J20 Stealth Fighter

scatterStorm

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Untrue. So far we've seen 2 layers of edge treatments. Images of the J20 in primer show either or both sawtooth paterns and composite stealth structures on all control surfaces:




In addition to the edge treatment, all access hatches and operating doors are sawtoothed and all apetures are edge-aligned as seen above.

The edge treatment on the J20 once painted in also obvious to see. The inlets, canards, LERX, wing leading edge, vertical stabilizers, tail booms and vertical fins are all treated.



Please provide the photos that show the untreated edges you allude to...


The APA modelling was done on the very 1st prototype shortly after its first flight; which is why it is a "preliminary assessment". There have been 3 iterative changes to the airframe since. Which is why they repeatedly allude to a "matured production airframe". Ofcourse the study has limitations judging by the fact that they do not have access to the actual airframe.



Exactly. So where do you hear him calling it a bomber? Large fuel capacity, good supersonic performance, LO airframe. Where does "bomber" come in? The F22 can carry 2 2000lb bombs or 8 SDB's internally but its never been called a bomber? I'm not even sure it has any cruise missiles integrated with it.

We've NEVER seen any kind of A2G ordinance on the J20. Even in its operations with J16's and J10's its always operated in an air superiority role to clear the way for A2G ladden J16's.

Your "bomber" assertions come with no evidence other that "its large". Well yeah, so is the SU35, but its not a bomber either. The performance requirements for the JXX programme have all pointed towards air superiority, not a bomber role. According to pentagon intel reports there are VLO strategic and regional bomber platforms in the works for the PLAAF.

Eventually the PLAAF will integrate a2g munitions on the J20 as the platform matures however, even being capable of undertaking SEAD or classic strike missions does not make it a "bomber".

Nice write up from Rick Joe from the diplomat below. I have a subscription, but I believe the first 5 articles are free or something.

https://thediplomat.com/2018/12/chinas-stealth-fighter-its-time-to-discuss-j-20s-agility/



  1. Again, the FC31 is not a PLA sanctioned project yet.
  2. In addtion, the FC31 does not have the same PERFORMANCE REQUIREMENTS as the JXX programme. its a medium-weight airframe with obviously a much smaller range.
  3. The FC31 even if it where purchased by the PLAAF is not a successor or replacement for the J20. The VLO intecerpt and air superiority mission would still fall to the J20, so your point is moot
  4. The losing bid for the JXX programme was a "conventional stealth airframe WITH CANARDS ie. the J20 met the requirements for stealth, supercruise, supersonic and transonic maneuvering better than the "conventional airframe".
  5. Just like the operational SU57, F35 and the yet to fly AMCA and KFX, the J20 is not VLO in the rear aspect because it uses conventional engine nozzles which brings compromises to detection in the IR spectrum. J20, SU57 and F35 have RCS reduction measures applied in the rear aspect, but overall, I believe its quite telling that none of them went the F22 route. How much does it really impact operational viability in the air superiority role not to have full all aspect stealth? Is it worth the price and weight penalties?



Was this "proposed design" subjected to aerodynamic modelling and wind tunnel testing? Which studies support the implementation of such a design? What are the aerodynamic implications of changing the shape and size of the canards? And what are the aerodynamic implications of placing the wings there? What are the weight penalties of using that nozzle arrangement and which engines will compensate for that weight with additional thrust? What with the abnormal placement of the vertical stabilizers? How will this design compensate for Yaw instability created by removing the vental fins? How does this model overcome the penalty of lift loss from the shift away from dihedral canards?

Armchair aeronautical engineers can put up all the fantasy designs they want on the net, but they :

  1. Do not have access to ALL the requirements put on the airframe
  2. Do not have access to the modelling required to produce a viable platform
  3. Do not have access to wind tunnels and anechoic chambers to assess the aerodynamic or VLO performance of their "designs"
  4. Do not know all the specific technological limitations on the Chinese aero industry
So I'd call that "design" worthless when weighed against the considerations made by Dr. Yang Wei, his team or their predecessors at 611 institute which materialized into the J20 programme as we see it today.
⭐ Counter to point 1: (read carefully this time)

👉 Canards torque arm have gaps. While moving those canards, radar waves will eventually get deflected by a large curved object that's.

👉 Misaligned Canard, not conforming to frontal planner form.

Tell me are they aligned to wing root? Untrue.



👉 The underwing bulged control surface actuator (nice round shape). (see below)



👉 Counterbalancing stealth using radio-spectrum-airfoil & its limitations to the fighter jet:

So you've reduced backscatter through sawtooth edge treatment, done some paint job so specular reflections are covered and surface em waves covered?

What about Mie scattering for which newer radars such as this one is developed for, exploiting's the resonance regions of a stealth jet?

"That why I said this model is not tested for real world conditions".

Infact, the emphasis on radio-spectrum-airfoils (stealth) for fighters and for reduced drag - can force:
  • Internal weapon bays / carriage restrictions. (Check for J20)
  • Reduced space for internal fuel. (Check for J20)
  • Which force increased aircraft size / or the use of external tanks. (Check J20)
  • All bad for "the element of surprise" Stealth's hallmark feature.

Draw down to Mie Scattering: 👇

"As the radar wavelength grows, non-specular reflections intensify and specular reflections widen. For flat surfaces, traveling waves grow with the square of wavelength and their angle of peak backscatter rises with the square root of wavelength: at 1/10th the surface length, it is over 15 deg. Tip diffractions and edge waves from facets viewed diagonally also grow with the square of wavelength. Specular reflections from flat surfaces decrease with the square of the wavelength, but widen proportionally: at 1/10th the surface length, they are almost 6 deg. wide. In addition, most RAM types become less effective as wavelength increases. For all these reasons, stealth specialists say the RCS of a stealth aircraft grows approximately with the square of wavelength from the lowest frequency for which it was designed, and that above-mentioned effects become significant when the wavelength reaches about 1/10th the size of a structure.

this regime —where the wavelength is between one and 1/10th the size of the structure—is known as the “resonance region.Maximum RCS is often reached when the wavelength reaches the approximate size of the structure. "

⭐ Counter to your point no 2:
So where do you hear him calling it a bomber?
Never said, he called it a bomber. I was putting the point to why its LO rather than VLO.

