| 摘要 |
PURPOSE:To reduce oscillation forces generated in a hull in an upward and downward directions, by providing a horizontal finny wing directly below a horizontal bottom portion of the hull. CONSTITUTION:When a prime mover 12 is started to rotate a crank disk in a direction as shown by an arrow 13, a horizontal finny wing 3 is rocked upwardly and downwardly in such a manner that a caudal fin of a dolphin moves, and thereby to generate a propelling power in an advancing direction of a hull 1. When the horizontal finny wing 3 is moved upwardly, fluid pressure having a large amount of vertical component in the downward direction is applied to the wing. However, since a horizontal bottom portion 2 is formed at a bottom of the hull 1 just above the horizontal finny wing 3, induction flow of fluid induced by the wing generates fluid pressure against the horizontal bottom portion 2 in the upward direction, and the fluid pressure acts to cancel a great part of the above-mentioned vertical component applied to the horizontal finny wing 3 over the hull. |
