JP2000296795A - Frictional resistance reducing ship - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce labor of maintenance work of blowoff ports, and to reduce a construction cost by collectively arranging gas blowing-out plural blowoff ports of a ship for reducing frictional resistance of a hull and water by blowing out gas in the water from the bow vicinity at sailing time in a limited area in the vicinity of a bow. SOLUTION: A hull S has a spherical bow, and has a curved part M where a bow 1a projects forward and downward. A gas blowoff part 2 has a downward curved curved surface 2a, and is formed in an almost dome shape of being integrated with a hull outside plate 1 via a horizontal plane. Plural blowoff ports 3 are collectively arranged on the stern side of the curved surface 2a of the gas blowoff part 2, and are limited to an easily performing area of maintenance work. Gas is blown out in the water from holes of the blowoff ports 3 to generate microbubbles to spread in the ship's space direction to be widely duffused over the ship's bottom 1c to thereby reduce frictional resistance of the hull S and water so as to perform maintenance work by little labor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frictional resistance reducing ship for reducing frictional resistance by interposing minute air bubbles on a hull outer plate of a hull in a sailing state, and more particularly to a structure of an air outlet for discharging gas.

[0002]

2. Description of the Related Art JP-A-50-83992 and JP-A-53-1983.
JP-A-136289, JP-A-60-139586, JP-A-61-71290, JP-A-61-39691, and JP-A-61-128185 disclose a technique relating to a ship with reduced frictional resistance. I have. This friction drag reduction ship,
In the navigation state, gas such as air is blown out into the water from the hull surface (hull skin), causing a large number of microbubbles to intervene on the hull skin. Is to reduce the frictional resistance acting on the surface.

[0003] The present applicant has proposed a technique relating to such a frictional resistance reducing ship, in which a gas (for example, air) is blown out into water from near the bow and microbubbles are interposed on the hull outer plate. I have. This technique intends to diffuse microbubbles generated by gas ejected from the vicinity of a bow along a streamline of water on a hull skin, and to widely cover the hull skin with microbubbles. Conventionally, in order to cover a wider area of the hull outer panel with a large number of microbubbles, a plurality of outlets for ejecting gas are conventionally arranged over a wide area on the ship side near the bow or on the bottom of the ship. Have done that.

[0004]

When a ship with reduced frictional resistance is navigated, marine organisms such as algae, aquatic plants, and shellfish in the water adhere to the hull outer plate. If such marine organisms adhere to the outlet, it may happen that a sufficient amount of gas cannot be ejected from the outlet, or the direction in which the gas is ejected from the outlet changes. For this reason, it is necessary to carry out a maintenance work for removing the marine organisms attached to the outlet at any time when the ship with reduced frictional resistance is sailed. However, in the above-described conventional frictional resistance reducing ship, since the plurality of outlets are arranged over a wide range of the ship side or the ship bottom, a work range for performing maintenance is wide, and labor is required for the work. . In addition, since a plurality of outlets are provided, the construction cost for constructing the hull tends to be high.

[0005] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a ship with reduced frictional resistance capable of reducing the labor required for maintenance work of an outlet and reducing construction costs.

[0006]

Means for Solving the Problems To solve the above-mentioned problems, the invention according to claim 1 is a method in which fine bubbles are interposed on a hull outer plate by jetting gas into the water from near the bow during navigation. A frictional resistance reducing ship for reducing frictional resistance between a hull and water, which employs means for collectively providing a plurality of air outlets for ejecting gas in a limited area near a bow. This vessel with reduced frictional resistance is provided with multiple outlets for ejecting gas in a limited area near the bow, so the work area of maintenance work such as removing marine organisms attached to the outlet is limited. Is done.

According to a second aspect of the present invention, in the first aspect, the plurality of outlets are collectively provided in a unit forming a partial area of the hull surface. In this frictional resistance reducing ship, the plurality of outlets are
Since the unit that forms a part of the surface of the hull is collectively provided, it is possible to perform a detailed operation such as providing an air outlet in the unit separately from the construction of the hull outer panel.

According to a third aspect of the present invention, there is provided the frictional resistance reducing ship according to the second aspect, wherein the unit is attached to the ship bottom near the bow in a state of protruding downward. In this frictional resistance reduction ship, the unit is attached to the bottom of the ship near the bow in a state protruding downward, so that the water flowing on the unit narrows the flow path and the flow velocity increases, and in places where the flow velocity is large, Hydrostatic pressure decreases. Therefore, by providing the outlet on the unit where the flow velocity increases, it is possible to lower the hydrostatic pressure at the outlet, and it is possible to eject gas with less power even in deep water. Become.

According to a fourth aspect of the present invention, there is provided the frictional resistance reducing ship according to the second aspect, wherein the unit is mounted on the right and left ship sides near the bow. In this frictional resistance reducing ship, since the units are mounted on the left and right ship sides near the bow, in a high-speed ship where the bottom is relatively small and the water flow from the ship side to the bottom is likely to be formed, fine bubbles are generated on the hull outer plate. Will spread effectively.

According to a fifth aspect of the present invention, there is provided the frictional resistance reducing ship according to any one of the second to fourth aspects, wherein the unit is detachably attached to the hull outer plate. In this frictional resistance reduction ship, since the unit is detachably attached to the hull outer plate, it is easy to remove the unit for maintenance and to replace the unit with a new one.

According to a sixth aspect of the present invention, in the ship of the fifth aspect, the unit is formed of resin. In this frictional resistance reducing ship, since the unit is formed of resin, it is possible to reduce material costs.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a ship for reducing frictional resistance according to the present invention will be described below with reference to FIGS. FIGS. 1A and 1B are diagrams showing a main part configuration near a bow of the frictional resistance reducing ship, wherein FIG. 1A is a side view and FIG. 1B is a bottom view. In FIG. 1, reference symbol S denotes a hull, 1 denotes a hull outer plate, 2 denotes a gas blowing portion, and L denotes a water surface.

The hull S has a forwardly protruding spherical bow such as a barbasbau.
a is formed in a shape having a curved portion M protruding forward and downward. The surface of the curved portion M is formed of a smooth curved surface Ma.

The gas blowing section 2 is a unit formed in advance separately from the hull shell 1, and is provided on the hull shell 1 so as to form a part near the top below the curved portion M. ing. As shown in FIG. 1A, the gas blowing portion 2 has a curved surface 2a that is curved downward, and is formed in a substantially dome shape so as to be integrated with the hull outer panel 1 via a horizontal plane. Although the front shape shown in FIG. 1B is substantially circular, it is formed in various shapes such as a substantially elliptical shape according to the shape of the curved portion M of the hull outer panel 1. The curved surface 2a of the gas blowing portion 2 is formed on the hull outer panel 1 so as to be identical to the curved surface Ma of the curved portion M. On the downstream side (stern side) of the curved surface 2a of the gas blowing unit 2, a plurality of outlets 3 are collectively arranged in a state of being arranged on the same circumference, whereby the plurality of outlets 3 , Is limited to an area where maintenance work is easily performed.

FIG. 2 shows a vertical cross-sectional shape of the gas blowing section 2. In the present embodiment, the gas blowing section 2 is formed from a metal member and is welded to the hull outer panel 1. Here, circumferential welding is performed from the outside, but the welded portion is provided in a smooth state so as not to generate a convex portion that generates wave-making resistance. The gas blowing section 2 has a structure in which a chamber 4 is formed inside by the partition wall 2b.
Further, a gas supply pipe 5 is joined to the inside of the hull S, and a gas supply pipe 6 is provided inside the hull S by a gas supply means 6.
Gas is supplied to the inside.

FIG. 3 is a longitudinal sectional view showing the details of the outlet 3. The outlet 3 is formed in a concave shape depressed from the curved surface 2a. The blow-out plate 7 curved toward the chamber 4 is welded to the partition 2b.
Are formed with a large number of holes 7a. As previously mentioned,
The gas outlet 2 is provided with a plurality of such outlets 3 arranged on the curved surface 2a so that the gas supplied into the chamber 4 is ejected into water.

In the thus constructed frictional resistance reducing ship, when gas (air) is supplied from the gas supply means 6 into the chamber 4 through the gas supply pipe 5 in the navigation state, the gas is supplied from the hole 7a of the outlet 3 into the water. Gas is ejected to generate microbubbles. The microbubbles diffuse along the streamlines of water on the hull skin 1 to cover the hull skin 1.

At this time, since the curved portion M is formed so as to protrude downward, water flows along the curved surface Ma of the curved portion M, so that the flow velocity of the water increases and the hydrostatic pressure at the outlet 3 decreases. At this low hydrostatic pressure, gas is ejected from the outlet 3. For this reason, the gas supply means 6 can inject gas with little power. In addition, gas blowing section 2
Are arranged in the vicinity of the bottom 1c near the bow 1a, and a plurality of outlets 3 are arranged side by side on the downstream side of the gas blowing portion 2, so that the generated microbubbles spread in the width direction of the ship and are widely diffused to the bottom 1c. You. Thereby, the frictional resistance between the hull S and the water is effectively reduced.

