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

[Ultima Thule]

I'm entitled to some drama.
Engineering is all about compromises, in this particular case between RCS and flight performance.

The bulkhead, radar, canard and inlet all make a significant contribution to RCS. The radars contribution to RCS can be reduced by the use of bandstop and bandpass filter combined with emission controls techniques such as chirping. Even the FCS can be programmed in response to RWR input so control surface actuation is reduced in response to hostile radar emissions.
I occasionally visit the J-20 thread to look at some pictures knowing full well that the Chinese will not divulge any technical information. Still, there are a few things one can conclude from pictures. Please tag me if there is an interesting revelation in the future.

You're not aviation Expert or professional, EVEN YOUR NASA SAID THAT THEIR EXPERIMENTAL CANARD DELTA X-36 WAS EXTREMELY STEALTHY AT ALL ANGLE, SO WE ASSUME SAME FOR J-20

 

[Figaro]

I'm entitled to some drama.
Engineering is all about compromises, in this particular case between RCS and flight performance.

The bulkhead, radar, canard and inlet all make a significant contribution to RCS. The radars contribution to RCS can be reduced by the use of bandstop and bandpass filter combined with emission controls techniques such as chirping. Even the FCS can be programmed in response to RWR input so control surface actuation is reduced in response to hostile radar emissions.
I occasionally visit the J-20 thread to look at some pictures knowing full well that the Chinese will not divulge any technical information. Still, there are a few things one can conclude from pictures. Please tag me if there is an interesting revelation in the future.

Honestly these days the thread is pretty dead. The only exciting J-20 pictures are those equipped with the WS-10s.

 

[dbc]

You're not aviation Expert or professional, EVEN YOUR NASA SAID THAT THEIR EXPERIMENTAL CANARD DELTA X-36 WAS EXTREMELY STEALTHY AT ALL ANGLE, SO WE ASSUME SAME FOR J-20

You do realize that the X-36 was a remotely piloted (19 ft) technology demonstrator restricted to 150 knots to prevent structural damage. For reference the top speed of an Airbus A380 is 500 knots.

Honestly these days the thread is pretty dead. The only exciting J-20 pictures are those equipped with the WS-10s.

I thought there was an ongoing debate about the engine? Has that debate concluded?

 

[Figaro]

You do realize that the X-36 was a remotely piloted (19 ft) technology demonstrator restricted to 150 knots to prevent structural damage. For reference the top speed of an Airbus A380 is 500 knots.

I thought there was an ongoing debate about the engine? Has that debate concluded?

What debate are you referring to? What I meant was we want more photos of grey J-20s equipped with WS-10s in combat patrol.

 

[dbc]

What debate are you referring to? What I meant was we want more photos of grey J-20s equipped with WS-10s in combat patrol.

There was an ongoing debate between a few members arguing if it was a Russian engine or the WS-10. I assume WS-10? I will have to go a few pages back to check.

 

[Figaro]

There was an ongoing debate between a few members arguing if it was a Russian engine or the WS-10. I assume WS-10? I will have to go a few pages back to check.

I believe it was last year or late 2018 when J-20 equipped WS-10s began to go into serialized production. The first WS-10 equipped J-20 appeared in September 2017 if I'm not mistaken.

 

[Indos]

There was an ongoing debate between a few members arguing if it was a Russian engine or the WS-10. I assume WS-10? I will have to go a few pages back to check.

You will waste your time to find debate about it. It was in 2017 just like what Figaro stated.


China’s J-20 fighter jet may get homemade engine
By Qu Qiuyan Source:Global Times Published: 2017/9/7 23:38:40

Most experts and netizens said they believe photos posted online of China's J-20 fighter jets show homemade Taihang engines have replaced their Russian-made counterparts.

A report released by thepaper.cn on Wednesday said the new engine is the Taihang based on its appearance on the online photos.

The J-20 used to be outfitted with the Russia-made AL-31F engine, according to the report, but the homemade engines could be mass-produced.

"It is necessary for the J-20 to use homemade engines. This way, the fighter jet will be completely developed and manufactured in China," Huang Jun, a professor at Beihang University, told the Global Times on Thursday.

According to the report, the insufficient supply of the Russian engines could have led to the change, since orders for the homemade engine also come from overseas, while the price of the Russian engine has been increased from $3 million to $ 5 million each.

"The Taihang engine's performance is nearly as good as the AL-31F. However, being new, the Taihang lacks the maturity of the Russian one," said Huang.

The report added it is much more complicated to change the engine of the fourth generation of J-20s than the second and the third one due to adjustments to the fourth generation's air inlet and engine compartment, among others.

