Chinese Engine Development

Blackstone said:

That's what the Communist Party-controlled news media says, but can we believe it? I'm not so sure.


And yet, we haven't seen any J-20 test planes using WS-10 engines. Why is that?

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If you're going to think like that, then there's no reason to be on this thread at all. What kind of "reliable" sources were you hoping to hear from? American spy uncovers truth about Chinese engine program and shares his findings with the public? LOL You should probably do some catch-up reading on engines if you're going to make accusations. It's been discussed before why J-20 probably doesn't use WS-10A and now you're making people explain the basics to you again about optimizing engine to airframe and how similarly powered engines can't just be replaced with each other without extensive redesign to the aircraft. People asking for information and education need to be a lot more humble and less accusatory.

Bltizo said:

Yes, a change from Al-31 to WS-10 will obviously require a degree of change to the airframe and will require some additional testing... but the difference in overall physical dimensions between Al-31 and WS-10 are not as great as say, WS-10 and RD-93.

The Al-31 and WS-10 are most definitely in the same general size class, thrust class and weight class as each other, and as we can see via the likes of SAC's Flankers (J-11B, J-16, etc) using WS-10s and J-10B/Cs being tested with WS-10s, they can adopt them with minimal (if any) external, visible modification to the airframe or the intakes compared to variants which use Al-31s.

So I do think that Al-31 and WS-10 can be swapped out in a near "plug and play" way, but it would require some modifications, testing and validation on the aircraft type in question to allow that kind of switch to viable in the first case.
In the case of J-20, that additional cost of such modifications, testing and validation to allow both Al-31 and WS-10 to be used probably isn't worth it for a mere interim engine.

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I don't have the exact dimensions of WS-10 especially its newer variants, but all the words out there are quite consistent to indicate that WS-10 is slightly larger than the Al-31, and it has caused problems when they try to install WS-10 on flankers for testing. They eventually solved the problem but it was clear that the fit was tighter and required significant effort to change design

A "semi-official" Chinese source that mentioned this:


There were also articles saying that one of the reasons newer J-10 didn't use WS-10 for mass production was that it made the rear section thicker and increased drag a bit too much (J-10 have more restrictive engine compartment than flankers and are more sensitive to any size change). I cannot find official source confirming this one so you may take it with a grain of salt.

So while they solved the problem for flanker platforms, it may still cause problems (solvable) for a plane like J-20 due to the reasons I mentioned earlier. It may not be as easy as you'd have imagined. But of course without further information this is at best an educated guess, there's nothing I can say for certain. Maybe the engine compartment of the J-20 is just as spacious or flexible as the flankers, or maybe newer WS-10s are just as compact as the Al-31, who knows?

Bltizo said:

Possibly, though I'd be wary of that line of reasoning. I can envision them being happy to continue using Al-31s even if WS-15s are many years away, due to the fact that it may still offer a perfectly competent interim engine capability that is already a known quantity on the airframe, and where the benefits of self sufficiency may be viewed as not worth the additional complexity of having a large number of J-20s with interim engines that are both Al-31s and WS-10s.

It will also depend on how many WS-10s they can produce, and the cost of the WS-10s relative to the Al-31s (Series 3), and how many J-20s they already have flying with Al-31s to begin with.

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What I said was that what would a change to WS-10 could indicate. It would most likely exclude the possibility that WS-15 can be ready soon. But yes it doesn't mean if the J-20 stays on Al-31 than the WS-15 is guaranteed to be ready soon, we can't say that for certain.

superdog said:

I don't have the exact dimensions of WS-10 especially its newer variants, but all the words out there are quite consistent to indicate that WS-10 is slightly larger than the Al-31, and it has caused problems when they try to install WS-10 on flankers for testing. They eventually solved the problem but it was clear that the fit was tighter and required significant effort to change design

A "semi-official" Chinese source that mentioned this:

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There were also articles saying that one of the reasons newer J-10 didn't use WS-10 for mass production was that it made the rear section thicker and increased drag a bit too much (J-10 have more restrictive engine compartment than flankers and are more sensitive to any size change). I cannot find official source confirming this one so you may take it with a grain of salt.

