JP6253073B1 - Friction resistance reduction device for ships - Google Patents

Abstract

A frictional resistance reduction device capable of simplifying an air supply mechanism and generating more bubbles is provided. An input side plate 21 that has a leading edge 211 fixed to a ship bottom 41 and tilted rearward of the ship, an output side plate 22 that has a rear edge 222 fixed to the ship bottom 41 and tilted rearward of the ship, an input side plate 21 and An exterior plate 23 that is connected to the output side plate 22 by the connection plate 25 and extends in parallel with the ship bottom 41 from the front edge 211 of the input side plate 21 to the rear edge 222 of the output side plate 22, and is surrounded by the ship bottom 41, the input side plate 21, and the output side plate 22. And a closing plate 24 that closes the left and right ends of the air reservoir 26. The rear edge 212 of the input side plate 21 and the front edge 221 of the output side plate 22 form a suction gap 261, and the rear edge 212 of the input side plate 21. The front edge 221 of the output side plate 22 is a frictional resistance reducing device 1 that forms a passage gap 27 with respect to the exterior plate 23 and the air introduction pipe 3 is connected to the air reservoir 26. [Selection] Figure 5

Description

  The present invention relates to a frictional resistance reducing device in a ship.

  In order to reduce the frictional resistance generated between the ship bottom and seawater, various frictional resistance reduction apparatuses that cover the ship bottom with air bubbles have been proposed. Patent Document 1 installs a frictional resistance reduction device on the bottom of a ship that generates a pressure that does not reach the negative pressure region using the speed of the ship. The frictional resistance reduction device disclosed in Patent Document 1 includes a cover plate parallel to the ship bottom and a wedge plate having a triangular cross section. The wedge plate has an air introduction pipe opened at a convex portion. As a result, a negative pressure region generated by seawater passing at a high speed through a narrow gap between the cover plate and the wedge plate sucks air from the air introduction pipe and releases bubbles into the sea.

JP 2007-131283 JP

  The frictional resistance reducing device disclosed in Patent Document 1 does not disclose in detail how to open the air introduction tube at the convex portion of the wedge plate. From the drawings showing the cross-sectional structure (Patent Documents 1 and 2), a large number of branch pipes from the main pipe of the air introduction pipe arranged outside or inside the ship with respect to the wedge plate extending in the width direction of the ship. It seems that the branch pipes are opened at the convex portions of the wedge plate at equal intervals in the width direction of the ship. If so, the configuration of such an air introduction pipe has the following problems.

  First, the structure of the air introduction pipe is complicated as an air supply mechanism, and the method of installing the air introduction pipe composed of the main pipe and the branch pipe becomes a problem. In particular, it is difficult to install main pipes and branch pipes on board while avoiding existing equipment. Further, the bubbles are discharged only from the opening provided in the convex portion of the wedge plate, and if more bubbles are generated, the number of branch pipes increases, which makes the installation problem more serious. Therefore, a frictional resistance reduction device that can simplify the air supply mechanism and generate more bubbles has been studied.

Was developed result of the examination is an input side plate which is inclined to the rear of the ship by fixing the front edge to the ship's bottom or broadside, inclined to the rear of the ship, and an output side plate which is fixed to the trailing edge to the ship's bottom or broadside, input An exterior plate that is connected to one or both of the side plate or the output side plate by a connecting post or a connection plate, and extends in parallel with the bottom of the ship or the side of the ship from the front edge of the input side plate to the rear edge of the output side plate; is composed of a closing plate for closing the right and left ends of the air pocket enclosed in, the front edge of the edge and the output side plate to form a suction gap after the input plate, for passing the edge and the outer Soban after the input plate It is a frictional resistance reduction device in which a gap is formed and an air introduction pipe is connected to an air reservoir.

  The frictional resistance reduction device according to the present invention is configured to flow water from an inflow port sandwiched between a front edge of an input side plate and a front edge of an exterior plate to an outflow port sandwiched between a rear edge of the output side plate and a rear edge of the exterior plate. A passage gap narrower than the inflow port and the outflow port is provided in the middle of the path. As a result, the seawater that flows in from the inlet reduces the static pressure while increasing the flow velocity toward the passage gap, creates a negative pressure area near the rear end of the passage gap, and the suction gap facing the negative pressure area. To suck air into the negative pressure region. The air sucked into the seawater is released as bubbles along with the seawater from the outlet. The bubble generation mechanism is the same as that of the frictional resistance reduction device described in Patent Document 1.