@MiG-29SMT posted a J20 with a pylon, with supersonic fuel EDT.

Now why do we do that on a "so called stealth jet"? If this huge jet cannot take ATGMs in its IWB, than it can surely carry on its pylons, a subsonic ATGMs. Since munitions are still developing, is highly likely, that it would carry a subsonic cruise missile, supersonic cruise missile or ATGM payloads.

"With its LO (stealthy) characteristics, it will eventually become a swing-role supersonic LO bomber fighter jet confining to the mission parameters of Mirage 2000 like fighter jet".




⭐ Counter to your Point no. 3: FC-31 and its shenanigan's.

👉 FC-31 is now being funded partially funded by PLAAF (unofficially). Its happening, as much as you deny it, its literally on the table. To provide weight here are some questions, Why the marketing? Why on this dudes desk? With a PLAAF army logo?




Now you would say, so what its a model, to which my argument is simply, why put models just for show, because you are marketing it already to the PLAAF.

Ok you are still not convinced then, a full gray paint job with a pitot tube would suffice and its a fairly recent one, I am pretty sure you have it seen already
👇



FC31 is VLO and would enter in both for airforce and navy roles, much like the F35B and F35C variants.

👉 I can clearly see that this jet was designed for VLO, rear end not much because of the engine technology which is understandable. In fact, it has taken lesson from J20 and improved upon it. All it requires damn good engines.

Conclusion:

1. J20 is LO jet, a "stealthy jet" for what SU57 is also mocked for by western BS media.

"However, SU57 is clearly a thought out technology, that's why I say "Russians had very different mission parameters stated for it, to counter F35 and F22".

2. J20 isn't a stealth jet (VLO), not much data is available for its EW capabilities which also adds to the stealthy characteristics of a jet. Much of the armaments are still in development, and we might see ATGMs for it.

"Hence its role for stealth is unclear".

3. J20 Mission parameter as you clearly stated,

"Do confine to regimes such as maneuverability, Long range endurance, air superiority fighter jet."

4. I would add my speculations as well,

"Swing-role, fighter bomber".
 
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shiphone

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the funny part is your so called 'viewpoint' were just from chinese members of some forum and social media accounts, including all pix and viewpoint ...nothing more...don't pretend to be know everything without basic language ability and comon sense about Chinese stuff.

again. this is the AVIC's (601+112 team) export projectFC-31' -the 3rd prototype (PT 31003),not any member of a national project. ..at this moment, the true prototype of new 'J-XX project' hasn't been revealed yet...it will be a little different ,and again , it will emerges as the 'shipboard fighter'...

'so called recent photo' actually was the one recently revealed not taken... that northern city has fewer Airplane photography enthusiasts with worse shooting conditions and strict info control. we saw it long time ago in a small group but no one 'dare' to reveal it on the internet.

so called PLAAF emblem ? where is it?

pitot tube is a common device on prototypes ,and a temporary device


------------------------------------
'at this stage ,in the PLAAF plan ,no other fighter porject would have higher priority than J-20. for the air force J20 is the king and everything. forget that 'FC-31' project' for export .

if you are expecting some new PLAAF toys in fighter catologue , I would recommend some new member of J-20 'family'... it will be the next star...lol



and his 'Wingman'

 
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MiG-29SMT

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the funny part is your so called 'viewpoint' were just from chinese members of some forum and social media accounts, including all pix and viewpoint ...nothing more...don't pretend to be know everything without basic language ability and comon sense about Chinese stuff.

again. this is the AVIC's (601+112 team) export projectFC-31' -the 3rd prototype (PT 31003),not any member of a national project. ..at this moment, the true prototype of new 'J-XX project' hasn't been revealed yet...it will be a little different ,and again , it will emerges as the 'shipboard fighter'...

'so called recent photo' actually was the one recently revealed not taken... that northern city has fewer Airplane photography enthusiasts with worse shooting conditions and strict info control. we saw it long time ago in a small group but no one 'dare' to reveal it on the internet.

so called PLAAF emblem ? where is it?

pitot tube is a common device on prototypes ,and a temporary device


------------------------------------
'at this stage ,in the PLAAF plan ,no other fighter porject would have higher priority than J-20. for the air force J20 is the king and everything. forget that 'FC-31' project' for export .

if you are expecting some new PLAAF toys in fighter catologue , I would recommend some new member of J-20 'family'... it will be the next star...lol



and his 'Wingman'
J-31 will not change


The J-31 will not change due to engine technology.

J-31 has 2 engines because China can not make now an engine like f135.

Ask your self a question do you think Lockheed Martin was so stupid to put the F-35 secrets online and China so great to hack them?

J-31 was designed with old R-93 engines which are 1/2 the power of a single F135.


Basically China like any communist power . well it is not communist, they claim J-20 is ready, it is not ready.

Why China buys Su-35s? well no Chinese clone copy has better engine than Su-35 and China and Russia are allies, it is more like Germany and the Soviet Union in 1939, they pretend to be friends while China desires Siberia and like Germany thinks its excessive population can have a new home there in Russia.


So J-20 has low yield engines Russia just made type 30 for Su-57 and unless the technology is very difficult to duplicate and Russia has something better, they very unlikely will sell it to China.

China with a very heavy J-20 will become an easy pray, huge canards, ventral fins, lots of external clutter, lower yield engines, wow a crap of aircraft really, and very expensive using 2 engines, the fiasco will be worse than F-35, because F-35 has a single engine allowing for higher producibility.
 
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MiG-29SMT

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⭐ Counter to point 1: (read carefully this time)

👉 Canards torque arm have gaps. While moving those canards, radar waves will eventually get deflected by a large curved object that's.

👉 Misaligned Canard, not conforming to frontal planner form.

Tell me are they aligned to wing root? Untrue.



👉 The underwing bulged control surface actuator (nice round shape). (see below)



👉 Counterbalancing stealth using radio-spectrum-airfoil & its limitations to the fighter jet:

So you've reduced backscatter through sawtooth edge treatment, done some paint job so specular reflections are covered and surface em waves covered?

What about Mie scattering for which newer radars such as this one is developed for, exploiting's the resonance regions of a stealth jet?

"That why I said this model is not tested for real world conditions".

Infact, the emphasis on radio-spectrum-airfoils (stealth) for fighters and for reduced drag - can force:
  • Internal weapon bays / carriage restrictions. (Check for J20)
  • Reduced space for internal fuel. (Check for J20)
  • Which force increased aircraft size / or the use of external tanks. (Check J20)
  • All bad for "the element of surprise" Stealth's hallmark feature.

Draw down to Mie Scattering: 👇

"As the radar wavelength grows, non-specular reflections intensify and specular reflections widen. For flat surfaces, traveling waves grow with the square of wavelength and their angle of peak backscatter rises with the square root of wavelength: at 1/10th the surface length, it is over 15 deg. Tip diffractions and edge waves from facets viewed diagonally also grow with the square of wavelength. Specular reflections from flat surfaces decrease with the square of the wavelength, but widen proportionally: at 1/10th the surface length, they are almost 6 deg. wide. In addition, most RAM types become less effective as wavelength increases. For all these reasons, stealth specialists say the RCS of a stealth aircraft grows approximately with the square of wavelength from the lowest frequency for which it was designed, and that above-mentioned effects become significant when the wavelength reaches about 1/10th the size of a structure.

this regime —where the wavelength is between one and 1/10th the size of the structure—is known as the “resonance region.Maximum RCS is often reached when the wavelength reaches the approximate size of the structure. "

⭐ Counter to your point no 2:

Never said, he called it a bomber. I was putting the point to why its LO rather than VLO.

@MiG-29SMT posted a J20 with a pylon, with supersonic fuel EDT.

Now why do we do that on a "so called stealth jet"? If this huge jet cannot take ATGMs in its IWB, than it can surely carry on its pylons, a subsonic ATGMs. Since munitions are still developing, is highly likely, that it would carry a subsonic cruise missile, supersonic cruise missile or ATGM payloads.

"With its LO (stealthy) characteristics, it will eventually become a swing-role supersonic LO bomber fighter jet confining to the mission parameters of Mirage 2000 like fighter jet".




⭐ Counter to your Point no. 3: FC-31 and its shenanigan's.

👉 FC-31 is now being funded partially funded by PLAAF (unofficially). Its happening, as much as you deny it, its literally on the table. To provide weight here are some questions, Why the marketing? Why on this dudes desk? With a PLAAF army logo?




Now you would say, so what its a model, to which my argument is simply, why put models just for show, because you are marketing it already to the PLAAF.

Ok you are still not convinced then, a full gray paint job with a pitot tube would suffice and its a fairly recent one, I am pretty sure you have it seen already
👇



FC31 is VLO and would enter in both for airforce and navy roles, much like the F35B and F35C variants.

👉 I can clearly see that this jet was designed for VLO, rear end not much because of the engine technology which is understandable. In fact, it has taken lesson from J20 and improved upon it. All it requires damn good engines.

Conclusion:

1. J20 is LO jet, a "stealthy jet" for what SU57 is also mocked for by western BS media.

"However, SU57 is clearly a thought out technology, that's why I say "Russians had very different mission parameters stated for it, to counter F35 and F22".

2. J20 isn't a stealth jet (VLO), not much data is available for its EW capabilities which also adds to the stealthy characteristics of a jet. Much of the armaments are still in development, and we might see ATGMs for it.

"Hence its role for stealth is unclear".

3. J20 Mission parameter as you clearly stated,

"Do confine to regimes such as maneuverability, Long range endurance, air superiority fighter jet."

4. I would add my speculations as well,

"Swing-role, fighter bomber".
J-20 has stealth treatment, it is a stealth aircraft, J-31 is like a F-22, but as mock combats have shown in WVR F-22 can be beaten by F-18F, Eurofighters or Rafales, and even Su-30MKI or Su-35 can do it.

The only two great advantages of F-22 is has longer range undetectability, stealth in few words and supercruise.

MiG-31 can supercruise too, well it uses afterburner but it has so much fuel internally it will fly as long as F-22 at higher speeds.

J-20 is slow, in the range of Mach 1.6 to Mach 1.8 due to its DSI intakes.

So stealth will be its main asset, if the jet is as agile as a Gripen, which i doubt, it will have i think no better agility than F-35, thus the jet indeed represent a Challenge for Japan or India, even Russia with S-500, but the reality the jet is overhyped.

J-31 repeats the same mistakes of F-35 with low power engines and less space for fuel than F-35, so China has focused on J-20 which can carry more fuel thus become more efective than J-31, why? because J-31 has no good engines and as you know stealth imposes weight compromises.

it carries more fuel and more weapons, so J-20 was chosen, it is better jet? no it is heavy and clumsy.

Over hyped, it is a threat because it has stealth and well it is more difficult to detect than J-10 or J-11, but by no means it is a super duper aircraft.
 

rockdog

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China's large-scale transonic wind tunnel fully operational


China’s FL-62 large-scale transonic wind tunnel has completed all its proving trials and commenced operations to generate data from test models, the Aviation Industry Corporation of China (AVIC) announced on 26 May.


The wind tunnel, which had been under development and construction since 2012, is regarded as a strategic facility and has been a major state investment.


AVIC announced on 26 May that its FL-62 large-scale transonic wind tunnel has commenced operations.

AVIC announced on 26 May that its FL-62 large-scale transonic wind tunnel has commenced operations.

It is configured as a continuous loop with a 2.4 m chamber for the structure undergoing tests, with previous reports indicating that it is expected to give more accurate and consistently reliable test results than facilities previously available to Chinese aircraft designers.


The facility has been built at AVIC’s Aerodynamic Research Institute in Shenyang, which is also the city in which one of China’s two primary combat aircraft manufacturers, the Shenyang Aircraft Corporation (SAC), is located.


SAC makes China’s ‘Flanker’ derivatives and is currently developing the FC-31 low-observable combat aircraft, which persistent rumours suggest is the leading candidate for next carrier-borne aircraft for the People’s Liberation Army Navy (PLAN).


