Question

The 3D flow characteristic attributed to the wings is a by-product of_____

(a) Pressure imbalance over top and bottom surfaces of the wing

(b) Pressure imbalance between leading and trailing edge of the airfoil

(c) Thickness of the wing

(d) Extra lift produced

I have been asked this question in class test.

I need to ask this question from Downwash and Induced Drag topic in chapter Flow over Airfoils over Finite Wing of Aerodynamics

Answer 1

Correct answer is (a) Pressure imbalance over top and bottom surfaces of the wing

Easiest explanation: Lift over an airfoil is produced by the pressure difference over top and bottom surfaces of airfoil. But for the finite wings, this creates a by-product in the form of span-wise flow, which gives a 3D flow. Thickness of the wing and extra lift produced are vague options.