JP2011251633A - Ship - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce hull resistance by preventing flow separation toward a bottom between skegs from a bottom further anterior to the skeg, concerning a ship having a plurality of skegs each supporting propeller shafts.SOLUTION: The ship 10 has the plurality of skegs 18a which is installed on a stern in a gunwale direction at intervals and each supports the propeller shafts 16a. The ship includes: an inflow port 19 installed on a bottom 30 facing to a stem side further than the skeg 18a; an exhaust port 20 installed on a bottom 41 between the skegs 18a; a flow passage 21 communicating between the inflow port 19 and the exhaust port 20; and a fluid deliverer 15 installed on the flow passage 21 and for delivering fluid toward the exhaust port 20, the fluid flowing into the flow passage 21 from the inflow port 19.

Description

  The present invention relates to a ship having a plurality of skeg portions that are provided at a stern portion at intervals in a ship's direction and support propeller shafts.

  In order to meet the demand for larger ships, the hull tends to be expanded in the width direction, that is, on the berth side, from the viewpoint of limiting the water depth of a port or the like. On the other hand, as the size of the ship increases, the propulsive force needs to be increased. However, the diameter of the propeller, which is a propulsion device, is affected by the water depth limitation and cannot be increased. Therefore, there is a problem that it is difficult to obtain a sufficient propulsive force for navigation of a large-sized ship with a single propeller.

  Therefore, in order to solve the above-described problems, a ship equipped with a plurality of propellers on a ship and provided with a plurality of skeg portions (bossing) to increase the amount of drainage is known.

  For example, as this type of ship, Patent Document 1 discloses a stern shape of a twin-screw twin skegg ship in which a pair of left and right skegs are provided with fins extending in a ship direction in order to reduce propeller vibration.

JP 2008-247322 A

  By the way, in a ship having a plurality of skeg portions such as a twin skeg ship, a tunnel-shaped ship bottom recess opened below the hull is formed by the plurality of skeg portions provided at the stern part. Therefore, at the time of navigation of the ship, for example, as shown in FIG. 4, the flow from the ship bottom 110 facing the front of the hull to the hull side, that is, the bow side, toward the tunnel-shaped ship bottom recess 120 as shown in FIG. The peeling causes a low-pressure part, and the low-pressure part may increase the hull resistance of the ship.

  SUMMARY OF THE INVENTION The present invention has been made in view of such problems, and an object of the present invention is to provide a ship having a plurality of skeg portions that are provided at the stern portion at intervals in the stern direction and each support a propeller shaft. Providing a ship capable of suppressing the generation of a low-pressure part and reducing hull resistance by preventing the flow toward the ship bottom between the skeg parts from the ship bottom facing the bow side from the ship. It is in.

  In order to achieve the above object, a ship according to the present invention is a ship having a plurality of skeg portions that are provided at the stern portion at intervals in the stern direction and each support a propeller shaft, and is located on the bow side of the skeg portion. An inflow port provided at the bottom of the ship facing the rim, a discharge port provided at the bottom of the ship between the skeg portions, a flow channel communicating the flow port and the discharge port, provided in the flow channel, Fluid delivery means for delivering fluid flowing into the flow path from the inlet toward the outlet is provided.

  Further, the discharge port may be provided facing a region where fluid separation occurs on the bow side of the bottom portion between the skeg portions.

  The opening area of the discharge port may be formed larger than the opening area of the inflow port, and the flow path may be formed so as to become narrower from the inflow port toward the discharge port.

  The fluid delivery means may increase the fluid delivery rate as the navigation speed of the ship increases.

  According to the ship of the present invention, in a ship having a plurality of skeg portions that are provided at the stern portion at intervals in the stern direction and respectively support the propeller shaft, the skeg from the bottom of the ship that faces the bow side of the skeg portion during navigation. It is possible to suppress the separation of the flow toward the ship bottom between the parts, thereby suppressing the generation of the low-pressure part and reducing the hull resistance.

