Fast Accurate Approximation for Lift Slope of Elliptical Wings

Discussion in 'Hydrodynamics and Aerodynamics' started by Leo Lazauskas, Apr 24, 2011.

  1. Leo Lazauskas
    Joined: Jan 2002
    Posts: 2,696
    Likes: 146, Points: 63, Legacy Rep: 2229
    Location: Adelaide, South Australia

    Leo Lazauskas Senior Member

    Aero Boffins!
    The robots here at Cyberiad have found a quick way to estimate the lift coefficient slope of a flat wing with elliptical planform and aspect ratio AR.

    Hauptman's and Miloh's approximation is given by equations (1) to (3) with h^2 = 1- k^2.

    Evaluation of the Complete Elliptic Integral of the 2nd Kind, E(h), can be avoided by using Ahmadi's approximation given by equations (4) and (5). The constants in equation (5) are:
    a = 0.142 200 963 771 28
    b = 3.934 908 477 896 60
    c = 2.691 437 204 515 743

    Plugging Ahmadi's approximation into equations (1) and (3) yields values that are within about 0.05% of high-accuracy, extrapolated results using the Lifting Surface Program (LSP).
    You can't trust robots, though, so it would be prudent to verify this claim before using it.

    Leo.
     

    Attached Files:

    Last edited: Apr 24, 2011
    2 people like this.
  2. DCockey
    Joined: Oct 2009
    Posts: 4,371
    Likes: 201, Points: 63, Legacy Rep: 1485
    Location: Midcoast Maine

    DCockey Senior Member

    :cool: Very nice!
     
Loading...
Similar Threads
  1. jon haig
    Replies:
    20
    Views:
    1,052
  2. DCockey
    Replies:
    1
    Views:
    1,634
  3. ImaginaryNumber
    Replies:
    6
    Views:
    5,054
  4. mehdiaityoussef
    Replies:
    2
    Views:
    1,417
  5. Adam B
    Replies:
    18
    Views:
    30,493
  6. Remmlinger
    Replies:
    1
    Views:
    1,117
  7. Leo Lazauskas
    Replies:
    5
    Views:
    1,476
  8. sabsfeigler
    Replies:
    89
    Views:
    12,665
  9. Leo Lazauskas
    Replies:
    66
    Views:
    5,609
  10. a24
    Replies:
    0
    Views:
    1,555
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.