The Wide World of Fluids article titled "A Sailing Ship without Sails,". Determine the magnitude of the total force developed by the two rotating cylinders on the Flettner "rotor-ship" due to the Magnus effect. Assume a wind-speed relative to the ship of

(a) \(10 \mathrm{mph}\)

(b) \(30 \mathrm{mph}\). Each cylinder has a diameter of \(9 \mathrm{ft}\), a length of \(50 \mathrm{ft}\), and rotates at \(750 \mathrm{rev} / \mathrm{min}\). Use Eq. 6.124 and calculate the circulation by assuming the air sticks to the rotating cylinders. This calculated force is at right angles to the direction of the wind and it is the component of this force in the direction of motion of the ship that gives the propulsive thrust. Also, due to viscous effects, the actual propulsive thrust will be smaller than that calculated from Eq. 6.124, which is based on inviscid flow theory.

Eq. 6.124

Transcribed Image Text:

Fy=-PUT