Further, in such a frictional resistance reducing ship, marine organisms such as algae and shellfish gradually adhere to the gas blowout portion 2 and the blowout port 3 as the ship travels. In the present embodiment, the outlet 3 is collectively provided in one gas outlet 2 disposed below the bow 1a, and therefore, for example, a sea where a diver of an operator dives and adheres to the outlet 3 is provided. In maintenance work such as removal of adult organisms, the working range of the diver is limited to the vicinity of one gas blowing unit 2, and maintenance work can be performed with a small amount of labor.

Further, since the gas blowing portion 2 is formed such that its curved surface 2a is identical to the curved surface Ma of the curved portion M, the boundary between the gas blowing portion 2 and the original hull outer plate 1 is smooth. It is in a state. For this reason, water flows smoothly, and marine organisms do not easily adhere to such a boundary or the curved surface 2a of the gas blowing portion 2. Further, even when marine organisms adhere to the border, there are almost no projections or the like that hinder the work, so that the marine organisms can be easily removed.

The gas outlet 2 is a unit formed separately from the hull shell 1, and is attached to the hull shell 1 by welding. This can be performed separately from the construction of the plate 1, so that the efficiency of the construction work of the hull S can be increased, and the construction cost can be reduced.

The hull shell 1 shown in FIG. 2 has a structure in which a large opening is provided below and the opening is closed by the attachment of the gas blowing section 2. As shown in FIG. Instead of providing a large opening, the gas outlet 2
It is also possible to provide a wall portion 1d that is in contact with the side, and to provide only a through hole for the gas supply pipe 5 in the wall portion 1d. By welding and joining the wall 1d and the gas supply pipe 5 from the inside of the hull, it is possible to reduce the labor required for welding work outside the hull S.

Next, a second embodiment of the present invention will be described.
This will be described with reference to FIGS. In the frictional resistance reducing ship of the present embodiment, the gas blowing portion 20 is detachably attached to the hull outer plate 21 by being fastened with bolts 22. That is, as shown in the vertical sectional view of FIG.
A nut 23 is welded to a wall of the hull outer plate 21 on the side of the gas blowout portion 2, and the hull outer plate 1 and the gas blowout portion 20 are fastened by bolts 22 with a gasket 24 interposed therebetween.

The gas blowing section 20 is provided with a space 25 for fastening the bolt 22. This space 25 is filled with a filler such as putty after the bolt 22 is fastened so that a sharp wave formed by the space 25 does not cause local wave-making resistance to water. And the gas blowing part 2
0, a plurality of outlets 26 as in the above-described embodiment.
Are arranged side by side on the curved surface 20a so as to eject gas into the water on the downstream side.

In the present embodiment, since the gas blowing portion 20 is not welded to the hull outer plate 21, the gas blowing portion 20 may be formed of a material having a low material cost such as a corrosion-resistant resin in addition to metal. It becomes possible. Further, in the present embodiment, since the gas blowing unit 20 is detachably provided on the hull outer plate 21 by the bolts 22, when the gas blowing unit 20 requires maintenance that cannot be easily treated from the outside, It is possible to easily perform maintenance by removing the gas blowing unit 20 and replace the gas blowing unit 20 with a new one.

Next, a third embodiment of the present invention will be described with reference to FIG. In this embodiment, the present invention is applied to a high-speed ship. In FIG. 7, reference symbol T denotes a hull, 30 denotes a hull outer plate, 31 denotes a gas blowing portion, and L denotes a water surface.

In the present embodiment, a curved portion N is formed on both sides of the bow 1a of the hull shell 1, and the gas blowing portion 31 is formed near the bow 30a so as to form a part of the curved portion N. It is arranged on both sides (boat side 30b) one by one. Also,
The gas blowing section 31 has a front shape shown in FIG. 7A formed by a droplet-shaped contour, and is arranged with its long axis directed in the longitudinal direction of the hull T. In addition, the hull outer plate 3 of the gas blowing section 31
And the structure of the outlet 32 are the first
Alternatively, the same one as that described in the second embodiment is applied.

In a high-speed ship like this embodiment, generally,
The area of the ship bottom 30c is relatively small,
A streamline of water from the ship side 30b to the ship bottom 30c is likely to be formed. Therefore, by disposing the gas blowing portion 31 on the ship side 30b as in the present embodiment, it is possible to effectively cover the hull outer plate 30 with microbubbles. Further, since the gas blowing portion 31 is formed in a droplet shape, the water flowing along the gas blowing portion 31 does not spread downstream, and the microbubbles move quickly to the ship bottom 30c. Thereby, the frictional resistance between the hull outer panel 30 and water can be effectively reduced.

