Question

What is the flow of velocity at the top of the cylinder?

(a) Higher

(b) Lower

(c) Constant

(d) Does not varies

This question was posed to me in unit test.

This intriguing question comes from Lifting Flow over Cylinder topic in section Inviscid & Incompressible Flow of Aerodynamics

Answer 1

Correct option is (a) Higher

For explanation I would say: On the top of the cylinder usual non-spinning flow this extra velocity contribution creates a higher than usual velocity at the top of the cylinder and a lower than usual velocity at the bottom. These velocities are assumed to be just outside the viscous boundary layer on the surface from Bernoulli’s equation.