Chinese Engine Development

Salyut has been working on an entirely Russian AI-222 replacement for some time, the SM-100:

If China for some reason cannot continue to buy AI-222s off the shelf, investing in this project is probably going to be faster than starting from scratch. In fact, the above presentation expressly notes the L-15 as a possible application, although there is always the chance that the Chinese might prefer a domestic alternative.

As for Motor Sich/Ivchenko Progress, with first the Russian and now the Chinese markets all but gone, their prospects look grim indeed. The only opportunity outside minor civilian turboprops/turboshafts I can see is Turkey, though in fairness that might actually just work out. There is a precedent (AI-450 turboprops on the Akinci UAV) and their TFX fighter project could soon be looking for an engine solution, if they fail to get what they want from the usual suspects.

Ukraine is hardly an ideal partner for such a venture, lacking experience in modern fighter engines and they are rather behind the curve by now in general. They have a project for an apparent MiG-29 engine to replace the RD-33 (AI-9500F) which has languished since 2009ish:

Nonetheless, a lot of their know-how from high-BPR turbofans would read across to a fighter engine and they do have some interesting design and turbine cooling capabilities. It won't be an Izd.30, but a somewhat improved F110-class engine should be feasible.

Tirdent said:

Salyut has been working on an entirely Russian AI-222 replacement for some time, the SM-100:

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If China for some reason cannot continue to buy AI-222s off the shelf, investing in this project is probably going to be faster than starting from scratch. In fact, the above presentation expressly notes the L-15 as a possible application, although there is always the chance that the Chinese might prefer a domestic alternative.

As for Motor Sich/Ivchenko Progress, with first the Russian and now the Chinese markets all but gone, their prospects look grim indeed. The only opportunity outside minor civilian turboprops/turboshafts I can see is Turkey, though in fairness that might actually just work out. There is a precedent (AI-450 turboprops on the Akinci UAV) and their TFX fighter project could soon be looking for an engine solution, if they fail to get what they want from the usual suspects.

Ukraine is hardly an ideal partner for such a venture, lacking experience in modern fighter engines and they are rather behind the curve by now in general. They have a project for an apparent MiG-29 engine to replace the RD-33 (AI-9500F) which has languished since 2009ish:

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Nonetheless, a lot of their know-how from high-BPR turbofans would read across to a fighter engine and they do have some interesting design and turbine cooling capabilities. It won't be an Izd.30, but a somewhat improved F110-class engine should be feasible.

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I think as deep as the well is for China, they still don't want to spread their resources that thin. If they haven't bothered to develop an alternative to Al-222 despite knowing potential risks of supply being cut ever since the Crimean fiasco (they would have certainly appreciated the possibility then), it means they won't bother spending the time and resources to develop one now. Since Russia is publicly working on an alternative, the Chinese would surely know and consider it as backup if off the shelf purchase from MS is stopped for whatever reason. It's also not that important for China to have perfect ideal delivery rate for JL-10 trainers.

I suspect China was more interested in purchasing a controlling stake in MS for accessing helicopter engines and manufacturing tech. China's own mid to high thrust low bypass tech (including manufacturing) should be fairly mature and not behind that of Ukraine overall if it could develop the WS-10 and WS-15 and reverse engineer a RD-33 so quickly with seeming ease. Perhaps there would be a few small worthwhile lessons here and there but overall, it isn't the low bypass stuff that interested China. Helicopter engines are a fairly obvious gap in Chinese capability. High bypass - unknown possibly like helicopter engines with value to gain.

Without Russian and Chinese markets (which are diminishing anyway which is why a sale of MS was most ideal for all including Ukraine and MS), their cashflow is sure to be in trouble. I don't think they'd shoot themselves fatally just to please the Americans so there's little doubt that they'd still be selling products off the shelf to China at least. Turkey's savings account is now basically China's wallet. MS thriving, even surviving just on selling product to Turkey is pretty precarious because do the Turks have such deep pockets to finance ALL those rather ambitious military projects and procurements?

I would not say the Chinese engine industry is weak with regards to helicopter engines when they have the WZ-9 (1000-1400 kW), WZ-10 (2000 kW?) engines for the Z-10 and Z-20 helicopters. Together soon with joint developments like the WZ-16 (1000-1500 kW) for the Avicopter AC352 helicopter. Not to mention licensed production of French helicopter engines like the WZ-8/Arriel (508 kW), WZ-6/Turmo (1200 kW).

The only thing really missing is a heavy helicopter engine >4000 kW. Perhaps a more modern light helicopter engine ~500 kW would help but the WZ-8 engine is still ok. Helicopter engines have a much slower pace of improvement versus airplane engines so it is understandable how China advanced so quickly in this field. Just think about how China for a long time only had licensed engine production, then they quickly got the WZ-9 and WZ-10 engines operational.

The rate of improvement and new engine development for helicopters has been much faster than in jet engines for airplanes. For airplanes they got the WS-10 but it took ages for them to improve the engine until it was reliable enough and the other engine programs are still delayed. Sure the WS-15 is much higher tech but the WS-20 should have been operational a long time ago.

