Expert: Paul Soderman - 8/9/2010

Question
I'm measuring upthrust of various wing types and angle of
attack. On a general consensus, what formula's would be useful
and what are they.
Thanks.

Answer
Dean
There is a wealth of information on airfoil performance in I. Abbott and A. vonDoenhoff - Theory of Wing Sections.  You can also find various computational tools on line such as:  http://www.mh-aerotools.de/airfoils/javafoil.htm

But for a simple equation to find lift of a wing you can use:

cl = m alpha,   lift coefficient of a simple wing such                 as an elliptical wing
m = 2 pi,       lift curve slope (pi = 3.14159)
alpha           angle of attack, radians

L = cl q S      lift on wing
cl              lift coefficient
S               area of wing planform
q               dynamic pressure = rho v^2/2
rho             air density
v               flight speed

Good luck.
Paul