The successful completion of the wind tunnel project was also reported by the state-owned Global Times newspaper, which noted that the first operational use of the facility was to conduct a test for “an undisclosed new aircraft”.


It also referred to a statement made in 2019 by Wang Haifeng, who was involved in the design of the J-10 and J-20 aircraft built by China’s other major combat aircraft producer – the Chengdu Aircraft Corporation –, in which he said that “China is eyeing to develop a next-generation fighter jet by 2035 or earlier”.


Global Times
 

J20!

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If you want a really low drag aircraft you make something like

View attachment 49233

Why then you need a canard?

to improve the delta wing.
:shock: Dude. Concorde didn't need canards because its an airliner that didn't pull high G maneuvers at supersonic speeds.

The Rafale has a superior design and t is a more beautiful aircraft too.

The reason is Eurofighter needs vortex generators due to the very ineffective canards it has.
The Rafale is a great looking aircraft, but it DOES NOT have a superior design for the air superiority mission. Even the Typhoon trumps it completely in this area, in part because of Rafales weak engines but also because of the differences in their aerodynamic designs.

The Typhoon is the better aircraft in the supersonic flight envelope. It flies higher, maneuvers better at supersonic speed and performs the high and fast airsuperiority mission better than Rafale.

Why? Because those were its performance requirements. The Germans, Brits and Italians focused more on the air superiority mission than the French. Rafale was designed around being omnirole, which translates to more emphasis on load carrying and maneuvering at lower altitudes ie close coupled canards to improve the high alpha performance of the wing.

J20 and Typhoon will obviously maneuver better at supersonic speeds than the Rafale because of the distance between their canards and the leading edge of the wing. It's not a mistake. Its by DESIGN because they are both air superiority mission focused airframes.

You keep implying that Rafale has the better configuration than J20 when they have different performance objectives. If the J20 Simply copied the Rafale's canard and wing configuration it's supersonic performance would be insufficient to meet its performance objectives.

The PLAAF has other airframes for the A2G mission, what they needed from the JXX programme was an air superiority platform. Rafale is the French Airforce's/Navy's main bomb truck.

The lower drag of Eurofighter type of canard is not as effective as a tailless design like Drakken or F-16XL

View attachment 49234
Dude. Again with comparing aircraft with very different missions. The F16XL was the bid that lost out to the F15 Strike Eagle... Its main mission was.... THE STRIKE MISSION. ie being a bomb truck that could defend itself against foreign interceptors.

The mission defines the airframe design, not the other way around. The J20 is not a bomb truck.

So why J-20 has canards? simple the contradictions of the design are as follows:


low drag versus controlability?

You get lower drag with a compound double delta and higher stealth, but a Tailless has the disadvantage in pitch control since a higher lift flap deflection makes a pitch down movement, thus most aircraft have tailerons to avoid that disadvantage

The canard does not help it in stealth, specially since its dihedral breaks planforming.

Will it improve a lot over Rafale?

see the size of Rafale canards

It is obvious J-20 has bigger canards with respects its wing than Rafale so it does not seem they generate less drag
View attachment 49235


View attachment 49236

The J20 has much smaller wing in relation to the airframe, its wing sweep is 43 degrees as opposed to Rafales 48 degree wing sweep and the wing is positioned further aft to minimise supersonic drag overall. Just by looking at those 2 pictures its obvious which airframe focuses more on supersonic performance.

With that huge wing, 48 degree wing sweep and the coupled canards the rafale will perform poorer than J20 in the supersonic regime. It will bleed more energy during supersonic turns too because of its canard configuration. The J20 produces much lower drag overall even with its larger canard.


see the J-20 canard is so big even with the dihedral that its tip gets already deep into the leading edge of the wing

View attachment 49240
The J-20 due to the dihedral seem smaller but if they were coplanar and horizontal they would be closer to the wing tip
View attachment 49241

Rafale has control canards since most of the lift is generated by the wing.
Most of the J20's lift is produced by the body, LERX's, its canards and inner portions of the wing, allowing for a much smaller wing ie lower drag. This is why you should stop trying to compare aircraft with completely different design goals.

I'll repeat. If J20 had wing as large as Rafale's(relative to the airframe) it's drag would increase significantly, hampering its core mission. If it used close coupled canards, its supersonic maneuvering would be much worse, hampering its core mission. The 2 aircraft have very different priorities.

The only reason J-20 is stealthier than Rafale is it carries weapons in weapons bays and twin tails, but Rafale is a much better aircraft in Aerodynamics
Even if Rafale had twin vertical stabilisers and flew clean, it would still have a much higher RCS than J20. Who are you trying to fool? I actually laughed out loud at this since you've spent pages and pages on this thread saying just the J20's canards make it unstealthy, now you're claiming the inherently unstealthy Rafale is steatlhier?

Even by your own argument, the Rafale's canards are not coplanar. So why would they be any stealthier than J20's. At least the J20's canard root is alligned with the wing, the Rafale's canard root is completely above the wing like the J10. They aren't even treated for RCS reduction as much as the J20's. RCS reduction measures do not equal a stealth combat aircraft.

Its sensors aren't edge aligned like the J20's. I'm not even going to discuss the airframe's stealth shaping vis-a-vis the J20. It's obvious for anyone with the eyes to see: VLO design features on the J20 are prominent and lacking in any meaningful way on the Rafale since its not a stealth aircraft.

Even with the restricted line of sight to the engines compressor face, its air intakes alone produce a much higher RCS than the J20's DSI's.



The reason J20 is stealthier than rafale is that stealth was a core priority to its designers since its a 5th gen aircraft. Rafale is an inherently unstealthy design even flying clean. Come on man, I was taking you seriously until that comment.
 
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MiG-29SMT

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:shock: Dude. Concorde didn't need canards because its an airliner that didn't pull high G maneuvers at supersonic speeds.



The Rafale is a great looking aircraft, but it DOES NOT have a superior design for the air superiority mission. Even the Typhoon trumps it completely in this area, in part because of Rafales weak engines but also because of the differences in their aerodynamic designs.

The Typhoon is the better aircraft in the supersonic flight envelope. It flies higher, maneuvers better at supersonic speed and performs the high and fast airsuperiority mission better than Rafale.

