プロペラの前方に取付けられたフィンの性能について

抄録

It is generally recognized that the short way of constructing the ship at small expence is to design the ship which has large block coeffcient and small ship length. Meanwhile, increase of hull fullness by this way sometimes causes unstable flow fields around the stern, which is so-called "unstable phenomena", during the self-propulsion test at a towing tank, and deteriorates propulsive efficiency. Practical solution for this matter is to equip suitable appendages in order to improve flow fields. Hitherto a stern fin in front of a propeller was treated as a regulator of flow fields around the stern on the view point of propeller exciting forces. Recent our research works reveal that a fin reduces viscous resistance of the ship and improves propulsive efficiency strongly. This paper describes hydrodynamic characteristics of a fin which locates in front of a working propeller.