Question

Why the circular cylinder will create more drag?

(a) The pressure difference between upstream and downstream direction of flow

(b) The pressure difference between relative wind and downstream direction of flow

(c) The pressure difference between upstream and direction of flow

(d) The pressure difference between downstream of flow

The question was asked during an interview for a job.

The above asked question is from Lifting Flow over Cylinder topic in portion Inviscid & Incompressible Flow of Aerodynamics

Answer 1

The correct choice is (a) The pressure difference between upstream and downstream direction of flow

For explanation I would say: A circular cylinder produces large drag due to the pressure difference between upstream and downstream of the flow. The difference in pressure is causes by the periodic separation of flow over the surface of the cylinder. This will increase the drag in the cylinder.