Why? Because those were its performance requirements. The Germans, Brits and Italians focused more on the air superiority mission than the French. Rafale was designed around being omnirole, which translates to more emphasis on load carrying and maneuvering at lower altitudes ie close coupled canards to improve the high alpha performance of the wing.

J20 and Typhoon will obviously maneuver better at supersonic speeds than the Rafale because of the distance between their canards and the leading edge of the wing. It's not a mistake. Its by DESIGN because they are both air superiority mission focused airframes.

You keep implying that Rafale has the better configuration than J20 when they have different performance objectives. If the J20 Simply copied the Rafale's canard and wing configuration it's supersonic performance would be insufficient to meet its performance objectives.

The PLAAF has other airframes for the A2G mission, what they needed from the JXX programme was an air superiority platform. Rafale is the French Airforce's/Navy's main bomb truck.



Dude. Again with comparing aircraft with very different missions. The F16XL was the bid that lost out to the F15 Strike Eagle... Its main mission was.... THE STRIKE MISSION. ie being a bomb truck that could defend itself against foreign interceptors.

The mission defines the airframe design, not the other way around. The J20 is not a bomb truck.



View attachment 49235


View attachment 49236

The J20 has much smaller wing in relation to the airframe, its wing sweep is 43 degrees as opposed to Rafales 48 degree wing sweep and the wing is positioned further aft to minimise supersonic drag overall. Just by looking at those 2 pictures its obvious which airframe focuses more on supersonic performance.

With that huge wing, 48 degree wing sweep and the coupled canards the rafale will perform poorer than J20 in the supersonic regime. It will bleed more energy during supersonic turns too because of its canard configuration. The J20 produces much lower drag overall even with its larger canard.




Most of the J20's lift is produced by the body, LERX's, its canards and inner portions of the wing, allowing for a much smaller wing ie lower drag. This is why you should stop trying to compare aircraft with completely different design goals.

I'll repeat. If J20 had wing as large as Rafale's(relative to the airframe) it's drag would increase significantly, hampering its core mission. If it used close coupled canards, its supersonic maneuvering would be much worse, hampering its core mission. The 2 aircraft have very different priorities.



Even if Rafale had twin vertical stabilisers and flew clean, it would still have a much higher RCS than J20. Who are you trying to fool? I actually laughed out loud at this since you've spent pages and pages on this thread saying just the J20's canards make it unstealthy, now you're claiming the inherently unstealthy Rafale is steatlhier?

Even by your own argument, the Rafale's canards are not coplanar. So why would they be any stealthier than J20's. At least the J20's canard root is alligned with the wing, the Rafale's canard root is completely above the wing like the J10. They aren't even treated for RCS reduction as much as the J20's. RCS reduction measures do not equal a stealth combat aircraft.

Its sensors aren't edge aligned like the J20's. I'm not even going to discuss the airframe's stealth shaping vis-a-vis the J20. It's obvious for anyone with the eyes to see: VLO design features on the J20 are prominent and lacking in any meaningful way on the Rafale since its not a stealth aircraft.

Even with the restricted line of sight to the engines compressor face, its air intakes alone produce a much higher RCS than the J20's DSI's.



The reason J20 is stealthier than rafale is that stealth was a core priority to its designers since its a 5th gen aircraft. Rafale is an inherently unstealthy design even flying clean. Come on man, I was taking you seriously until that comment.
You added a lot of Fantasy.

J-20 is not a fast design why?

well like Rafale has fixed intakes.

Pressure recovery for the DSI is around 89% by around Mach 1.7

basically all DSI intakes top up at mach 1.6. JF-17 is not fast and same applies to J-31 or F-35.
These aircraft top up at mach 1.7.

Now to claim J-20 is the better fighter at high speed is just fantasy.


for starters faceting adds drag see this

1591354512392.png


this is the ideal aerodynamic shape


it is called sears hack body you will see this shape from bullets, missiles, high speed jets like Concorde or Tu-144, Blackbird SR-71, in fact J-20 due to faceting goes far far away from those shapes look at very high speed things

1591354740491.png


As you can see the J-20 is not a sears-haack type of body

Stealth compromises aerodynamics


See Rafale
1591354849654.png


it is closer than J-20 to a searshaack body

look at our famous friend Su-27


1591354914768.png


Now look at our friend J-20

1591354970839.png


The J-20 has DNA of a typical faceted aircraft, yes it i s an evolution of the F-117 darth vader, which is not really very aerodynamic

1591355021799.png


if you look at the rear of J-20 its engine nacelles are rounded, why? yes its rounded nozzles and rear part reduce drag


So you forget Rafale was designed thinking in speed and less drag with much less stealth in Mind see our friend Eurofighter

1591355215655.png


has smaller canards than J-20 because see the wing its farther than J-20`s wing from the nozzle pipes.

Eurofighter has strakes where the canards should be if it was a closed couple canard fighter.

J-20 you like it or not is far more draggy than Rafale or Eurofighter, yes it is stealthier, but it is not more aerodynamic
 

BangaliBabu

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You added a lot of Fantasy.

J-20 is not a fast design why?

well like Rafale has fixed intakes.

Pressure recovery for the DSI is around 89% by around Mach 1.7

basically all DSI intakes top up at mach 1.6. JF-17 is not fast and same applies to J-31 or F-35.
These aircraft top up at mach 1.7.

Now to claim J-20 is the better fighter at high speed is just fantasy.


for starters faceting adds drag see this

View attachment 49403

this is the ideal aerodynamic shape


it is called sears hack body you will see this shape from bullets, missiles, high speed jets like Concorde or Tu-144, Blackbird SR-71, in fact J-20 due to faceting goes far far away from those shapes look at very high speed things

View attachment 49404

As you can see the J-20 is not a sears-haack type of body

Stealth compromises aerodynamics


See Rafale
View attachment 49405

it is closer than J-20 to a searshaack body

look at our famous friend Su-27


View attachment 49406

Now look at our friend J-20

View attachment 49407

The J-20 has DNA of a typical faceted aircraft, yes it i s an evolution of the F-117 darth vader, which is not really very aerodynamic

View attachment 49408

if you look at the rear of J-20 its engine nacelles are rounded, why? yes its rounded nozzles and rear part reduce drag


So you forget Rafale was designed thinking in speed and less drag with much less stealth in Mind see our friend Eurofighter

View attachment 49409

has smaller canards than J-20 because see the wing its farther than J-20`s wing from the nozzle pipes.