So while they solved the problem for flanker platforms, it may still cause problem for a plane like J-20 because of the reasons I mentioned earlier. It may not be as easy as you'd have imagined. But of course without further information this is at best an educated guess, there's nothing I can say for certain. Maybe the engine compartment of the J-20 is just as spacious or flexible as the flankers, or maybe newer WS-10s are just as compact as the Al-31, who knows?

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They seem to have equipped the couple of J-10Bs using WS-10s without any visible outward structural changes compared to J-10Bs using Al-31s, so I'm not sure how true those rumours are.

I think it's likely that the Al-31s and WS-10s are a little bit different in terms of overall dimensions, and probably weight as well (in absence of fully accurate specs of WS-10), but I also think if an aircraft is able to accommodate an Al-31 then I think it can probably be able to physically accommodate a WS-10 as well, with some modifications, tests, and re jigging to validate the engine change that will be necessary for the aircraft in question.

In the case of J-20, I think that it will almost definitely be able to accommodate WS-10 even if WS-10 is slightly larger than Al-31, because we need to remember that J-20 was built with WS-15 in mind (which will almost definitely be a slightly larger engine than Al-31 as well as WS-10), meaning it is more likely than not that it has been designed with "excess" free space for WS-15 to eventually be integrated with minimal redesign.

All this isn't to say that changing J-20s (or J-10s) engines from Al-31 to WS-10 (or eventually to WS-15) will be "easy" -- integrating the engine, validating the engine aboard the aircraft across the entire flight profile will take a lot of time and money -- but I do think that structural, physical space for the engines will not be a major issue.

What I said was that what would a change to WS-10 could indicate. It would most likely exclude the possibility that WS-15 can be ready soon. But yes it doesn't mean if the J-20 stays on Al-31 than the WS-15 is guaranteed to be ready soon.

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Possibly, but another potential reason for if they do somehow switch to WS-10, may be due to having access for Al-31 Series 3 being cut off.

Though like you said, the overall point I was making is that just because they're still on Al-31s now doesn't mean the WS-15 will be ready immediately soon, or that if they do use WS-10 eventually it may not mean that WS-15 is significantly delayed.

Bltizo said:

They seem to have equipped the couple of J-10Bs using WS-10s without any visible outward structural changes compared to J-10Bs using Al-31s, so I'm not sure how true those rumours are.

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A slight increase in rear section dimensions is not necessarily noticeable to the eye unless you have accurate blueprints to compare it with. But then one could doubt how much of an impact it would have on drag. So yes that piece of info is not completely trustworthy.

Bltizo said:

I think it's likely that the Al-31s and WS-10s are a little bit different in terms of overall dimensions, and probably weight as well (in absence of fully accurate specs of WS-10), but I also think if an aircraft is able to accommodate an Al-31 then I think it can probably be able to physically accommodate a WS-10 as well, with some modifications, tests, and re jigging to validate the engine change that will be necessary for the aircraft in question.

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I also said it is possible, just not plug and play or "near" plug and play, which means an engine switch to WS-10 would require some significant reason for justification, that's my point. We have more in common than differences here.

Bltizo said:

In the case of J-20, I think that it will almost definitely be able to accommodate WS-10 even if WS-10 is slightly larger than Al-31, because we need to remember that J-20 was built with WS-15 in mind (which will almost definitely be a slightly larger engine than Al-31 as well as WS-10), meaning it is more likely than not that it has been designed with "excess" free space for WS-15 to eventually be integrated with minimal redesign.

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Why is the WS-15 "most definitely" larger than the Al-31? I mean yes it is a possibility, but why so sure? An increase in power does not necessarily mean an increase in diameter, especially for these low bypass engines.

superdog said:

A slight increase in rear section dimensions is not necessarily noticeable to the eye unless you have accurate blueprints to compare it with. But then one could doubt how much of an impact it would have on drag. So yes that piece of info is not completely trustworthy.

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Sure.

I also said it is possible, just not plug and play or "near" plug and play, which means an engine switch to WS-10 would require some significant reason for justification, that's my point. We have more in common than differences here.

