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Chengdu J-20 5th Generation Aircraft News & Discussions

Yu3aR.jpg

Hydraulically-powered aileron control systems

Look at the location of the J-20 pods. They are located next to the ailerons. Hence, the pods are most likely hydraulically-powered aileron control systems encased in a radar-deflecting enclosure.

Martian2, i would not try to convince naysayers here about the potential of the Chinese J-20 fighter.


The only slight worry is whether they can have the WS-15 ready on time. There seems very little doubt that it will be top notch in terms of stealth, avionics and missiles like the ramjet-powered PL-21D are just really scary.

They are just jealous and envious of China's massive military strides. While all countries are progressing, China is just progressing quicker than anyone else at the moment.
 
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The creamy white nozzled engine in fact could be WS-15, but they are very careful with it by applying a WS-10G and a WS-15 on each side.

BTW, we might be able to see the twin WS-15 in the next year.
 
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Yu3aR.jpg

Hydraulically-powered aileron control systems

Look at the location of the J-20 pods. They are located next to the ailerons. Hence, the pods are most likely hydraulically-powered aileron control systems encased in a radar-deflecting enclosure.


I know what those are for. You made a cheap claim about the pak-fa while claiming that the J-20 has nothing 'jetting out'--that was wrong. Now recall how you claimed spheres are 'bad for stealth'. Those protrusions are no different than a sphere when looking at the J-20 from bellow. Either way you were wrong about the J-20 being flat. Your hero Kopp made a clever illustration of how the F-35's belly with sphere and all would increase radar returns, so with you being such a die hard Kopp beleiver what makes you think that the J-20 is excluded? If Kopp claimes that the F-35's sphere is poor for 'stealth' what makes you think that four spheres on the J-20 wouln't be?


Look at the size of an oval aileron control pod and compare it to one of the tires. Each pod is merely the size of a tire, not an automobile. Feel free to retract your claim "about the size of [an aileron control pod being] a small automobile" and thank me for correcting your error.

And that is a good thing? When i made the comment about them being the size of an automobile i was being sarcastics, how can anyone take that literally?
 
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For those of you that followed the original J-20 thread and continued onto this thread, you remember that Gambit has made a big deal about "edge diffraction."

Also, Gambit makes a big deal about "edge diffraction" again with regard to Australia Air Power's point #1. To wit:



I have already mentioned that "the resulting error will be mitigated...by edge treatments."

However, I want to ask all of you an important question. Why isn't the supposed "military professional" informing you that NASA considers edge diffraction effects to be trivial?

Planet Quest: Technology - A Close Look at Diffraction

"A Closer Look at Diffraction

When an electromagnetic wave passes by an obstacle in space, the wave is bent around the object. This phenomenon is known as diffraction. The effects of diffraction are usually very small, so we seldom notice it."

After all the articles that Gambit has read on edge diffraction, why hasn't he ever told you that Jet Propulsion Laboratory/NASA states the effects of diffraction are trivial?

I did tell you guys that Gambit will mislead you to pursue his anti-China agenda. He hides behind technical terms to make false claims. In contrast, I explain "backscatter from edge diffraction" in understandable terms and provide a citation from a mainstream source.

Do you trust NASA's claim that "edge diffraction" is trivial or would you rather trust Gambit's anti-China agenda that "edge diffraction" is a really big problem (and only for the J-20, but not for the F-22 or F-35)?

[Note: The web address for my citation shows its from "jpl.nasa.gov".]
Here is the difference between you and I: critical thinking skills.

The NASA source is an explanation of WHAT is edge diffraction and how does it pertain to certain applications...

All telescopes must take diffraction into account. In the case of telescopes intended to resolve objects (planets) that, at best, will appear as a single pixel in the image, diffraction must be managed to allow that pixel to shine through.
In other words, different needs will deal with certain properties and/or behaviors differently. This is not just about edge diffraction effects but for all things in life. For NASA, the astronomers are not trying to hide anything. They need to understand edge diffraction effects so they can deal with it to REVEAL very faint objects.

For military purposes such as 'stealth', it is a different need so even though the basic understanding of edge diffraction effects is still the same, we must deal with it differently because we are trying to CONCEAL some things. That is why snipers pay close attention to details that could reveal their positions. That is why there are so many arguments about the PAK-FA's data measurements probes typical of developmental flights.

Another example of this is the wheel. Most people could not conceive of the tank tread as a wheel but that is exactly what it is: a mechanical wheel. We understand the basic principles of sidewalls, tread dimensions, flexibility, and so on...But for different needs, we created the 'tank tread', the typical rubber 'tire', the old wooden and steel wagon 'wheel', and so on...For different applications.

You want to dismiss these effects because you have a substantial emotional investment in the J-20 out of nationalistic pride. If these effects are so trivial, then why are they such a big deal for any one who is trying to develop a 'stealth' aircraft. The reason is because they, like me, exercised their critical thinking skills and determine that different needs require different methods of negotiations of these effects. That is why the Iranians published their report that different tools such as GTD must be employed at different locations on a complex body. That is why we have something called Iterative Physical Optics (IPO) to deal with cavity RCS measurement...

