The J-20-engine discussion is over and other speculative topics ... to separate from the J-20-news !

[clibra]

The J-20 is more of a long range interceptor, and may rely on its weapons to do most of the turning for it. The canards, while definitely accounted for across all signatures, especially RCS, may only be a factor if the J-20 gets close to another 5th generation platform.

Once 5th generation technology is perfected on the J-20, especially the super cruising engines, there maybe a few conventional layout stealth fighters unveiled in China; a conventional layout carrier fighter, a vertical takeoff fighter for its LHDs and a mass production Air Force fighter, which might even have a pelican tail like this proposed European Stealth fighter mockup. (China may even develop two version of this pelican tail fighter; one with WS-13/19 engines for export (to compete with the F-35) and one with WS-15 engines for its Air Force)

multiple designs out of multiple factories will also allow the PLAAF and PLANAF catch up in fielding 5th gen fighters in numbers to reach parity with its adversaries on its borders.

The intake looks ridiculous small, it's impossible for these 2 small holes to meet the air flow requirement of two 4-gen turbo fan engines. This mockup is a joke.

 

[FuturePAF]

The intake looks ridiculous small, it's impossible for these 2 small holes to meet the air flow requirement of two 4-gen turbo fan engines. This mockup is a joke.

Looks can be deceiving. They wouldn’t have put out the mockup unless they had factored the needed airflow, presumably.

 

[Figaro]

The J-20 is more of a long range interceptor, and may rely on its weapons to do most of the turning for it.

No it isn't. Do some basic research besides looking at the likes of National Interest or Business Insider.

 

[FuturePAF]

No it isn't. Do some basic research besides looking at the likes of National Interest or Business Insider.

While we have a difference of opinion, please don’t resort to ads hominem statements.

IMHO, in its “current” design (although it is a continuously improving design), I think the J-20 is MORE of an interceptor then a fighter (“Offensive Counter-Air”)

It’s focus on frontal stealth (http://www.ausairpower.net/APA-2011-03.html) and its presumably long range make it more suited for destroying enemy targets from BVR (in the air, on the ground, and at sea; carrier battle groups for example) from long range with its long range missiles or long range electronic weapons against enemy networks. The J-20 may also not have a gun, which could also indicate it is not intended to be used at close range, but use its WVR missiles for the closest engagements, if needed. So the J-20 can definitely be used against other fighters, but the tactics will be presumably different based upon its design strengths.

This is not a view out of thin air, but one also expressed by officers in other air forces. Having said that, These 5th gen aircraft are more sensor/shooter platforms, as well as nodes to enable other platforms to carry out their missions.

Some References I looked at:
https://chinapower.csis.org/china-chengdu-j-20/
https://www.aspistrategist.org.au/the-return-of-the-interceptor/
https://www.iiss.org/blogs/military-balance/2020/04/air-launched-missiles-china-plaaf-j-20-fighter

 

[Figaro]

While we have a difference of opinion, please don’t resort to ads hominem statements.

IMHO, in its “current” design (although it is a continuously improving design), I think the J-20 is MORE of an interceptor then a fighter (“Offensive Counter-Air”)

It’s focus on frontal stealth (http://www.ausairpower.net/APA-2011-03.html) and its presumably long range make it more suited for destroying enemy targets from BVR (in the air, on the ground, and at sea; carrier battle groups for example) from long range with its long range missiles or long range electronic weapons against enemy networks. The J-20 may also not have a gun, which could also indicate it is not intended to be used at close range, but use its WVR missiles for the closest engagements, if needed. So the J-20 can definitely be used against other fighters, but the tactics will be presumably different based upon its design strengths.

This is not a view out of thin air, but one also expressed by officers in other air forces. Having said that, These 5th gen aircraft are more sensor/shooter platforms, as well as nodes to enable other platforms to carry out their missions.

Some References I looked at:
https://chinapower.csis.org/china-chengdu-j-20/
https://www.aspistrategist.org.au/the-return-of-the-interceptor/
https://www.iiss.org/blogs/military-balance/2020/04/air-launched-missiles-china-plaaf-j-20-fighter

A dedicated air superiority fighter can be a long range interceptor but a dedicated long range interceptor cannot be an air superiority fighter.

 

[FuturePAF]

A dedicated air superiority fighter can be a long range interceptor but a dedicated long range interceptor cannot be an air superiority fighter.
View attachment 647021

The design of the J-20 indicates how it will try to gain air superiority; fast intercepts as shown in the placard you have attached. The J-20 will utilize Energy-manuerability principles to reach an advantageous position over its most likely opponent; the F-35. Higher speed, possibly faster acceleration, and longer range will allow the plane to Use the right tactics to engage these kinds of threats.

