Chengdu J-20 5th Generation Aircraft News & Discussions

[sms]

As I had mentioned in the Pak Fa/FGFA thread, one possibility is to recess the IRST equipment into the airframe. That is hard to do on the T-50/Pak-Fa, which is mostly based on the non-stealthy Su-30 MKI airframe.

That's a very good idea. Can you show us where IRST located on J20?
Just curious because a stealth (LO) fighter without IRST will less effective.

 

[DrSomnath999]

As I had mentioned in the Pak Fa/FGFA thread, one possibility is to recess the IRST equipment into the airframe. That is hard to do on the T-50/Pak-Fa, which is mostly based on the non-stealthy Su-30 MKI airframe.

he asked u about J20 's IRST probe not pakfa

 

[DrSomnath999]

IRST
well i think this is the most important avionics a 5th gen fighter must have as more future wars would be fought within
visual range as stealth planes comes in future wars .Remember it is very difficult to achieve complete suppresion of IR
signature no matter how a stealthy a plane .So u can compromise some stealth for it as it is definiltely worth of having it in
your plane.

 

[DARKY]

That's a very good idea. Can you show us where IRST located on J20?
Just curious because a stealth (LO) fighter without IRST will less effective.

Yes Since It would be Forced to use His radar in Active mode and all the Stealth goes in Drain... Passive Sensors like IRST is a way to go... against Stealth planes and to keep ones plane Stealth.... May be It doesn't applies to Chinese design.. which is offcourse Unique and laws of Physics for the outside world does not apply... according to the self esteemed stealth/VLO expert we have here.

 

[amalakas]

Your problem is obvious: That you are incapable of integrating disparate items into a single coherent idea.

Well now you hit the nail on the head with this one.

 

[Martian2]

That's a very good idea. Can you show us where IRST located on J20?
Just curious because a stealth (LO) fighter without IRST will less effective.

I have no idea. I was answering Firemaster's question on a solution to a non-stealthy and protruding IRST on the T-50/Pak-Fa.

If a stealth aircraft has a nose designed to house a recessed IRST then a retracting door can be used to unveil the IRST only when needed. With this design, the fighter aircraft remains stealthy until the IRST is needed. This minimizes the possibility of detection.

Another route is to redesign the IRST to minimize its footprint. Huge advances have been made in electronics and optics in the past decades. However, you would have to ask electronics and optics experts.

 

[amalakas]

.................. get a brain.

Dear Martian2.

You are an amateur and it clearly shows. That is not a bad thing. I have met amateurs that really love what they do and really contribute to science. You are not one of them. Reason being you are stubborn and you refuse to open your eyes. Plus you have an unhealthy fascination with the words "mighty dragon". Do you also play AD&D in your basement?

I have on a number of occasions asked you to open your eyes and consider what you are saying. you haven't. Let me enlighten you on some things.

According to the paper, the ITAE researchers had found materials that solved the dominant problem in the Sukhoi design: straight-through inlets to the compressor face, with no line-of-sight blockage. Rather than placing an absorber-treated blocker in front of the engine, as on the Super Hornet, ITAE developed a radar absorbent material (RAM) that could be applied to the first-stage compressor blades. The rest of the RAM suite included a metallic treated canopy and sprayed-on RAM coatings on the missiles

I think I have asked you again to read the said paper and you have refused. Fine. The only reason I am pointing this out, it once again to show you and others what engineers (you clearly aren't one) know from day one. Engineering is the discipline of finding solutions to problems. And there are always more solutions than one. The only way to verify your solution against someone else's is to go out and compare/compete.

The ITAE paper clearly illustrates why the russians may not care about the straight through ducts or the IRST nose ball.
They have foundations made in engineering principles, principles which you ignore.
They may be proved lacking if their plane goes out tomorrow and proves inferior as an engineering solutioni, but they have made a hypothesis, conducted their experiments, got their measurements and evaluated their results.

What have you got to offer other than assumptions and 2nd grade calculations?

If they have managed to reduce the dBs of the Su-27 class target by as much, imagine what the same treatment can do to an already LO design.

and again, I am not saying the T-50 is better or worst than the J-20 (Mighty dragon if it makes you wet) or the F-22 /35 .
All I am saying is that there is more behind every engineering choice made than you will ever understand it seems.

 

[Martian2]

Dear Martian2.