In the present embodiment, since the gas blowing portions 31 are provided one by one on both sides (the ship side 30b), the work range is set at both sides when performing maintenance work such as removing marine organisms. It is limited to the vicinity of the arranged gas blowing section 31, and the labor required for the operation can be reduced.

It should be noted that the present invention is mainly applicable to a large ship having a larger bottom than the ship side, in which the gas blowing portion shown in the first embodiment is installed at the bottom of the ship, while a high speed ship has the third embodiment. A gas outlet is installed on the ship side as indicated by. However, according to the flow of water on the hull outer panel, the hull outer panel is formed with a curved portion at an appropriate position, and the gas blowout section is flexibly installed in accordance with the position of the curved portion. Determined. For example, in a high-speed ship, when a curved portion protruding downward is formed near the bow,
It is also possible to install a gas blowing unit not only on the ship side but also on the ship bottom. Further, the present invention can be applied to a hull having a shape such as a catamaran, and in that case, the above-described gas blowing unit is installed on the bottom or the side of each hull.

[0031]

As described above, according to the present invention, the following effects can be obtained. In the frictional resistance reducing ship according to claim 1, since a plurality of outlets for ejecting gas are collectively provided in a limited area near the bow, maintenance work such as removing marine organisms attached to the outlet is performed. The work range is limited, and the labor required for maintenance work can be reduced.

In the frictional resistance reducing ship according to the second aspect, since the plurality of outlets are collectively provided in the unit forming a part of the surface of the hull, fine operations such as providing the outlets in the unit are performed. This can be performed separately from the construction of the hull outer panel, so that the efficiency of the construction work of the hull can be improved, and the construction cost of the hull can be reduced.

According to the third aspect of the present invention, since the unit is attached to the bottom of the hull near the bow so as to protrude downward, the hydrostatic pressure at the outlet can be reduced, and the water depth can be reduced. Gas can be ejected with little power even in deep places.

According to the fourth aspect of the present invention, since the units are mounted on the left and right sides of the ship near the bow,
In a high-speed ship in which the bottom is relatively small and the water flow from the ship side to the bottom is likely to be formed, fine bubbles can be effectively diffused on the hull outer plate, and the frictional resistance can be reduced.

According to the fifth aspect of the present invention, since the unit is detachably attached to the hull outer plate,
Maintenance can be easily performed by removing the unit, and the unit can be easily replaced with a new one. For this reason, even when the unit is damaged, it is possible to promptly take measures such as repair and replacement.

In the frictional resistance reducing ship according to the sixth aspect, since the unit is formed of resin, material costs can be reduced, and a large number of molded products can be formed. Cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a side view and a bottom view showing a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a gas blowing section according to the first embodiment of the present invention.

FIG. 3 is a longitudinal sectional view of the air outlet according to the first embodiment of the present invention.

FIG. 4 is a longitudinal sectional view showing another embodiment of the gas blowing section.

FIG. 5 is a schematic view from a ship bottom direction showing a state in which a gas blowing portion according to a second embodiment of the present invention is attached to a hull outer plate.

FIG. 6 is a longitudinal sectional view of a gas blowing section according to a second embodiment of the present invention.

FIG. 7 is a side view and a bottom view showing a third embodiment of the present invention.

[Explanation of symbols]

 S, T Hull L Water surface M, N Curved portion Ma Curved surface 1, 21, 30 Hull skin 1a, 30a Bow 1b, 30b Ship side (both sides) 1c, 30c Bottom 2, 20, 31 Gas blowing unit (unit) 2a, 20a Curved surface 3,26,32 Air outlet

Claims (6)

[Claims] 1. A frictional resistance is reduced by jetting gas into the water from the vicinity of a bow (1a) during navigation, thereby reducing frictional resistance between the hull and water by interposing fine bubbles on the hull outer plate (1). A ship having a plurality of outlets (3) for ejecting gas at a bow (1).
a) A ship for reducing frictional resistance, which is provided collectively in a nearby limited area. 2. The frictional resistance reducing ship according to claim 1, wherein the plurality of air outlets (3) are provided collectively in a unit (2) forming a partial area of the hull surface. 3. The frictional resistance reducing ship according to claim 2, wherein the unit (2) is attached to a ship bottom (1c) near the bow (1a) so as to protrude downward. 4. The unit (31) includes a bow (30).
3. A ship with reduced frictional resistance according to claim 2, wherein the ship is mounted on the left and right ship sides (30b) in the vicinity of a). 5. A boat with reduced frictional resistance according to claim 2, wherein the unit (20) is detachably attached to the hull shell (21). 6. The ship of claim 5, wherein the unit (20) is formed of a resin.