In civilian and transport aircraft is where the problems are the most acute I think.

gelgoog said:

I would not say the Chinese engine industry is weak with regards to helicopter engines when they have the WZ-9 (1000-1400 kW), WZ-10 (2000 kW?) engines for the Z-10 and Z-20 helicopters. Together soon with joint developments like the WZ-16 (1000-1500 kW) for the Avicopter AC352 helicopter. Not to mention licensed production of French helicopter engines like the WZ-8/Arriel (508 kW), WZ-6/Turmo (1200 kW).

The only thing really missing is a heavy helicopter engine >4000 kW. Perhaps a more modern light helicopter engine ~500 kW would help but the WZ-8 engine is still ok. Helicopter engines have a much slower pace of improvement versus airplane engines so it is understandable how China advanced so quickly in this field. Just think about how China for a long time only had licensed engine production, then they quickly got the WZ-9 and WZ-10 engines operational.

The rate of improvement and new engine development for helicopters has been much faster than in jet engines for airplanes. For airplanes they got the WS-10 but it took ages for them to improve the engine until it was reliable enough and the other engine programs are still delayed. Sure the WS-15 is much higher tech but the WS-20 should have been operational a long time ago.

In civilian and transport aircraft is where the problems are the most acute I think.

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If I recall, all those helicopter engines are foreign licensed, heavily dependent on foreign components, or entirely off the shelf. China's own are much lower thrust classes?

ougoah said:

If I recall, all those helicopter engines are foreign licensed, heavily dependent on foreign components, or entirely off the shelf. China's own are much lower thrust classes?

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The Z-10 and Z-20 helicopter's engines (WZ-9, WZ-10) are Chinese designed and built. The WZ-16 engine is based on Safran's Ardiden engine but it was jointly developed, not just licensed, with Safran from France. The WZ-9 in its most recent iteration has more or less the same thrust as the WZ-16 is supposed to have. I think they had both programs simultaneously as insurance. The fact that China can at least collaborate with Europe on helicopter engines unlike with military aircraft engines sure helps a lot.

Compare that with civilian aircraft or military transport engines. Much less developed. I think part of it was lack of funding by the Chinese central government and probably lack of skilled engineers even just a decade ago which meant they had to focus their resources more. The CJ-1000 is supposedly being developed with help from MTU Aero from Germany and Avio from Italy but both those companies have way less design experience than required for a project like that.

gelgoog said:

The CJ-1000 is supposedly being developed with help from MTU Aero from Germany and Avio from Italy but both those companies have way less design experience than required for a project like that.

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I'm curious about the status of their participation actually - you didn't hear much about it after the initial announcement. Both (though especially Avio - the relevant gas turbine business unit was sold to GE!) would be liable to cut their exposure to this project if sanctions entered into force, obviously.

That said, while they do not have much complete engine experience worth mentioning, they are among the world leaders for certain individual aspects. MTU have outstanding HP compressor capabilities (EJ200, PW6000) and Avio are the go-to guys for accessory drives and other ancillaries, both are highly experienced in LPTs. So depending on what skills ACAE is looking for from these partners, they could be very good choices.

Excellent primer on 3rd Generation Emei Turbine technology via Grandy and why it is so difficult to design and fabricate 3rd generation Turbine blade

Turbine blade performance comparison under different processes

At this time, the bearing temperature of turbine blades made of directional casting superalloy has reached 1000℃ (approximately 1273K). With an increase of about 200°C, combined with simple blade air cooling technology, the temperature in front of the turbine of the second-generation aero gas turbine engine has reached 1300K-1500K, and the performance of the aero engine has been further improved.

The first generation of single crystal alloy + film cooling technology

in the 1970s , The alloying theory and heat treatment process have been breakthroughs. The process at this time can completely eliminate the grain boundary on the basis of the directionally solidified alloy. The single crystal alloy turbine blade manufacturing technology was born, and it also set off a second revolution in the materials used for turbine blades. , The thermal performance of alloy blades has been further improved (about 30℃), and the bearing temperature of turbine blades has reached 1050℃ (about 1323K).


However, the requirements of the third-generation aero gas turbine engine also further increase the working temperature and load-bearing temperature of the turbine blades.Since then, the cooling technology of turbine blades has been paid more attention. By designing cooling channels and cooling holes on the blades, the "low temperature gas" of several hundred degrees Celsius in the compressor is introduced into the turbine blades, and then sprayed from the cooling holes on the blade surface to form a gas film, which has a relatively high temperature isolation. The low turbine blades and the high temperature gas in the working environment are called film cooling technology.



Close-up of the cooling holes on the engine blade

The application of film cooling technology enables the working temperature of the turbine blade to be much higher than the bearing temperature of the blade material itself. Therefore, under the comprehensive application of the first-generation single-crystal alloy + single-channel film cooling technology, the third-generation aeroengine's temperature in front of the turbine reached 1680K-1750K, and turbofan engines with a thrust-to-weight ratio of 8 began to appear (currently turbofan-10 Just be in this generation).

