Maximum G Loading evaluations...

Discussion in 'Technical Requests' started by Ernst, Mar 6, 2010.

  1. Ernst

    Ernst New Member

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    #1 Ernst, Mar 6, 2010
    Last edited: Mar 6, 2010
    Im searching about structural resistance of WWII fighters against g-loadings. I would like any charts, pictures, manuals etc. Like this one on p-51:

    [​IMG]

    Would like info about P-51, FW 190, Spitfire and 109.
     
  2. Ernst

    Ernst New Member

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    #2 Ernst, Apr 30, 2010
    Last edited: Apr 30, 2010
    Difficult to find it! And how about a list of limit load factor on several aircraft? I found a matchcad simplified procedure to draw this pictures, but i need some aircraft parameters.

    I do not known if it is valid for WWII aircraft but I d like to play with that formulas. As a check we could draw it for P-51 and compare with the picture above. If someone do this first please post your results here.

    I need for each aircraft Gross Wing Area, Gross Weight, Maximun Wing Lift Coeficient, Limit Load Factor and Air Density. Post it for some of them. See this link: Click Here

    I checked manuals area and cannot find the values for all this parameters.
     
  3. MikeHoulder

    MikeHoulder New Member

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    Ernst, you seem to be doing some very good stuff. I understand a little of the calculations shown in the page you reference. But I need to study a great deal more.

    My interest is the Avro Lancaster. I would like to see data for the Lanc similar to that of the P-51 you have presented.
    My problems at the moment are with resonance and inertia.
    Best wishes
    Mike
     
  4. Njaco

    Njaco The Pop-Tart Whisperer
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    Ernst, the only thing I could suggest is check throughout the forum for threads that compare various aircraft against others such as "P-51 vs Fw 190". Many members while discussing the attributes of the planes in question provide source material such as you are asking. One member , Hohun I believe does some very fine graphs. Thats about the best advice I can give. Those graphs are here, it just take a little bit of investigating. Good luck!
     
  5. drgondog

    drgondog Well-Known Member

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    Most US WWII fighters were designed to 8g limit/12 g ultimate - positive vertical load and 1/2 of that for negative vertical loads. In the example above the plot is for the Mustang at 8000 pounds gross weight. If the airplane was heavier (like a P-51D at at takeoff (say 10,600) the limit load woul be ~64,000/10,600 or ~ 6g vertical (positive axis)..

    The Limit speed in a dive was determined by flight test and represents the limit Q load or maximum dynamic pressure loads (1/2 * rho * V*V)

    Rho, the air density, is a function of altitude (both pressure and temp). The value presented in your link is the air density at 59.0 degrees F. The value for pound sec squared/cubic foot is .002377*(Psl/Palt)*(Talt/Tsl) -see below.

    - for all other heights (up to 36,089 feet, you need to correct for density altitude pressure and Temp. For density in lb sec squared/cubic foot = .00237*(P/P")*(T*/T) where P and T are the reference seal level valuse and P* and T* are the values at the altitude you are solving for - all available in tables for Atmospheric values.


    Last the values apply to non compressible flow regimes ~ .5 Mach is the approximate threshold.
     
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