Abstract

The present invention relates to a duct structure, for a ship, which does not have great increase in resistance due to a boundary layer even at a high speed and thus enables enhanced thrust at a speed of 10 knots or less as well as greater thrust generation than the increase in resistance due to the duct shape even at a high speed exceeding 10 knots, and thus can be applied at both low speed and high speed.

IPC Classes  ?

• B63H 5/15 - Nozzles, e.g. Kort-type

Abstract

The present invention relates to a propulsion device, for a ship, comprising: a cylindrical duct body having a predetermined inside diameter; and a plurality of guide fins disposed on the inlet of the duct body and extending from the center toward the inner peripheral surface of the duct body, by a predetermined length in the direction of the diameter of the duct body, wherein the guide fins each have a slope portion having a predetermined included angle with respect to the inflow direction of a fluid flowing into the duct body, thereby enabling usage at both a low speed and a high speed.

IPC Classes  ?

• B63H 5/15 - Nozzles, e.g. Kort-type

Abstract

A propeller for a ship according to an embodiment of the present invention comprises: a hub; a blade protruding in a radial direction from the hub; and a fin protruding from the edge of the blade.

IPC Classes  ?

• B63H 1/28 - Other means for improving propeller efficiency

Abstract

A duct-type ship energy reducing device according to an embodiment of the present invention comprises: a duct disposed to surround a part of the rear protruding part of a ship; and a support part for connecting the rear protruding part to the inner surface of the duct to fix the position of the duct with respect to the rear protruding part. The support part comprises a first support disposed on a first side of the ship and having a first end connected to the rear protruding part and a second end connected to the inner surface of the duct, the ends being curved in opposite directions, respectively. The support part may further comprise a second support disposed on a second side of the ship and having a positive average slope with respect to a propelling shaft of the ship.

IPC Classes  ?

• B63H 5/16 - Arrangements on vessels of propulsion elements directly acting on water of propellers characterised by being mounted in recessesArrangements on vessels of propulsion elements directly acting on water of propellers with stationary water-guiding elementsMeans to prevent fouling of the propeller, e.g. guards, cages or screens
• B63H 1/28 - Other means for improving propeller efficiency

Abstract

According to one embodiment of the present invention, a ship comprises: a hull; a propeller provided at the rear of the hull; and vortex generating fins respectively arranged at optimal points (Po) of the port and the starboard of the hull, and generating a vortex so as to change a flow field passing a rotational surface of the propeller. The optimal point (Po) is positioned 0-0.1 stations apart toward a stem along a reference streamline (Sr), in which a limiting streamline flowing along the surface of the hull passes a reference point (Pr), which is closest to the stem, among the intersecting points when viewed from the side of the hull, when the flow field around the hull is simulated on the assumption that the ship operates at a design speed before the vortex generating fins are arranged on the hull. The reference streamline (Sr) is the limiting streamline positioned lower at the stem side, between two limiting streamlines passing the reference point (Pr).

IPC Classes  ?

• B63H 5/16 - Arrangements on vessels of propulsion elements directly acting on water of propellers characterised by being mounted in recessesArrangements on vessels of propulsion elements directly acting on water of propellers with stationary water-guiding elementsMeans to prevent fouling of the propeller, e.g. guards, cages or screens
• B63H 1/28 - Other means for improving propeller efficiency