| 摘要 |
PURPOSE:To enhance the propelling efficiency of a ship, by fitting a ring-like structure to a hull in such a way that a space is defined between the rear end edge of the ring-like structure and a propeller, and as well by providing small type propellers in a stern bilge part front of this ring-like structure. CONSTITUTION:A ring-like structure 2 is attached to a hull 5 in such way that a space (d) is defined between the rear end edge of the ring-like structure 1 and a propeller 4, and the ring-like structure 1 is fitted in the hull 5, more than 20% of the length L of the upper section of a ring-like structure 1. Further, small-type propellers 8 are attached to both sides of the stern bilge part 5' of the hull 5 front of the ring-like structure 1. These small-type propellers 8 are rotationally controlled to apply outer-peripheral rotation to three-dimensional separation vortices. Accordingly, the ascending stream passing around the stern bilge part 5' is applied with outer peripheral rotation by the small-type propellers 8 so that the generation of three-diemensional separation vortices may be prevented. Thereby, the stream flowing in the ring-like structure 1 is rectified by the latter and thereafter is fed to the working surfaces of the propeller 4. |
