J-XY next generation carrier-borne fighter

Discussion in 'Navy' started by Deino, Sep 19, 2017.

  1. ougoah
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    ougoah Senior Member
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    Lol Brumby... here's your 19T :D
     
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  2. manqiangrexue
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    manqiangrexue Captain

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    It's the most trustworthy info that we've got. Obviously, it's far less so than an official government disclosure, but we likely won't see that for many many years.
    I don't know what you're talking about. You're not a known big shrimp and I wouldn't take it seriously if some random person said it was any weight... which is how the 19T claim came about. Is the bold part for me?
    No, it's not that. I have not and would never guess how heavy a jet is or whether an aircraft carrier could launch it. It's just not possible to calculate that without extremely specialized engineering training plus classified information. I would never even attempt it.

    How this discussion evolved? Tam came in here super confident that J-20 is 19.4T and J-31 is 17.6T and I asked him where the heck he got those numbers, and I gave my summary of the big shrimp reports. That's when Brat came in here with "no that's impossible because I know everything about 3D printing" and Brumby followed up with, "What do the engines have to do with the aircraft?" and that's where we are now.
     
    #362 manqiangrexue, Aug 31, 2019
    Last edited: Aug 31, 2019
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  3. Brumby
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    Brumby Major

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    The 19 ton number came from Tam who was commenting on its weight.

    The problem I have is so call authoritative source who may or may not exist in the manner as described and therefore its credibility on true weight.

    In any case it is entirely secondary because this came about from the additive parts claim of 40 % weight reduction. As AFB rebutted and which I pointed out is not supported by the known weight of the J-20. Even at 17.5 tons it is only a 8 % difference to that of the F-22 - hardly anywhere near the 40 % claim especially when a bunch of materials, expertise and Phd's were cited to justify the hyperbole claim. This is generally the problem I have when claims are based on conjectures, inferences, assumptions and grasping of straws .
     
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  4. ougoah
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    ougoah Senior Member
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    As far as I understand and correct me if I'm wrong. J-20 has never been advertised or promoted for sale. No classified information has ever been shared from the source ie CAC or any branch of the government. The numbers being thrown around are therefore total guesses including the Chinese figures. The 15-16T claim is dubious at best but I agree that it is theoretically closer to a government leak or statement which in itself would also be untrustworthy... why on earth would PLAAF or CCP show the real weight of J-20?!

    That was sarcasm to make the point that anyone can make up numbers and not back them up. Someone who has a tendency or reason to make up numbers could potentially perpetuate it online and get it on wiki.

    Fair enough. I couldn't be bothered reading through 3 or 4 pages again but seems about right.
     
  5. ougoah
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    ougoah Senior Member
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    We've gone through several cycles of speculation on carrier-borne J-XY with the agreement shifting between J-31 and J-20. Maybe it's time to just leave it until more official news come out. The decision won't be on size and weight alone.
     
  6. manqiangrexue
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    manqiangrexue Captain

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    [​IMG]
    No problem. I never said it's authoritative. I just said it's the best we've got.
    Brat "rebutted" it with what he knows about 3D printing, and there is no known weight for the J-20. 17.5T is the most likely number but 19 is out of thin air.
    Oh my goodness, I'm finally seeing how truly unprepared you came into this conversation! I specifically said 40% reduction in analogous components so you wouldn't confuse that with a 40% reduction in the weight of the aircraft! (That's not to mention that the aircraft size/volume are not equal.) If there is a 40% reduction in a component, the actual reduction in aircraft weight will depend entirely on how much of the aircraft weight is from that (or those) component(s). The jet is not 100% bulkheads and support beams! If 25% of the jet's weight comes from bulkheads (making this number up), and you found a way to reduce the weight of the bulkheads by 40%, you will have reduced aircraft weight by 10%, not the full 40%!! This is some incredibly basic logic...
     
    #366 manqiangrexue, Aug 31, 2019
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  7. Brumby
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    Please refer to your own post #343 regarding your arguments about a 40 % reduction and how disingenuous your argument have become. The reduction is either meaningful or it is not. If it is not meaningful as evident by the J-20 weight, there seems to be a disproportional effort to portray something which is not and that was the essence of Brat's rebuttal and mine because the claim in perspective was misleading. .
     
  8. manqiangrexue
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    manqiangrexue Captain

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    First of all, very impressive that you're continuing this conversation after the humiliating mistake that you made in the last post. You must be really immune to the feeling.
    "I simply believe that engineers from China can create a structure to be 40% lighter than an American analogue made in the 90's-early 2000's using new techniques because that is what they said."

    You mean this sentence right here, the only sentence in #343 in which I mentioned 40%? If you don't see the clearness with which I specifically said the "structure" and its "analogue" rather than the aircraft, you are just proving that your English is not equal to the task of debate.
    Haahahahaha What does that mean? To fighter jet designers, every gram is to be fought for. The word "meaningful" is not meaningful to an engineer. What is the weight? What is the number? I will not tell you if a 10% or 40% weight reduction or a reduction from 19T or 20T or whatever to 17.5T is meaningful. You figure that out yourself with the numbers you have. It would not strain most people but for someone who thinks it ridiculous that the designers of an aircraft's engines might have knowledge on its weight, it could prove to be quite the thinking exercise...
     
    #368 manqiangrexue, Aug 31, 2019
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  9. Jura
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    Jura General

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    could be an interesting quadratic (?) programming problem:

    to minimize "lifetime operating cost"

    knowing the cost; durability; maintenance requirements of new materials (and of course the associated weight-reduction)
     
    #369 Jura, Aug 31, 2019
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  10. Brumby
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    The problem is with your grandiose claims and then your attempts at obfuscation when being called out. You have yet to present any evidence besides offering ridicule as if you can hide behind such tactics. It does not work with me. .
     
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