  The input side plate has a front edge fixed to the bottom or side of the ship and is directly supported on the bottom or side of the ship. Further, the output side plate is fixed to the bottom or side of the ship, and is directly supported on the bottom or side of the ship. The input side plate and the output side plate are also indirectly supported on the ship bottom or the anchor side via the connection pillar or the connection plate by fixing the connection column or the connection plate to the ship bottom or the anchor side. The input side plate and the output side plate are bent plates or curved plates bent in the front-rear direction of the ship with the suction gap interposed therebetween, and can be configured as a first half portion and a second half portion with the suction gap interposed therebetween. In this case, since a portion where the input side plate and the output side plate are connected to each other remains, the suction gap is formed intermittently in the width direction of the ship.

  The exterior plate is supported on the ship bottom or the berth side via one or both of the input side plate and the output side plate connected by the connection pillar or the connection plate. As long as the connecting pillar does not hinder the flow of seawater, it does not matter in shape or inclination. The connecting plate extends the surface direction perpendicular to the exterior plate in the front-rear direction of the ship. The closing plate that closes the left and right ends of the air reservoir may be connected to the exterior plate to close the flowing water path from the inlet to the outlet. The air introduction pipe can be exemplified by a configuration in which the air passage extends from the deck through the ship bottom or the shore side and is connected to the air reservoir, or a configuration in which the deck is connected to the air reservoir along the shore side.

  As described above, the frictional resistance reduction device of the present invention can be installed only by (1) fixing the front edge of the input side plate and the rear edge of the output side plate to the ship bottom or the anchor side. In this case, the connecting pillar or connecting plate or closing plate may also be fixed to the ship bottom or the anchor side. In addition, (2) the air reservoir is formed continuously in the width direction of the ship, so if an air introduction pipe is connected to any part of the air reservoir, the air can be sent to the entire area of the air reservoir. A supply mechanism can be configured. (3) The suction gap is formed continuously in the width direction of the ship and communicates with the air reservoir throughout the area, so that a large amount of air can be sucked from a wide range in the width direction of the ship.

  The frictional resistance reduction device of the present invention can be configured by connecting, for example, an input side plate and an output side plate having a length corresponding to the width of a ship, and an exterior plate with a connection column or a connection plate. However, the work of fixing the front edge of the input side plate and the rear edge of the output side plate having a length corresponding to the width of the ship to the ship bottom is difficult. Therefore, the input side plate, the output side plate, and the exterior plate are divided in the width direction of the ship, and the unit in which one or both of the input side plate or the output side plate and the exterior plate are connected by the connecting pillar or the connection plate is arranged in the width direction of the ship. It is preferable to arrange the frictional resistance reduction devices side by side. Units that are small in the width direction of the ship are arranged on the bottom or side of the ship so that the air pools, suction gaps and passage gaps communicate with each other, and the front edge of each input side plate and the rear edge of the output side plate are By adhering to the heel side, the frictional resistance reducing device of the present invention is configured.

  The frictional resistance reduction device of the present invention simplifies the air supply configuration and generates more bubbles. The simplification of the air supply mechanism can be installed simply by fixing the front edge of the input side plate and the rear edge of the output side plate to the bottom or side of the ship, and it is possible to form a continuous air reservoir and suction gap in the width direction of the ship. It is an effect. The increase in the amount of bubbles generated is due to air being sucked into the negative pressure region from the entire suction gap formed continuously in the width direction of the ship.

  In addition to the effect of connecting the input side plate and the output side plate to the bottom or the side of the ship, the connecting column or connection plate that connects one or both of the input side plate or the output side plate and the exterior plate can be installed with a frictional resistance reduction device. In addition, the positional relationship among the input side plate, the output side plate, and the exterior plate is constrained to improve the mechanical strength of the frictional resistance reduction device. In addition, as a result of restraining the positional relationship between the left and right intermediate portions of the input side plate, the output side plate, and the exterior plate, the flow path from the inflow port to the outflow port through the passage gap is stabilized, and the function of adjusting the flow of seawater is also obtained. .

  Since the frictional resistance reduction device of the present invention configured by arranging units divided in the width direction of the ship can be individually fixed to the ship, the installation becomes easier. Further, the frictional resistance reduction device of the present invention configured by arranging units divided in the width direction of the ship has an advantage that the number of units can be increased or decreased according to the width of the ship. This means that if a large number of single-type units are made, a frictional resistance reduction device corresponding to a wide variety of ships can be configured, and the advantage of cost reduction by increasing the production of units can be obtained.

It is a right view showing an example of the cargo ship which installed the frictional resistance reduction apparatus of this invention. It is a bottom view showing the cargo ship of this example. It is a front view showing the cargo ship of this example. FIG. 4 is an enlarged view taken from an arrow X in FIG. 3. FIG. 5 is a cross-sectional view taken along a line YY in FIG. 4. It is a fragmentary perspective view of the frictional resistance reduction apparatus of this example. It is a perspective view of the unit which comprises the frictional resistance reduction apparatus of this example. It is a perspective view showing the installation relationship of the frictional resistance reduction apparatus of this example. It is a perspective view showing the installation relationship of the frictional resistance reduction apparatus of another example.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. As shown in FIGS. 1 to 3, for example, the frictional resistance reduction device 1 of the present invention includes a unit 2 in which an inlet 271 is directed forward in the traveling direction of the ship 4 and an outlet 272 is directed backward in the traveling direction of the ship 4. They are arranged on the ship bottom 41 in the width direction of the ship 4 and have a flat plate-like appearance. The frictional resistance reducing device 1 is preferably installed as close to the front of the ship 4 as possible for the purpose of reducing the frictional resistance of the surface in contact with the sea by bubbles released from the outlet 272. Are arranged side by side.

  The frictional resistance reduction device 1 of the present example has a single air introduction pipe 3 lowered from the deck of a ship 4 passing through a bottom 41 directly above the unit 2 disposed in the center of the left and right, and communicates with the units 2 side by side. Air is taken into the reservoir 26. The air inlet pipe 3 of this example is bent horizontally at the upper end and further provided with a funnel-shaped air inlet 32. The air inlet 32 may be fixed toward the front, which is the main traveling direction of the ship 4, or may be provided with a direction correcting device that follows the wind direction so that the direction can be changed as appropriate.

Frictional resistance reduction device 1, as seen in FIGS. 4 and 5, an input side plate 21 previous fixed edge 211 to the vessel bottom 41 inclined rearwardly of the vessel 4, inclined to the rear of the ship 4, after The output side plate 22 having the edge 222 fixed to the bottom 41, and both the input side plate 21 and the output side plate 22 are connected by the connection plate 25, and are parallel to the bottom 41 from the front edge 211 of the input side plate 21 to the rear edge 222 of the output side plate 22. And a closing plate 24 that closes the left and right ends of the air reservoir 26 surrounded by the ship bottom 41, the input side plate 21 and the output side plate 22. The air introduction pipe 3 is connected to the air reservoir 26.

  The frictional resistance reduction device 1 of the present invention has a passage gap 27 narrower than the inflow port 271 and the outflow port 272 in the middle of the flowing water path from the inflow port 271 to the outflow port 272. As a result, the seawater W that flows in from the inlet 271 decreases the static pressure while increasing the flow velocity toward the passage gap 27, and is negatively placed near the rear end of the passage gap 27 that has passed through the horizontal portion 213 of the input side plate 21. A pressure region is created, and air A is sucked into the negative pressure region from the suction gap 261 facing the negative pressure region. The air A sucked into the seawater W becomes bubbles B and is discharged together with the seawater W from the outlet 272 (see FIG. 5).

  The air A supply path includes an air introduction pipe 3, an air reservoir 26, and a suction gap 261. The air reservoir 26 is surrounded by the bottom 41, the input side plate 21 and the output side plate 22 arranged in the width direction of the ship 4, and the closing plate 24, and is formed continuously in the width direction of the ship 4, and air is introduced into the left and right center. Tube 3 is connected. The suction gap 261 is formed between the rear edge 212 of the input side plate 21 aligned in the width direction of the ship 4 and the front edge 221 of the output side plate 22, and is formed continuously in the width direction of the ship 4. As shown in FIG. 6, the air A supplied from the air introduction pipe 3 diffuses in the width direction of the ship 4 through the air reservoir 26 and is sucked into the seawater W from the entire suction gap 261.

  The frictional resistance reduction device 1 of this example is configured by arranging units 2 divided in the width direction of the ship 4 in the width direction. The unit 2 has a size in which the frictional resistance reduction device 1 is divided at the interval of the connection plate 25, and the input side plate 21 descends from the front edge 211 toward the rear edge 212 and from the front edge 221 toward the rear edge 222. An exterior plate that is connected to the output side plate 22 of the ascending slope and a pair of connection plates 25 sandwiching the input side plate 21 and the output side plate 22 and extends in parallel with the ship bottom 41 from the front edge 211 of the input side plate 21 to the rear edge 222 of the output side plate 22 It consists of 23.