Eurofighter has strakes where the canards should be if it was a closed couple canard fighter.

J-20 you like it or not is far more draggy than Rafale or Eurofighter, yes it is stealthier, but it is not more aerodynamic
well, 5th gen fighters are also planes, aren't they? Then what about the F22? Is it draggy too?? Please explain the sears-hack body type and why 5th gen aerostructures aren't such!!
 

MiG-29SMT

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well, 5th gen fighters are also planes, aren't they? Then what about the F22? Is it draggy too?? Please explain the sears-hack body type and why 5th gen aerostructures aren't such!!
they balance stealth and aerodynamics.

The ideal aerodynamic shape is like Air to air missiles, but aircraft need wings, air intakes, nozzles thus there are compromises, so no aircraft can be as close to the sears-haack body.


However some aircraft get closer to this ideal

F-104 is one
1591357576724.png

concorde is another
1591357653083.png



other due to different needs like Stealth in F-117 or air intake type like F-15 or MiG-25 go farther from this ideal.

F-22 has a radome trying to be close to an ogive but still respeting faceting
1591357897265.png


due to diffraction F-22 keeps flat sides

due to creeping wave returns

1591357961634.png



So what is ideal for aerodynamics is not for stealth

J-20 opted for more drag, but it will reduce diffraction and creeping waves.

So its forebody has flat walls and no circular cross section but the typical rhomboid cross section of stealth aircraft
 

J20!

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⭐ Counter to point 1: (read carefully this time)

👉 Canards torque arm have gaps. While moving those canards, radar waves will eventually get deflected by a large curved object that's.

👉 Misaligned Canard, not conforming to frontal planner form.

Tell me are they aligned to wing root? Untrue.



👉 The underwing bulged control surface actuator (nice round shape). (see below)

You're grasping at straws to come to your pre-decided conclusion mate.

The control surface actuator fairings on the F22 and Su57 are exactly the same.



not to mention the mass of bulges and curves on the F35's underside(apparently that's by design and it works)


The very small gap between the airframe and the canard is actually smaller than the gaps between the wing and the control surfaces. If it was a hot spot for radar returns then surely those gaps (on all operational 5th gens) would be catastrophic for RCS no?

👉 Counterbalancing stealth using radio-spectrum-airfoil & its limitations to the fighter jet:

⭐ Counter to your point no 2:

Never said, he called it a bomber. I was putting the point to why its LO rather than VLO.
Again, you're grabbing at straws to prove your point. VLO and LO are terms with very inconsistent definitions. Some, like Dr Carlo Kopp define Low Observable as aircraft with an RCS of -10 to -30 dBSM, and Very Low Observable as an RCS ranging from -30 to -40 dBSM

The retired Major General you're referencing from that video - David Deptula - has been a longtime advocate for 5th gen integration into the US military. And yet he doesn't define the F22 and F35 as VLO aircraft either.:laugh: Here's an article he penned for Airforce Magazine where he lays it out:

https://www.airforcemag.com/article/the-case-for-fifth-generation-and-ngad-airpower/

"But neither the F-22 nor F-35 compromise performance to become “very low observable (VLO).” Thanks to advanced computer processing, lessons learned from earlier stealth designs, and innovative radar-absorbing materials, these fifth-generation aircraft deliver “all-aspect stealth” while still exceeding the air combat maneuverability of fourth-generation fighters."

So if you believe his calling the J20 LO was a jibe at the aircraft, you're wrong.

@MiG-29SMT posted a J20 with a pylon, with supersonic fuel EDT.

Now why do we do that on a "so called stealth jet"? If this huge jet cannot take ATGMs in its IWB, than it can surely carry on its pylons, a subsonic ATGMs. Since munitions are still developing, is highly likely, that it would carry a subsonic cruise missile, supersonic cruise missile or ATGM payloads.

"With its LO (stealthy) characteristics, it will eventually become a swing-role supersonic LO bomber fighter jet confining to the mission parameters of Mirage 2000 like fighter jet".

Be more accurate with your terminology mate. A fighter bomber and a multirole fighter are two different things. The Tornado is a fighter bomber. The JH7A is a fighterbomber. A J10 is a multirole fighter. J20 is a multirole fighter with a heavy focus on the air superiority mission. It's not a fighter-bomber.

Capture.PNG


https://www.dia.mil/Portals/27/Documents/News/Military Power Publications/China_Military_Power_FINAL_5MB_20190103.pdf

I took the table above from the Defense Intelligence Agency's 2019 China Millitary Report. There's a clear distinction between Fighter-Bombers and Multirole fighters. But also note that this report was the first open source confirmation from the Pentagon that China is developing a dedicated stealth Tactical bomber alongside a stealth strategic bomber.

So no. The J20's design is completely focused on air superiority. It may do reconnaissance, or some sort of SEAD mission later on, but as of right now, there is a dedicated tactical bomber in development to fill that role within the PLAAF.

It's large because it has a huge fuel load. Not so that it does bombing runs but (as your friend David pointed out in your video) so that it can maintain presence (or stay on station) over a long period of time over a large area in the air superiority role.

And to your point regarding the pylons being tested on prototype 2013; Those are twin rails for mounting air to air missiles mate.

Yes it has a main internal weapons bay, but that restricts carrying capacity. Just using those 2 pylons with the twin rails would double its BVR missile load out (4 to 8). Or allow it to carry the very long range BVR missiles seen recently on J16's and J11B's which are too long for the IWB's. Its all about tactics. A J20 Quarterback carrying 8 PL15's or 4 ER BVR missiles could be cued by a clean J20 operating closer to enemy contacts. Even in this configuration it could expend the missiles, then blow off the pylons to regain its minimized RCS.

The pylons increase flexibility for the platform. But they don't make it a "fighter bomber " all of a sudden mate.


⭐ Counter to your Point no. 3: FC-31 and its shenanigan's.