The J-20 is expected to undergo another engine change with the homemade WS-15, which is currently being developed, said the report of thepaper.cn.

http://www.globaltimes.cn/content/1065401.shtml

 

[PeacefulWar]

I'm entitled to some drama.
Engineering is all about compromises, in this particular case between RCS and flight performance.

"Engineering is all about compromises" agreed.
"in this particular case between RCS and flight performance" I can't agree this.
I will be shocked if CAC compromise RCS for flight performance for its 5G fighter.

 

[dbc]

"Engineering is all about compromises" agreed.
"in this particular case between RCS and flight performance" I can't agree this.
I will be shocked if CAC compromise RCS for flight performance for its 5G fighter.

May be you are right - we don't have enough data to reach a conclusion.

 

[Akasa]

"Engineering is all about compromises" agreed.
"in this particular case between RCS and flight performance" I can't agree this.
I will be shocked if CAC compromise RCS for flight performance for its 5G fighter.

Maybe the compromise was warranted seeing how the J-20 needs a way to maintain its WVR maneuverability while waiting for the high-thrust engines.

It's all a balance of parameters.

 

[PeacefulWar]

Maybe the compromise was warranted seeing how the J-20 needs a way to maintain its WVR maneuverability while waiting for the high-thrust engines.

It's all a balance of parameters.

There are just too many possibilities, we can never draw a conclusion that everyone agree with.
I think the stealthy is most important for 5G fighters, if CAC is not that stupid then it won't compromise that.
But then who knows, we human do make stupid mistakes

 

[Deino]

There was an ongoing debate between a few members arguing if it was a Russian engine or the WS-10. I assume WS-10? I will have to go a few pages back to check.

The debate you are referring to was most of all a private crusade by one single member who constantly trolled and derailed the regular J-20 thread with endless pages of stupid arguments, why the J-20 is already flying from day one with a +210 kN thrust serial WS-15!

Therefore I created a new thread as some sort of play-ground for this guy.

https://defence.pk/pdf/threads/the-...arate-from-the-j-20-news.514445/#post-9800065

Otherwise - at least as I understand the situation - the discussion has been settled with the agreement by most, that all so far delivered serial ones assigned to the 176th, 172nd and 9th Air Brigades are using some sort of an AL-31FN-based engine and since last summer all are using the WS-10C with serrated nozzles.

The point however is as @Figaro pointed out, so far we haven't seen any of these birds in PLAAF grey nor in service.

 

[Figaro]

The debate you are referring to was most of all a private crusade by one single member who constantly trolled and derailed the regular J-20 thread with endless pages of stupid arguments, why the J-20 is already flying from day one with a +210 kN thrust serial WS-15!

Therefore I created a new thread as some sort of play-ground for this guy.

https://defence.pk/pdf/threads/the-...arate-from-the-j-20-news.514445/#post-9800065

Otherwise - at least as I understand the situation - the discussion has been settled with the agreement by most, that all so far delivered serial ones assigned to the 176th, 172nd and 9th Air Brigades are using some sort of an AL-31FN-based engine and since last summer all are using the WS-10C with serrated nozzles.

The point however is as @Figaro pointed out, so far we haven't seen any of these birds in PLAAF grey nor in service.

Why is @Asoka no longer posting? I enjoyed his frequent tirades ... he was very respectful in presenting his arguments however wrong he was

 

[Deino]

Why is @Asoka no longer posting? I enjoyed his frequent tirades ... he was very respectful in presenting his arguments however wrong he was

Actually i don't know, he was last seen active in January.

 

[samsara]

The debate you are referring to was most of all a private crusade by one single member who constantly trolled and derailed the regular J-20 thread with endless pages of stupid arguments, why the J-20 is already flying from day one with a +210 kN thrust serial WS-15!

Therefore I created a new thread as some sort of play-ground for this guy.

https://defence.pk/pdf/threads/the-...arate-from-the-j-20-news.514445/#post-9800065

Otherwise - at least as I understand the situation - the discussion has been settled with the agreement by most, that all so far delivered serial ones assigned to the 176th, 172nd and 9th Air Brigades are using some sort of an AL-31FN-based engine and since last summer all are using the WS-10C with serrated nozzles.

The point however is as @Figaro pointed out, so far we haven't seen any of these birds in PLAAF grey nor in service.

Deino, may you please move the latest batch of opinion posts to that particular thread:

https://defence.pk/pdf/threads/the-...arate-from-the-j-20-news.514445/#post-9800065

That extra thread should be expanded to not only cover the engine matters but other aspects that tend to trigger many subjective opinion exchanges such as RCS / stealthiness; materials and so forth.

The J-20 is a MAJOR thread within the PLA Air Force, should not be cluttered with the many opinion exchanges. Feel annoyed to have this thread being flashed repeatedly by the many opinions. Let such exchanges be accomplished in that designated, complimentary thread. Thanks.