  The input side plate 21 is composed of an inclined surface having a rectangular outer shape with a descending slope and a horizontal portion 213 having a rectangular outer shape extending horizontally from the rear edge of the inclined surface. The front edge 211 of the input side plate 21 is the front edge of the inclined surface. A rear edge 212 of the input side plate 21 is a rear edge of the horizontal portion 213. The output side plate 22 is composed only of an inclined surface having a square outer shape that is an upward slope. The front edge 211 of the output side plate 22 is a front edge of the inclined surface, and is positioned immediately above the rear edge of the input side plate 21 with the height of the suction gap 261 opened. The rear edge 212 of the output side plate 22 is a rear edge of the inclined surface.

  The connecting plate 25 is a rectangular vertical surface with the front edge 251 aligned with the front end of the horizontal portion 213 of the input side plate 21 and the rear edge 252 positioned about 1/4 of the front side of the output side plate 22. 213 and the front 1/4 of the output side plate 22 are sandwiched from the left and right. The connection plate 25 of this example connects the lower edge 254 to the exterior plate 23 and specifies the positional relationship among the input side plate 21, the output side plate 22, and the exterior plate 23. When attaching the unit 2 to the ship bottom 41, the connection plate 25 fixes the upper edge 253 to the ship bottom 41. The connecting plates 25 of the adjacent units 2 are brought into contact with each other.

  The exterior plate 23 is a square-shaped plate surface having a front edge 231 positioned immediately below the front edge 211 of the input side plate 21 and a rear edge 242 positioned directly below the rear edge 222 of the output side plate 22. The exterior plate 23 forms a passage gap 27 between the rear edge 212 of the input side 21. The passage gap 27 in this example is formed as a space having the length of the horizontal portion 213 because the rear edge 212 of the input side plate 23 is also the rear edge of the horizontal portion 213. The portion sandwiched between the front edge 211 of the input side plate 21 and the front edge 231 of the exterior plate 23 is the inlet 271, and the portion sandwiched between the rear edge 222 of the output side plate 22 and the rear edge 232 of the exterior plate 23 is the outlet. 272.

  The frictional resistance reduction device 1 of this example is configured as seen in FIG. 8, for example. The unit 2 is configured such that the side edges of the input side plate 21, the output side plate 22 and the exterior plate 23 are in contact with each other, the opposing connection plates 25 are in contact with each other and arranged on the ship bottom 41, the front edge 211 of each input side plate 21; The rear edge 222 of the output side plate 22 and the upper edge 251 of the connection plate 25 are fixed by welding. The adhesion of the front edge 211 of the force side plate 21 and the rear edge 222 of the output side plate 22 to the ship bottom 41 also serves to seal the air reservoir 26 in the longitudinal direction of the ship 4. The air reservoirs 26 of the units 2 arranged side by side are in communication with each other except for the connection plate 25, and are configured as an integral space.

  The air reservoir 26 closes the open end surface appearing in the unit 2 located at the left and right ends with the closing plate 24 so that the supplied air does not leak from the open end surface. In this example, the closing plate 24 includes a front edge 241 connecting the front end of the input side plate 21 (end portion of the front edge 211) and the front end of the exterior plate 23 (end portion of the front edge 231), and the rear end (rear end) of the output side plate 22. Edge 222) and the rear edge of the exterior plate 23 (the end of the rear edge 232), the upper edge 243 that connects the front end of the input side plate 21 and the front end of the exterior plate 23, and A square-shaped plate surface surrounded by a lower edge 244 connecting the front end of the exterior plate 23 and the rear end of the exterior plate 23 opens not only the air reservoir 26 but also the flow path of water flowing from the inlet 271 to the outlet 272. The end face is also closed.

  The air introduction pipe 3 only needs to be connected to the air reservoir 26. The air introduction pipe 3 of this example penetrates from the deck through the ship to the bottom 41 and is connected to the air reservoir 26 from directly above the center of the units 2 aligned in the width direction of the ship 4 (eighth from the left back in FIG. 8). . Since the air reservoir 26 extends in the width direction of the ship 4, for example, the air reservoir 26 may be connected from directly above the left end of the units 2 aligned in the width direction of the ship 4 (first in the back left in FIG. 8). There may be a plurality of air introduction pipes 3. In addition, although not shown, the air introduction pipe 3 may be disposed outside the ship along the side 42 and may be connected to the air reservoir 26 through the closing plate 24.

