Question

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/m, what is the angle of attac

Answer 1

Answer:

4°

Explanation:

Given,

chord in the airstream, c = 2 m

speed, v = 50 m/s

lift per unit span = 1353 N/m

density of air, ρ = 1.225 kg/m³

Lift,$L = c_L \times \dfrac{1}{2} \rho v^2(c \times s)$

$\dfrac{L}{s}=c_L \times \dfrac{1}{2} \rho v^2\times c$

$50=c_L \times 0.5\times 1.225\times 50^2\times 2$

$c_L = 0.44$

From the plot of c_L and angle of attack

Angle of attack is equal to 4°