Magnus effect (1)
Two 15-m high rotors 3 m in diameter are used to propel a ship. Estimate the total longitudinal force exerted upon the rotors when the relative wind velocity is 25 knots, the angular velocity of the rotors is 220 revolutions per minute and the wind direction is at 60? from the bow of the ship. Perform the calculations for
(a) an ideal fluid with irrotational motion and
(b) a real fluid.
(c) What orientation of the vector of relative wind velocity would yield the greatest propulsion force upon the rotorship? Calculate the magnitude of this force Assume a real fluid flow. The result is trivial for ideal fluid with irrotational flow motion.
(d) Determine how nearly into the wind the rotorship could sail. That is, at wind angle would the resultant propulsion force be zero ignoring the wind effect on the ship itself.