It is typical sectional drawing which shows a part of principal part of the ship which concerns on one Embodiment of this invention. It is the typical figure which looked at the ship concerning one embodiment of the present invention from the stern side. It is a figure which shows the relationship between the navigation speed of the ship which concerns on one Embodiment of this invention, and the amount of fluid delivery. It is a side view which shows the ship which has the conventional several skeg part.

  Hereinafter, based on FIGS. 1-3, the ship which concerns on one Embodiment of this invention is demonstrated. The same parts are denoted by the same reference numerals, and their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  As shown in FIGS. 1 and 2, the ship 10 rotates with a hull 11, an engine 12 provided in the hull 11, a generator 13 that operates at the output of the engine 12, and electric power supplied from the generator 13. An electric motor 14 to be driven, a pump 15 connected to an output shaft 14a of the electric motor 14, a pair of left and right propeller shafts (propeller shafts) 16a and 16b, and propellers mounted on the rear ends of the propeller shafts 16a and 16b, respectively. 17a, 17b, a pair of left and right skeg portions 18a, 18b provided on the stern portion and supporting the propeller shafts 16a, 16b, an inlet (inlet) 19 for taking in seawater, fresh water, etc. (hereinafter referred to as fluid), A blowout port (discharge port) 20 that discharges fluid in the stern direction of the hull 11 and a fluid passage (flow path) 21 that connects the intake port 19 and the blowout port 20 are provided. It is configured. In FIG. 2, 17a and 17b indicate propeller circles.

  The engine 12 is a main engine for propulsion of the ship 10 and is operated by fuel supplied from a fuel tank (not shown). The output shaft (not shown) of the engine 12 is connected to the propeller shafts 16a and 16b.

  The generator 13 is operated by power extracted from an output shaft (not shown) of the engine 12 and supplies the generated AC power to the electric motor 14. That is, the generator 13 is configured to receive rotational energy from an output shaft (not shown) of the engine 12 and to convert the rotational energy into electrical energy and then supply the electrical motor 14 with the rotational energy. In the present embodiment, the generator 13 is described as operating with the power of the engine 12 as the main engine. However, for example, an auxiliary engine (not shown) for the generator 13 may be provided separately.

  The electric motor 14 is rotationally driven by AC power supplied from the generator 13 and transmits the rotational driving force to the pump 15 connected to the output shaft 14a. The rotational drive of the electric motor 14 is controlled by the motor drive control unit 22.

  An output signal is input to the motor drive control unit 22 from a navigation speed detection means (not shown) of the ship 10, and the navigation speed V of the ship 10 and the fluid delivery amount Q of the pump 15 that are created in advance through experiments or the like. A map (FIG. 3) showing the relationship is stored. In other words, the electric motor 14 is driven by AC power supplied from the generator 13 so as to output a rotational driving force in which the fluid delivery amount Q of the pump 15 gradually increases as the navigation speed V of the ship 10 increases. It is controlled by being adjusted by the drive control unit 22. In the present embodiment, the fluid delivery amount Q is described as being increased in proportion to the navigation speed V as shown in the map of FIG. 3. For example, the fluid delivery amount Q is increased by the navigation speed V. It can also be increased as a curve.

  As shown in FIG. 1, the pump 15 is interposed in a fluid passage 21 to be described in detail later. The pump 15 is provided with one or a plurality of impellers (not shown) connected to the output shaft 14a. By rotating the impeller, the fluid taken in from the suction port 15a is pressurized. Thus, it is configured to be sent out from the discharge port 15b. That is, the fluid flowing in the fluid passage 21 from the intake port 19 (arrow A in FIG. 1) is sent to the blowout port 20 by the pump 15 and discharged from the blowout port 20 in the stern direction of the hull 11 (arrow in FIG. 1). C).

  As shown in FIGS. 1 and 2, the pair of left and right skeg portions 18 a and 18 b are provided to extend downward at the stern portion of the ship 10 and are formed integrally with the hull 11. In the present embodiment, the protruding heights of the skeg portions 18a and 18b are set so that the lower end portions of the skeg portions 18a and 18b and the ship bottom portion 30 coincide with each other. Propeller shafts 16a and 16b are supported at intermediate positions in the height direction of the skeg portions 18a and 18b.

  As shown in FIG. 2, a tunnel-shaped ship bottom concave portion 40 opened below the hull 11 is formed between the skeg portions 18 a and 18 b. As shown in FIG. 1, the ceiling surface 41 of the ship bottom recess 40 (the ship bottom 41 between the skeg portions 18 a and 18 b) is formed so as to increase from the bow side to the stern side of the hull 11.

  As shown in FIG. 1, the intake port (inflow port) 19 is provided in the ship bottom portion 30 located on the bow side of the hull 11 with respect to the skeg portions 18 a and 18 b. Further, the intake port 19 has an opening surface formed in a rectangular shape, and is provided so that the longitudinal direction thereof coincides with the ship's direction. Moreover, the opening area of the inlet 19 is set larger than the opening area of the blower outlet 20 mentioned later. In the present embodiment, the intake 19 is provided at the stern side end of the ship bottom 30. For example, the intake 19 may be provided on the bow side of the ship bottom 30. In the case of being provided on the bow side, the length of the fluid passage 21 described later may be extended.

  As shown in FIGS. 1 and 2, the air outlet (discharge port) 20 is provided on the ceiling surface 41 of the ship bottom recess 40 (the ship bottom 41 between the skeg portions 18 a and 18 b). The air outlet 20 is provided so as to be positioned at the lower end portion of the ceiling surface 41 when the ship body 11 is viewed from the stern side, that is, when the hull 11 is viewed from the stern side. . Moreover, as shown in FIG. 2, the opening surface of the blower outlet 20 is formed in the rectangle, and it is provided so that a longitudinal direction may correspond with a ship's direction. In addition, as for the blower outlet 20, it is desirable to face the area | region where peeling of a fluid occurs. For example, when the depth from the LWL (planned flooding line) indicated by a two-dot chain line in FIG. 1 to the ship bottom 30 is 15 to 20 m, the opening center of the outlet 20 is at a height of 1 m from the ship bottom 30. It is provided so that it may be located.

  As shown in FIG. 1, the fluid passage (flow path) 21 is formed so as to communicate the intake port 19 and the air outlet 20, and a pump 15 is provided at a predetermined position. The fluid passage 21 is formed so as to narrow from the intake port 19 toward the blower port 20.

  With the configuration as described above, the ship 10 according to the embodiment of the present invention has the following operations and effects.

  When the ship 10 navigates, the electric motor 14 is rotationally driven by AC power supplied from the generator 13, and the rotational driving force of the electric motor 14 is transmitted to the pump 15. When the impeller of the pump 15 rotates, the fluid (arrow A in FIG. 1) flowing into the fluid passage 21 from the intake port 19 is pressurized in the pump 15 and sent to the outlet 20. Then, the fluid that has flowed from the pump 15 through the fluid passage 21 to the outlet 20 is discharged from the outlet 20 in the stern direction of the hull 11 as indicated by an arrow C in FIG.

  Therefore, the flow of fluid (arrow B in FIG. 1) from the ship bottom 30 toward the tunnel-shaped ship bottom recess 40 is separated by the flow (arrow C in FIG. 1) discharged from the outlet 20 in the stern direction of the hull 11. Since it is turned to the stern direction of the hull 11 without doing, generation | occurrence | production of the low voltage | pressure part in the stern part of the ship 10 can be suppressed, and hull resistance can also be reduced. As a matter of course, the reduction in the hull resistance can achieve a reduction in fuel consumption when sailing the ship 10.

  Moreover, since the blower outlet 20 is provided so that it may be located in the bow side front end of the ceiling surface 41, the fluid sent to the blower outlet 20 from the pump 15 is the blower outlet 20 as shown in FIG. To the vicinity of the rising portion of the tunnel-shaped ship bottom recess 40.

