Rotor ship
Rotor ships are vessels of different types, the same instead of a sail drive with the help of the Flettner rotor or modifications. They are frequently also equipped with a motor drive. A rotor ship was first introduced in 1924 by Anton Flettner. At that time, however, the rotor drives had over the emerging diesel engines no chance. In the now existing price increase of the fuel oil the old idea of rotor ships will be taken up again recently.
1983 equipped the U.S. company Windship Development of a small motor yacht with a Flettner rotor. In the same year, a study was performed in Sweden, in which a prototype has been tested on a 6 m- boat.
1984 equipped the British firm Gifford Technology ( Southampton ) a 11 m high Flettner rotor as a slave drive on the 445 -tonne sailing ship " Clipper Patricia " (built in 1932).
Presently known rotor ships:
- Buckau - 1924
- Barbara - 1926
- Alcyone ( research vessel by J. Cousteau ) - 1983
- Uni- Kat Flensburg ( catamaran) - 2006
- E-Ship 1-2008
Principle
The flow around rotating cylinders can be understood as the superposition of a homogeneous flow and a vortex around the body. Due to the uneven distribution of the total flow results in an unbalanced pressure distribution on the cylinder circumference. The cylinder generated by surface friction thus a flow build against the direction of flow and on the side opposite a flow acceleration with the direction of rotation. The resulting lateral force ( dynamic lift ) points to the direction in which the flow and direction of rotation of the body are in the same direction.
At right angles to the apparent wind arises, as described on the rotor a force acting at a Half - hauled course parallel to the longitudinal axis of the vessel in the direction of travel, ie generated directly propulsion. Along with the boat hull and keel or sword ( lateral plane ) is also used in downwind and upwind courses creates propulsion. The afford generated by the rotation angles to the wind acting driving forces of the rotors, like normal sailing, no propulsion at The Downwind and, in contrast to normal sailing, even in courses from the wind. For this, the rotor area is compared to the sail area very efficiently, a square meter of rotor area is approximately 10 square meters of sail area. In this case, at the usual geometrical configurations already reaches a speed of one revolution per second. The direction of rotation of the rotor needs to be reversed at a tack or jibe. The angular speed of the rotor must be increased with the wind speed, so that it is also to provide high driving energy for the rotors even under high wind.