EP-4098535-B1 - FLUID RESISTANCE REDUCTION APPARATUS FOR SHIP

Inventors

• PARK, LEEN CHUL

Dates

Publication Date

20260506

Application Date

20200128

Claims (1)

1. An apparatus for reducing fluid resistance of a ship, the apparatus comprising: a fluid flow guide plate (50) which has a modified V-shape or U-shape whose two sides are installed at a predetermined gap so that, at an outer bottom portion of a hull (10) of the ship (100) that includes a propeller (11) disposed on a stern (10b), a fluid transfer passage (53) is formed in a shape that surrounds the shape of the hull (10); a fluid inlet (51) of the fluid flow guide plate (50) that is formed at the bow (10a) side of the hull (10) and formed to protrude in a direction in which the ship proceeds; a fluid outlet (52) of the fluid flow guide plate (50) that is formed at the stern (10b) side of the hull (10); and the fluid transfer passage (53) configured to connect the fluid inlet (51) and the fluid outlet (52), wherein the fluid outlet (52) has a shape in which an inner diameter is reduced due to arc-shaped curved plates (52a) added to entirely surround the propeller (11) and to face an inner side of the fluid flow guide plate (50) and which progressively expands toward an end to reach the same size as the fluid inlet (51), and the propeller (11) is installed in the reduced inner diameter portion so that seawater forcibly introduced due to a rotational force of the propeller (11) is promptly discharged due to the fluid outlet progressively expanding toward the end to reach the same size as the fluid inlet (51).

Description

[Technical Field] The present invention relates to a fluid resistance reduction apparatus for a ship, and more particularly, to an apparatus for reducing fluid resistance of a ship, the apparatus capable of significantly reducing wave-making resistance as well as frictional resistance caused by seawater during navigation of a ship, thus improving speed, allowing stable navigation, and saving fuel. [Background Art] Generally, a navigating ship receives fluid resistance caused by seawater, that is, frictional resistance and wave-making resistance due to forming waves on a water surface. In particular, frictional resistance accounts for a large part of the resistance that the hull receives from water, resulting in great energy loss during sailing, and at the same time, wave-making resistance also accounts for one part of the resistance that the hull receives from the water, causing loss of propulsion and resulting in energy loss that increases fuel consumption. Therefore, research in the field of hulls of ships has been focused on developing a hull form that can reduce frictional resistance and wave-making resistance. As an example, in order to reduce frictional resistance, various methods have been devised, such as applying paint on a hull to reduce a frictional coefficient, spraying air bubbles to reduce frictional resistance, or making a surface of a hull to be smooth and have a streamlined shape like a dolphin's body, but such methods have not been that effective. Also, a typical way of reducing wave-making resistance is by using a bulbous bow which is a bulb having a form that protrudes forward in a spherical shape from a bow below the water surface to create a wave that can offset a wave created by the bow to reduce a height of the wave formed near the bow, thus reducing wave-making resistance. However, since the bulbous bow is designed to have an optimal effect under a condition in which a ship maintains a fully loaded state and sails at a designated speed, there are problems that the bulbous bow rather increases wave-making resistance under actual sailing conditions in which a full load draft line and a designated speed are usually not maintained, and the length of the hull increases. Meanwhile, various other technologies for reducing fluid resistance caused by seawater have been proposed. For example, Japanese Unexamined Patent Application Publication No. 2016-112950 (Date of Publication: June 23, 2016) discloses a technology in which a water conveyance tunnel is formed at a port and a starboard of a ship so that, while seawater passes through the water conveyance tunnel, fluid resistance is reduced, and hydroelectric power is generated. However, the technology is for generating hydroelectric power using a fluid passing through the water conveyance tunnel and is not able to reduce fluid resistance during sailing of the ship. Also, Korean Utility Model Publication No. 20-2010-0004331 discloses a technology in which seawater that acts as a hydraulic pressure at the bow side is introduced through an intake and discharged with a high pressure to the stern side so that the bow-side hydraulic pressure of the ship is reduced, and propulsion increases at the stern side. However, despite having an effect of increasing propulsion, it is insufficient to reduce frictional resistance and wave-making resistance that are generated in a direction in which the ship proceeds when the ship sails. In addition, Korean Patent Publication No. 10-2015-0047812 discloses a non-ballast system of a ship in which a seawater passage is formed in the ship and, when the ship is stopped or initially sails, a rotator in the seawater passage helps speed up the flow of seawater through a motoring operation, thus keeping the ship in equilibrium. According to this technology, the seawater passage only has an effect of keeping the ship in equilibrium, and does not have an effect of reducing frictional resistance and wave-making resistance. KR 2018 0043459 A discloses an apparatus for reducing fluid resistance of a ship according to the state of the art. Therefore, there is an urgent need for development of a technology that increases efficiency of reducing frictional resistance and wave-making resistance using a relatively simple structure. [Disclosure] [Technical Problem] The present invention is directed to providing an apparatus for reducing fluid resistance of a ship, the apparatus capable of guiding the flow of seawater in a direction in which the ship proceeds when the ship sails, thus significantly reducing frictional resistance caused by seawater colliding with the ship and wave-making resistance caused by waves, thereby improving speed, allowing stable navigation, and saving fuel. [Technical Solution] The present invention provides an apparatus for reducing fluid resistance of a ship, the apparatus including: a fluid flow guide plate which has a modified V-shape or U-shape whose two sides are installed at a predetermined gap so th