J-20 5th Gen Fighter Thread V

[Inst]

Except we know that the WS-10B has already reached 140 kN. 140 kN is an extremely unreasonable lower bound for the WS-15, when it's a new design. Assuming it's of the same paradigm as the F-119, which I've shown is actually a thrust-reduced F-135, even if in details it is significantly inferior reducing thrust by 25% is excessive.

 

[Quickie]

The WS-15 180 kN figure from information brochure provided in the CHINA AEROSPACE PROPULSION TECHNOLOGY SUMMIT is likely based on theoretical research and should be what they're aiming for. I think achieving 160 kN would be the minimum requisite for the project to be considered viable. 140 kN is the stuff for WS-10 variants and would be way off the mark and unimaginable for the WS-15.

 

[manqiangrexue]

the only folks wet dreaming are the 180-190 folks, I'm gonna stand by my 140 to 160, as that's a solid and reasonable goal and expectation, I was wrong on here "once", the Chinese did buy the SU-35. I have a record, I stand by it, if? and when I am wrong, I admit, make appropriate apologies and "move on". If the WS-15 reaches 140 that will be a start, and we can reasonably expect to see WS-15s start to populate on the J-20, in fact that is the most likely scenario, I do expect they are hoping to reach 160, and in your own words?? "160kn is a really admirable improvement",,,, I'd say we are in principle agreement.

If and when the Chinese develop and build a 140kn engine, it will be in the J-20, or the very least Flankers, when it is reliable and economical enough to do so, you should trust me on this. "in the real world, its "crawl, walk, run", that's how it works, nobody is born a "track start", the genetics might be there, but it takes a lot of development and hard work. So my prediction is 140kn pushing eventually to 160, and yes those early prototypes are very much a part of the whole genesis of this type of advanced development, you can't "fool mother nature"???

Those SU-35s tell us a lot more, that most of us don't want to hear, but I'll let you come to those conclusions on your own. I have said the J-20 is a very fine "clean sheet Chinese aircraft", and its one that anyone could be proud of!

Alright, you can stand by your 140-160 prediction but I say (and it seems other people say too) that it doesn't make sense at all for them to spend all that time designing an engine for it to be significantly heavier and larger than any WS-10 variant with only 5kN more. You can push WS-10X to 140kN as it is.

My whole point about the track athlete was that it was completely different from a machine. Crawl, walk run is already what happened; China crawled with engines like WS-9, then started walking with WS-10 early prototypes, was jogging with refined versions going over 130kN and now it's time to run. You seem to think that this is China's first engine when you made that remark.

Despite that I think 160kN is good enough for J-20, I'm not an engineer on that project. If what was written is true, that a WS-15 prototype reached 160kN in 2009, then it makes very little sense for it to move so slowly, taking more than 8 more years so far with barely any visible progress, unless they were aiming for a higher target. I don't quite understand your difficulty in believing the 180kN target. These aren't internet rumors; those go way higher. This is the official figure provided by the designers of the engine and the authorities which preside over them (I provided the link a few pages ago). This figure has remained consistent through time.

The only situation I can see for WS-15 to be fitted into J-20 with 160-180kN is if the engineers missed their tater and found later that they could not reach their intended goal. I see that as an unlikely situation (though more likely as you get to numbers approaching 180 like 175) but that would be a different scope. The goal is 180.

If you wanted to analyze the possible reasons for the Su-35 purchase, then head over to that thread and read what everyone's been thinking. If you wanted to say that foreign purchases point to domestic inability, well, then I guess the US has that issue too as they've bought Harriers from the UK, way more than 24, I might add.

 

[SanWenYu]

If what was written is true, that a WS-15 prototype reached 160kN in 2009, then it makes very little sense for it to move so slowly, taking more than 8 more years so far with barely any visible progress, unless they were aiming for a higher target.

While I definitely hope J-20 be fitted with WS-15 soon, I wouldn't be too surprised that this air engine project is having troubles at the moment. Comparing to WS-10, WS-15 is a whole new generation. The engineers face new challenges never seen before. Integrating the FADEC with J-20's FCS, new materials and designs of turbine blades for higher burning temperature, just to name a few. These might require very different know-hows than what have learned. Even with experience from all previous projects, building WS-15 in its fully designed capacity might be still a lot more difficult than building WS-10.

That said, whatever difficulties the WS-15 project might have, the Chinese air engine industry will have to push it through. The industry cannot afford abandoning yet another critical project.

 

[Inst]

It is more likely that the J-20 will be fitted with WS-10Gs than a compromised WS-15 design. If issues occur, you'll get ~150kn from the WS-10s instead of 160kn from the WS-15s, since the former is already mature.