You are an amateur and it clearly shows. That is not a bad thing. I have met amateurs that really love what they do and really contribute to science. You are not one of them. Reason being you are stubborn and you refuse to open your eyes. Plus you have an unhealthy fascination with the words "mighty dragon". Do you also play AD&D in your basement?

I have on a number of occasions asked you to open your eyes and consider what you are saying. you haven't. Let me enlighten you on some things.



I think I have asked you again to read the said paper and you have refused. Fine. The only reason I am pointing this out, it once again to show you and others what engineers (you clearly aren't one) know from day one. Engineering is the discipline of finding solutions to problems. And there are always more solutions than one. The only way to verify your solution against someone else's is to go out and compare/compete.

The ITAE paper clearly illustrates why the russians may not care about the straight through ducts or the IRST nose ball.
They have foundations made in engineering principles, principles which you ignore.
They may be proved lacking if their plane goes out tomorrow and proves inferior as an engineering solutioni, but they have made a hypothesis, conducted their experiments, got their measurements and evaluated their results.

What have you got to offer other than assumptions and 2nd grade calculations?

If they have managed to reduce the dBs of the Su-27 class target by as much, imagine what the same treatment can do to an already LO design.

and again, I am not saying the T-50 is better or worst than the J-20 (Mighty dragon if it makes you wet) or the F-22 /35 .
All I am saying is that there is more behind every engineering choice made than you will ever understand it seems.

I haven't read any of your posts for almost a year. You never write anything worthwhile. So, I ignore them.

Feel free to keep writing if it makes you feel better to keep slandering me. It takes me 0 second to skip over your post.

You have 916 posts and 287 "thanks." Virtually everyone agrees your posts are worthless.

It took you two years to accumulate 287 "thanks." It will take you roughly 20 years to accumulate 2,870 "thanks." My current 2,966 "thanks" will still exceed yours in the year 2030.

My point is that you're just a clown.

If you want to earn my respect, try writing an informative post like the one below. If you can accomplish this feat, I might consider reading your posts.

Top 6 reasons why Type 039G Song-class submarine is very quiet

"Chinese Type 039G Song-class No. 314 naval submarine docks at the Ngong Shuen Chau naval base in Hong Kong."

1. Modern teardrop hull shape

2. Engine mounted on shock absorbers

3. Anechoic tiles. "Internet-source photos of Type 039s under construction also show Chinese mastery of advanced multi-layer rubber/polymer hull coatings that greatly reduce hull-radiated noise while also limiting the effectiveness of active-sonar detection."

4. "Large asymmetrical seven-bladed skewed propeller" to reduce cavitation

5. Diesel-electric engine design "insulates the noisy diesel engines from the pressure hull, making the submarine quieter." A diesel-electric submarine can "operate virtually silently while on battery power."

6. Tight tolerances during manufacturing by using advanced Chinese 7-axis machine tools. "It probably should be noted that blade noise among Soviet/Russian submarine types dropped dramatically after Japanese electronics company Toshiba and Norwegian company Kongsberg sold advanced milling machinery and control equipment to the USSR in the mid 1980s."

References:

a. Type 039 submarine - Wikipedia, the free encyclopedia [1,2,3]

b. International Assessment and Strategy Center > Research > Top Ten Chinese Military Modernization Developments (see section VIII) [3; second sentence]

c. Chinese Navy [3,4]

d. http://www.globalsecurity.org/military/systems/ship/systems/propellers-supercavitating.htm [4; reduce cavitation]

e. Submarine - Wikipedia, the free encyclopedia [5; first sentence]

f. http://www.hsdl.org/?view&did=445936 (p. 29) [5; second sentence]

g. HarpGamer > Tactics 101: Anti-Submarine Warfare - Part 3 (see Target Identification) [6; second sentence]

----------

From my April 14, 2011 post:

China's CKX5680 Digitally Controlled 7-axis Contour Milling Machine

The Wuhan Heavy Industry Corp. just made a breakthrough in an 863 Project. This is the CKX5680 Digitally Controlled 7-axis Contour Milling machine. This is significant as it is specialised in building ship propellers, like this one, for aircraft carriers and submarines. It is much more precise than 5-axis machines.

[Note: Thank you to "pugachev_diver" for the post.]

----------

Type 039 Song-class submarine with asymmetric seven-bladed skewed propeller to reduce cavitation

 

[amalakas]

I haven't read any of your posts for almost a year. You never write anything worthwhile. So, I ignore them.

