A PROPULSION APPARATUS FOR SHIP

摘要

The present invention relates to a propulsion apparatus for a vessel, which comprises a propeller for generating propulsive force by being installed in the stern of the vessel and a duct attached to the stern. The duct includes: an upper part which is positioned above the axial center of the duct; and a lower part which is positioned under the axial center of the duct and has a cross section having a semielliptical shape or a shape which is same as the shape of a cross section under the axis of the propeller of the stern. The propulsion apparatus for a vessel according to the present invention has effects of: improving the propulsive force of the vessel by reducing the weight of the vessel and a slamming load by installing the duct formed with a semicircular upper part and a semielliptical lower part in the front side of the propeller; and increasing propulsion efficiency of the vessel and saving sailing expenses by increasing the speed of water flowing into the propeller and changing the flow of fluid as the lower part of the duct has a shape similar to the lower part of the stern. The propulsion apparatus for a vessel according to the present invention is also able to maximally use rotatory force of the propeller as propulsive force by changing the inflow of the propeller by additionally installing a fin in a space at 90-300° from the upper side perpendicular to the axis of the propeller in the duct formed with the semicircular upper part and the semielliptical lower part. Thereby the present invention is able to remarkably improve propulsion performance of a vessel, hugely reduce energy consumption, and improve durability of the propeller.