Chengdu J-20 5th Generation Aircraft News & Discussions

[Black Widow]

Yes Russia lacks the ability to manufacture a bubble canopy just like the Americans lacked the ability to manufacture a bubble canopy in the X-35 and YF-23


And yes, Russia can not develop a big lump in front of an intake, aka DSI. All the engineers, designers, scientists, with all the money available to them and resources such as wind tunnels, computers, machining tools can’t develop a lousy hump in front of the intake. They must be ripping their hair out


But I know what’s coming you need supercomputers to develop such as device, and the answer to that is not you do not, you need a wind tunnel. And just for the brain dead Russia has supercomputers both domestic as well as foreign.


The 1950’s Migs had divertless intakes in the form of cones but those could be adjusted, unlike the Chinese ones, thus there was no loss in certain flight regimes.


Check this out:






Congratulations, you’re boasting about 1950’s technology.

I have made a rule for me,I don't reply to those who have lesser posts (say less than 1000). This really help... I am annoyed of the visual inspectors,

These chines kids knows that J20 is better coz
1. It is black in color.
2. It has canard
3. It has DSI (though in your earlier post you have cleared that DSI has nothing to do with stealth.
4. and coz its Chinese...

 

[antonius123]

Why does it has to be DSI, don't you see it is like in the X-35 like stage

See this pause at the second 2, you see that vent? They improved on it and so will the Russians.

Why is it so hard to just say it man, spit it out that either you have experience or not, just do it man(nike)

OK, you may say that PAKFA could eventually tranform to be like F-22

But the point is: even the most recent prototype of PAKFA still has NO such feature, does it mean that Russia still unable to incorporate that technology to the recent their most advanced 5th Fighter?

I hope you got it

 

[antonius123]

Yes Russia lacks the ability to manufacture a bubble canopy just like the Americans lacked the ability to manufacture a bubble canopy in the X-35 and YF-23

Exactly!

But now USA is obviously capable to incorporate DSI and buble canopy to their most modern aircraft, earlier than China.

How about Russia?

And yes, Russia can not develop a big lump in front of an intake, aka DSI. All the engineers, designers, scientists, with all the money available to them and resources such as wind tunnels, computers, machining tools can’t develop a lousy hump in front of the intake. They must be ripping their hair out


But I know what’s coming you need supercomputers to develop such as device, and the answer to that is not you do not, you need a wind tunnel. And just for the brain dead Russia has supercomputers both domestic as well as foreign.


The 1950’s Migs had divertless intakes in the form of cones but those could be adjusted, unlike the Chinese ones, thus there was no loss in certain flight regimes.


Check this out:






Congratulations, you’re boasting about 1950’s technology.

You obviously dont know what DSI.
Just as usual you are talking something you dont know

Check this out:
Diverterless supersonic inlet - Wikipedia, the free encyclopedia

I have made a rule for me,I don't reply to those who have lesser posts (say less than 1000). This really help... I am annoyed of the visual inspectors,

These chines kids knows that J20 is better coz
1. It is black in color.
2. It has canard
3. It has DSI (though in your earlier post you have cleared that DSI has nothing to do with stealth.
4. and coz its Chinese...

Obviously you have poor reading comprehension capability, you dont get the point why we are saying J-20 is better in stealth shaping compared to PAKFA.


About DSI, check this:

It was found that the DSI gave high performance, high total pressure recovery, low integrated distortion and good engine/intake matching.[2]
Diverterless supersonic inlet - Wikipedia, the free encyclopedia

 

[Esc8781]

OK, you may say that PAKFA could eventually tranform to be like F-22

But the point is: even the most recent prototype of PAKFA still has NO such feature, does it mean that Russia still unable to incorporate that technology to the recent their most advanced 5th Fighter?

I hope you got it

I am saying that it might come out with a stealthier air-frame.

 

[ptldM3]

Exactly!

But now USA is obviously capable to incorporate DSI and buble canopy to their most modern aircraft, earlier than China.

How about Russia?

Why are you under the assumption that Russia would want DSI? If they would want it they would have it, there is nothing special about it.

As for a one piece canopy, it’s very heavy and expensive. Perhaps the production aircraft will incorporate it but if not than the weight and price would not be worth it.

