Chinese UCAV/CCA/flying wing drones (ISR, A2A, A2G) thread

[latenlazy]

F-110 hasn't been improved on much performance wise since the early 2000s. TIT of the later F-110 is about 1780K from sources while rumors were saying that WS-10C could reach 1830K. These are strong numbers for 4th gen engines but when it comes to 5th gen and the latest comercial engines these numbers gets dunked on. F-135 is said to have a TIT of ~2260K and PW1000G uses technology from F-135 and thus can't be that much worse off considering its also a newer engine. LEAP series apparently have a TIT of approx 2120K(Not sure how reliable this source is). WS-15/19/CJ-1000A and their derivatives should be able to hit these numbers as well. On paper the gain in relative thermal efficiency from 1830K to 2200K is around 26 percent, accounting in all the loses(like extra turbine cooling loses, non ideal circumstance) even if actual TSFC is down by 10 percent, it could mean a siginificant boost in range for a vehicle with 10000nmi+ range(might mean 2-3 extra hours of on station time which is significant). You could also get less TSFC via higher bypass ratio, H-20's intended engine from what we know should be a medium bypass engine that might be based on WS-15 core which IMO is perfect for this job.

The F110 stopped being upgraded because it stopped getting funding. Given that the CFM Leap is itself derived from the CFM-56 tech tree there’s really no reason that an F110 level engine can’t reach the same TITs. That’s all just a question of the materials used, not an inherent question of the engine cycle design itself. The “technology” the PW1000 uses from the F135 is also the materials, not the engine cycle design. Raw thermal efficiency gain also does not translate directly to fuel efficiency. There is transmission into mechanical efficiency. I’m not saying some performance uplift wouldn’t be nice but it’s not really a deal breaker. You’re haggling about margins that aren’t going to make or break what these platforms can do.

There is virtually no chance the H-20’s medium bypass engine is based on the WS-15 lol. Insofar as that engine is still in the picture development started well before the WS-15 was a mature enough design to start forking variations from. I’m not sure where you heard that this medium bypass engine would be WS-15 based.

 

[sunnymaxi]

There is virtually no chance the H-20’s medium bypass engine is based on the WS-15 lol. Insofar as that engine is still in the picture development started well before the WS-15 was a mature enough design to start forking variations from. I’m not sure where you heard that this medium bypass engine would be WS-15 based.

H-20 Engine is indeed an interesting topic.

initially all research papers indicate, XAC was planning to use 4 WS-18 engines. but as we know that, plan changed because of PLAAF requirement in 2030's and beyond. so H-20 mostly likely to redesign.

H-20 Engine project led by AECC Sichuan. they have developed a new medium bypass Engine in 2022, first flight took in 2023. so the big question is, which engine core they have used. most probably WS-10 but they can use WS-15's core too if want more optimal design and higher thrust. AECC Sichuan have more options as well. though nobody knows.

people talking about BPR/TIT but Precision in critical components is as important as Material/design for Engine efficiency.

Design
Materials
Precision manufacturing

these three things determine the Engine quality and efficiency.

 

[latenlazy]

H-20 Engine is indeed an interesting topic.

initially all research papers indicate, XAC was planning to use 4 WS-18 engines. but as we know that, plan changed because of PLAAF requirement in 2030's and beyond. so H-20 mostly likely to redesign.

H-20 Engine project led by AECC Sichuan. they have developed a new medium bypass Engine in 2022, first flight took in 2023. so the big question is, which engine core they have used. most probably WS-10 but they can use WS-15's core too if want more optimal design and higher thrust. AECC Sichuan have more options as well. though nobody knows.

people talking about BPR/TIT but Precision in critical components is as important as Material/design for Engine efficiency.

Design
Materials
Precision manufacturing

these three things determine the Engine quality and efficiency.

Usually when you are doing a derivative design you choose the more mature tech tree to reduce risk and speed up development. It all comes back to matching requirements with your portfolio of available technology.

Keep in mind also that a good bit of the WS-15’s performance gain is a larger diameter core, which means a higher bypass version would also be larger diameter than a WS-10 derivative with the same bypass.

Precision manufacturing is not specific to one design tree. Again this is a factor that’s agnostic to the core engine cycle you’re choosing.

 

[latenlazy]

But personally I think China has been recently moving from the mindset of always picking the cheapest/most conservative design to actually trying higher risk/more advanced design. J-36's unique design based on completely new doctrine is a good proof of this shift in strategy IMO.

