Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Lift and Drag from Pressure Distribution over an Air Foil

  1. May 13, 2010 #1
    Pretty simple question:

    Is it possible to completely calculate Lift and Drag from the pressure distribution over an airfoil?

    Atm, I have Lift worked out as well as the Induced drag ( correct me if I'm wrong. ) but am having trouble working out how it would be possible to get the skin friction / parasitic drag.

    Thanks for your help!
  2. jcsd
  3. May 13, 2010 #2


    User Avatar
    Homework Helper

    How would you determine the pressure distribution over an airfoil? Perhaps some form of intrumentation, but that would have some effect on the flow. A simplified model could use static pressure distribuition and the normals (line perpendicular) to the sections of surface of a wing, but there are other factors. Static pressure isn't directional, but dynamic pressure and any related changes in momentum of the air are directional. Skin friction is nearly parallel to a wing surface. The shear boundary layer thickens over time, may detach and reattach as it transitions from laminar to turbulent, so that changes the effective air foil shape.

    The best mathematical models for lift and drag are usually based on some simplified form of Navier Stokes equations:

    Last edited: May 13, 2010
  4. May 13, 2010 #3
    Hey thanks for the response,

    Last edited by a moderator: Jun 25, 2010
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook