Chinese Engine Development

Re: Shenyang J-31 Fighter

thunderchief said:

I doubt Chinese could have make it run at higher temperature and produce more thrust, because that would mean changing some critical parts (like turbine blades and others ) that have to endure said high temperature . Russians are still somewhat ahead in material science (no disrespect to China , just facts ) and best they have for now in this class is RD-33MK with moderate increase of thrust . There is also prototype of RD-133 with TVC and max thrust in A/B mode of 91kN , but neither of these engines have been offered to China , not to mention Pakistan .

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China poached a lot of Russian minds when the Soviet Union collapsed. At the same time Russian industries weren't very discrete about what technologies and expertise they wouldn't sell, since all of them were scrambling for cash and struggling to survive. There actually isn't much the Russians know that the Chinese don't, except maybe the benefits of experience.

Re: Shenyang J-31 Fighter

thunderchief said:

I doubt Chinese could have make it run at higher temperature and produce more thrust, because that would mean changing some critical parts (like turbine blades and others ) that have to endure said high temperature . Russians are still somewhat ahead in material science (no disrespect to China , just facts ) and best they have for now in this class is RD-33MK with moderate increase of thrust . There is also prototype of RD-133 with TVC and max thrust in A/B mode of 91kN , but neither of these engines have been offered to China , not to mention Pakistan .

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Why not? There is no doubt China still behind the Russia in engine technology, but we are not talking about China improving the 117 engine used by the PAK FA here. It's just an old engine from Soviet era.

Re: Shenyang J-31 Fighter

nemo said:

You are presuming that RD-33 is still state of art and Chinese technology has not improve to the level of the Soviet technology as of twenty years ago, while Russian technology has not improve much since the fall of the Soviet Union due to the lack of resources and dispersion of expertise. And now China has some tools and methods that even Russia does not have. The fact that China has engines in development such as WS-15 that exceed the performance of the RD-133 makes your reasoning suspect.

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Actually, if China has better technology then Soviet Union, they would make their own engine in that class ( WS-13 would be a good example) or at least they would make improved copy of RD-33 .

Whole point of using Russian engines on JF-17 and on J-31 is lack of suitable Chinese engine . That is especially true for JF-17, where Russian engine makes considerable stumbling block for export of that aircraft .

Btw, WS-15 is not in the same class as RD-133, you should compare it with AL-41S , AL-41F and so on .

Re: Shenyang J-31 Fighter

JayBird said:

Why not? There is no doubt China still behind the Russia in engine technology, but we are not talking about China improving the 117 engine used by the PAK FA here. It's just an old engine from Soviet era.

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Turbine inlet temperature and thrust-to-weight

I would give you one example : AL-31 has inlet temperature of 1685K and RD-33 1680K . Coincidence ? Nope . Both use same materials and same technology for turbine blades and some other critical parts that need to endure high temperature . Therefore , both have similar thrust-to-weight (Al-31 7.87:1 , RD-33 7.9:1 )

If Soviets had , for example , technology to achieve inlet temperature of lets say 2000K , they would produce better engines in both classes . If China has such technology now, China would produce better engines . Unfortunately, currently best Chinese engine in production is WS-10A with inlet temperature of 1750K (somewhat better then old Soviet engines) but with worse thrust-to-weight 7.5:1 . Therefore, China is currently unable to improve RD-33 thrust , until technology in WS-15 matures.And when that happens they would not need to improve it, they would simply build their own engine (WS-13)

Re: Shenyang J-31 Fighter

thunderchief said:

Turbine inlet temperature and thrust-to-weight

I would give you one example : AL-31 has inlet temperature of 1685K and RD-33 1680K . Coincidence ? Nope . Both use same materials and same technology for turbine blades and some other critical parts that need to endure high temperature . Therefore , both have similar thrust-to-weight (Al-31 7.87:1 , RD-33 7.9:1 )

If Soviets had , for example , technology to achieve inlet temperature of lets say 2000K , they would produce better engines in both classes . If China has such technology now, China would produce better engines . Unfortunately, currently best Chinese engine in production is WS-10A with inlet temperature of 1750K (somewhat better then old Soviet engines) but with worse thrust-to-weight 7.5:1 . Therefore, China is currently unable to improve RD-33 thrust , until technology in WS-15 matures.And when that happens they would not need to improve it, they would simply build their own engine (WS-13)

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Except if the blade technology is ready they don't need to wait for a new engine design to make immediate improvements. They can implement some upgrades and changes through improved parts.

Re: Shenyang J-31 Fighter

Zahid said:

Brat, the RD-93 has been made a lot less smoky. If certain reports are to be believed, Chinese have tweaked it so that it runs at a higher temperature and produces more thrust as a result. Obviously fuel consumption would have improved too.

