PURPOSE: To exhibit the thrust efficiency of sails at maximum, by providing such a method that an optimum sail angle is set by the performance curve of a single sail obtained by wind tunnel test, then the angle of a sail below the wind is gradually decreased until air-stream exfoliates from the sail surface, and the optimum sail angle is determined by the angle at which air-stream exfoliates.
CONSTITUTION: With the use of the performance curve of a single sail obtained beforehands by tunnel-wind test, the initial set values of sail angles of sails 1, 2 are determined. The thrust F2 of the sail 2 below the wind is detected by a thrust detector 7, and is set as an initial thrust F0. Thereafter, the sail 2 is turned by a drive device 10 to the angle θS2 of the sail 2 by, for example, two times, and by comparing thrusts F1, F0 at this time, if F1>F0, the similar steps are repeated. Further, when the sail 2 exceeds its attack angle α0, air- stream exfoliates from the sail 2 so that thrust Fn becomes equal to or less than Fn-1. The sail angle of the sail 2 is returned to the angle which is obtained by adding about 5 deg. to a measured sail angle θS2(n). Thereby, the sail angle may be set at a large thrust point.
ARIE TATSUO
KUSUMOTO KATSUNORI
NEZU YUUZOU
OKADA TAKAFUMI
TANAKA MINORU
KONDOU KAZUHIKO
YOSHIMURA ATSUSHI
KOMURA HIROSHI
AKAI KENICHI
FUJIMURA YUZURU
SUDOU MASANOBU
NIHON MARINE ENG