J-20 5th Generation Fighter VII
- Thread starter siegecrossbow
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Agree, this spine actually improves its lines IMHO (the Su-15 as mentioned by somebody else is an apt comparison). Only disappointment is that the ventral strakes still refuse to die!
True, given the tight net thrust margin without reheat, drag reduction is an essential component in supercruise though. T = D for cruise, after all. Less D at a certain Mach means the T requirement to sustain that Mach is correspondingly relaxed. Even if it is transonic (as opposed to supersonic) area ruling which the spine is intended to improve, that might mean a better ability to accelerate through Mach 1.0 in dry thrust which will safe fuel and improve supercruise radius. That said, I agree that with AL-31F or WS-10 the J-20 won't be supercruising regardless (the jet velocity margin just isn't there).
Just a thought that the hump on 2051 may be motivated by adoption of TVC and a necessity for it. I think when TVC is engaged the aircraft would be flying at a lower air speed for the same turn rate (higher turn rate for the same air speed) compared to without TVC. This will worsen the airflow behind the back creating even worse low pressure region behind the canopy.
Based on this thought, I think CAC is doing a parallel development in two tracks:
Track 1, WS-10 TVC to integrate TVC in flight control SW without risk of new engine.
Based on this thought, I think CAC is doing a parallel development in two tracks:
Track 1, WS-10 TVC to integrate TVC in flight control SW without risk of new engine.
- 2051 to test WS-10 to prove its airframe change.
- 2051 or 205X to switch to WS-10TVC to finalize the airframe design.
- 2012 + ONE WS-15 to prove WS-15 is safe to be adopted.
- 2012 + TWO WS-15 to certify it.
- 205X switch to WS-15 (TVC)
drunkmunky
Junior Member
I don't really understand the dog fighting initiative / tvc for this chassis. I understand supercruise, but directional thurst? It's stealth capabilities lead it to be a bird-of-prey beyond visual range attack craft.....whilst that level of engine upgrade (tvc) would mean that they are preparing for close combat.....? but it doesn't even have a gun?
The short range missiles will benefit from TVC enhanced nose pointing in the same way as to the gun. TVC also increase the chance to defeat the enemy's short range missiles.
But why would they make two different prototype series if they’re just going to be merged in the end? Seems like a very unnecessary and wasteful extra step. Frankly since we’ve *never* heard of a 204X until now and there’s no confirmation of its existence that I’ve seen, only interpolation based on test serial, and since we’ve seen CAC skip 4 multiple times before (2004 and 2014 have never been spotted as far as I can recall) I think we’d need a lot more solid evidence before we can conclude there even is a 2041.
This might be more risk adverse than they need to be. If 2051 isn’t flying with the WS-15 it’s probably just flying with regular WS-10Cs. Presumably the photos we’ve been getting of that J-20 with a single swapped engines is showing us the WS-15 with TVC. My thinking now is that basic TVC control laws for the engine were probably developed with the J-10. And the J-20 flying with the TVC WS-15 is probably meant for development and integration of flight control laws for both the WS-15 and TVC together. Meanwhile the WS-15’s own reliability and basic flight characteristic testing were done with modern test fixtures. If they were doing integration testing with a single WS-15 with TVC it should mean the engine itself without TVC is already pretty mature in its R&D cycle at this point. An ultra-conservative integration process is also probably unnecessary for the level of maturity and confidence they now have with jet engine technology in general, especially if they’ve adopted a more patient engine testing process. The entire test paradigm seems to have changed in the last decade, and if your testing paradigm becomes more rigorous your integration process can be less.
So in summary, my guess is that 2051 will test basic airframe and internal changes, and then integration testing is complete with the single installed WS-15 with TVC plane they’ll just go straight to two WS-15 with TVC in 2051/205X. This approach should carry very little to no risk since much of the risk should have already been ironed out in earlier phases and because TVC itself should help relax flight risk margins since it’s supposed to help expand control authority of the plane.
I would add that we've also already had indications that J-20 has test flown with a TVC engine before in the past for the last few years. Whether it's a WS-10 or WS-15 with TVC nozzles (or both), we do not know.
In theory if they were ultra conservative then they could break all of the above into small steps and integrate them onto 2051 one by one, but it seems a bit much considering they should already have been flying a TVC engine and WS-15 on existing J-20s for a few years now and a year and a half now, respectively, with a decent chance that the WS-15 itself has a TVC nozzle.
Personally I don't think there's any point in implementing TVC on the J-20 engines.
It costs extra money and time to implement TVC. Plus it has a negative effect on the plane weight and engine thrust.
And given the very high lethality of modern short range AAMs, they shouldn't need to dogfight against the small number of F-22s in service. And remember the F-22s will start retiring in 2030
It costs extra money and time to implement TVC. Plus it has a negative effect on the plane weight and engine thrust.
And given the very high lethality of modern short range AAMs, they shouldn't need to dogfight against the small number of F-22s in service. And remember the F-22s will start retiring in 2030
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