PIER Online - Computation of EM Field Scattered by an Open-Ended Cavity and by a Cavity Under Radome Using the Iterative Physical Optics
Abstract:
It is always a challenge to predict Radar Cross Section (RCS) of a full scale military platform with a good accuracy. Most of the time antennas and cavities are the main contributors of aircrafts RCS. Several methods have been developed to compute the RCS of cavities such as analytical methods (modal methods) and asymptotic methods (geometrical optics (GO) methods and physical optics (PO) methods). This article presents the Iterative Physical Optics (IPO) method which consists in an iterative resolution of the Magnetic Field Integral Equation (MFIE) to compute the currents on the inner walls of the cavity. This method allows computing arbitrarily shaped cavity with a good accuracy even for cavity with a depth inferior to the wavelength. Comparisons of IPO results with Rays and Finite element methods show a better accuracy of IPO than Rays especially for cross polarization. But computation time represents one of the main limitations of the IPO method. We present here a new formulation of the Segmented IPO method which coupled with the generalized reciprocity theorem decreases significantly the complexity of the method and consequently the computation time. The S-IPO method has been validated by comparisons with Modal method and measurements. We have observed that the repartition of the electric currents density on the inner walls of the cavity is quite the same with IPO and S-IPO computations. Lastly we propose an evolution of the IPO method we have developed to compute the RCSof cavities under radome. This method has been validated by comparison with finite element results.
Does APA know about IPO? If not then why not?

This is why no one who has relevant experience in this matter do not take seriously your video, the one that boosted your ego with your repeated boast of view count. Talk about vanity...:rolleyes:

What APA did was wrong on several levels, but the most egregious are two: questionable physical dimensions and the use of physical optics (PO) as the ONLY tool.

Did China give APA the precise physical dimensions? If not, then why is it wrong for us to be suspicious that what dimensions APA used are undersized and therefore their data are naturally skewed towards a smaller RCS, the one that you have so much emotional investment in? The computing adage 'Garbage in. Garbage out.' is very true when the basic information required is in doubt.

You once argued since the US never allowed anyone to have his own independent analysis of the F-22 but everyone pretty much acknowledged that the F-22 is the premier 'stealth' aircraft, why not give the J-20 the same latitude? That is a reasonable argument but only on its surface.

If I apply for a loan, the lender will look at two main factors: income and credit history. Income is a variable. I may receive a pay raise or not or even a reduction. I may continue to have employment or be terminated. The lender does not know but only have some faith based upon income history. Credit history is a different issue. It is established and quite unalterable. The lender can look at my credit history and assess my ability to repay debts of various sizes. Income and credit history are like the parallel rails for a train.

Does China have a history that involve an F-117 equivalent? The reality is that the US does not care what people believe about the F-117, let alone the B-2 or the F-22. But the reason why people are willing to give US a healthy measure of their faith is because of established combat record of our 'stealth' aircraft, as in credit history, and our lead in aviation, as in potential income. Chinese aviation is still far behind US but here you are asking intellectual 'lenders' to exercise faith in its military variant when contrasted against US military aviation history and combat record?

b-52_b-2_1433-719.jpg


One of the pair above is the size of a bird for radar detection. When China can demonstrate the same then intellectual 'lenders' will be willing to give China the same faith as they have given US.
 
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And that is a good thing? When i made the comment about them being the size of an automobile i was being sarcastics, how can anyone take that literally?

I see. All of your comments and Gambit's downplaying the J-20 Mighty Dragon and talking up the Pak-Fa/T-50 have been sarcasm. It all makes sense now. I should not have called the two of you J-20 trolls. I should have called you J-20 jokers.

Gambit, you've been suspicious to the point of paranoia. How else can you explain your suspicion that the J-20 was having software integration problems (even after I pointed out the J-10 had been using a fly-by-wire control system for over 10 years) based on one picture of a parked J-20 Mighty Dragon?

However, I grow weary of both of you. Both of you are clearly wrong in many instances and have a bad tendency of refusing to admit it.
 
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Gambit, you've been suspicious to the point of paranoia. How else can you explain your suspicion that the J-20 was having software integration problems (even after I pointed out the J-10 had been using a fly-by-wire control system for over 10 years) based on one picture of a parked J-20 Mighty Dragon?

By acknowledging that programming wasn't his work a few posts back. :lol:

Programming is not my work...

ChineseTiger. Daokou is primarily a navy person. Some of his allegations, such as Feng Bu Bei and Hao hai zi being agents of the CAC who purposefully photoshopped the WS-10 nozzles to conceal the TVC, are simply absurd. I liked his naval interviews but you mustn't believe him superstitiously.
 
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I see. All of your comments and Gambit's downplaying the J-20 Mighty Dragon and talking up the Pak-Fa/T-50 have been sarcasm. It all makes sense now.



