×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Wing and Tail plane design info needed (model aircraft)

Wing and Tail plane design info needed (model aircraft)

Wing and Tail plane design info needed (model aircraft)

(OP)
We are building a model plane, unfortunately we ran in to some problems where we need to change the 2 dimensional data for the 'lift curve slope' (a1w) and the (a1t) values to 3 dimensional data. Can anyone provide information on this?
Also can anyone point me in the right direction of where I might get some data on the M06-13-128 airfoil.

RE: Wing and Tail plane design info needed (model aircraft)

   AC Horiz Tail:

Lift Slope: dCl/dAoA ~ 2*Pi (AR/AR+1) * COS (sweep)

  Sometimes AR/(AR+2) is used to convert from section lift data to finite wings.

  In any case, the Aspect Ratio of the Horiz Stab is generally less than that of the Wing, so the lift slope is lower.  

  Pitch Damping is mainly due to the H. Stab, and varies as Sh/S * (Dh/MAC)^2.  Thus, relative distance from the MAC/4 comes in squared.

  Finally, tail efficiency has to be taken into account. Due to the shielding of the tail surfaces by the wing and fuselage dynamic pressure, q at the tail is generally lower than the freestream value.  Values of 0.80 for efficiency seem typical, but a high H. Stab on the vertical fin may be near 100%.

  The H. Stab generally has negative camber so it pushes the tail down to increase static pitch stability. The H. Stab can also be angled down at the LE.  Enought so cruise trim is near zero.

  Downwash angle, epsilon of air flowing aft of the main wing reduces the effective Ang of Incidence of the H. Tail surface.  More positive lift/Incidence is required than would otherwise be the case.  That may be enough so no camber and/or Angle of Incidence for the H. Stab is sufficient.  

  Ron Freimuth

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources