RE: what is the angle of attack?
Consider an NACA 2412 airfoil with a 2\;m chord in an airstream with a velocity of 50\; m/s at standard sea level conditions. If the lift per unit span is 1353\; N, what is the angle of attack?
We need to find here the angle of attack.Lift per unit span is {L}’=\frac{1}{2}\rho _{\infty}V_{\infty}^{2}sc_{l}
q_{\infty}=\frac{1}{2}\rho _{\infty}V_{\infty}^{2}=\frac{1}{2}\times1.23\times50^{2}=1538\;N/m^{2}
c_{l}=\frac{{L}’}{q_{\infty}s}=\frac{1353}{1538\times2}=0.44
For NACA 2412 airfoil coefficient of lift of 0.44 is at 2 degrees angle of attack.