No one has down played anything, if you haven't noticed the discussion about RCS guestemates have been aimed at the methods used and not whether the J-20's RCS is whatever Goon claimed. Similarly the canards and edge diffraction discussion has been in response to J-20 fanboys claiming canards pose no problem. The only thing I have claimed about canards is that edge diffraction is a real phenomenon and that all wing structures give off edge diffraction, I always used a disclaimer when talking about edge diffraction- I never made any ridiculous claims that said canards increase RCS by a fact of X. But J-20 fanboys have made similar claims about the pak-fa.

Ironic that for someone that calls others trolls and accuses people of downplaying you are the one that brings up the pak-fa into every post and you are the one that shamelessly made threads about how poor the pak-fa is. Who is downplaying what? If anyone insults or downplays it is you, if anyone goes off topic by randomly bashing other aircraft it is you. If you don't like it when others criticize the J-20 than keep quite about other aircraft , you have no problems insulting the Rafale, pak-fa and F-22 but cry foul when someone challenges your beloved J-20.
 
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By acknowledging that programming wasn't his work a few posts back. :lol:



ChineseTiger. Daokou is primarily a navy person. Some of his allegations, such as Feng Bu Bei and Hao hai zi being agents of the CAC who purposefully photoshopped the WS-10 nozzles to conceal the TVC, are simply absurd. I liked his naval interviews but you mustn't believe him superstitiously.

I know he is not an insider of the J-20 and other air force related stuffs.

But this guy is damn brilliant, and he is unbelievable accurate in most of the speculation because his perception is so damn good.

I will put my bet on him this time. Even Huzigeng also confirmed that WS-15 will be installed on J-20 in the next year, so this year they already start to testify a single WS-15, then next year it will be a twin WS-15.
 
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I know he is not an insider of the J-20 and other air force related stuffs.

But this guy is damn brilliant, and he has unbelievable accurate in most of the speculation because his perception is so damn good.

I will put my bet on him this time. Even Huzigeng also confirmed that WS-15 will be installed on J-20 in the next year, so this year they already start to testify a single WS-15, then next year it will be a twin WS-15.

Then wait till next year. Huzigeng is more trustworthy on air force related matters. Once we notice something unusual happened to the nozzles then we'll know.
 
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Then wait till next year. Huzigeng is more trustworthy on air force related matters. Once we notice something unusual happened to the nozzles then we'll know.

Huzigeng should be almost a first hand source, but daokou is still quite reliable when it comes to this matter. I'd say he is 9/10 at least.
 
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Gambit, you've been suspicious to the point of paranoia. How else can you explain your suspicion that the J-20 was having software integration problems (even after I pointed out the J-10 had been using a fly-by-wire control system for over 10 years) based on one picture of a parked J-20 Mighty Dragon?
Just because Boeing and Airbus has FBW FLCS does that mean the flight control laws are the same? You have a problem grasping the concept of these laws in the first place. But for those who have relevant experience in flight control systems, from its mechanical aspects to the architecture of these laws to the integration of both and finally to flight testing, there is nothing wrong with observing behaviors and making informed guesses.

For example...

v33_elev-rudd_combined.jpg


Beechcraft Bonanza has a v-tail variant as well as a conventional rudder and horizontal stabs configuration...

Beechcraft Bonanza - Wikipedia, the free encyclopedia
This feature started with the V-tail and persists on the current production model.
The flight control laws, as defined by mechanical construction, will be slightly different against the conventional arrangement.

The concept of these laws is mainly philosophical: a one-meter long stick will increase your reach by one meter, not two. So if we create a virtual one meter stick in a program, the output of whatever that uses this virtual meter stick will be increased by one meter.

Failure to grasp this philosophy is the cause of your belief that all FBW FLCS are the same.

However, I grow weary of both of you. Both of you are clearly wrong in many instances and have a bad tendency of refusing to admit it.
Please...:lol:...More like as time goes by, you found yourself running out of credible arguments.
 
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No has down played anything, if you haven't noticed the discussion about RCS guestemates have been aimed at the methods used and not whether the J-20's RCS is whatever Goon claimed. Similarly the canards and edge diffraction discussion has been in response to J-20 fanboys claiming canards pose no problem. The only thing I have claimed about canards is that edge diffraction is a real phenomenon and that all wing structures give off edge diffraction, I always used a disclaimer when talking about edge diffraction- I never made any ridiculous claims that said canards increase RCS by a fact of X. But J-20 fanboys have made similar claims about the pak-fa.

Ironic that for someone that calls others trolls and accuses people of downplaying you are the one that brings up the pak-fa into every post and you are the one that shamelessly made threads about how poor the pak-fa is. Who is downplaying what? If anyone insults or downplays it is you, if anyone goes off topic by randomly bashing other aircraft it is you. If you don't like it when others criticize the J-20 than keep quite about other aircraft , you have no problems insulting the Rafale, pak-fa and F-22 but cry foul when someone challenges your beloved J-20.
Intellectual consistency has never been these guys' strong suit.
 
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By acknowledging that programming wasn't his work a few posts back. :lol:
Then we should disqualify every Chinese member here since NONE of you even served in the military, let alone yak about technical issues relating to military gear. Like I said, intellectual consistency has never been the Chinese boys' strong suit.
 
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