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Yes, we agree in the bottom line which is that an engine switch would have a significant cost and thus require an equally significant reason to do so.

The point of disagreement is whether a change from Al-31 to WS-10 would require significant structural physical redesign.

Why is the WS-15 "most definitely" larger than the Al-31? I mean yes it is a possibility, but why so sure? An increase in power does not necessarily mean an increase in diameter, especially for these low bypass engines.

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Actually I wrote "almost definitely" -- but I agree, in hindsight, "probably" or even "possibly" is a more suitable word.
That said, I do think some of the higher thrust goals of WS-15 that have been thrown around may result in a slightly larger engine compared to 4th generation contemporaries due to my belief that XAEC and their subcontractors likely still remain slightly behind their contemporary companies of the era in the US; whereas US manufacturers like PW or GE were able to develop 5th gen engines that managed to maintain similar weight and dimensions to their 4th gen engine predecessors.

siegecrossbow said:

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According to CAIC, over 400 WS-10 engines have been delivered to PLAAF and PLAN. They've been used to equip domestic flankers like the J-11B/Ds and J-16s. Despite numerous challenges encountered during the developmental phase, not a single WS-10 equipped fighter crashed due to engine failure.

I'd say that the WS-10 is ready and good to go. Should the Russians stop delivering AL-31s for some reason, China could still use WS-10s on J-20 as a stop-gag measure.

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Sorry, I don't Understand Chinese Language from that News.
and Translate Engine doesn't help me too.

400 WS-10 Engines Delivered,
from Beginning until 2015 or
from 2015 until today or
from January 2015 until December 2015?

I am little Confused.

Blackstone said:

That's what the Communist Party-controlled news media says, but can we believe it? I'm not so sure.

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Give Solid Proof before Judge.
Because, Judgement without Solid Proof is called Bias.

AVIC report: China's Taihang engine widely deployed in military
By Jiang Jie () 14:45, July 07, 2016



China’s Taihang engines have become a significant, large-scale presence in the military, making China the third country in the world that has mass deployment of domestically-produced high-thrust engines for military use, according to the Aviation Industry Corporation of China (AVIC) annual report.

AVIC's social responsibility report showed that the company is capable of independently conducting research and development on the next generation of high-thrust aerial engines, along with advanced drones such as Wing Loong, which have also been deployed in the military.

The People’s Liberation Army (PLA) Air Force has deployed no less than 400 Taihang engines in five air force regiments. Various types of fighter jets are equipped with the engine, including the J-11B and J-15 carrier-based fighter jets, reported China Science Communication, a news site under the Chinese Academy of Sciences. So far there have been no crashes due to engine failure among Taihang engine-equipped fighter jets, the news site also noted.

Some doubts have been voiced about the originality of the Taihang engine, as there are people who believe the Chinese-made engine is a copy of its Western counterparts. However, according to China Science Communication, the development of the Taihang engine was based on accumulated experience and technological advances gathered since 1978. The engine was also based partially on its predecessor, WS-6, which spent some 20 years in development.

Meanwhile, the engine also took inspiration from the control system of Russia's AL-31F aircraft turbofan engine, China Science Communication admitted, calling the Taihang engine a result of “independent development combined with technology from the Soviet Union and the U.S.”

“China has become the fourth country in the world to independently design and produce large transportation aircraft, as well as the third country to independently develop stealth fighter jets,” the AVIC report said, adding that China has advanced its air-to-air and air-to-ground missiles to the fourth generation.



Finally Got the answer

Daniel707 said:

Sorry, I don't Understand Chinese Language from that News.
and Translate Engine doesn't help me too.

400 WS-10 Engines Delivered,
from Beginning until 2015 or
from 2015 until today or
from January 2015 until December 2015?

I am little Confused.

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More than 400 delivered since the engine was put into service.

superdog said:

More than 400 delivered since the engine was put into service.

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This number is also helpful for determining the total number of J-11Bs and J-16s currently in service. It has to be less than 200 since you always need to keep spares.

superdog said:

More than 400 delivered since the engine was put into service.

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Thanks for the info, sir.
Happy to hear this Good news.