J-20 5th Gen Fighter Thread IV (Closed to posting)

[by78]

Wait a minute. I thought the J-20 prototypes are being powered by WS-10G, not Russian engines, at least according to multiple Chinese sources, some of which are quite credible.

Did I miss something here? When did the consensus shift to J-20 being powered by interim Russian engines?

 

[LesAdieux]

It shouldn't be significantly bigger. A portion of the thrust increase will come from increased mass flow, but a portion will also come from increased inlet temperatures.

Flight tests should be fine actually, because they can just reduce the weight of the aircraft with less fuel to simulate the appropriate T:W ratio.

yes, I just checked F119/F100 on the wiki, the difference in size is not big.

 

[Blitzo]

Wait a minute. I thought the J-20 prototypes are being powered by WS-10G, not Russian engines, at least according to multiple Chinese sources, some of which are quite credible.

Did I miss something here? When did the consensus shift to J-20 being powered by interim Russian engines?

Quite a while ago, I think.

 

[by78]

Quite a while ago, I think.

Is there a source that states the prototypes are powered by Russian engines?

I remember back when the J-20 were still tech demonstrators (all black 2001/2002), it was paired with two different engines, with the silver nozzles being the WS-10G and the black nozzles being the Russian engines.

Pre-production prototypes (2011, 2012) inherit the same silver nozzles, indicating that they are powered by WS-10G. Did we definitively determine the silver nozzles belong to a Russian engine?

Would someone please provide a source/link to get me up-to-date?

Thanks.

 

[Blitzo]

Is there a source that states the prototypes are powered by Russian engines?

I remember back when the J-20 were still tech demonstrators (all black 2001/2002), it was paired with two different engines, with the silver nozzles being the WS-10G and the black nozzles being the Russian engines.

Pre-production prototypes (2011, 2012) inherit the same silver nozzles, indicating that they are powered by WS-10G. Did we definitively determine the silver nozzles belong to a Russian engine?

Would someone please provide a source/link to get me up-to-date?

Thanks.

Initital Black nozzles on 2001 were Al-31, the consensus is that the silver nozzles on 2001 and all subsequent prototypes are also Al-31, only with modified nozzles

No real links unfortunately, apart from huitong's page.
Just aggregates of various tidbits over the years.
But this is the consensus.

The exact type of engine powering prototypes is unclear, even though a Chinese or Russian turbofan engine including AL-31F (AL-31F-M1? 13.3t class) and enhanced WS-10 (WS-10G?) (14t class) was speculated. In the end the Russian engine is believed to be the likely candidate (initially AL-31F-M1 later AL-31F-M2/14.5t class).

 

[Verum]

At what stage is WS15 in now?

I personally doubt it will be equipped when J20 enters service. It'll most likely be equipped in 2nd to 3rd blocks, around 10 - 15 years after initial fielding. But by then, it's performance will just be average, if not a little obselete compared to newer generation of engines coming out at that time. Use J10 as an example, it entered service in limited numbers about 8 - 10 years ago? Yet, now its upgrade (J10B) development still shows no sign of completion. And that's just mainly avionics changes, not even as drastic as a big engine swap. Usually engine swaps require extensive redesign, especially for 5th gen jets with very complex designs needed for stealth and maneuverability. Changing the engine would cause a lot of delays. It makes more sense to field the plane first, then introduce design changes and swap the engine in later batches, like the Super Hornet.

 

[latenlazy]

Is there a source that states the prototypes are powered by Russian engines?

I remember back when the J-20 were still tech demonstrators (all black 2001/2002), it was paired with two different engines, with the silver nozzles being the WS-10G and the black nozzles being the Russian engines.

Pre-production prototypes (2011, 2012) inherit the same silver nozzles, indicating that they are powered by WS-10G. Did we definitively determine the silver nozzles belong to a Russian engine?

Would someone please provide a source/link to get me up-to-date?

Thanks.

