J-20... The New Generation Fighter III

Player99 said:

I feel kinda bad now... because I'm still not sure I get it. Do you mean the what I had thought to be a crowd/line of "people" in front of the plane? Well, now I see that those things can be seen as a picket fence... But he said "spike" instead of "spikes", that's why I thought of the pitot (as a spike is a long piece of something with a sharp point).

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Meh, no worries, don't feel bad..I thought it could a crowd of people as well when someone mentioned it.

I suspect that TVC will go away just as swing wings went away. Dr Song and his collegues might well have found that in future the advantages of TVC will always be less than the disadvantages, the result of superior aerodynamics. At this time it is just a suspicion.

Well I think TVC might catch on in a big way with UAVs, just like how TVC is very popular with the latest missiles today.

With manned airplanes, the pilot has been the biggest limiting factor to agility since 3rd gen fighters. What good is better turn rates if the G-forces involved will end up mushing your pilots? With the latest air combat doctrines stressing the importance of energy management and transonic maneuverability, G-forces become an even bigger factor.

In exercises, Typhoon pilots have gone on record to state that they had nothing to fear in WVR combat with TVC Raptors, and TVC Su30MKIs didn't really give Typhoons any nasty surprises either. That all goes to show that TVC has nothing over a top canard delta design in terms of agility in realistic combat scenarios.

You can see that 2001 also has serrated pattern near the nose. Meaning that the housing should already be there and 2002 is just a matter of actually putting a radar plus changing cover there. Also there are some chinese characters near the 2001 intake.





Couldn't they do radar testing at Yanliang, or have they reserved 2001 for aerodynamic testing and 2002 for avionics and radar test?

Here are some colorful shots.

no_name said:

Also there are some chinese characters near the 2001 intake.

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Hehe... Those characters are watermarks from the poster (it's his ID 起个名字想半天）. I know this because I happen to have read some of his posts.

why are the serrations on the nose curved, instead of angular/straight? That seems mighty odd to me. Almost as if the pattern is painted, instead of being an edge of a different section altogether?

latenlazy said:

But the claim of C is equal to or better than A cannot be made either, nor is there any accounting for A+C, especially since A is not mutually exclusive from either B or C. It's a nice little rhetorical roundabout that dodges the primary point.

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The primary point remains that there is no valid premise for the argument of A being better than C to hold. There isn't anything I need to say beyond that.

latenlazy said:

Nothing quoted so far has indicated that canards are better than TVC in supersonic flight, nor anything proving vice versa. However, we do know that deflection of aerodynamic surfaces at supersonic flight does increase drag. Until you can demonstrate that canards either incur less drag than TVC or have benefits that mitigate increased drag in supersonic flight, this disagreement isn't going anywhere.

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On the contrary, points #2 and #4 are already pretty clear that canard configuration is superior to traditional configuration in reducing supersonic drag. In other words, J-20 has no need for TVC to reduce supersonic drag. Until you can demonstrate that TVC actually incur less drag than canard, this disagreement isn't going anywhere.

latenlazy said:

New technology compounds difficulty, period. I'm not disagreeing with you about the potential risks, but that does not mean they won't pursue it. A new engine could lengthen the J-20 programme by years, but that does not mean they won't pursue a new engine.

Nothing is ever conclusive with PLA watching. If we're going on the reliability of rumours, I have not yet heard rumours that they won't install TVC, but I have heard rumours for years that they will. This is simply a dispute about how ambitious China is willing to be. I think they will be a bit more ambitious. You think they won't be. No matter what we say, that won't actually tell us whether the J-20 actually will or will not have TVC.

To say that the contingency plan to TVC is to not have TVC is to say that TVC is part of the main plan . The (or A) contingency to the WS-15 is to buy Russian engines with TVC. Both what you and I just said are a bit of speculative a red herring.

Anyways, if the PLAAF really had no intention to install TVN to begin with, then rumours have been misleading. The PLAAF also has a history of taking on ambitious projects and exploring the feasibility of theoretical superiority if it means strengthening their hand. Like a stealth fighter, for example.

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Development of WS-15 is a necessity, while TVC is an option. You cannot use the former to argue for the latter since they are not similar. On the other hand, it is very reasonable for J-20 to make do without TVC, so that PLAAF's ambition of 2017 induction date can be made.

Engineer said:

The primary point remains that there is no valid premise for the argument of A being better than C to hold. There isn't anything I need to say beyond that.

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You have not really tackled the validity of the premise. I presented one reason for considering the possibility that A is better than C in terms of aerodynamic control, under a specific context, which is the discussion of supersonic drag. That reasoning was based on the argument that minimizing deflections of any aerodynamic surface also minimizes supersonic drag. The argument behind the premise remains unaddressed by you.

On the contrary, points #2 and #4 are already pretty clear that canard configuration is superior to traditional configuration in reducing supersonic drag. In other words, J-20 has no need for TVC to reduce supersonic drag. Until you can demonstrate that TVC actually incur less drag than canard, this disagreement isn't going anywhere.

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That's still besides the point. It doesn't tell us whether a traditional configuration+tvc is better (assuming optimized flight controls), or a canard configuration+tvc is better, or indeed if relying on TVC alone with neither is better for limiting drag. You're arguing on the premise of a comparison between a canard configuration and a traditional configuration. I'm arguing on (or exploring) the premise of which options are the best to minimize supersonic drag.

Development of WS-15 is a necessity, while TVC is an option. You cannot use the former to argue for the latter since they are not similar. On the other hand, it is very reasonable for J-20 to make do without TVC, so that PLAAF's ambition of 2017 induction date can be made.

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I can use the former argument for the latter under the premise of what's developmentally feasible. If we hold strictly that the PLAAF's ambitions are for a 2017 induction date, with a necessity of having a plane that isn't the final configuration to meet that deadline, that means the same options that exist for introducing a better engine also exists for any other technology later on.

Anyways, I don't really see a point in continuing this discussion. I find your arguments for why the J-20 won't/shouldn't have TVC to be reasonable but unconvincing. Let's agree to disagree.