| 摘要 |
PURPOSE:To make it possible to eiminate the problem of cavitations, by disposing a propller at a specified distance from the rear end of bottom running surface of a hull so that the propeller is completely submerged into water upon low speed sailing to obtain a sufficient propelling force and the propeller is used as a surface propeller upon high speed sailing. CONSTITUTION:Since a propeller 2 is positioned at a distance by (l), D/2<l<0.5L, from the rear end 5 of a running surface, the back wash from the rear end 5 of the running surface rises up near to the water surface in this area even though a boat sails a certain low speed. Further, since the propel ler is positioned in this area, the propeller is completely submerged in the water so that it servers as a normal propeller for generating sufficient propelling force. Accordingly, the problem of insufficient thrust may be eliminated, and further since the propeller may serve as a surface propeller upon high speed sailing, no problem of cabitation is there, thereby it is possible to offer a high speed performance exceeding 50 knot. |
