Did I miss something? why are we considering a supersonic H-20 at all?
H-20 bomber (with H-X, JH-XX)
- Thread starter Deino
- Start date
D-30KP-2 is an engine with a relatively high bypass ratio for a combat aircraft. It would make it harder to reduce RCS for stealth.
I doubt they would use that engine for the H-20. Way more likely would be a version of WS-10 or WS-15 without afterburner.
I am assuming the H-20 will be a subsonic flying wing type.
Ha, I told you all that the H-20 will just be the next iteration of the H-6 bomber and yus all didn't believe me
I think the WS-18 stuff is complete nonsense. I don't think you can put something with bypass ratio of that in H-20.
And I have not seen anywhere where they said that.
I think either WS-10 or WS-15 is reasonable. If they want to do supersonic fly wing, then add in afterburner.
The best estimate for the B-21 Raiders engines are PW9000 medium bypass turbofans, while the diameter is unknown, it is suspected to use a the F135 for it's low pressure section and have a bypass ratio of 4:1. This was after many lessons learned from the B-2, where they were worried about engine stalls with a non linear intake, and were unwilling to attempt any more fuel efficient turbine given the technology at the time. WS-18 is not completely unreasonable, the D-30KP-2/3's are not impossible to fit into a flying wing configuration, and there have even been speculation that the B-21 could use PW1500 engines, which have a fan diameter of 74" or 1850mm, although take that with a huge amount of salt. My point being that medium bypass turbofans are not crazy at all. The Larger engines also offer greater fuel efficiencies, which are key for a subsonic long range bomber.
It would be the 'safe option' to use low bypass as China doesn't have much flying wing experience, but it would be completely foolish. The B-2s technology limitations were that it entered service nearly 40 years ago. Equipping China's next generation bomber that could be entering service 50 years after the B-2, yet following it's exact footsteps would be building weapons of the past not the future. That is how the Raider, despite being smaller in size, is estimated to have a much greater range than it's predecessor.
That is why I completely believe people like Orca, who have said previously that the H-20 would use an engine like the D-30KP2. Or an engine like the WS-18, with improved technologies to improve efficiency. Medium bypass is the right way to go.
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@tphuang sir that paper was published in 2020.
They were considering D-30KP-2/WS-18 at the beginning of the design. back then even WS-10 wasn't completed. and as per the source that has already been replaced with newer engines.
complete details of that paper.
in early 2023 we have seen IL-76 test bed flying with new medium bypass engines. could be WS-10 or WS-15 variant.
This is all really great, although the paper doesn't specify the aircraft. A new medium bypass engine based on WS-10 or WS-15 technologies for it's core would certainly be much more efficient than any WS-18 or D-30 variant. It may be just a variant, but honestly I would like to believe it could be given a new number designation.
yes. it make zero sense to use WS-18/D-30 variant in 2025 when you have better technology available and WS-18 also doesn't make sense economically. will take enormous efforts to bring back WS-18 into modern world. yes that engine is pretty old now.
that new medium bypass ratio engine indicate either WS-10 or WS-15 variant exclusively developed for H-20 bomber.
I'm starting to think whether a flying wing is the only way to design a sub-sonic stealth bomber. The long wing span of the B-2/B-21 gives the best lift to drag ratio but the same long wings are also structurally weak and spatially inefficient, which translates to more structural weight and less internal volume for fuel. The short fuselage also makes it difficult to store long weapons internally.
Other than the flying wing, we also have J-36's tailless double delta. J-36's swept angle is optimized for super cruise but if we reduce the sweep angle and make the crank more pronounced for vortex lift, it may also be possible to optimized the double delta for high sub-sonic. We lose a bit of aerodynamic efficiency and stealth, but we gain structural strength, internal volume and the ability to install a long weapons bay. According to my very unprofessional guesswork, it is possible to put 4x medium bypass engines (say about 1.4m fan diameter), a huge centerline weapons bay as well as a lot of wing area and fuel into an aircraft not much longer than the H-6. After reading the paper about the 6-engine monster, it becomes suspicious whether XAC is planning for something big.
Other than the flying wing, we also have J-36's tailless double delta. J-36's swept angle is optimized for super cruise but if we reduce the sweep angle and make the crank more pronounced for vortex lift, it may also be possible to optimized the double delta for high sub-sonic. We lose a bit of aerodynamic efficiency and stealth, but we gain structural strength, internal volume and the ability to install a long weapons bay. According to my very unprofessional guesswork, it is possible to put 4x medium bypass engines (say about 1.4m fan diameter), a huge centerline weapons bay as well as a lot of wing area and fuel into an aircraft not much longer than the H-6. After reading the paper about the 6-engine monster, it becomes suspicious whether XAC is planning for something big.
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No, it is not the only way.
But it is the most optimal one, all things considered.