Chinese Engine Development

I have DeVore's "Chinese aerospace and industry guide" published in 2000. Seems to be saying that a chinese company builds turbofan blade parts for Mirage 2000 engine. How correct is he?

"The US Sikorsky Aircraft Corporation is reportedly establishing a joint venture aero-engine repair and
parts supply centre in co-operation with the Chengdu Engine Company. Subcontracts for foreign
aero-engine manufacturers are becoming increasingly sophisticated. Notable examples include Snecma
CFM56 blades and components for the Mirage 2000's M53 aero-engine produced by plants at Xi'an and
Shenyang Liming. Significant recent US and Russian technologies have reportedly been integrated into the
new generation WS10 Chinese turbofan aero-engines for the J-10 and other advanced fighter aircraft
programmes, possibly with thrust vectoring capabilities. The Xi'an XRA Aerocomponents Ltd. is a new
joint venture between Xi'an Aero-Engine Corporation and the UK's Rolls-Royce for the casting and
machining of Rolls-Royce and BMW Rolls-Royce aero-engine components"

tphuang said:

cost of setting up these lines, whether or not individual suppliers can supply enough parts for assembly and such. And you are not going to see imported aircraft anymore imo. I don't expect anything more than 14 su-33s.

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To be honest i preffered China to only purchase 5 Su-33. Reason behind this is that i recon that china can produce the Su-33 variant from the J-11 which they have already mastered pretty well. Purchasing 5 Su-33 can give them the aircraft to examine and reverse engineer them or to use the knowledge and apply them to the J-11. Eg: Foldable wings. Though i would prefer a J-10 naval variant launching of a carrier first.

crobato said:

I don't think the compression ratio is really the problem. Military turbofans even have lower compression ratios than civilian turbofans which has more compressor stages. The fact that a stationary version power plant version of the WS-10A got certified first and is already available for sale tell you that's not the problem.

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I don't buy that. Getting a design certified does not mean you know how to mass produce it with the same original quality. In other words, it's more difficult to make 100 engines with the same quality than making just one engineering model.

It is true that military turbofans don't achieve the same level of pressure ratio as civilian turbofans, but that's not my point. My point was that their pressure ratio was much higher than the turbojets that the Chinese are used to making in the past. F110 is has compression ratio around 30:1, EJ200 is about 25:1, AF-31 is about 23.8:1. Compare these to a GE H class gas turbine: 23:1. I'm not sure what kind of pressure ratio the J-7 engines achieve, but I'm guessing around 10:1.

You can get an engineering model ceritified by cherry-picking the best part candidates just for the sake to proving the design, but that practice is too expensive for mass production. For mass production, you need to find ways to produce the same quality parts over and over again with an acceptable cost.

oringo said:

I don't buy that. Getting a design certified does not mean you know how to mass produce it with the same original quality. In other words, it's more difficult to make 100 engines with the same quality than making just one engineering model.

It is true that military turbofans don't achieve the same level of pressure ratio as civilian turbofans, but that's not my point. My point was that their pressure ratio was much higher than the turbojets that the Chinese are used to making in the past. F110 is has compression ratio around 30:1, EJ200 is about 25:1, AF-31 is about 23.8:1. Compare these to a GE H class gas turbine: 23:1. I'm not sure what kind of pressure ratio the J-7 engines achieve, but I'm guessing around 10:1.

You can get an engineering model ceritified by cherry-picking the best part candidates just for the sake to proving th design, but that practice is too expensive for mass production. For mass production, you need to find ways to produce the same quality parts over and over again with an acceptable cost.

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Heat is the problem of the engines, not the compression ratios. The Chinese had achieved very high compression ratios before (check their stationary engines), and even supply crystal blades for export to turbine manufacturers around the world. Exhibitors even boasted of a "2nd generation" crystal blade back in 2004. Problems with the 052B's DA-80 turbines from the Ukraine led to the Chinese replacing the blades with Chinese made crystal blades, and the Ukrainians were surprised with the result.


Another thing is that you have to understand, GE like all othet US companies investing in China, is under heavy watch. They're going to be extremely careful not to pass any technology that is potentially militarily useful to the Chinese.

GE Liming sounds like one of those ventures that intend to build products that are a mix of domiestic and imported components for domestic consumption. In other words, they will manufacture engines that use a combination of GE and Shenyang Liming parts. GE for example, may provide the engine core and some components, while Liming provides others. You're not going to learn much from that model.

GE won't be entering into a partnership with Shenyang Liming unless SL's technological achievement have been feat accompli. If SL learned anything from GE, it would be far too late for the Taihang and even the Taishan engines.

