Question

For a finite wing and an infinite wing (airfoil), zero lift angle of attack is zero.

(a) True

(b) False

This question was addressed to me in final exam.

Question is from Prandtl’s Classical Lifting-Line Theory in chapter Flow over Airfoils over Finite Wing of Aerodynamics

Answer 1

The correct answer is (a) True

Explanation: When the lift is zero, there are no induced effects i.e. induced drag and induced angle of attack are zero. Also, since the induced angle of attack is zero, the geometric angle of attack is the same as the effective angle of attack. This means zero lift angle of attack is the same for wing and airfoil.