Per the following article, the J-20 is larger than the F-22 but the wing area of the J-20 is estimated to be 25% less than the F-22. The wing loading is estimated to be similar to that of the F-35. So in the end the maneuverability of the J-20 would be better than the F-35, on par with the J-11B.

https://www.realcleardefense.com/articles/2017/10/30/the_us_f-35_versus_the_prc_j-20_112550.html

The J-20 is currently under powered. When the WS-15 reaches its intended dry and wet thrusts of 125kn and 197kn (44,000lb) respectively, it will be powerful enough to enable the plane to be fitted with 2d thrust vectoring nozzles and still compensate for the added weight, and minimizing the need to use the canards (to maintain stealth) to maintain its trim. The design can then be optimized (wing shape/size) to provide all aspect stealth and maximize maneuverability.

something like the following:

Here is a more technical review. I think an evolution of the J-20 design (once the engines are ready) will be a true air superiority fighter, but all publicly available analysis say its current design is more of that of an interceptor. Which is why I think China is not going into mass production of this plane until it can get its engines ready and will then finalize a preferred design for mass production. The current design will probably see limited production for the interceptor role and to test out all of the current systems while more advanced Versions are developed for the final fighter design.

Besides, many expect a follow on air superiority fighter to be in the works for the USAF to supersede the F-22, because the F-35 won’t be enough to keep up with the fighter variant of the J-20, and a few dozen F-22 are only available in the entire IndoPacom Area.

http://www.dept.aoe.vt.edu/~mason/Mason_f/J20Spr11.pdf

https://www.popularmechanics.com/mi...etrating-counter-air-f-22-raptor-replacement/

 

[Figaro]

The design of the J-20 indicates how it will try to gain air superiority; fast intercepts as shown in the placard you have attached. The J-20 will utilize Energy-manuerability principles to reach an advantageous position over its most likely opponent; the F-35. Higher speed, possibly faster acceleration, and longer range will allow the plane to Use the right tactics to engage these kinds of threats.

Just read this article ... https://thediplomat.com/2018/12/chinas-stealth-fighter-its-time-to-discuss-j-20s-agility/. It explains the J-20s role and agility way better than I ever could. I am shocked that in 2020, there are those who still believe the J-20 is primarily a long range interceptor.

 

[FuturePAF]

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

I will have a look, but I request you look into the references I have attached in the previous two posts, including the technical review from Virginia Tech (yes I notice the Indian reference at the bottom of their analysis) but look at the numbers.

When the WS-15 engines are ready then the plane can be redesigned to maximize for maneuverability, but currently it looks to be optimized for range and frontal stealth and modest maneuverability.

I will just end with that this is all just my opinion, you can take it or leave it. I just wanted to bring up a different viewpoint based on some data I have seen.

 

[Figaro]

I will have a look, but I request you look into the references I have attached in the previous two posts, including the technical review from Virginia Tech (yes I notice the Indian reference at the bottom of their analysis) but look at the numbers.

When the WS-15 engines are ready then the plane can be redesigned to maximize for maneuverability, but currently it looks to be optimized for range and frontal stealth and modest maneuverability.

I will just end with that this is all just my opinion, you can take it or leave it. I just wanted to bring up a different viewpoint based on some data I have seen.

The J-20 was designed with the assumption that the engine would be underpowered (i.e. no F-119 level engine). There is an excellent paper by Song Wenchong (J-10 designer) on this, which basically states why the J-20 design maximizes maneuverability.

 

[FuturePAF]

The J-20 was designed with the assumption that the engine would be underpowered (i.e. no F-119 level engine). There is an excellent paper by Song Wenchong (J-10 designer) on this, which basically states why the J-20 design maximizes maneuverability.

I just finished reading the article. It addresses the points I raised, so I thank you for pointing me towards this article. I have always said I am a lay person and not an engineer, reading up on publicly available discussions on this plane.

As this article states, its current performance in terms of maneuverability is that of the J-10 and only expected to be enhanced when the WS-15 engine ready.

What I don’t understand is, why hasn’t this plane then gone into serial production, considering it has under development for nearly 2 decades, but already capable enough to exceed F-35 capabilities? The Japanese are starting to field the F-35 and the US has F-35s and F-22s on Okinawa.

 

[serenity]

I just finished reading the article. It addresses the points I raised, so I thank you for pointing me towards this article. I have always said I am a lay person and not an engineer, reading up on publicly available discussions on this plane.

As this article states, its current performance in terms of maneuverability is that of the J-10 and only expected to be enhanced when the WS-15 engine ready.

What I don’t understand is, why hasn’t this plane then gone into serial production, considering it has under development for nearly 2 decades, but already capable enough to exceed F-35 capabilities? The Japanese are starting to field the F-35 and the US has F-35s and F-22s on Okinawa.

J-20 is in serial production and has been since 2018.

 

[Figaro]

I just finished reading the article. It addresses the points I raised, so I thank you for pointing me towards this article. I have always said I am a lay person and not an engineer, reading up on publicly available discussions on this plane.

As this article states, its current performance in terms of maneuverability is that of the J-10 and only expected to be enhanced when the WS-15 engine ready.

What I don’t understand is, why hasn’t this plane then gone into serial production, considering it has under development for nearly 2 decades, but already capable enough to exceed F-35 capabilities? The Japanese are starting to field the F-35 and the US has F-35s and F-22s on Okinawa.

The J-10 itself is already a very maneuverable aircraft. But you are right. In order to reach F-22 or Su-57 super maneuverability, the J-20 needs the WS-15, which incorporates 3D TVC. As for serial production, I believe the J-20 already entered this phase in the middle of 2017.

 

[Figaro]

I think they should just investigate variable cycle. If WS15 first trial was done just when J-20 was ready and they decided to restart so many of its components then I suspect newer WS15 for 2025 or around then is variable cycle. Or I hope it is. Even if it is higher bypass ratios similar to F135/6 levels, I will be so amazed. China will have super high thrust level turbofan which is only limited by variability in bypass ratio. Even then it will hopefully become obsolete technology in coming decades.

I divide military low bypass turbofans in five thrust levels:

1. Weak - For garage enthusiasts and various experiment concept levels useless for military fighters and generally we ignore for this purpose.

2. Low thrust - Honeywell engine etc or WS-5 WS-11 etc of various low thrusts for drones and up to very small light fighters requiring two of such engines in higher end like FCK-1.

3. Medium thrust - M88, RD-33 series up to higher end of EJ200, F414, M53 - European low bypass turbofan achieve these highest thrust level but of course this doesn't mean they cannot produce higher thrust levels but there are challenges certainly and a lot of time and money to spend if they want to.

4. High thrust - AL-31, WS10, F100, F110 these are Russian, American, and Chinese now with WS10 being mature enough with over 10 years of flying service with J-11B series and now applied to J-10 and various other kinds even including thrust vectoring forms.

5. Super high thrust - F119 to higher end of F135 F136. So far only USA has this level of technology already accomplished and conquered. This is our Himalaya peak to conquer because it represent the level when we can sit side by side with the best if we achieve this before they achieve their next breakthroughs which will be variable cycle and even higher thrust than F135. Even if we can do this by around 2025, it is going to be amazing for us who just 70s years ago was struggling to feed ourselves with full bellies. WS15 hopefully considers variable cycle and I suspect the reason for total complete redesign was to incorporate variable cycle so in one leap we can get to the next stage anyway because the core design and materials for F135 is actually already there since years. For variable cycle it is not so much. About Russia's project type 30, who knows. Their latest report suggest roughly ready around 2025 as well.



Well let's finish this argument we both disagree but one thing I personally think is correct is J-20 is not designed for close combat. It doesn't even have a gun. PL-10 is must in case for close combat and is helmet guided and very high off boresight anyway. J-20 uses long arm canard we can disagree here but reality is whatever it is and one of us is right about it. Long arm canard is generally for good supersonic turning and mechanical stability. Eurofighter is also famous for supercruising and supersonic turning. F-22 is also fantastic in its own way and can use thrust vectoring to full advantage due to advanced incorporation of its thrust vectoring and flight control. J-20 hopes to get 3D thrust vectoring here so minimal canard movement is required. This can help with stealth too but right now canard movements are not as important to stealth because again it is 90% material and electromagnetic now.

Turning the WS-15 into a vce? I'm not sure that's feasible.

 

[S10]

A new variant of WS-10 (WS-10C?) is being installed on J-20 (J-10C too maybe?), with 14.5 tons of thrust. There is a even more powerful WS-10 (IPE?) in the works, possibly with up to 16 tons of thrust. WS-15 is still in testing and won't be ready for a few years. J-20 is likely to fly with WS-10 variants until 2025.

https://lt.cjdby.net/thread-2634840-1-1.html

According to pupu, WS-15 has met designed specifications, but the PLAAF isn't satisfied with its fuel consumption.

 

[Figaro]

According to pupu, WS-15 has met designed specifications, but the PLAAF isn't satisfied with its fuel consumption.

When did Pupu say this? I don't see anything in the thread that shows Pupu stated the WS-15's fuel consumption.