Question

For a finite wing, the local airfoil section sees the angle of attack which is called as ____

(a) Downwash angle

(b) Induced angle of attack

(c) Relative angle of attack

(d) Effective angle of attack

I have been asked this question during an online exam.

This interesting question is from Downwash and Induced Drag topic in division Flow over Airfoils over Finite Wing of Aerodynamics

Answer 1

Correct choice is (d) Effective angle of attack

The best explanation: The actual angle of attack seen by the local airfoil section is the effective angle of attack. This is the angle between the chord line and the local relative wind. Or in other words,

Effective angle of attack = Geometric angle of attack – induced angle of attack.