Lastly let me remind you again, that an engine that works perfectly in a static test bench may not work perfectly once its flying in a plane. That's because the conditions facing an aviation engine is so varied than a stationary engine.

crobato said:

Heat is the problem of the engines, not the compression ratios.

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I don't buy that either. Thermodynamics tells us that heat and pressure of a fluid are essentially interchangable when holding volume constant (PV=nRT). In other words, compression ratio plays just as an important role as temperature in determining the stress on the blades.

crobato said:

The Chinese had achieved very high compression ratios before (check their stationary engines), and even supply crystal blades for export to turbine manufacturers around the world.

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Are you talking about the stationary WS-10? If yes then see my previous argument.

crobato said:

Another thing is that you have to understand, GE like all othet US companies investing in China, is under heavy watch. They're going to be extremely careful not to pass any technology that is potentially militarily useful to the Chinese.

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I think there's something you don't understand here. GE like all other companies around the world are just businesses with a bottom line. If they care about getting the market share in China, they will do whatever it takes to get it, even if it means placing themselves in the grey area. I also want to remind you that GE is not a small guy, and they have lots of influence in Congress to get things done their way.

Of course, I'm not accusing GE of exporting an F-110 to China. But think about the following scenario: GE-Liming makes a part for the gas turbine, due to quality issues the part fails 50% of the time. GE then tells GE-Lming, hey instead of heat-treating your part at XXX degree for YY hours, do it at ZZZ degree for WW hours. Small things like that are usually not under the watch, and it's something that Liming could've figured out if they had tried it out themselves. But it would've taken them 6-12months to figure it out, and this experience/knowledge can sometimes be quite portable when you apply to military engines.

Again, I'm going to point out to you that the article was dated 2005. China's been working on their WS10A for how long?

So your original assertion that China owe's it's success with the WS10A to GE is false.

skyhawk2005 said:

Again, I'm going to point out to you that the article was dated 2005. China's been working on their WS10A for how long?

So your original assertion that China owe's it's success with the WS10A to GE is false.

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Good point Skyhawk. One has to admire the extent to which some will go to imply all of China's tech advances are from stealing & copying.
With all the M&A, joint-ventures, outsourcing, migration of talents etc in the high tech fields around the world these days, it's easy to point fingers in all directions isn't it ?

One has to distinguish technology demonstrator projects and projects that are intended to be mass produced. If one merely tries to see what kind of engine can he make, using all means allowed, then yeah, ramping up the production of final product may indeed prove very problematic. But, if the whole project was planned from the beginning to be in widespread use, its design would have taken into account potential technological obstacles. Only fairly mature technologies and production processes which have been reasonable proven to be affordable would be used. It is the only logical thing to do, and every company does that.

Now, unless ws10 project has been a great deception where in fact it is only a technological demostrator, or unless there is such lack of goverment body control and widespread corruption within the official military procurement channels which would allow for hiding the fact that engine can't be produced cheaply - then yeah, ws10 might not get inducted into service for some time to come. First possibility, however far fetched, is concievable, however improbable. Second possiblity is, in my opinion, almost impossible.

Totoro said:

One has to distinguish technology demonstrator projects and projects that are intended to be mass produced. If one merely tries to see what kind of engine can he make, using all means allowed, then yeah, ramping up the production of final product may indeed prove very problematic. But, if the whole project was planned from the beginning to be in widespread use, its design would have taken into account potential technological obstacles. Only fairly mature technologies and production processes which have been reasonable proven to be affordable would be used. It is the only logical thing to do, and every company does that.

Now, unless ws10 project has been a great deception where in fact it is only a technological demostrator, or unless there is such lack of goverment body control and widespread corruption within the official military procurement channels which would allow for hiding the fact that engine can't be produced cheaply - then yeah, ws10 might not get inducted into service for some time to come. First possibility, however far fetched, is concievable, however improbable. Second possiblity is, in my opinion, almost impossible.

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But wouldn't you think that the domestic WS10 engine would be cheaper then the foreign bought engine? As making the engine yourself would usually be cheaper then buying it from another country. PLAAF should reallly try to rely on its own engines now.

Chengdu J-10 said:

But wouldn't you think that the domestic WS10 engine would be cheaper then the foreign bought engine? As making the engine yourself would usually be cheaper then buying it from another country. PLAAF should reallly try to rely on its own engines now.

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That was not what i was talking about, nor was i replying to your post, but yeah, i agree that domestic production is better for china than buying foreign equipment.