lift and drag coefficient definition?
 

Hallo,

i want to calc the forcecoeffs with the "libforces.so" Library. I also got it to work but now i have a problem how the coefficients are defiened?

i know the definition: c_d = (2 * F_d)/(rho*U²*Aref)

In aeronautics the Aref is the area of the Wing from above ( projected area), and in automobile problems Aref is the projected area from the front.

And for want do i need a lref?

greetings,
draufunddran

solved... :)