I can not say if these sources are perfectly credible, but PAF people are saying that RD-93 thrust has been increased by Chinese to the point where FC-1 / JF-17 TWR approaches 1.1

So one can think that this is a part of the progression of 'little' improvements that you were talking about in your post.

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Roger That Zahid, and I was just "pontificating" in general about the J-31, I have no doubt that the Chinese have upgraded the RD-93, just as they have the Chinese Flankers, which I consider very likely to be of a higher level of precision than the older Russian Export birds or kit birds. I certainly meant no disrespect, and I really like the J-31, in fact I have been saying since day one, that this aircraft is likely to be the combat air-patrol aircraft for the Chinese Carriers, and let me say thank you, much of my information is older/intuition on my part. I always like for fellow posters to share their insights with me, as I have NO desire to ever mislead or post inaccurate information, one of the reasons I continue to pull whats left of my hair out, is Sino Defensers who "knowingly" post "krap", so thank you for the upgrade information, and thank you for your kind and gracious attitude toward the old brat.

Re: Shenyang J-31 Fighter

latenlazy said:

Except if the blade technology is ready they don't need to wait for a new engine design to make immediate improvements. They can implement some upgrades and changes through improved parts.

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China already has new engine designs (WS-13, WS-15, WS-10 etc ) ... All they need is blade technology and they are good to go - no need to import Russian engines, then to improve blades , re-test them and only after that install them in aircraft .

Re: Shenyang J-31 Fighter

thunderchief said:

China already has new engine designs (WS-13, WS-15, WS-10 etc ) ... All they need is blade technology and they are good to go - no need to import Russian engines, then to improve blades , re-test them and only after that install them in aircraft .

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Is "blade technology" really very very difficult ? I am not sure if China is still behind Russia for that .. for sure China is still behind the US, the UK and French .....

Re: Shenyang J-31 Fighter

thunderchief said:

Actually, if China has better technology then Soviet Union, they would make their own engine in that class ( WS-13 would be a good example) or at least they would make improved copy of RD-33 .

Whole point of using Russian engines on JF-17 and on J-31 is lack of suitable Chinese engine . That is especially true for JF-17, where Russian engine makes considerable stumbling block for export of that aircraft .

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Why invent the wheel when you don't have to? Besides, WS-13 is only used for exports-- none of the aircraft used by PLA uses that. So instead of spending time and effort to create a new engine for low production aircraft (by PLA standard), you might as well just license an existing engine and and start from there.

thunderchief said:

Turbine inlet temperature and thrust-to-weight

I would give you one example : AL-31 has inlet temperature of 1685K and RD-33 1680K . Coincidence ? Nope . Both use same materials and same technology for turbine blades and some other critical parts that need to endure high temperature . Therefore , both have similar thrust-to-weight (Al-31 7.87:1 , RD-33 7.9:1 )

If Soviets had , for example , technology to achieve inlet temperature of lets say 2000K , they would produce better engines in both classes . If China has such technology now, China would produce better engines . Unfortunately, currently best Chinese engine in production is WS-10A with inlet temperature of 1750K (somewhat better then old Soviet engines) but with worse thrust-to-weight 7.5:1 . Therefore, China is currently unable to improve RD-33 thrust , until technology in WS-15 matures.And when that happens they would not need to improve it, they would simply build their own engine (WS-13)

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Russian actually used a more permissive criteria to calculate trust to weight ratio. If you actually use the same criteria, then the calculated thrust to weight ratio would actually be somewhat the same as WS-10. But that's besides the point. WS-10 also have higher dry thrust (non-afterburning) thrust than AL-31, and that's more useful operationally.

If you tries to improve RD-33, you only modifies part of the engine anyway. I fail to see how the new parts weights so much that thrust to weight ratio fails to improve.

Re: Shenyang J-31 Fighter

antiterror13 said:

Is "blade technology" really very very difficult ? I am not sure if China is still behind Russia for that .. for sure China is still behind the US, the UK and French .....

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Actually, jet engines are not that complex devices from mechanical standpoint. Toughest problem to solve is temperature resistance, i.e. materials needed to achieve desired mechanical properties at certain temperatures. Blade technology was and still is at the center of that problem . There are dozens of good text on internet describing various techniques like directional solidification, single crystal materials etc ... Of course, complete know-how is a closely guarded secret. Russia gladly sells its engines to China, but I don't think they would ever part with their blade technology . Even India had problems with that - according to rumors, they practically build whole Su-30 MKI from scratch, except those turbine blades that still have to be imported