No. Composites can’t be used in the hot section of compressors or turbines where you have the most challenging temperature and strain conditions. CMCs are being looked at as replacements but it’s unclear whether they can handle strain from the highest pressure segments of a compressor.
Chinese Engine Development
- Thread starter jackbh
- Start date
It has pretty authentic look as the demonstrator J-10. The white pieces can be seen in the two photos on the left and the top right one.
Of course, there is no reason to put a real engine in a mock-up in theme park.
The higher the gen，the higher the temperature it can withstand
I think @Icloo is merely asking for any sources from your part regarding the the SCB technologies applied to in-development or recently inducted engines. I think it's a very valid question. Issues with high yield mass production aside, we can't assert for certain the level of technology regarding overall engine design and design of components (like ball bearings, fuel mixers, Oil lubricants, gears etc).
CJ1000A is leading the innovation in Turbofans in China (along with WS20). We may see a reversal in Turbofan knowledge flow from the traditional military to civil base to a civilian to military base.
Last edited:
Do anyone know of a ShangFa Gear manufacturer? Any details on this company/entity would be welcome. Nothing comes up in my searches. This company maybe a supplier of gears for High bypass Turbofans.
( There is a ShangFa Valve manufacturing company but gears don't seem to be their focus area)
( There is a ShangFa Valve manufacturing company but gears don't seem to be their focus area)
Generations of SCB in Propulsion devices
The rhenium content is regarded as an intuitive parameter for the generation of superalloys due to its significant strengthening effect. For example, the first generation of nickel-based single crystal superalloys does not contain rhenium, and the second and third generations contain 3% and 6% (mass fraction) respectively. The third-generation nickel-based single crystal superalloy has a life of up to 2500 hours at 750 ℃/500 MPa creep, and the life of the first-generation alloy without rhenium is only 250 hours under the same test conditions. The main difference in composition between the third generation and the first generation of nickel-based single crystal superalloys lies in the presence or absence of rhenium, while the content of other alloying elements is basically the same, that is to say, adding 6% (mass fraction) of the alloying element rhenium makes the superalloy creep life Improved by a full 10 times.
Ni based SCB in China have been in application with the first generation of DD3, second generation DD6, to the third generation of DD9, and the fourth and fifth generations of superalloys under research& development.
To note, The CJ1000AX was then shown to have used DD6, five years ago
And one can expect it to welcome third gen SCB's just like the wider industry.
Do remember that engines are much more than SCBs or the Hot section/core. Overall Engine design and the robustness of individual components or systems have a big part to play in determining the performance and quality of the engines.
If an engine design has been refined without much growth forward, then improving the Core with better generation of SCB's will lead to higher temperature and thus better collision of fuel particles with oxygen molecules, leading to more efficient and powerful thrust.
The rhenium content is regarded as an intuitive parameter for the generation of superalloys due to its significant strengthening effect. For example, the first generation of nickel-based single crystal superalloys does not contain rhenium, and the second and third generations contain 3% and 6% (mass fraction) respectively. The third-generation nickel-based single crystal superalloy has a life of up to 2500 hours at 750 ℃/500 MPa creep, and the life of the first-generation alloy without rhenium is only 250 hours under the same test conditions. The main difference in composition between the third generation and the first generation of nickel-based single crystal superalloys lies in the presence or absence of rhenium, while the content of other alloying elements is basically the same, that is to say, adding 6% (mass fraction) of the alloying element rhenium makes the superalloy creep life Improved by a full 10 times.
Ni based SCB in China have been in application with the first generation of DD3, second generation DD6, to the third generation of DD9, and the fourth and fifth generations of superalloys under research& development.
To note, The CJ1000AX was then shown to have used DD6, five years ago
And one can expect it to welcome third gen SCB's just like the wider industry.
Do remember that engines are much more than SCBs or the Hot section/core. Overall Engine design and the robustness of individual components or systems have a big part to play in determining the performance and quality of the engines.
If an engine design has been refined without much growth forward, then improving the Core with better generation of SCB's will lead to higher temperature and thus better collision of fuel particles with oxygen molecules, leading to more efficient and powerful thrust.
