How do you determine the zero lift angle using "PROFILI"

On Profili, click on the toolbar button for the polars, marked with a "P". Select your airfoil and the other settings and click draw. It will draw the CL vs CD polar. Then, a 2nd row of buttons appears at the toolbar. One says CL(alpha), CD(alpha). Click that and it will draw the lift and drag curves. Where the lift curve crosses the axis is the zero lift angle. See the pic:

John,
Thanks for the information.
What chart plots the airfoil moment & how do you get to it using "PROFILI"

HO-229

Try the 50/50 rule (see Example).

For those comparing my accuracy - RONCZ R1145MS AIRFOIL

_________
Schpankme


"Always remember you’re unique, just like everyone else."