Feel free to keep writing if it makes you feel better to keep slandering me. It takes me 0 second to skip over your post.

You have 916 posts and 287 "thanks." Virtually everyone agrees your posts are worthless.

It took you two years to accumulate 287 "thanks." It will take you roughly 20 years to accumulate 2,870 "thanks." My current 2,966 "thanks" will still exceed yours in the year 2030.

My point is that you're just a clown.

If you want to earn my respect, try writing an informative post like the one below. If you can accomplish this feat, I might consider reading your posts.

You have just proved my point. QED

 

[ptldM3]

As I had mentioned in the Pak Fa/FGFA thread, one possibility is to recess the IRST equipment into the airframe. That is hard to do on the T-50/Pak-Fa, which is mostly based on the non-stealthy Su-30 MKI airframe.

You're a moron


The J-20 must also be based on the J-10 and the F-22 must also be based on the F-15. And why are you still avoiding my questions? I have asked you on many, many occasions to explain how the WZ-10 is 'stealthy' with a large FLIR while the pak-fa is not 'stealth' with a small IRST, how is the WZ-10 stealth with countless 90 degree angles, how is the WZ-10 stealth with a multiple piece canopy, how about rivets? Or more surface discontinuities than possibly any other aircraft in history.

As usual you are shamelessly using double standards.

 

[amalakas]

You're a moron


The J-20 must also be based on the J-10 and the F-22 must also be based on the F-15. And why are you still avoiding my questions? I have asked you on many, many occasions to explain how the WZ-10 is 'stealthy' with a large FLIR while the pak-fa is not 'stealth' with a small IRST, how is the WZ-10 stealth with countless 90 degree angles, how is the WZ-10 stealth with a multiple piece canopy, how about rivets? Or more surface discontinuities than possibly any other aircraft in history.

As usual you are shamelessly using double standards.

double standards ?? this is his biggest problem you think? read what he answered to my post.. haha ..

 

[ptldM3]

double standards ?? this is his biggest problem you think? read what he answered to my post.. haha ..

Yes I know, I already read it. He claimed he ignores what you write, which is a pitty and childish. The point of a forum is to discuss topics and or counter challenge other people. In reality I do think he reads your post, or at least some because (he still quotes and replies) but he has no counter arguments so he just ignores you just like he has no counter arguments for me when I asked him to explain how the WZ-10 defies every rule in the stealth world yet in Martian's eyes is still stealthy. He still has just ignored me because he realized he made an epic blunder in which there is no way to get around. Like I said I still want an explanation as to why a large FLIR is stealthy and a small IRST is not, why 90 degree angles are stealth, why pylons are stealthy, why fixed landing gears are stealthy?

Notice the pattern, Martian will crucify the pak-fa on something such as IRST but, on the other hand claim the WZ-10 is stealthy with a FLIR, he will crucify the pak-fa for having rivets while claiming the WZ-10 is stealthy with rivets, he will crucify the pak-fa for having a two piece canopy while the WZ-10 has a multiple piece canopy. The guy is being laughed at in multiple forums and not just by Indians or Russians but by all nationalities.

Moral of the story is that he will ignore anything that is official and or anything that disproves him or gives praise to the pak-fa but he will pick up and quote armature and unofficial crap if it works in his favor.

 

[amalakas]

Yes I know, I already read it. He claimed he ignores what you write, which is a pitty and childish. The point of a forum is to discuss topics and or counter challenge other people. In reality I do think he reads your post, or at least some because (he still quotes and replies) but he has no counter arguments so he just ignores you just like he has no counter arguments for me when I asked him to explain how the WZ-10 defies every rule in the stealth world yet in Martian's eyes is still stealthy. He still has just ignored me because he realized he made an epic blunder in which there is no way to get around. Like I said I still want an explanation as to why a large FLIR is stealthy and a small IRST is not, why 90 degree angles are stealth, why pylons are stealthy, why fixed landing gears are stealthy?

Notice the pattern, Martian will crucify the pak-fa on something such as IRST but, on the other hand claim the WZ-10 is stealthy with a FLIR, he will crucify the pak-fa for having rivets while claiming the WZ-10 is stealthy with rivets, he will crucify the pak-fa for having a two piece canopy while the WZ-10 has a multiple piece canopy. The guy is being laugh at multiple forums and not just by Indians or Russians but by all nationalities.

Hard not to. He reminds me of that southpark episode "0 friends" i think it was called about facebook.

The point however is here that we have a twisted mentality. Basic engineering principles and rules are not respected in favour of simple estimations based on visual inspections of SUPERSONIC FIGHTER PLANES!!!!! as if that is a trivial matter on its own right.

I cannot as an engineer sit idle by and allow him to do that. It is unprofessional and unethical.

On every decent, grounded, supported claim any of us has made he has come back with.. nothing. and yet he still believes that the credibility of what he says comes from the amount of people who thank him. man that is just sad.

 

[pissybits]

Hard not to. He reminds me of that southpark episode "0 friends" i think it was called about facebook.

The point however is here that we have a twisted mentality. Basic engineering principles and rules are not respected in favour of simple estimations based on visual inspections of SUPERSONIC FIGHTER PLANES!!!!! as if that is a trivial matter on its own right.

I cannot as an engineer sit idle by and allow him to do that. It is unprofessional and unethical.

On every decent, grounded, supported claim any of us has made he has come back with.. nothing. and yet he still believes that the credibility of what he says comes from the amount of people who thank him. man that is just sad.

Lol I also thought of that episode when he started going on about the number of "thanks" he's got.
Might as well grab your rulers and pull down your zippers; settle this once and for all...

I think it's fun and interesting to examine the physical implications of shifting geopolitics in terms of military hardware and how they are deployed. I'm Chinese by ethnicity, and I would be lying if I were to say that the rise of China as a major strategic player isn't an exciting (or at least extremely interesting) development. I must acknowledge the fact that China is by no means a perfect country, just as the J-20 though impressive is by no means a perfect fighter. What I cannot understand is the blind nationalist zeal and lack of self-examination in some posts by fellow Chinese members on this forum.

Perhaps I am wrong to single out Chinese posters as we all know that it is not only the Chinese that like to shamelessly toot their own horns, because I spend more time in the Chinese Defense section of these forums so that this simply seems more apparent to me. Remember folks that you don't damage your own reputation when you post blowhard claims and antagonize others on this site, you damage the reputations of whichever flags you fly and whatever countries you represent in front of people from all over the world.

Don't toot your own horn when you're playing off key.

 

[gambit]

Gambit only has himself to blame for making ridiculous arguments. I caught him and now he's embarrassed.

1. In post #1587, he raised the "threshold" argument. When I challenged him by mentioning that X-band has a wavelength of 2.5 (one inch) to 4cm, he quietly withdrew his goofy "threshold" argument.

Did I really? Do not presume your simplemindedness onto my arguments.

When Denys Overholser said this: "shape, shape, shape and materials", what he mean is very much threshold and this...

Shaping includes treatments of structures of various sizes, of curvatures, and of planes. For the above illustration, what Overholser meant is to focus on the largest EM structure/radiator/contributor (singular) that your modeling/predicting hinted at and measurement revealed BEFORE you work on the lesser structures/radiators/contributors (plural). If you cannot reduce that single contributor to below a threshold, any work done on the lesser contributors would be a waste of time, effort, and money because that single dominant radiator would give the aircraft away anyway. Then once that dominant radiator is no longer the dominant contributor you can move on to the lesser contributors, find out which among them became the next dominant radiator, and the process of treatment starts all over again on this new dominant contributor.

With supercomputers, things can accelerate considerably. If your modeling/prediction of the RCS contributorship of one or more dominant radiators hinted at successful reduction by the time of measurement, and if those reductions will reveal potential new dominant radiators, then you can safely perform parallel treatment of those potential dominant radiators. This is a push/pull relationship that must have 'milestones' or pauses to perform genuine measurements between work of modeling/predicting to verify if everyone and every computers have 'carried the two' in their figures.

Threshold -- Get it?

In shaping, what Overholser meant was that you should avoid the 'corner reflector' as much as possible, but if you cannot, then avoid having the 90 deg 'corner reflector' type. That was why the General Dynamics competitor design failed against Lockheed's and Northrop's. The GD design had a single vertical stabilator, creating the typical tail-end vertical-horizontal stabs 'corner reflector' while Lockheed's and Northrop's designs each had twin canted vertical stabs. The 'corner reflector' structures do exist but by canting them away from perpendicular to the fuselage, the Lockheed and Norhthrop designs avoided the 90 deg 'corner reflector'.

But there was the catch: If the (rejected) GD design was competing against pre F-117 aircrafts or 'pre-stealth' but newer designs, most likely it would have beaten them all in the low radar observability area. That was how good (or how low) it was. But against Lockheed's or Northrop's, the GD design could not descend to the lower threshold set by its competitors. In the end, Lockheed and Northrop had to battle it out in other 'non-stealth' or 'less stealth significant' areas such as avionics and aerodynamics to win the contract.

In RCS control, what Overholser meant was that you use the angled faceting technique when applicable, curvatures of various radii to control surface wave behaviors when applicable, material absorber when applicable, geometric absorber or 'saw tooth' devices when applicable, and combinations of these techniques whenever applicable to lower the overall body to meet a certain threshold. Northrop's was lower in RCS but Lockheed's scored higher in other areas and both were lower in the low radar observability threshold.

HAVE BLUE - Experimental Survivable Testbed (XST)

A study began of whether a manned stealth aircraft could be produced. Perko asked five U.S. aircraft companies to examine two questions. First, what were the signature thresholds that an air vehicle would have to achieve to be essentially undetectable at an operationally useful range?

McDonnell Douglas was the first to identify what appeared to be appropriate RCS thresholds (although it couldn't design an aircraft to meet those values). Hughes Aircraft confirmed these. DARPA defined these thresholds as program goals. It was clear that Lockheed and Northrop were far ahead of the others in terms of stealth aircraft design. Northrop had a more comprehensive RCS prediction capability than Lockheed, but, at the time, both capabilities were based on heuristics and empirical testing.

RCS threshold -- Get it?

Major global aviation masters get it. DARPA get it. People here get it. Why not you?

What is that 'operationally useful range'? About 150-200 km distance based upon the typical radar antenna size of the typical fighter, not the AWACS, but the fighter class. That 150-200 km distance is a threshold among many. It is a criteria that you mock and effectively call Overholser -- the man you often quote -- an 'idiot'. Congratulations, you are the first debater I know who calls his supporting source stupid.

Echo 1 was limited to calculations in only two dimensions; this led designers to a faceted design rather than a smooth, seamless one.

This totally shreds your arguments. The more dimensions we are able calculate reflection behaviors, both on surfaces and in free space, the better we are able to understand where and how to set those thresholds to minimize development time.

Threshold -- Get it?

That is why it is laughable for you to declare definitively that a certain structure is 'not stealthy'. Based upon what measurements have you PERFORMED? Your crayola based ray tracing or full range and anechoic chamber testing? This is why it is laughable for you to say that those saw-toothed geometric absorber devices are 2D while the IRST device is 3D. May be it should be YOU who should have his eyes checked. Just like the other Chinese boys here who have no relevant experience, you do not understand words in their proper technical contexts and proceed to make absurd pronouncements based upon your flawed understanding and nationalistic zeal.

Go back to CDF and sinodefence where other gullible Chinese will mindlessly swallow what you peddle.

2. In post #1589, he tried to use 2-D saw-toothed edges to illustrate the possibility of a stealthy IRST probe. This Jedi mind trick only works on clueless members. I called him on his b.s. and put up a citation that large round 3-D objects, like the T-50/Pak-Fa IRST probe, are excellent radar reflectors.

News for you, kid, your source -- howstuffworks -- give only the most general information of anything. Not wrong. Just not enough.

In RCS control, a concave structure is far far deadlier to RCS contributorship than a convex structure.

Moral of the story: Don't try to b.s. your way into arguing the T-50/Pak-Fa IRST probe is stealthy. It is not. Raising non-applicable analogies will only draw my withering fire and a citation to prove you wrong. You'll look like an idiot. You have only yourself to blame for trying to pull a cheap trick.

[Note: Quite frankly, I enjoy debating Gambit when he's at his best. However, when Gambit tries to pull a fast one, I will call him on it. That is not why I'm here.

Sooner or later, Gambit will demonstrate a deeper knowledge in some niche area that I find useful. I have a lot of respect for Gambit when he's objective. I find him annoying when he's playing politics and twisting arguments to achieve a political end. Unlike him, I always try to stick to the facts.]

The moral of the story here is that 'Chinese physics' are not applicable in this world. The difference between you and I is that I have nearly 20 yrs of aviation experience with most of that in avionics, in and out of the military. It has been YOU and the Chinese boys here who have tried to pull many fast ones with your ridiculous claims. Not once have any of you explained things at the foundational level. You may claim to stick to the facts, but you consistently twist the interpretations of them to mislead people.