And sorry, there is nothing special about a one piece canopy. All it is, is either Acrylate polymers or an Acrylic compound that is vacuumed in a mold.


Even civilian aircraft have one piece canopies:

You obviously dont know what DSI.
Just as usual you are talking something you dont know

Check this out:
Diverterless supersonic inlet - Wikipedia, the free encyclopedia

More like you don’t know what you are talking about. Lets use your source, Wekipedia to disprove you.

Some air inlets feature a biconic centrebody to form two conic shock waves, both focused on the lip of the intake. This improves pressure recovery. Some aircraft (F-35 Lightning II, Mirage III) use a semi-conic centrebody.

Now would you look at that, the Mirage and F-35 use the same type of intakes, not identical but the same. Both do the same thing.


Lets look further into this:


DSI first:


Diverterless supersonic inlet - Wikipedia, the free encyclopedia

It consists of a "bump" and a forward-swept inlet cowl, which work together to divert boundary layer airflow away from the aircraft's engine while compressing the air to slow it down from supersonic speed.
The main purpose of an inlet cone is to slow the flow of air from supersonic flight speed to a subsonic speed before it enters the engine.

Now a cone intake:



Inlet cone - Wikipedia, the free encyclopedia

Air passing through the conical shock wave (and subsequent reflections) slows to a low supersonic speed.

Interesting the two do exactly the same thing, yet those stupid Russian can’t create a wart in front of an intake.







And now lets look at more, this from the very source you posted:



Diverterless supersonic inlet - Wikipedia, the free encyclopedia

The DSI can be used to replace conventional methods of controlling supersonic and boundary layer , such as the intake ramp and inlet cone, which are more complex, heavy and expensive.

Russia can not produce a DSI? The inlet cone of the Mig-21 does exactly the same thing as your precious ‘DSI’ it just goes under a different name. More importantly is that the cone intake is far more complex than the DSI, so now the question is how is Russia not capable of producing a DSI or basically a bump in front of the intake if they produced a system in the 1950s that is far more complex than a DSI, a systems that adjust at different airspeeds.

About DSI, check this:

It was found that the DSI gave high performance, high total pressure recovery, low integrated distortion and good engine/intake matching.[2]
Diverterless supersonic inlet - Wikipedia, the free encyclopedia

And I bet you have no clue as to what ‘high total pressure recovery, low integrated distortion and good engine/intake matching’ is.

I have a hench you don't know what any of those mean, and since you mocked me by telling me i don't know anything about DSI inlets which it turns out i knew far more than you, i am now calling you out, the self proclaim expert that 'studied' aviation.

Lets see who is talking about things they don't know

 

[antonius123]

Why are you under the assumption that Russia would want DSI? If they would want it they would have it, there is nothing special about it.

That is your assumption?

As I said because you have no clue about DSI but thinking as if you knew.

I have posted why DSI is better, why dont you read?

As for a one piece canopy, it’s very heavy and expensive. Perhaps the production aircraft will incorporate it but if not than the weight and price would not be worth it.

And sorry, there is nothing special about a one piece canopy. All it is, is either Acrylate polymers or an Acrylic compound that is vacuumed in a mold.

As usual your talking is demonstrating your clueless about the topic you intend to debate.

The size matters. Manufacturing small single canopy require small mold; while big 1 piece canopy like that of J-20/F-22 require huge mold. And the huge piece/mold require more complicated technology.

You cannot distinguish the size, as you cannot distinguish the shape (remember you cant distinguish curvature vs round, and cone / ovoid vs cylinder)

Even civilian aircraft have one piece canopies:

Yeah, on what plane? and how is the size?

Again your blind claim legitimate your clueless.

More like you don’t know what you are talking about. Lets use your source, Wekipedia to disprove you.


Now would you look at that, the Mirage and F-35 use the same type of intakes, not identical but the same. Both do the same thing.

Your claim that Mirage already use DSI just because they share some similarity - more demonstrating your clueless and idiocy.

The same type of intake doesnt mean the intake of Mirage meets the requirement to be DSI, if the intake doesnt have the feature of DSI.

