J-20 5th Gen Fighter Thread V

[manqiangrexue]

Actually, there were rumors saying the next phase development of J20 could be the replacement of AL31 with the latest version WS10, considering WS15 won't be ready before 2020. Just like recently revealed J10B/Cs that are powered with WS10, there must be something in WS10 they like over AL31, probably the slightly higher trust/reliability or foreseeable future for upgrading.

Even if the first several production batches will still use Al31, I don't see why they should not built a few testing prototypes powered with WS10s.

I also thought like you guys that they should just put some Taihang engines into the J-20, and that just because they are indigenous, unless they have serious drawbacks, they would be preferable over Russian AL-31. But that's before I learned that engines are not plug-and-play. If you wanted to switch from AL-31 to Taihang, you needed to do a whole new series of tests including optimizing the intake and re-balancing the jet. It's a lot of work and causes the program to enter a new testing phase. Unless these tests can bring something very significant to the J-20, it most likely will not be worth the extra time, money and work especially for an interim engine. So J-20's current configuration is optimized to AL-31; if you wanted to switch to Taihang because let's say the WS-10 offered 140kN instead of 137kN for AL-31, that would not be worth the work at all to throw the project into a renewed testing phase, delaying IOC. The only situation in which I see China integrating a WS-10 onto the J-20 is if a new WS-10 variant provided significantly more thrust (say 155kN), the WS-15 was delayed, and there was a foreseeable near-term security threat that might require an optimally-performing J-20 to secure.

 

[Blitzo]

Actually, there were rumors saying the next phase development of J20 could be the replacement of AL31 with the latest version WS10, considering WS15 won't be ready before 2020. Just like recently revealed J10B/Cs that are powered with WS10, there must be something in WS10 they like over AL31, probably the slightly higher trust/reliability or foreseeable future for upgrading.

Even if the first several production batches will still use Al31, I don't see why they should not built a few testing prototypes powered with WS10s.

Well if they do seek to integrate WS-10s onto J-20s as another interim engine prior to WS-15's arrival around 2020 then they must have good reason for it.

They will only build prototypes with WS-10s if they intend on pursuing integration of WS-10s with replacement of Al-31s on J-20s. The fact is we have yet to see J-20s with WS-10s. If that changes then our speculation will change as well.

 

[Blackstone]

Well if they do seek to integrate WS-10s onto J-20s as another interim engine prior to WS-15's arrival around 2020 then they must have good reason for it.

They will only build prototypes with WS-10s if they intend on pursuing integration of WS-10s with replacement of Al-31s on J-20s. The fact is we have yet to see J-20s with WS-10s. If that changes then our speculation will change as well.

But, what if WS-15 mirrors WS-10 development? It means two more decades before they would go on J-20s. Three more.

 

[latenlazy]

But, what if WS-15 mirrors WS-10 development? It means two more decades before they would go on J-20s. Three more.

That seems unlikely, since a huge reason the WS-10 took so long was that they literally started with nothing.

 

[Blitzo]

But, what if WS-15 mirrors WS-10 development? It means two more decades before they would go on J-20s. Three more.

At present we have no rumours as of yet that WS-15s development will take that long, if new rumours come to light then we will change our consensus and our projections of J-20's interim engine solutions.

 

[Tyloe]

At present we have no rumours as of yet that WS-15s development will take that long, if new rumours come to light then we will change our consensus and our projections of J-20's interim engine solutions.

What is the general projected time-frame of when WS-15/WS-XX engines will be ready? Between 2020-2030?

 

[Blitzo]

What is the general projected time-frame of when WS-15/WS-XX engines will be ready? Between 2020-2030?

The last predictions seem to indicate it was intended to be ready by 2020... with the possibility that it may slip a few years to early 2020s.

But those were predictions from a while ago, we haven't had much updates since then.

edit: those dates I think were in reference with J-20 being in service with WS-15 rather than J-20 making first test flights with WS-15.

 

[davidwangqi]

There are still several years ahead before WS15 comes out. If they keep improving WS10 variant's performance (which is almost certain), I see no reason not to integrate it to J20. Withing the next 5 years, WS10 variants could be the only realistic engine they can obtain that will outperform the current AL31s considering the chance of getting 117s is low.

I also thought like you guys that they should just put some Taihang engines into the J-20, and that just because they are indigenous, unless they have serious drawbacks, they would be preferable over Russian AL-31. But that's before I learned that engines are not plug-and-play. If you wanted to switch from AL-31 to Taihang, you needed to do a whole new series of tests including optimizing the intake and re-balancing the jet. It's a lot of work and causes the program to enter a new testing phase. Unless these tests can bring something very significant to the J-20, it most likely will not be worth the extra time, money and work especially for an interim engine. So J-20's current configuration is optimized to AL-31; if you wanted to switch to Taihang because let's say the WS-10 offered 140kN instead of 137kN for AL-31, that would not be worth the work at all to throw the project into a renewed testing phase, delaying IOC. The only situation in which I see China integrating a WS-10 onto the J-20 is if a new WS-10 variant provided significantly more thrust (say 155kN), the WS-15 was delayed, and there was a foreseeable near-term security threat that might require an optimally-performing J-20 to secure.

 

[Blitzo]

There are still several years ahead before WS15 comes out. If they keep improving WS10 variant's performance (which is almost certain), I see no reason not to integrate it to J20. Withing the next 5 years, WS10 variants could be the only realistic engine they can obtain that will outperform the current AL31s considering the chance of getting 117s is low.

It depends how much more powerful a potential new WS-10 variant is compared to whatever Al-31 variant J-20 is using, as well as how much longer WS-15 would be ready compared to how long it would take (and how much it would cost) to integrate the new WS-10 variant.

For instance, if a new higher rated WS-10 variant emerges in 2018, but it is a few kN extra thrust than Al-31 that J-20 is using, and if WS-15 is expected by CAC to be ready for J-20 integration and testing by 2020, then it may not be worth integrating WS-10 into J-20 given it offers only a minimal increase in thrust and possible other capabilities than Al-31s and given WS-15 would be ready for the aircraft within an acceptable timespan.

So, I think the main variables that would make J-20 being integrated with WS-10 a sensible choice, are:
-if WS-15 is heavily delayed
-and/or if no higher rated Al-31s can be acquired to power J-20 as an interim engine (or if there is some other reason which makes current Al-31s unsuitable for J-20)
-and/or if a new WS-10 variant is significantly more capable than current interim Al-31s

 

[davidwangqi]

Agreed. But there is another reason which is to integrate indigenous trust-vector turbofan engine. It can only be WS10 if not 117s. Since WS10 is now reliable enough, it can be a reasonable test bed for their newly developed trust-vector technology.

It depends how much more powerful a potential new WS-10 variant is compared to whatever Al-31 variant J-20 is using, as well as how much longer WS-15 would be ready compared to how long it would take (and how much it would cost) to integrate the new WS-10 variant.

For instance, if a new higher rated WS-10 variant emerges in 2018, but it is a few kN extra thrust than Al-31 that J-20 is using, and if WS-15 is expected by CAC to be ready for J-20 integration and testing by 2020, then it may not be worth integrating WS-10 into J-20 given it offers only a minimal increase in thrust and possible other capabilities than Al-31s and given WS-15 would be ready for the aircraft within an acceptable timespan.

So, I think the main variables that would make J-20 being integrated with WS-10 a sensible choice, are:
-if WS-15 is heavily delayed
-and/or if no higher rated Al-31s can be acquired to power J-20 as an interim engine (or if there is some other reason which makes current Al-31s unsuitable for J-20)
-and/or if a new WS-10 variant is significantly more capable than current interim Al-31s