Chinese Engine Development


t2contra

Major

China's self-developed plane engine completes test run​

Source: Xinhua| 2018-05-20 22:49:12|Editor: Yurou
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SHANGHAI, May 20 (Xinhua) -- China's self-developed demonstrator aircraft engine CJ-1000AX has completed a successful test run in Shanghai, the engine maker said Sunday.
AECC Commercial Aircraft Engine Co. Ltd. (ACAE) designed CJ-1000AX for China's homemade large C919 passenger jet, developed to rival global leading airliners such as Airbus A320 and Boeing B737.
The engine reached a rotational speed of up to 6,600 revolutions per minute in the test run, ACAE said.
The company inked a deal with Commercial Aircraft Corporation of China, the maker of the C919 jetliner, on developing its engine system in December 2016, and completed assembling CJ-1000AX in December, 2017.
ACAE has more than 110 global and domestic partners in commercial aircraft engine industry.
Found this
 

t2contra

Major
Could be the one among a slew of lengthy test runs.

Surge tests, Water ingestion tests, Debris ingestion tests, Ice ingestion tests...
I think testing will Continue into the final years of 2020s.

Also, the sanctions placed by US on Chinese aviation industry could disrupt the supply chain for CJ-1000A.
MTU and Avio are participating in the program. I could not find anything on American companies' involvement. But I agree 2030 is likely.
 

by78

Brigadier
I have some screen captures of a TV report that I cannot locate, so I cannot judge its credibility. Does anyone have a link to the video? The captioning and Weibo poster's summary state the following:
- The titanium-aluminum alloy engine blades developed by the Institute of Metal Research of the Chinese Academy of Sciences will be used in the CJ1000 turbofan destined for C919.
- The blades have passed vibration and fatigue assessments. The performance was satisfactory.
- The blades will next be installed on an actual engine for further testing and assessments.
- The CJ1000 turbofan is making rapid progress.
- R&D for CJ2000 is also being stepped up.





 

Tirdent

Junior Member
Registered Member
I have some screen captures of a TV report that I cannot locate, so I cannot judge its credibility. Does anyone have a link to the video? The captioning and Weibo poster's summary state the following:
- The titanium-aluminum alloy engine blades developed by the Institute of Metal Research of the Chinese Academy of Sciences will be used in the CJ1000 turbofan destined for C919.

Nice! This would seem to confirm that the statement about the engine not having TiAl blades did apply only to the (first) demonstrator, while the production version is planned to have this technology. Makes sense, it seemed strange for the press release to emphasize the fact that prototype did not have hollow LPT blades, if not to make the point that the final product would. That means the technology underlying the CJ-1000A will ultimately become practically identical to the Russian PD-14, although the engine architectures and cycles have some notable differences. I'll take this opportunity to give my two cents on ougoah's earlier question:

The WS-20 may not be designed for those commercial demands but is the CJ-1000A somewhat efficient and competitive? Not to mention, safe and reliable enough for commercial?

We will know that it meets safety standards when it gets certified (preferably also outside China) and final proof of reliability is only in regular commercial operation of an engine.

In terms of efficiency, the available specs suggest that the CJ-1000A should do ok, with slightly higher BPR and OPR than the PD-14 resulting in a lower SFC. But SFC is a purely engine thrust specific measure, it does not account for the possibility that one engine might necessitate higher thrust settings due to higher weight and drag when actually installed on the aircraft than another in an otherwise identical scenario. This is where I have some reservations about it, I suspect it will turn out to be a very heavy engine - potentially heavier even than the LEAP-1C (which is already heavier than the PW1100G & PD-14 by a not insignificant margin). It seems to me that ACAE is attempting to achieve as close a copy of the LEAP-1C architecture and cycle as possible, without however having all of the technological building blocks necessary to execute such a design without further weight penalties.

By contrast, the Russians appeared to realize that aiming for the same BPR & SFC as the PW1100G and LEAP-1A would require a number of solutions which they considered too immature in their industry, namely composite fan blades and a composite fan case. As you increase BPR, fan diameter increases, which means longer and heavier fan blades for a given manufacturing method which in turn requires a larger and beefier fan case to contain the blade out contingency. There comes a point where the weight of of the fan and associated structure eats up the benefits of higher BPR. At the aircraft level anyway - looking at the engine in isolation on a test stand, the more BPR the merrier! So the PD-14 seems to be the result of an attempt to design the optimum engine achievable within the technology available, while the CJ-1000A (based on very similar technology over all) might be trying too hard for its own good to be a LEAP-1C.
 

reservior dogs

Junior Member
Registered Member
Nice! This would seem to confirm that the statement about the engine not having TiAl blades did apply only to the (first) demonstrator, while the production version is planned to have this technology. Makes sense, it seemed strange for the press release to emphasize the fact that prototype did not have hollow LPT blades, if not to make the point that the final product would. That means the technology underlying the CJ-1000A will ultimately become practically identical to the Russian PD-14, although the engine architectures and cycles have some notable differences. I'll take this opportunity to give my two cents on ougoah's earlier question:



We will know that it meets safety standards when it gets certified (preferably also outside China) and final proof of reliability is only in regular commercial operation of an engine.

In terms of efficiency, the available specs suggest that the CJ-1000A should do ok, with slightly higher BPR and OPR than the PD-14 resulting in a lower SFC. But SFC is a purely engine thrust specific measure, it does not account for the possibility that one engine might necessitate higher thrust settings due to higher weight and drag when actually installed on the aircraft than another in an otherwise identical scenario. This is where I have some reservations about it, I suspect it will turn out to be a very heavy engine - potentially heavier even than the LEAP-1C (which is already heavier than the PW1100G & PD-14 by a not insignificant margin). It seems to me that ACAE is attempting to achieve as close a copy of the LEAP-1C architecture and cycle as possible, without however having all of the technological building blocks necessary to execute such a design without further weight penalties.

By contrast, the Russians appeared to realize that aiming for the same BPR & SFC as the PW1100G and LEAP-1A would require a number of solutions which they considered too immature in their industry, namely composite fan blades and a composite fan case. As you increase BPR, fan diameter increases, which means longer and heavier fan blades for a given manufacturing method which in turn requires a larger and beefier fan case to contain the blade out contingency. There comes a point where the weight of of the fan and associated structure eats up the benefits of higher BPR. At the aircraft level anyway - looking at the engine in isolation on a test stand, the more BPR the merrier! So the PD-14 seems to be the result of an attempt to design the optimum engine achievable within the technology available, while the CJ-1000A (based on very similar technology over all) might be trying too hard for its own good to be a LEAP-1C.
How difficult it it to replace the components with the composite counterpart once the material is ready? Is it almost like re-starting then engine design?
 

gelgoog

Senior Member
Registered Member
How difficult it it to replace the components with the composite counterpart once the material is ready? Is it almost like re-starting then engine design?

You'll basically have to redesign the low pressure sections of the engine and the external casing of the engine. The reason being that you can use much larger fans with composites. In fact the larger the fan diameter the more performance benefit you will see with composites.
 

reservior dogs

Junior Member
Registered Member
You'll basically have to redesign the low pressure sections of the engine and the external casing of the engine. The reason being that you can use much larger fans with composites. In fact the larger the fan diameter the more performance benefit you will see with composites.
Thanks Gelgoog.
 

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