You should read and learn again:


It consists of a "bump" and a forward-swept inlet cowl, which work together to divert boundary layer airflow away from the aircraft's engine while compressing the air to slow it down from supersonic speed. The DSI can be used to replace conventional methods of controlling supersonic and boundary layer airflow, such as the intake ramp and inlet cone, which are more complex, heavy and expensive
Diverterless supersonic inlet - Wikipedia, the free encyclopedia

Lets look further into this:


DSI first:


Diverterless supersonic inlet - Wikipedia, the free encyclopedia


Now a cone intake:



Inlet cone - Wikipedia, the free encyclopedia

Such an idiotic and delusional thinking.

You only talk about 1 feature that CONE and DSI share, but ignore other things they dont share.

CONE is CONE, DSI is DSI. Those 2 never meant to be the same thing/system. There is glaring reasons as explained in the article why both called differently, idiot.

Interesting the two do exactly the same thing, yet those stupid Russian can’t create a wart in front of an intake.

And now lets look at more, this from the very source you posted:



Diverterless supersonic inlet - Wikipedia, the free encyclopedia


Russia can not produce a DSI? The inlet cone of the Mig-21 does exactly the same thing as your precious ‘DSI’ it just goes under a different name. More importantly is that the cone intake is far more complex than the DSI, so now the question is how is Russia not capable of producing a DSI or basically a bump in front of the intake if they produced a system in the 1950s that is far more complex than a DSI, a systems that adjust at different airspeeds.

Such a silly and delusional.

CONE is CONE, DSI is DSI. Those 2 never meant to be the same thing/system. There is glaring reasons as explained in the article why both called differently, idiot.

Those 2 do the same/exactly thing, with difference performance (DSI better).

CONE has NO bump and a forward-swept inlet cowl, which work together to divert boundary layer airflow away from the aircraft's engine while compressing the air to slow it down from supersonic speed.

Those things which are unavailable on Mirage/Mig21 air intake - which create DSI and give high performance, high total pressure recovery, low integrated distortion and good engine/intake matching

Intake Ramp and Cone said to be more complex - in the meaning that it involve a lot of mechanical plate/system which is heavier, more expensive, and detrimental to RCS, not about TECHNOLOGY.

Dont be delusional.

And I bet you have no clue as to what ‘high total pressure recovery, low integrated distortion and good engine/intake matching’ is.

I have a hench you don't know what any of those mean, and since you mocked me by telling me i don't know anything about DSI inlets which it turns out i knew far more than you, i am now calling you out, the self proclaim expert that 'studied' aviation.

Lets see who is talking about things they don't know

It is you who dont know the meaning and have no clue about that sentence.

If you have a brain even if a little, you should realize that JF-17II and F-35 wont use DSI if the performance is the same as Mirage/Mig 21 style CONE

 

[gambit]

LOL still stick on old trick, old guy

For someone who claimed to have aviation 'experience' and 'study' and do not know the answer to the question: What is the dominant variable in longitudinal stability? Is inexcusable.

What is the degree of corner reflector? 120 deg?

Yes, there are many degrees of corner reflectors and the 120 deg design is one of them.

The answer to the question: What is the dominant variable in longitudinal stability? Is: Power.

That is basic aerodynamics, as in FIRST YEAR aerodynamics or even ground school.

Aeronautics

Power or thrust can also have a destabilizing effect in that an increase of power may tend to make the nose rise.

Also in either that first year aerodynamics or ground school, one learn that the dominant variable in lateral stability is the wing's dihedral.

There are four main design factors that make an airplane stable laterally: dihedral, keel effect, sweepback, and weight distribution.

So for someone to claim that he has aviation 'experience' then backed it down to 'study' and yet cannot answer a basic aerodynamics question, what else can we see but a fraud?

It is telling of your maturity that you started off telling the Indians to shut up because you have aviation 'experience', in other words, you tried to use experience as a foundation to challenge others. But now you are busted as a fraud you criticize those who use their REAL aviation experience to challenge the Chinese.

The reason the Chinese boys 'Thanked' you is not because you posted anything genuinely 'useful'. We already know at least half of what they posted are debunked as nonsense anyway. No...The reason the Chinese boys 'Thanked' you is because you serve as nothing more than a useful parroting idiot to echo their debunked nonsense.

If you cannot answer the most basic of aerodynamics questions, the kind that even a first year drop-out would remember for the rest of his life, when you claimed to have aviation 'experience' and 'study', am not going to bother with deeper issues like stabaug configurations or pitot-static tube functions in CADC systems.