👉 FC-31 is now being funded partially funded by PLAAF (unofficially). Its happening, as much as you deny it, its literally on the table. To provide weight here are some questions, Why the marketing? Why on this dudes desk? With a PLAAF army logo?




Now you would say, so what its a model, to which my argument is simply, why put models just for show, because you are marketing it already to the PLAAF.

Ok you are still not convinced then, a full gray paint job with a pitot tube would suffice and its a fairly recent one, I am pretty sure you have it seen already
👇



FC31 is VLO and would enter in both for airforce and navy roles, much like the F35B and F35C variants.

👉 I can clearly see that this jet was designed for VLO, rear end not much because of the engine technology which is understandable. In fact, it has taken lesson from J20 and improved upon it. All it requires damn good engines.
So you think a jet built for export is going to be stealthier than the PLAAF's premier stealth air superiority platform?:shock: Your theory doesn't make sense mate.

As @shiphone already pointed out, the FC31 is not a PLAAF project. Its an AVIC project for export. There are reports that Shengyang won the Navy competition to provide a carrier borne stealth fighter for the navy with an airframe based on the FC31. That still does not make it a PLAAF project and there have been no indications that a medium weight stealth fighter is being developed for the PLAAF. You're just speculating with 0 evidence.

The picture above is of the 2nd FC31 prototype. It has a pitot tube because its a test article. Being grey does not make it a PLAAF fighter mate. You need to learn more about the Chinese military before making bold claims like that.

Conclusion:
1. J20 is LO jet, a "stealthy jet" for what SU57 is also mocked for by western BS media.

"However, SU57 is clearly a thought out technology, that's why I say "Russians had very different mission parameters stated for it, to counter F35 and F22".

2. J20 isn't a stealth jet (VLO), not much data is available for its EW capabilities which also adds to the stealthy characteristics of a jet. Much of the armaments are still in development, and we might see ATGMs for it.

"Hence its role for stealth is unclear".

3. J20 Mission parameter as you clearly stated,

"Do confine to regimes such as maneuverability, Long range endurance, air superiority fighter jet."

4. I would add my speculations as well,

"Swing-role, fighter bomber".
Mate, your argument is literally that "because it has canards, its not a stealth fighter". Modelling does not show HUGE spikes in RCS from the canards like you allude to. And additionally, The VLO shaping on the J20 far exceeds what we've seen so far from the Su57. Any objective analyst can see that.

Actual studies on the J20's RCS confirm robust stealth performance. All unclassified reports from the Pentagon allude to the same. The only people claiming that the canards aren't stealthy are internet commentators.

I've already addressed the "bomber" speculation above. Being a large aircraft or carrying external loads does not a bomber make.
 

scatterStorm

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the funny part is your so called 'viewpoint' were just from chinese members of some forum and social media accounts, including all pix and viewpoint ...nothing more...don't pretend to be know everything without basic language ability and comon sense about Chinese stuff.

again. this is the AVIC's (601+112 team) export projectFC-31' -the 3rd prototype (PT 31003),not any member of a national project. ..at this moment, the true prototype of new 'J-XX project' hasn't been revealed yet...it will be a little different ,and again , it will emerges as the 'shipboard fighter'...

'so called recent photo' actually was the one recently revealed not taken... that northern city has fewer Airplane photography enthusiasts with worse shooting conditions and strict info control. we saw it long time ago in a small group but no one 'dare' to reveal it on the internet.

so called PLAAF emblem ? where is it?

pitot tube is a common device on prototypes ,and a temporary device


------------------------------------
'at this stage ,in the PLAAF plan ,no other fighter porject would have higher priority than J-20. for the air force J20 is the king and everything. forget that 'FC-31' project' for export .

if you are expecting some new PLAAF toys in fighter catologue , I would recommend some new member of J-20 'family'... it will be the next star...lol



and his 'Wingman'

:facepalm:
What you don’t like someone started raising questions on the jet which has already been detected by IAF?

👉🏼 J20 is nothing but large jet compromised too much to be called even stealth jet, hence LO jet. Not a true VLO jet like F22. Clearly it’s designer, Mr. Lin thought it to somewhat stealthy, but swing role was thought of, maneuverability too.

⭐If your prototype jet haven’t got a badge than it doesn’t mean the program is over. It’s been marketed heavily by AVIC, I don’t suppose to tell you that it’s on the homepage of AVIC website. 👀

⭐ Tell me this, does AVIC is making the prototypes for free? It has been partially funded. It’s clear by design, that PLAAF wanted a copy of F35 that could support J20 in its interceptor missions, or even in bomber missions in future. Considering trip to Taiwan isn’t short. :playball:

⭐ If your PLAAF is so confident in your J20 than why it isn’t re-deployed over Tibet already... recently? Gimme a brake already.

Your banana planes doesn’t match with IAF experience, otherwise it would’ve been already redeployed. Go figure!
 

scatterStorm

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J-20 has stealth treatment, it is a stealth aircraft, J-31 is like a F-22, but as mock combats have shown in WVR F-22 can be beaten by F-18F, Eurofighters or Rafales, and even Su-30MKI or Su-35 can do it.

The only two great advantages of F-22 is has longer range undetectability, stealth in few words and supercruise.

MiG-31 can supercruise too, well it uses afterburner but it has so much fuel internally it will fly as long as F-22 at higher speeds.

J-20 is slow, in the range of Mach 1.6 to Mach 1.8 due to its DSI intakes.

So stealth will be its main asset, if the jet is as agile as a Gripen, which i doubt, it will have i think no better agility than F-35, thus the jet indeed represent a Challenge for Japan or India, even Russia with S-500, but the reality the jet is overhyped.

J-31 repeats the same mistakes of F-35 with low power engines and less space for fuel than F-35, so China has focused on J-20 which can carry more fuel thus become more efective than J-31, why? because J-31 has no good engines and as you know stealth imposes weight compromises.

it carries more fuel and more weapons, so J-20 was chosen, it is better jet? no it is heavy and clumsy.

Over hyped, it is a threat because it has stealth and well it is more difficult to detect than J-10 or J-11, but by no means it is a super duper aircraft.
Of course F22 has been beaten in WVR. Many times. Well they say “if you paint a fox as wolf, would not make it a wolf”. Stealth technology is been countered already, recent deployment of resonance based radars can pick VLO jets at 600km. Russian tech, and Russians are damn good at making better radars. When SU57 weren’t deployed in Syria SU35S were already in airspace deterring F35s. Every enthusiast knows F22 were covertly being deployed under cover of ISIS.

J20 engines are almost done, so mach no. can be 1.8 or even 2. Yes they compromised on stealth, hence the larger design, meaning more resonance will be produced approximate of its size.

J20 was detected, IAF former chief doesn’t go saying that they haven’t been detected over Tibet, if it was a statement made confidently than I trust the man, because I trust IAF with more combat experience than PLAAF can muster.
 

scatterStorm

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they balance stealth and aerodynamics.

The ideal aerodynamic shape is like Air to air missiles, but aircraft need wings, air intakes, nozzles thus there are compromises, so no aircraft can be as close to the sears-haack body.


However some aircraft get closer to this ideal

F-104 is one
View attachment 49410
concorde is another
View attachment 49411


other due to different needs like Stealth in F-117 or air intake type like F-15 or MiG-25 go farther from this ideal.

F-22 has a radome trying to be close to an ogive but still respeting faceting
View attachment 49412

due to diffraction F-22 keeps flat sides

due to creeping wave returns

View attachment 49413


So what is ideal for aerodynamics is not for stealth

J-20 opted for more drag, but it will reduce diffraction and creeping waves.

So its forebody has flat walls and no circular cross section but the typical rhomboid cross section of stealth aircraft
True, ideal aerodynamics is for A2A missiles. Jets are now designed to be aerodynamically unstable, hence drag becomes a key variable in determining Endurance. J20 in its FOC variant though has smooth surfaces, so drag is somewhat managed, however recent F35 incidents and F22 incidents with there paint being Chipped off while going supersonic could be a problem with J20 too. Expensive affair indeed.
 

MiG-29SMT

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You're grasping at straws to come to your pre-decided conclusion mate.

The control surface actuator fairings on the F22 and Su57 are exactly the same.



not to mention the mass of bulges and curves on the F35's underside(apparently that's by design and it works)


The very small gap between the airframe and the canard is actually smaller than the gaps between the wing and the control surfaces. If it was a hot spot for radar returns then surely those gaps (on all operational 5th gens) would be catastrophic for RCS no?





So no. The J20's design is completely focused on air superiority. It may do reconnaissance, or some sort of SEAD mission later on, but as of right now, there is a dedicated tactical bomber in development to fill that role within the PLAAF.











Actual studies on the J20's RCS confirm robust stealth performance. All unclassified reports from the Pentagon allude to the same. The only people claiming that the canards aren't stealthy are internet commentators.

I've already addressed the "bomber" speculation above. Being a large aircraft or carrying external loads does not a bomber make.
1591416422999.png


1591416541208.png


If you see those graphs show the gains of Thrust vectoring.

You can see F-22 is not that great without thrust vectoring, consider it has a huge wing but also consider is 6000 kg heavier than an F-15 and 10000 kg heavier than F-16 at empty weight.

Now J-20 is at least 10000 kg heavier than J-10; and at full weight it is around 36000 kg at least 15000 kg more than a fully loaded J-10.

So you get the need for engines in the region of 15000 kg of thrust.

without them J-20 is an interceptor regardless you claim is an air superiority.


without thrust vectoring that extra weight means not better agility than J-10.

All the stealth aircraft are heavy, very heavy the light weight F-35 weighs 13000 kg empty and has an engine in the region of 18000kg

Got it?


J-20 to be better than F-22 needs engines like f135 that power F-35.
1591417287210.png


now reality check why China bought Su-35?

engine? radar?
 

MiG-29SMT

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Of course F22 has been beaten in WVR. Many times. Well they say “if you paint a fox as wolf, would not make it a wolf”. Stealth technology is been countered already, recent deployment of resonance based radars can pick VLO jets at 600km. Russian tech, and Russians are damn good at making better radars. When SU57 weren’t deployed in Syria SU35S were already in airspace deterring F35s. Every enthusiast knows F22 were covertly being deployed under cover of ISIS.

J20 engines are almost done, so mach no. can be 1.8 or even 2. Yes they compromised on stealth, hence the larger design, meaning more resonance will be produced approximate of its size.

J20 was detected, IAF former chief doesn’t go saying that they haven’t been detected over Tibet, if it was a statement made confidently than I trust the man, because I trust IAF with more combat experience than PLAAF can muster.
well F-22 is an excellent aircraft, but so are Eurofighter or Rafale.


Stealth has the problem that the hardware will get obsolete sooner or later, but F-22 was designed with the power to supercruise, that will be a good asset once stealth becomes obsolete.

J-20 probably can not supercruise and its DSI intakes reduces thrust as it goes supersonic meaning less thrust and worse acceleration.
 

MiG-29SMT

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True, ideal aerodynamics is for A2A missiles. Jets are now designed to be aerodynamically unstable, hence drag becomes a key variable in determining Endurance. J20 in its FOC variant though has smooth surfaces, so drag is somewhat managed, however recent F35 incidents and F22 incidents with there paint being Chipped off while going supersonic could be a problem with J20 too. Expensive affair indeed.
it is always to understand aerodynamics to see the compromises
1591426737539.png

Tails positioned behind of the main-wing like VT and HT also affects the high AoA characteristics of the jet fighters. As described in the conventional theory, Horizontal Tail is swallowed by downstream of the main-wing, and generate negative lift and positive pitching moment. Recent fighters like F-22, F-35, Pak-Fa, J-31 in Fig. 2.40 positioned HT very closed to main-wing to avoid such a problem. When the HT is closed to main-wing, there is no room to face downstream for HT. Thus, HT could avoid downstream of main-wing which improve L/D characteristics of the jet fighters. Most famous example of VT design for jet fighters is F/A-18 as described in the previous contents. Vortex generated by strake, nose or main-wing is designed to pass around VT to maintain controllability in high AoA as shown in Fig. 2.50 [9].

 

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