Whether you go with a more conservative or more ambitious design is dependent on your project requirements and overall project risk assessment relative to your available capabilities. It has nothing to do with sentimental preferences. These are engineering management decisions that follow a process measured against physically determinable parameters and the imperatives of deliverable deadlines, not vibes.

 

[Amistrophy]

Usually when you are doing a derivative design you choose the more mature tech tree to reduce risk and speed up development. It all comes back to matching requirements with your portfolio of available technology.

Keep in mind also that a good bit of the WS-15’s performance gain is a larger diameter core, which means a higher bypass version would also be larger diameter than a WS-10 derivative with the same bypass.

Precision manufacturing is not specific to one design tree. Again this is a factor that’s agnostic to the core engine cycle you’re choosing.

Unsure if the larger diameter core is the contributing factor for increased performance.
Other speculation points towards that design being used on a WS-10CXX (discussed recently on J-20 and Engine thread), and there’s also some additional murkiness considering the WS-15 project has also itself undergone major revisions, so this info may be out of date.

 

[latenlazy]

Unsure if the larger diameter core is the contributing factor for increased performance.
Other speculation points towards that design being used on a WS-10CXX (discussed recently on J-20 and Engine thread), and there’s also some additional murkiness considering the WS-15 project has also itself undergone major revisions, so this info may be out of date.

It’s part of the equation for the WS-15 and F119 class engines vs WS-10 and F100/110 class engines. If the WS-15 is a similar diameter to the WS-10 (they should be since they’re sized for the same nacelle!) and is meant to have a lower bypass ratio then by physical mechanical necessity it will have a larger diameter core. This is guaranteed because physics.

Anyways maybe we should move this discussion to the engines thread.

 

[tphuang]

https://twitter.com/i/web/status/1936819335873675731

It's amazing what 5 to 10 years of material science improvement allow you to build. WZ-7/10 was what they were developing 10 years ago and WZ-X is what they can build now.

By using the latest high strength, light and heat tolerant CFRP wings + honeycomb aramid composite structure in between, you can have extremely large + long wings without pushing weight to beyond what 2 WS-10 can power. By having heat tolerant and wave permissive composite material for your EW/radar/antenna/nose cover, you can fly higher, maximally allow RF to go out and return/receive as well as fly higher altitude. There by becoming harder to detect and fly at lower drag. By using the latest meta-material, you can achieve even greater stealth without pushing weight of your fly wing aircraft beyond what 2 WS-10 can power.

So instead of getting these 1IC large drones for ISR and EW, you now what 1 super drone that can do both job much better and fly beyond 2IC.

 

[tphuang]

this probably won't surprise others, but on the recent guancha video, yankee did say GJ-11 is still conducting flight testing. As such, it is unlikely to be part of the parade.

 

[TheWanderWit]

I'm honestly surprised that this drone isn't in service yet and mass production, given it was officially unveiled six years ago and had its first flight years prior. WZ-9 is another example. Two drones whose developments span back over a decade ago, and yet both aren't seemingly in any form of service or mass production (although GJ-11 may be in limited service with a test unit).

We've seen more images/videos of testing in the past few months, but I guess we'll have to wait and see. I find it funny how China seemingly moves far faster with the development of new aircraft than these two specific drones that have been in testing for years now. J20/A/S, J-35/A, J-15T/D, KJ-600, Y-20B, etc. are all examples. Really looking forward to the GJ-11, as it's likely to be the first stealth strike UCAV in service and mass production from any country, with a variety of roles for the PLAAF and PLAN.

 

[siegecrossbow]

I'm honestly surprised that this drone isn't in service yet and mass production, given it was officially unveiled six years ago and had its first flight years prior. WZ-9 is another example. Two drones whose developments span back over a decade ago, and yet both aren't seemingly in any form of service or mass production (although GJ-11 may be in limited service with a test unit).

We've seen more images/videos of testing in the past few months, but I guess we'll have to wait and see. I find it funny how China seemingly moves far faster with the development of new aircraft than these two specific drones that have been in testing for years now. J20/A/S, J-35/A, J-15T/D, KJ-600, Y-20B, etc. are all examples. Really looking forward to the GJ-11, as it's likely to be the first stealth strike UCAV in service and mass production from any country, with a variety of roles for the PLAAF and PLAN.

WZ-9 is definitely in service. Have been flying over SCS and East China Sea.