Fool.

I am saying that it might come out with a stealthier air-frame.

Why are you under the assumption that Russia would want DSI? If they would want it they would have it, there is nothing special about it.

Guys, let this idiot go. He ain't that smart and he is too stupid to know how stupid he is.

 

[jha]

LOL still stick on old trick, old guy

What is the degree of corner reflector? 120 deg?




Let me guess.

That picture shows how Russia still lack technology to develop/manufacture "bubble canopy" and "DSI" technology ??

Oh boy... Do you have any idea about Stealth..? or, just read some wikipedia pages..?

 

[zzzz]

And I bet you have no clue as to what ‘high total pressure recovery, low integrated distortion and good engine/intake matching’ is.

I have a hench you don't know what any of those mean, and since you mocked me by telling me i don't know anything about DSI inlets which it turns out i knew far more than you, i am now calling you out, the self proclaim expert that 'studied' aviation.

Lets see who is talking about things they don't know

That imbecile doesnt even understand the difference between missile and warhead or what is ballistic trajectory. And you are asking him such questions

 

[antonius123]

For someone who claimed to have aviation 'experience' and 'study' and do not know the answer to the question: What is the dominant variable in longitudinal stability? Is inexcusable.

For someone who claimed to have aviation 'experience' and 'study' and do not know what is the corner reflector is inexcusable.

Yes, there are many degrees of corner reflectors and the 120 deg design is one of them.

The answer to the question: What is the dominant variable in longitudinal stability? Is: Power.

That is basic aerodynamics, as in FIRST YEAR aerodynamics or even ground school.

Aeronautics

Also in either that first year aerodynamics or ground school, one learn that the dominant variable in lateral stability is the wing's dihedral.

Wrong! corner reflector is perpendicular (~ 90 degree).

Radar corner reflectors are designed to reflect the microwave radio waves emitted by radar sets back toward the radar antenna. This causes them to show a strong "return" on radar screens. A simple corner reflector consists of three conducting sheet metal or screen surfaces at 90° angles to each other, attached to one another at the edges, forming a "corner".
Corner reflector - Wikipedia, the free encyclopedia

See.. how could people believe your self claimed as expert if you dont know the basic.

So for someone to claim that he has aviation 'experience' then backed it down to 'study' and yet cannot answer a basic aerodynamics question, what else can we see but a fraud?

It is telling of your maturity that you started off telling the Indians to shut up because you have aviation 'experience', in other words, you tried to use experience as a foundation to challenge others. But now you are busted as a fraud you criticize those who use their REAL aviation experience to challenge the Chinese.

The reason the Chinese boys 'Thanked' you is not because you posted anything genuinely 'useful'. We already know at least half of what they posted are debunked as nonsense anyway. No...The reason the Chinese boys 'Thanked' you is because you serve as nothing more than a useful parroting idiot to echo their debunked nonsense.

If you cannot answer the most basic of aerodynamics questions, the kind that even a first year drop-out would remember for the rest of his life, when you claimed to have aviation 'experience' and 'study', am not going to bother with deeper issues like stabaug configurations or pitot-static tube functions in CADC systems.

Fool.

Guys, let this idiot go. He ain't that smart and he is too stupid to know how stupid he is.

You've just demonstrated big MISTAKE about corner reflector by saying 120 degree is corner reflector, and now you still dare to act like Expert ?

Oh boy... Do you have any idea about Stealth..? or, just read some wikipedia pages..?

Do you have intellect and capability to discuss about the STEALTH? or just act like cheerleader ?

Why dont you tell us where is the mistake in my statement above, according to your understanding, instead cheerleading?

That imbecile doesnt even understand the difference between missile and warhead or what is ballistic trajectory. And you are asking him such questions

It is you who dont understand the difference between missile and warhead, and have demonstrated clueless in another thread about ballistic missile.

Now, do you understand why DF-21D is far more advanced than R-27K - as you stupidly claim DF-21D is a copy of R-27K

 

[j20blackdragon]

China will be using a high-low mix of J-20 and J-21 very soon.

Meanwhile, the Indian trolls and haters continue to flap their lips with no actual results.

 

[Esc8781]

Anyone know what is the area rule?