Second-generation single crystal alloy + composite cooling technology

By the end of the last century, the fifth The generation fighter has put forward the requirement of "supersonic cruise", and the thrust-to-weight ratio and thrust of the engine need to be further improved. The second-generation single crystal alloy further improves the microstructure stability of turbine blade alloys by increasing muscle rhenium, cobalt, molybdenum and other elements, and achieves a good balance between endurance strength and oxidation and corrosion resistance, so that its bearing temperature is once again It has increased by about 30°C, reaching a level of 1100°C (about 1370K).



The development path of materials used in turbine blades

At this time, it has become difficult to increase the working temperature of turbine blades by improving material performance, and single-channel film cooling technology has begun to be insufficient. A composite cooling technology with simultaneous application of a variety of cooling technologies (convection, impingement, film structure, divergent cooling, etc.) has been developed. At present, through compound cooling of the turbine blades, the working temperature of the blades (temperature before the turbine) can be about 400K higher than the bearing temperature, reaching 1850K-1980K.



The development of blade cooling technology

The second-generation single crystal alloy combined with compound cooling technology for turbine blades,It has been applied to the current mainstream fourth-generation aero engine (mainly represented by F-119 and EJ-200 engines).

Third-generation single crystal alloy/ceramic matrix composite material + multi-channel double-layer hollow wall cooling technology

_!--H2--21!-- H2--
At present, the research and development of the sixth-generation fighter has been put on the agenda, but there is still relatively little information about the fifth-generation gas turbine engine. According to the breakthroughs made in related technologies in recent years, further optimization of alloy elements The third-generation single crystal alloys and new ceramic-based composite materials derived from the composition will become the first choice materials for the fifth-generation gas turbine engine blades. Among them, the improvement of ceramic-based composite materials is more obvious (the bearing temperature can reach 1200℃, and the weight is only It is 1/3 of the nickel-based single crystal alloy), but the technology is not yet mature.



The development of turbine blades of each generation of engines

In the next generation of turbine blade cooling technology, the cooling channels inside the turbine blades will be further increased to make the scattering of the blades more uniform; adopt double-layer hollow wall cooling technology , Adding a hollow structure to the double-layer splint of the turbine blade can further improve the cooling efficiency. As the research on multi-channel double-layer hollow wall cooling technology is relatively complicated, there are relatively few domestic researches in this area at present.

As I said before it take a lot of trial and error to make advance gas turbine that is why it takes so long
Conclusion
Summary and prospects for the development of aero-engine turbine blades

In general, the manufacturing and optimization of aero-engine turbine blade materials is an extremely complex process that requires a lot of experimentation to find the optimal or near optimal The optimization of the turbine blade cooling scheme is based on the design and manufacturing. Every time the cooling technology optimization of the turbine blade is also a huge test for the blade design and manufacturing. Therefore, it is no exaggeration to say that the price of a single crystal blade exceeds the same weight of gold.


Ceramic-based composite turbine blades exhibited by GE

From the perspective of the development of aero-engine turbine blades, the development of more high-temperature-resistant turbine blades is the key to improving engine performance. And after decades of development,The potential of single crystal alloy blades seems to have been tapped out. If you want to further improve the performance of aero-engines, looking for new directions has become a choice that has to be faced in the development of turbine blades; although there is still a lot of optimization in the cooling technology of aero-engine turbine blades Space, but it will undoubtedly further increase the difficulty of blade processing and manufacturing.

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ougoah said:

In engineering of any practice (and especially true for high tech and complex things) blueprints themselves are worth very little. They are the executive summary of the technology world and honestly absolutely nothing much more... useful for certain parts but only with all the design/test phase work done and understood by the supply chain. Good for references and records.

They make up such a small part of the entire project. Blueprints also DO NOT reveal many aspects of design. They certainly don't give much if any insight into materials, material fabrication and more importantly the overall steps, timing, methodology, procedural checks/tests, equipment used, tools, machinery etc that are behind making something real. What temperature to set the autoclave? What density within a certain chamber? What gases to apply and their concentrations for this and that? Few factors out of hundreds if not thousands. To sell or supply all the above in a way that makes it possible for another party to execute and implement, there would be 1000 more things on top of blueprints that naive people like to think is the be all end all of advanced technologies. You could give the best minds and organisations the blueprint of an advanced alien integrated circuit board and we wouldn't be able to reproduce it without many more peripheral breakthroughs and probably decades if not many centuries.

China can still purchase the originally intended low thrust Ukrainian JL-10 engine can they not?

Preventing Chinese state from purchasing Motor Sich doesn't mean preventing China from purchasing the engines off the shelf right?

The engine itself is nothing spectacular or difficult but it does take time and resources to develop. If China cannot realistically afford to wait years for domestic industry to develop a suitable engine for the JL-10 trainer, they can purchase a suitable engine from Russia (that exists btw already off the shelf) if Motor Sich won't even sell their product?

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Do they have the Guizhou WS-17 engine ready to put in the jl-10 ? They were testing them no?

It was called the Minshan too I think, what happened with that engine ?