Mitsubishi Heavy Industries Limited

Seijiro Higasa

Shuji Mizokami

Shinichi Takano

Chiharu Kawakita

Makoto Kawabuchi

Shoichi Kameyama

Takashi Mine

Shinsuke Sato

Yoichiro Kodan

Kiyomitsu Mukou

Mitsuhiro Kawano

Eiji Furuyama

Hiromitsu Matsumoto

Takehiro Kubo

Yoshinori Nagayama

A device for reducing frictional resistance includes: a chamber which is provided to a draft part of a hull and in which blowing holes blowing out air into the water of the outside of the hull from different positions to each other in a height direction of the hull are formed; a supply pipe supplying the air to an internal space of the chamber; and a distributor provided to each of the blowing holes, and guiding a part of the air, which was supplied inside the chamber from the supply pipe, to each of the blowing holes. The plurality of distributors has a flow-amount adjuster adjusting a flow amount of the air guided to the blowing hole corresponding to each of the distributors so that the flow amount of the air blown out from the plurality of blowing holes is equalized in each of the blowing holes.

Device for reducing frictional resistance, ship comprising the device, and method of reducing frictional resistance of ship

A ship air lubrication system of an external installation type has good efficiency. An air ejecting unit includes an ejecting side chamber installed in a ship bottom of a ship and having air ejecting holes formed in a surface opposite to the ship bottom on a lower side, and a supply section which supplies air into an inner space of the ejecting side chamber. When the air in the ejecting side chamber is ejected from the air ejecting holes, the air is sheared by an external water stream, and small air bubbles are supplied to the ship bottom.

Air lubrication system of ship

An air lubrication system of an outer installation type has good efficiency. An air recovering device includes a recovery side chamber provided on a bottom of a ship on a stern side from an air ejecting device which supplies air bubbles to the ship bottom. The recovery side chamber includes air intake holes formed in a portion of the recovery side chamber opposite to the ship bottom through a gap. The air recovering device also includes a recovering section recovering air inside a recovery side chamber. The air bubbles acquired from the air intake holes are accumulated inside the recovery side chamber to generate pushing pressure so that air can be smoothly recovered from the recovering section.

A gas room is arranged in a hull to cross a longitudinal frame and extend in a width direction. A scattering member is arranged in the gas room to cross the longitudinal frame and extend in the width direction. Air blown into the gas room from an air supply pipe hits the scattering member to scatter in the width direction, and is blown from an air blowing hole formed in a bottom of the gas room into water. Because the gas room crosses the longitudinal frame and extends in the width direction, an air bubble flow with a wide width forms in the width direction by the single gas room. Therefore, the number of gas rooms for air bubble flow which covers the whole width of a ship bottom is reduced, and the number of air supply pipes which are provided to every gas room is reduced.

Frictional resistance reducing device of ship

In a friction reducing device for a ship body by forming an air bubble curtain on a ship's bottom by generating air bubbles from air ejection holes formed on the bottom, the air ejection holes are arranged in a ship width direction to constitute a plurality of air-ejection hole groups. The air-ejection hole groups include at least a center air-ejection hole group formed at the center of the ship width direction at a bow side and a pair of side air-ejection hole groups formed at a stern side from the center air-ejection hole group at both sides of the center air-ejection hole group in the ship width direction. A length of the center air-ejection hole group in the ship width direction is formed to be longer than a length of each of the side air-ejection hole groups in the ship width direction.

Device for reducing frictional resistance of ship body

A ship-body frictional resistance reducing device for reducing frictional resistance of a sailing ship body by forming an air bubble curtainon a ship's bottom by generating air bubbles includes an air chamberprovided on the ship's bottominside the ship body, a plurality of air ejection holes formed in an arrayed manner on the ship's bottomthat becomes a bottom portion of the air chamber, and a sea chestprovided on the ship's bottominside the ship body in a manner such that the sea chestcovers the air chamber. With this configuration, it is possible to perform maintenance of the air chamber, and at the same time, it is possible to take a watertight structure to prevent ingress of the sea water into the ship body.

A ship-body frictional resistance reducing device for reducing frictional resistance of a sailing ship body by forming an air bubble curtain on a ship's bottom by generating air bubbles includes an air chamber provided on the ship's bottom inside the ship including an air supply port formed thereon, a plurality of air ejection holes formed in an array on the ship's bottom that serves as a bottom of the air chamber, and a diffusion plate provided inside the air chamber intervening between the air supply port and the air ejection holes. The diffusion plate is formed in a manner that it includes at least a supply-port facing area covering the air supply port and a pair of ejection-hole facing areas covering air ejection holes located at both edges of the air ejection holes in an arrangement direction.

In a ship-body frictional resistance reducing device, an ejection chamber having an air ejection hole is fixed to a bottom of a ship body, and an air supply path for supplying air to the ejection chamber and a marine-biofouling preventing-fluid supply path for supplying a marine-biofouling preventing fluid to the ejection chamber are connected to the ejection chamber. An on-off valve is provided on each of the paths, by which either one of the paths can be connected in a selective manner, making it possible to prevent adhesion of marine species to the air ejection hole of the ship body while suppressing power consumption therefor.

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Tokyo, Japan

Seijiro Higasa