There might be a pic or two where one of the nozzles was clearly the AL-31 and the other one was the silver one, and they both had the exact same dimensions, and they were clearly the same engines because the interior of the nozzles were identical. We also had a long discussion on CDF a while back about whether the engines were just AL-31s with painted nozzles when a closeup of either 2001's or 2002's nozzle was taken and the plating of the nozzles looked like AL-31s. Finally, someone on a Chinese forum did an acoustic analysis with several videos of Al-31s and WS-10s and matched them to the sound of the J-20's, and the acoustics clearly matched the AL-31s. (You can actually try this just by looking at videos online, they sound distinctly different). Like Blitzo said it wasn't any one thing.

 

[latenlazy]

At what stage is WS15 in now?

I personally doubt it will be equipped when J20 enters service. It'll most likely be equipped in 2nd to 3rd blocks, around 10 - 15 years after initial fielding. But by then, it's performance will just be average, if not a little obselete compared to newer generation of engines coming out at that time.
Use J10 as an example, it entered service in limited numbers about 8 - 10 years ago? Yet, now its upgrade (J10B) development still shows no sign of completion. And that's just mainly avionics changes, not even as drastic as a big engine swap.

Prototype testing. I don't think it will take 10 years after the initial fielding. Maybe 5, but not 10. I suspect engine testing will be complete sometime between 2016 and 2017, and it will take another year or two to set up the assembly line while they perform tests with the engine installed in a J-20. It's not like China's doing nothing else but develop the WS-15 either. There was a report that they had already started working on a 15 T:W engine and that they would be building the engine core in 2016.

As unfortunate as it is for the US, I wouldn't worry too much about the WS-15 being obsolete when it's installed in the J-20. I suspect military procurement for the US will slow down drastically for the next decade or two, especially while they're still committed to bringing the F-35 into full service.

 

[AssassinsMace]

Tiny gif said to be 2013.

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[Blitzo]

At what stage is WS15 in now?

I personally doubt it will be equipped when J20 enters service. It'll most likely be equipped in 2nd to 3rd blocks, around 10 - 15 years after initial fielding. But by then, it's performance will just be average, if not a little obselete compared to newer generation of engines coming out at that time.
Use J10 as an example, it entered service in limited numbers about 8 - 10 years ago? Yet, now its upgrade (J10B) development still shows no sign of completion. And that's just mainly avionics changes, not even as drastic as a big engine swap.

I'd say the differences between a J-20 with interim engines and a J-20 with WS-15 would be far less than between J-10A and J-10B. J-10B has changes in aerodynamics, intake, cockpit, new Al-31 variant, and mission avionics -- and the last one cannot be dismissed as "just mainly avionics" as if it's something superficial like a paintjob -- I'd argue an extensive avionics upgrade using new generation systems are just as drastic as re-engining a plane.
So using J-10B's schedule as a comparison is not entirely accurate. I also suspect resources that could've gone to J-10B are being shuffled to J-20 instead, which may have also contributed to its slower introduction, but that's my own speculation.
(And I'm not sure how having over 40 J-10B serial production planes equals "no signs of completion")

The big determinant is when WS-15 will be ready. I do not know why you think WS-15 will only be ready 10-15 years after J-20's initial fielding (let's say 2018); so you're saying 2028-2033? If it's just skepticism regarding Chinese engine development in general, then fair enough, but I think that is far too excessive a delay.
I think I heard the first complete prototype WS-15 may have been completed a while ago, so within a year or two we might see it on the Il-76 testbed. We know quite confidently that it finished simulated high altitude testing a few years back.

Your conclusion imo is misinformed, due to false premises regarding J-10B's development, and excessive (and at this stage, premature) skepticism regarding WS-15's development.
It isn't Shenyang-Liming developing WS-15 -- it's Xi'an, so it may not be fair to use WS-10 development timetable as a guide to WS-15 development. That is to say, it is worth giving XAEC the benefit of doubt.