 

[j20blackdragon]

Anyone know what is the area rule?

What about it?

From JAST To J-20

Posted by Bill Sweetman 11:42 AM on Jan 14, 2011

Sometimes the analysis of a new design is one of those areas where you get a whack-on-the-side-of-the-head moment.

This one was induced by the discussion here of the origins of the F-35 design, wherein I suddenly realized what the J-20 reminded me of - Lockheed's immediate pre-JAST/JSF design, tested in the form of a large powered mock-up.

The similarity is quite close in terms of wing/canard relationship, sweep angles, and body shaping, although the Chengdu engineers decided to align the trailing edges of the canards (and rudders) with the trailing edges of the opposite wings, giving them more sweep at the quarter-chord line.

I remember talking this over with Paul Bevilaqua at the 1993 Powered Lift Conference in Palo Alto. If I remember correctly, one reason for the canard delta was that it was good for the cross-sectional area distribution (area ruling) and hence transonic drag.

The challenge was that the shaft-driven lift fan design inevitably had a big cross-section peak well forward, where the inlets wrapped around the fan bay (it needed a large-diameter fan and lots of airflow to work). A canard delta compensated for that by moving the thickest part of the wing as far back as possible.

Somehow I don't think we're going to see a J-20 with a lift fan. However, don't be surprised if the weapons bays turn out to be more capacious (and versatile) than on other designs. It looks like the idea of the canard configuration is to get a large-volume mid-body section through the transonic zone and into supersonic flight with minimal fuss, bother and expenditure of fuel.

Bevilaqua's paper on the origins of the F-35 design cites risk as the reason for the reversion to a quad-tail design for the JSF competition in 1996 - and at the time both Eurofighter and Saab were dealing with unexpected issues in this area.

However, another Lockheed Martin engineer explained that the final JSF planform design was more flexible in terms of being enlarged to meet Navy requirements (given that LO constraints and commonality mandated the same sweep angle for all versions).

That may have been the biggest non-STOVL driver to affect the design, although canards were definitely not popular in the US in the mid-1990s - and I suspect that fitting the canard design on to an LHA elevator might have been a challenge.

From JAST To J-20

 

[amalakas]

For someone who claimed to have aviation 'experience' and 'study' and do not know what is the corner reflector is inexcusable.



Wrong! corner reflector is perpendicular (~ 90 degree).

You are wrong and you are utterly uneducated and over your head.

After I debunked and uncovered Martian2 as a big mouth only, I think it was high-time I did the same to you so you can quit coming here and go back and finish school so you can one day become a productive member of society.

And because you are hiding behind that false need of yours for citations and references I am including all references from the highest institution on this planet for engineering. IEEE. I even include the page numbers .. let's see how you will wiggle your way out of this one little boy!

Here we go..

From:
Optimum corner reflectors for calibration of imaging radars
Sarabandi, K.; Tsen-Chieh Chiu
Antennas and Propagation, IEEE Transactions on
Volume: 44 , Issue: 10
Digital Object Identifier: 10.1109/8.537329
Publication Year: 1996 , Page(s): 1348 - 1361

From:
Cylindrical and three-dimensional corner reflector antennas
Elkamchouchi, H.
Antennas and Propagation, IEEE Transactions on
Volume: 31 , Issue: 3
Digital Object Identifier: 10.1109/TAP.1983.1143063
Publication Year: 1983 , Page(s): 451 - 455

From:
Dihedral corner reflector antenna excited by a probe inside rectangular ring
Lamultree, S.; Phongcharoenpanich, C.; Kosulvit, S.; Krairiksh, M.
Communications, 2003. APCC 2003. The 9th Asia-Pacific Conference on
Volume: 2
Digital Object Identifier: 10.1109/APCC.2003.1274463
Publication Year: 2003 , Page(s): 773 - 776 Vol.2

From:
The Corner-Reflector Antenna
Kraus, J.D.
Proceedings of the IRE
Volume: 28 , Issue: 11
Digital Object Identifier: 10.1109/JRPROC.1940.228959
Publication Year: 1940 , Page(s): 513 - 519