Also, I have to correct myself; the F135 is a low-bypass engine while the F119 is a high bypass engine. But the former does not represent significant technological advances over the latter, if you accept that the F119's thrust is crippled by the choice of flat nozzles.

 

[latenlazy]

It is more likely that the J-20 will be fitted with WS-10Gs than a compromised WS-15 design. If issues occur, you'll get ~150kn from the WS-10s instead of 160kn from the WS-15s, since the former is already mature.

Also, I have to correct myself; the F135 is a low-bypass engine while the F119 is a high bypass engine. But the former does not represent significant technological advances over the latter, if you accept that the F119's thrust is crippled by the choice of flat nozzles.

You mean the F135 is a high bypass engine and the F119 is a low bypass engine.

 

[Air Force Brat]

It is more likely that the J-20 will be fitted with WS-10Gs than a compromised WS-15 design. If issues occur, you'll get ~150kn from the WS-10s instead of 160kn from the WS-15s, since the former is already mature.

Also, I have to correct myself; the F135 is a low-bypass engine while the F119 is a high bypass engine. But the former does not represent significant technological advances over the latter, if you accept that the F119's thrust is crippled by the choice of flat nozzles.

The F-119 was designed and optimized with those flat OVT nozzles in mind. Your assertion of a 17% loss of thrust is nonsense? No doubt those flat nozzles are not optimized for flow volume, but to assume, as you have, that the F-119 is losing 17% thrust is inaccurate. That would increase fuel consumption and thrust loss to an unacceptable level, and the F-22 supercruises faster than any other aircraft at between Mach 1.6 and 1.8.

That's outstanding performance that would be not achieveable, if indeed the F-119 were that "bottled up", anyway the F-119 makes more than abundant thrust...

The J-20 was initially designed for a larger core, higher thrust engine, that's why the inlets were redesigned and "tightened up on 2011, to optimize airflows and thrust with the AL-31FN engines. So the J-20 inlets and mounts will have to be returned to the larger inlet when the WS-15 is installed in the J-20

 

[Hyperwarp]

Except we know that the WS-10B has already reached 140 kN. 140 kN is an extremely unreasonable lower bound for the WS-15, when it's a new design. Assuming it's of the same paradigm as the F-119, which I've shown is actually a thrust-reduced F-135, even if in details it is significantly inferior reducing thrust by 25% is excessive.

Max thrust for a WS-10 version (WS-10B) is 137 kN (14,000 kgf).
WS-10IPE (WS-10G) maybe a 145+ kN turbofan. It may very well be powering the J-20 LRIP.

It seems according to the the 2nd attachment, there are multiple turbofan projects (including E'mei/WS15) with thrust ranging from 200 kgf to 20,000 kgf (20 kN to 196 kN). Can someone give the full translation?

 

[manqiangrexue]

The F-119 was designed and optimized with those flat OVT nozzles in mind. Your assertion of a 17% loss of thrust is nonsense? No doubt those flat nozzles are not optimized for flow volume, but to assume, as you have, that the F-119 is losing 17% thrust is inaccurate. That would increase fuel consumption and thrust loss to an unacceptable level, and the F-22 supercruises faster than any other aircraft at between Mach 1.6 and 1.8.

That's outstanding performance that would be not achieveable, if indeed the F-119 were that "bottled up", anyway the F-119 makes more than abundant thrust...

The J-20 was initially designed for a larger core, higher thrust engine, that's why the inlets were redesigned and "tightened up on 2011, to optimize airflows and thrust with the AL-31FN engines. So the J-20 inlets and mounts will have to be returned to the larger inlet when the WS-15 is installed in the J-20

I have also seen the source that says that flat nozzles trade off 14-17% thrust for stealth. I don't see why it wouldn't reduce thrust when you force round airflow into a rectangular slit. I re-tracked the article down. The source is dubious, but the writing seems very professional and the article is in general very well-supported by citations. Here it is:

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I have also seen one source say that the engineers at Lockmart were able to reduce that supposed loss to an acceptable number.

 

[manqiangrexue]

Max thrust for a WS-10 version (WS-10B) is 137 kN (14,000 kgf).
WS-10IPE (WS-10G) maybe a 145+ kN turbofan. It may very well be powering the J-20 LRIP.

It seems according to the the 2nd attachment, there are multiple turbofan projects (including E'mei/WS15) with thrust ranging from 200 kgf to 20,000 kgf (20 kN to 196 kN). Can someone give the full translation?

View attachment 36234 View attachment 36235

I have a question. Why do you always suggest that the J-20's engine is unknown or could be a WS-10 derivative when it's pretty clear to everyone on visual inspection that it's AL-31.

Just because the poster says that China is working on engines from 200-20,000kgf thrust doesn't necessarily mean that the 20,000kgf figure is WS-15...