Chinese Engine Development

Deino

Lieutenant General
Staff member
Super Moderator
Registered Member
The ZF850 turbojet from Jiangxi Zhongfa Tianxin Engine Technology Ltd. It will soon be used on the Cloud Shadow UCAV. Two pre-production samples have already been delivered, with four more to be delivered by year end 2020. Serial production will commence in 2021. The company is currently exhibiting the engine at the ongoing Nanchang Aviation Conference/Show.

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Will be interesting to see which branch will use them? The PLAAF? naval Aviation, civil or other agencies?
 

Tirdent

Junior Member
Registered Member
This could be WS-20

Seems plausible - the blades clearly do not take advantage of 3D aerodynamic design to the extent that the CJ-1000A does, which is expected. Similar to the V2500 or CFM56-7B, which is again credible.

As for engine TWR, a great deal can be achieved by simplifying the architecture, that is to say reducing stage count. Compressor and turbine disks are pretty much the heaviest parts, so that helps a lot. A turbofan (as opposed to turbojet) cycle works against this by increasing complexity, generally most features that improve fuel consumption and durability come at a weight penalty.

Once exception is possibly turbine inlet temperature as that requires improved cooling or more exotic materials but also improves specific thrust (thrust per mass flow). Since mass flow relates to area, you get more net thrust without increasing the size of the engine and with clever engineering you might be able to make this benefit outpace the weight gain from better cooling.

20:1 for a turbofan that is supposed to last a few thousand hours is clearly an ambitious goal, but not totally unrealistic. Almost 60 years ago, short-life turbojets intended as lift engines for VTOL aircraft (where minimizing dead weight in cruise was paramount) were practically there already:

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With the immense progress in materials and design since then I would not dismiss the possibility out of hand.
 

latenlazy

Brigadier
Seems plausible - the blades clearly do not take advantage of 3D aerodynamic design to the extent that the CJ-1000A does, which is expected. Similar to the V2500 or CFM56-7B, which is again credible.

As for engine TWR, a great deal can be achieved by simplifying the architecture, that is to say reducing stage count. Compressor and turbine disks are pretty much the heaviest parts, so that helps a lot. A turbofan (as opposed to turbojet) cycle works against this by increasing complexity, generally most features that improve fuel consumption and durability come at a weight penalty.

Once exception is possibly turbine inlet temperature as that requires improved cooling or more exotic materials but also improves specific thrust (thrust per mass flow). Since mass flow relates to area, you get more net thrust without increasing the size of the engine and with clever engineering you might be able to make this benefit outpace the weight gain from better cooling.

20:1 for a turbofan that is supposed to last a few thousand hours is clearly an ambitious goal, but not totally unrealistic. Almost 60 years ago, short-life turbojets intended as lift engines for VTOL aircraft (where minimizing dead weight in cruise was paramount) were practically there already:

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With the immense progress in materials and design since then I would not dismiss the possibility out of hand.
I mean, it ultimately comes down to what the physics will allow. Your mechanical factors don’t scale as well as your thermodynamic and fluid dynamic factors.
 

by78

General
The ZF850 turbojet from Jiangxi Zhongfa Tianxin Engine Technology Ltd. It will soon be used on the Cloud Shadow UCAV. Two pre-production samples have already been delivered, with four more to be delivered by year end 2020. Serial production will commence in 2021. The company is currently exhibiting the engine at the ongoing Nanchang Aviation Conference/Show.

50550567112_9476260712_o.jpg

50550440181_df969c14bc_h.jpg


Two more engines from Jiangxi Zhongfa Tianxin Engine Technology Ltd (ignore the graphics on the left side, as they are meant to demonstrate the intended use):
- ZF1000A Turbofan, based on the ZF1000 with increased output, intended for unmanned aerial combat drones. The graphic seems to suggest something in the class of Loyal Wingman.
- ZFP450 Turboprop, based on the core of ZF260, intended for high-altitude and high endurance UAVs, can replace ROTAX-914.

50567471198_38cfe50578_o.jpg
 

free_6ix9ine

Junior Member
Registered Member
The ZF850 turbojet from Jiangxi Zhongfa Tianxin Engine Technology Ltd. It will soon be used on the Cloud Shadow UCAV. Two pre-production samples have already been delivered, with four more to be delivered by year end 2020. Serial production will commence in 2021. The company is currently exhibiting the engine at the ongoing Nanchang Aviation Conference/Show.

50550567112_9476260712_o.jpg

50550440181_df969c14bc_h.jpg

Turbojet? Seems strange for a subsonic drone.
 

free_6ix9ine

Junior Member
Registered Member
The ZF850 turbojet from Jiangxi Zhongfa Tianxin Engine Technology Ltd. It will soon be used on the Cloud Shadow UCAV. Two pre-production samples have already been delivered, with four more to be delivered by year end 2020. Serial production will commence in 2021. The company is currently exhibiting the engine at the ongoing Nanchang Aviation Conference/Show.

50550567112_9476260712_o.jpg

50550440181_df969c14bc_h.jpg

Looks similar to similar to the firebee engine. Yikes. I can't believe China is still copying an old turbojet from the 60s. Why not make improvements, ie add a power turbine and fan....

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free_6ix9ine

Junior Member
Registered Member
Has China ever attempted to convert the design of the old WP-7 turbo jets used in the J-7/mig 21s into a more modern turbofan by adding a power turbine stage connected to a bypass fan? This would be much more efficient and would create a nice little 30kn turbofan for applications like heavy UCAVs, trainer jets, small business jets that can be converted into military use, etc.

Currently China has one or maybe two turbofans in service? The WS-10 and the WS-9? The WS-10 is too big for most UAV applications, the WS-9 i heard wasnt a big success either due to quality control reasons. All Upcoming turbofans like the WS-15 or WS-20 are far too powerful for UAVs.

So a WP-7 based low bypass turbofan would fit a nice niche that could be used on large UAVs, in the same class as the global hawk, GJ-11.
 

latenlazy

Brigadier
Has China ever attempted to convert the design of the old WP-7 turbo jets used in the J-7/mig 21s into a more modern turbofan by adding a power turbine stage connected to a bypass fan? This would be much more efficient and would create a nice little 30kn turbofan for applications like heavy UCAVs, trainer jets, small business jets that can be converted into military use, etc.

Currently China has one or maybe two turbofans in service? The WS-10 and the WS-9? The WS-10 is too big for most UAV applications, the WS-9 i heard wasnt a big success either due to quality control reasons. All Upcoming turbofans like the WS-15 or WS-20 are far too powerful for UAVs.

So a WP-7 based low bypass turbofan would fit a nice niche that could be used on large UAVs, in the same class as the global hawk, GJ-11.
This is not a good way to develop engines. And also China already has light turbofan designs.
 

free_6ix9ine

Junior Member
Registered Member
This is not a good way to develop engines.

I disagree. Engine tech is essentially an iterrative process. The AL 41 came from the AL 31 which was a turbofan adaptation of the AL 21 by the addition of a power turbine and bypass fan. The F100 has its roots in the J79 turbojet which also served as the gas generator aka "core" of the CF-6 high bypass turbofan which powered the C-5 galaxy.
 
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