Question

The span-wise component of flow over the top surface of the wing flows______

(a) From wing-tip to root

(b) From root to wing-tip

(c) Along the free-stream direction

(d) Perpendicular to the wing upwards

The question was posed to me in unit test.

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

Answer 1

The correct option is (a) From wing-tip to root

Best explanation: The pressure imbalance is such that there is a low pressure region on top and high pressure region at the bottom. This creates a flow from the bottom surface towards the top surface of the wing. Naturally, the flow moves from the wing-tips towards the wing root.