From:
Radar cross-section enhancement of dihedral corner reflector using fractal-based metallo-dielectric structures
Chandran, A.R.; Gopikrishna, M.; Aanandan, C.K.; Mohanan, P.; Vasudevan, K.
Electronics Letters
Volume: 42 , Issue: 20
Digital Object Identifier: 10.1049/el:20061712
Publication Year: 2006 , Page(s): 1135 - 1136

From:

Backscattering analysis of coated plate and coated dihedral corner reflector
Zanqin Jiang; Zhensen Wu; Xiang Su; Xiaobing Wang
Electronics and Optoelectronics (ICEOE), 2011 International Conference on
Volume: 3
Digital Object Identifier: 10.1109/ICEOE.2011.6013381
Publication Year: 2011 , Page(s): V3-361 - V3-364



What possibly can you invent to say now?


So .. now that you are exposed for the utter 10 year old that you are, I suggest you stop flooding this nice thread with nonsense. OK boy ???

 

[antonius123]

You are wrong and you are utterly uneducated and over your head.

After I debunked and uncovered Martian2 as a big mouth only, I think it was high-time I did the same to you so you can quit coming here and go back and finish school so you can one day become a productive member of society.

And because you are hiding behind that false need of yours for citations and references I am including all references from the highest institution on this planet for engineering. IEEE. I even include the page numbers .. let's see how you will wiggle your way out of this one little boy!

Here we go..

From:
Optimum corner reflectors for calibration of imaging radars
Sarabandi, K.; Tsen-Chieh Chiu
Antennas and Propagation, IEEE Transactions on
Volume: 44 , Issue: 10
Digital Object Identifier: 10.1109/8.537329
Publication Year: 1996 , Page(s): 1348 - 1361

From:
Cylindrical and three-dimensional corner reflector antennas
Elkamchouchi, H.
Antennas and Propagation, IEEE Transactions on
Volume: 31 , Issue: 3
Digital Object Identifier: 10.1109/TAP.1983.1143063
Publication Year: 1983 , Page(s): 451 - 455

From:
Dihedral corner reflector antenna excited by a probe inside rectangular ring
Lamultree, S.; Phongcharoenpanich, C.; Kosulvit, S.; Krairiksh, M.
Communications, 2003. APCC 2003. The 9th Asia-Pacific Conference on
Volume: 2
Digital Object Identifier: 10.1109/APCC.2003.1274463
Publication Year: 2003 , Page(s): 773 - 776 Vol.2

From:
The Corner-Reflector Antenna
Kraus, J.D.
Proceedings of the IRE
Volume: 28 , Issue: 11
Digital Object Identifier: 10.1109/JRPROC.1940.228959
Publication Year: 1940 , Page(s): 513 - 519

From:
Radar cross-section enhancement of dihedral corner reflector using fractal-based metallo-dielectric structures
Chandran, A.R.; Gopikrishna, M.; Aanandan, C.K.; Mohanan, P.; Vasudevan, K.
Electronics Letters
Volume: 42 , Issue: 20
Digital Object Identifier: 10.1049/el:20061712
Publication Year: 2006 , Page(s): 1135 - 1136

From:

Backscattering analysis of coated plate and coated dihedral corner reflector
Zanqin Jiang; Zhensen Wu; Xiang Su; Xiaobing Wang
Electronics and Optoelectronics (ICEOE), 2011 International Conference on
Volume: 3
Digital Object Identifier: 10.1109/ICEOE.2011.6013381
Publication Year: 2011 , Page(s): V3-361 - V3-364



What possibly can you invent to say now?


So .. now that you are exposed for the utter 10 year old that you are, I suggest you stop flooding this nice thread with nonsense. OK boy ???

Hahahahaha ..

Do you understand what the article you are dragging from internet are trying to explain?

Tell me what is the meaning/definition of "corner reflector" in the article you drag above!

You act like your master Gambit by only dragging article and highlight the word "corner reflector" without understanding and ability to explain. That is far from enough to make you seem like an expert than an internet boy.

Then now explain us: why that non 90 degree corner behave like corner reflector? show us the ray path of those non 90 degree corner! just like many people here have explained and show the the ray path like bellow picture, or you are just able to drag article without capability to explain?

Remember "corner reflector" here meant the corner that return the radar wave back to its origin. We are talking about stealth right? IF the corner only reflect but not returning to its origin, it must be the corner reflector in other meaning.