Last edited:
China and Geared Turbofans research
China's aviation powerplant manufacturing/research institutes of AECC CAE along with universities tied to it has been researching Geared TurboFans. Note that this is just Commercial Turbofan research and sensitive (military) ones would never be accessible to outside world.
Before we look into GTF, GTF is a Turbofan with a Gear separating the LP/ N1 spool of a Turbofan with the Ducted Fan at the Front. The differences in the RPM of the Fan and the shaft bring significant benefits regarding efficiency, fewer stages etc. This comes at the cost of complexity of gears and associated penalties.
The most famous representatives of today of this technology are the PW1000G and RR UltraFan. The PW GTF series had recent spotlight due to the issues it was facing ( thanks to the complexity).
But China's introduction to GTF technology was probably with the storied Allied Signals that was purchased to power the . The engine sale happened in the 1992s after US reset the relations following the Tiananmen Square Incident. There was a tussle between the DoD and Do Commerce over this. China however only got 59 examples of the TFE731 2A ( The 2A were quite underpowered and backward versions on US DoD pressures and tantrums). But the 59 or so engines reached the JL8 Trainers. Anyway, the export was stopped soon after as China was again put into the sanction crosshairs over alleged support to Pakistan's nuclear program.
A1996 scmp article on it.
A thing to note is that the TFE731 has little in common with the modern GTF including the Planetary gears ( the Garrett TFE731 had a relatively simple helical gears while the modern 21st century ones are Double Helical type with advanced tapered bearings, matallurgy, lubrication systems and arrangement.
TFE7321 planetary gearset
Modern Planetary Gearset
We can discount what is happening in the AECC military turbofan development (because of dearth of information) but the papers published by AECC Civilian Turbofan division tells that studies are active and increasing. It will only increase as next gen HBP Turbofans set to be introduced are GTF technology.
Many small tests, models and studies some universities conduct are using the French DGEN380 geared small Turbofan. Development of some technologies ( like gearsets, metallurgy) may be making progress while others still looked into (lubrication, bearings, vibration etc).
Almost all of the public articles admit that a civilian GTF is only in research/development stage with no Full Scale prototypes being built. But then, that conclusion is drawn from a handful of articles (7).
China's aviation powerplant manufacturing/research institutes of AECC CAE along with universities tied to it has been researching Geared TurboFans. Note that this is just Commercial Turbofan research and sensitive (military) ones would never be accessible to outside world.
Before we look into GTF, GTF is a Turbofan with a Gear separating the LP/ N1 spool of a Turbofan with the Ducted Fan at the Front. The differences in the RPM of the Fan and the shaft bring significant benefits regarding efficiency, fewer stages etc. This comes at the cost of complexity of gears and associated penalties.
The most famous representatives of today of this technology are the PW1000G and RR UltraFan. The PW GTF series had recent spotlight due to the issues it was facing ( thanks to the complexity).
But China's introduction to GTF technology was probably with the storied Allied Signals that was purchased to power the . The engine sale happened in the 1992s after US reset the relations following the Tiananmen Square Incident. There was a tussle between the DoD and Do Commerce over this. China however only got 59 examples of the TFE731 2A ( The 2A were quite underpowered and backward versions on US DoD pressures and tantrums). But the 59 or so engines reached the JL8 Trainers. Anyway, the export was stopped soon after as China was again put into the sanction crosshairs over alleged support to Pakistan's nuclear program.
A1996 scmp article on it.
A thing to note is that the TFE731 has little in common with the modern GTF including the Planetary gears ( the Garrett TFE731 had a relatively simple helical gears while the modern 21st century ones are Double Helical type with advanced tapered bearings, matallurgy, lubrication systems and arrangement.
TFE7321 planetary gearset
Modern Planetary Gearset
We can discount what is happening in the AECC military turbofan development (because of dearth of information) but the papers published by AECC Civilian Turbofan division tells that studies are active and increasing. It will only increase as next gen HBP Turbofans set to be introduced are GTF technology.
Many small tests, models and studies some universities conduct are using the French DGEN380 geared small Turbofan. Development of some technologies ( like gearsets, metallurgy) may be making progress while others still looked into (lubrication, bearings, vibration etc).
Almost all of the public articles admit that a civilian GTF is only in research/development stage with no Full Scale prototypes being built. But then, that conclusion is drawn from a handful of articles (7).
Last edited: