J-20... The New Generation Fighter II

Discussion in 'Air Force' started by Asymptote, Jan 10, 2011.

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  1. MiG-29
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    MiG-29 Banned Idiot

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    Let us see facts. all aircraft with canard foreplanes, can use them as roll control, however due to wing canard interaction the roll control is negligible, thus they need to resort to elevon control (trailing edge flaperons),the J-10 and well as the Eurofighter or Rafale and Gripen can use their foreplanes as roll control devices, however they usually leave that task to the elevons.
    In the video you can see the canard not moving simply because the J-10 wing can be used as the wing of a Mirage 2000 or LCA and achieve roll control without the use of any canard input.
    tailplanes are different and in that aspect more effective, because their wake does not down wash the wing its use is less restricted
    you can see it in the same in the Eurofighter

    [video=youtube;8JXOssmp5Io]http://www.youtube.com/watch?v=8JXOssmp5Io&feature=related[/video]
     
    #2741 MiG-29, May 28, 2011
    Last edited: May 28, 2011
  2. delft
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    delft Brigadier

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    I found the discussion on drag coefficients somewhat simple. There is the drag due to friction, as recognized by MiG-29, more drag is due to lift. which is extremely important during manoevers, and wave drag is important when you go supersonic and is dependent on volume and the distribution of that volume over the length of the aircraft (greater length is better there ). Total drag is the sum of those and their relative and absolute sizes vary greatly.
     
  3. johnqh
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    johnqh Junior Member

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    So you just ignore what I pointed in the video you posted?

    Roll control is not for when the airplane is rolling only. Under different flying conditions, different control surfaces can have different results. If designing an airplane is so easy, you would be a real designer.

    For one, controlling canards will not only generate roll force, but also change the strength of the vortex. So, most designers will only use flaps for roll under normal flight conditions, but can work the canards in under high AoA.

    By the way, don't use other fighters video to make your argument. There isn't any evidence that any other canard/delta fighters have the ability to move canards independently, so really, what's your point?

    And I have noticed that you have ignored quite a few posts which you couldn't respond. Good job on debating!
     
    #2743 johnqh, May 28, 2011
    Last edited: May 28, 2011
  4. Engineer
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    You don't see the flaperons move either. Low resolution videos don't allow you to see any detail, but the fact that you cannot see anything does not support your argument that the canards aren't use differentially.

    Of course canards can be used for roll, and you don't see it because
    1. the J-10 in the video is taking off, not rolling,
    2. deflection of canards at higher speed, where rolling usually take place, is much smaller than deflection at lower speed when the aircraft is at V2,
    3. the videos are very low resolution and taken from very far away that you don't see movement of any control surfaces.
    Instead of cherry picking videos from youtube, show some real proof that the differential canards can't be used on roll instead.

    All the control surfaces on the J-20 are involved in all the maneuvering, including roll and yaw.
     
  5. Engineer
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    There's no evidence that roll control from canards is negligible. Flaperons being used in roll control is not evidence that canards cannot be used in roll control.

    None of the above planes other than J-10 have differential canards, and therefore only the J-10 can use its canards in roll control.

    There is no such evidence that say tail planes are more effective in roll control than canards.
     
  6. Engineer
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    Their entire thread is about how machine translation sucks, lol.

    But really, as one poster there pointed out, there isn't anything of substance in the current "debate". It just consist of one person who wants to see things that are not real coming up with irrelevant facts to support his belittling of J-20, and us picking apart his arguments. For example:
    Person in question: Everything encounters drag, therefore J-20 has higher drag.
    Us: Everything encounters drag is not a proof that J-20 has higher drag.
     
  7. siegecrossbow
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    siegecrossbow Brigadier
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