Rocks & mirror
Encyclopedia of Marine and Energy Technology

Flettner rotor


Unconventional ship propulsor based on the Magnus effect. Flettner rotor is a vertical cylinder rotated around its axis by a motor. As wind blows past the rotating cylinder, high pressure on one side is formed with a corresponding low pressure area on the opposite side. This pressure difference generates a lift force perpendicular to the wind’s direction. There is also a drag force. The forward components of these forces result in thrust driving the ship forward. A Flettner rotor has about 10 times more lift with the same “sail” area than normal soft sails.