Question about Spitfire Mk.21's redesigned wing

Discussion in 'Aviation' started by gomwolf, Oct 18, 2014.

  1. gomwolf

    gomwolf Member

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    #1 gomwolf, Oct 18, 2014
    Last edited: Oct 18, 2014
    Hello~.

    First, sorry for same thread twice. I want write this thread here, but I confused and I wrote this thread wrong bulletin board before.

    There is a problem about Spitfire Mk.21's redesigned wing. I try to find information about this wing and found some articles confront each other. It make me confuse, please help me guys!

    Some articles told this redesign wing have laminar flow airfoil. But there is no information about this wing's airfoil, even name of airfoil's form.
    others told redesign wing have same airfoil with before spitfire(NACA 2213(root), NACA 2209.4(tip). Changed thing is aileron for high speed.

    In the book 'Spitfire's forgotten designer' written by Mike Roussel, Spitfire Mk.21's wing have laminar flow airfoil.
    I think, if Spitfire Mk.21 have laminar flow airfoil, it have to big change in performance, especially in top speed. but Spitfire Mk.21's top speed(around 446mph at +18lb) is not big different with Spitfire Mk.XIV(around 447mph at +18lb). It is weird
    In UIUC Applied Aerodynamics Group's airfoil data(The Incomplete Guide to Airfoil Usage), Spitfire Mk.21's airfoil is NACA2213(root), NACA2209.4(tip)


    Which one is right? There is no certain evidence which give me answer?(Blue prints or documents?) I want the evidence that solve this question. Please guys, help me!
     
  2. Glider

    Glider Well-Known Member

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    Don't take this as a perfect reply but it was my understanding that the Spitfire with a Laminar wing was the Spiteful. The Mk21 I believe that Mk 21 wing had a number of modifications, in particular to allow a standard 4 x 20mm cannon. There were also changes to reduce the impact of high speed manoeuvres, the traditional Spitfire wing started to get very heavy to throw around the sky at high speed and the Mk21 reduced this by changing the design of the ailerons. The aircraft was a lot heavier due to a new engine and this also had to be taken into account.

    No doubt there are other differences and any comments are welcome
     
  3. tomo pauk

    tomo pauk Creator of Interesting Threads

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    This might not be a proof, but the source is the creditable 'Spitfire - the history' by Morgan Shacklady (pg. 464, issue of 1987):
    On 1 May 1943 the Type Record for the prototype 356/1 Spitfire F Mk 21 was issued by Supermarine and following details were relevant [snip] Wing aerofoil section NACA 22 series of elliptical planform of Spitfire Mk I extended 1.67 ft etc.

    You might also want to check out the excerpt from that book, on this Forum kindly provided by Aozora, where the laminar flow wing was discussed for the Spiteful, but not for any mark of the Spitfire.
     
  4. gomwolf

    gomwolf Member

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    Thank you tomo pauk! I will find that book.
     
  5. tomo pauk

    tomo pauk Creator of Interesting Threads

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  6. Edgar Brooks

    Edgar Brooks Active Member

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    The 21 wing was strengthened, with ailerons on "piano" hinges, rather than the original Frise type, and the wheel tracking was widened.
    It's rather too simplistic, but, basically, the wings were pushed out by a wider centre section, and the elliptical tips were cut short. The wing was not laminar, though there had been a partial laminar wing tested on a Mk.VIII.
     
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