflect much less its feathers than F-35, so yes TVC nozzles can also extend range

F-22 having less drag, yes. But more stealth? Debatable. Some USAF senior officials are claiming that F-35 turned out stealthier than F-22. One clue is the use of newer stealth coating tech like Fiber Mat that is said to have an almost full radar spectrum coverage.

 

[MiG-29SMT]

F-22 having less drag, yes. But more stealth? Debatable. Some USAF senior officials are claiming that F-35 turned out stealthier than F-22. One clue is the use of newer stealth coating tech like Fiber Mat that is said to have an almost full radar spectrum coverage.

deflecting your rudders ailerons or tailplanes means you are breaking planform alignments, got it? F-22 will deflect much less thanks to TVC nozzles, F-35 has no TVC nozzles, so despite you think it has Su-57 or F-22 agility, it has not such agility, on air to air combat Su-30MKI, Su-35 or Su-57 will beat it, it has small wings, low lift, why? the designers needed a small wing for V/STOL, a large wing makes drag when the Harrier is taking off vertically and same is F-35, so the F-35 is fat due to the need to carry internal weapons bays and has a small wing to reduce drag at vertical take off.
got it?
F-22 has a large wing, Su-57 too, lots of lift and TVC nozzles makes it more maneuverable, big wings make for less wing enhancements devices like F-15, small wing makes for poor fighters, low aspect ratio makes it unfitted to replace the high capacity loitering of A-10 at low speeds, got it?


F-35 is crap, at the most will replace F-16 in the attack role but with a more delicate fuselage