  Further, the air introduction pipe 3 of this example incorporates a check valve 31 in the vicinity of a connection portion with the air reservoir 26. The check valve 31 prevents seawater that enters through the air gap 26 from the suction gap 261 from entering the air introduction pipe 3 while the ship 4 is stopped or sails at low speed. Seawater that has entered the air reservoir 26 is sucked out of the suction gap 261 when the speed of the ship 4 increases and a negative pressure region is generated. If the intake port 32 is higher than the draft line, the air introduction pipe 3 does not allow seawater to overflow even without the check valve 31. However, after the negative pressure region is generated, it is desirable to dispose the check valve 31 at a position that limits the amount of seawater that enters in order to reduce the amount of seawater to be discharged and to suck air quickly.

  The frictional resistance reduction device 1 configured by arranging the units 2 in this way has an air reservoir 26 in which a partition plate is provided on a plate corresponding to the passage gap 27 and a flowing water path by the connection plate 25 of each unit 2. Form. In the flowing water path, the connection plate 25 as a partition plate exhibits a function of adjusting the flow of seawater. Further, since each of the connection plates 25 is fixed to the ship bottom 41, the positional relationship of the input side plate 21, the output side plate 22 and the exterior plate 23 with respect to the ship bottom 41 is fixed at equal intervals in the width direction of the ship 4. It also serves as a strength member to hold.

  The frictional resistance reduction device 1 configured by individually fixing the unit 2 to the ship bottom 41 has an object of facilitating the work of fixing the input side plate 21 and the output side plate 22 to the ship bottom 41. On the other hand, when it is not difficult to fix, as shown in FIG. 9, another example of friction from the input side plate 21, the output side plate 22, and the exterior plate 23, which are one plate surface extending in the width direction of the ship 4. The resistance reduction device 1 may be configured. The closing plate 24 is the same as the frictional resistance reducing device 1 of this example (see FIG. 8). In addition, the frictional resistance reduction device 1 of another example is provided with connection plates 25 at equal intervals in the width direction of the ship 4 in anticipation of rectification of seawater and a function as a strength member.

  The frictional resistance reduction device 1 of this example configured by arranging the units 2 can adopt a device configuration of an appropriate size for various ships 4 by adjusting the number of the units 2. Further, if the left and right open end faces are closed with the closing plate 24 by the unit 2 alone, there is an advantage that the minimum frictional resistance reduction device 1 can be configured. On the other hand, the frictional resistance reduction device 1 as another example from the input side plate 21, the output side plate 22, and the exterior plate 23 extending in the width direction of the ship 4 is adapted to each ship 4 when the units 2 are difficult to be arranged. There is an advantage that the length of the output side plate 22 and the exterior plate 23 can be determined or curved.

1 Friction resistance reduction device 2 units
21 Input side plate
22 Output side plate
23 Exterior plate
24 Closure plate
25 Connection board
26 Air pocket
261 Gap for suction
27 Passing gap 3 Air inlet pipe 4 Ship
41 Ship bottom
42 Mineral side W Seawater A Air B Bubble

Claims (2)

An input side plate that has a leading edge fixed to the bottom of the ship or the side of the ship and is inclined to the rear of the ship;
Inclined to the rear of the ship, and an output side plate which is fixed to the trailing edge to the ship's bottom or broadside,
An exterior plate that is connected to one or both of the input side plate or the output side plate by a connecting column or a connection plate, and extends in parallel with the ship bottom or the anchor side from the front edge of the input side plate to the rear edge of the output side plate;
Consists of a bottom plate or a berth side, an input side plate and a closing plate that closes the left and right ends of the air pocket surrounded by the output side plate,
The rear edge of the input side plate and the front edge of the output side plate form a suction gap,
Edge and the outer Soban to form a gap for passage after the input plate,
A frictional resistance reduction device in which an air introduction pipe is connected to an air reservoir. Divide the input side plate, output side plate, and exterior plate in the width direction of the ship, and configure a unit in which one or both of the input side plate or output side plate and the exterior plate are connected by a connecting pillar or connection plate in the width direction of the ship The frictional resistance reduction device according to claim 1.

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