  Therefore, separation of the fluid flow (arrow B in FIG. 1) from the ship bottom 30 toward the tunnel-shaped ship bottom recess 40 can be effectively suppressed in the vicinity of the rising portion of the tunnel-shaped ship bottom recess 40. It is possible to reliably suppress the generation of the portion and to effectively reduce the hull resistance.

  Further, the opening area of the outlet 20 is formed smaller than the opening area of the inlet 19, and the fluid passage 21 is formed so as to become narrower from the inlet 19 toward the outlet 20. Then, the fluid to be delivered is further pressurized in the fluid passage 21 leading to the outlet 20 and is exhausted from the outlet 20 vigorously.

  Therefore, the separation of the flow of fluid (arrow B in FIG. 1) from the ship bottom 30 toward the tunnel-shaped ship bottom recess 40 is ensured by the flow of fluid (arrow C in FIG. 1) discharged vigorously from the outlet 20. This can be prevented and the hull resistance can also be reliably reduced. Naturally, the hull resistance can be surely reduced, so that it is possible to promote a reduction in fuel consumption during navigation of the ship 10.

  Further, the fluid delivery amount Q delivered from the pump 15 to the outlet 20 increases as the navigation speed V of the ship 10 increases.

  Therefore, an appropriate fluid delivery amount Q corresponding to the navigation speed V is discharged from the outlet 20 when the ship 10 is sailing, and unnecessary driving of the electric motor 14 and the pump 15 is omitted when the ship 10 is stopped. The fuel efficiency of the ship 10 can be more effectively promoted while reliably reducing the hull resistance.

  In addition, this invention is not limited to the above-mentioned embodiment, In the range which does not deviate from the meaning of this invention, it can change suitably and can implement.

  For example, in the above-described embodiment, the air outlet 20 has been described as being located at the fore side front end portion of the ceiling surface 41 of the bottom concave portion 40. However, the position of the air outlet 20 is determined between the bow side of the ceiling surface 41 and the stern. You may provide in the intermediate position with the side. Also in this case, generation | occurrence | production of a low voltage | pressure part can be suppressed and hull resistance can be reduced.

  Moreover, in the above-mentioned embodiment, although the inlet 19 and the blower outlet 20 were demonstrated as what has an opening surface formed in a rectangle, you may form this opening surface in a round shape or an ellipse, for example. Also in this case, the same effect as the above-described embodiment can be obtained. Moreover, you may provide the partition plate which changes the direction of a flow inside the blower outlet 20. FIG.

  Further, it is possible to provide a plurality of air outlets 20 in the direction of the ship and to provide the same number of pumps 15 so as to respectively correspond to the air outlets 20.

  Further, in the above-described embodiment, the electric motor 14 has been described as being rotationally driven by the AC power supplied from the generator 13, but for example, the DC power charged in a capacitor (not shown) provided in the hull 11 is used. The inverter may be configured to be converted into AC power and supplied. Also in this case, the same effect as the above-described embodiment can be obtained.

  Further, the ship 10 of the present invention is not limited to a twin skeg ship having a pair of skeg portions 18a and 18b, and can be applied to a ship having three or more skeg portions, for example.

10 Ship 15 Pump (fluid delivery means)
16a, 16b Propeller shaft (propeller shaft)
18a, 18b Skeg part
19 Inlet (Inlet)
20 Air outlet (discharge port)
21 Fluid passage (flow path)
30 Ship bottom (ship bottom facing the bow side from the skeg)
41 Ceiling surface (ship bottom between skegs)

Claims (4)

It is a ship having a plurality of skeg portions that are provided at intervals in the stern portion at a stern direction and support propeller shafts,
An inlet provided at the bottom of the ship facing the bow side of the skeg part,
A discharge port provided at the bottom of the ship between the skeg parts;
A flow path communicating the inlet and the outlet;
A ship provided with fluid delivery means provided in the channel and delivering fluid flowing into the channel from the inlet toward the outlet. The ship according to claim 1, wherein the discharge port is provided facing a region where fluid separation occurs on a side of a bow of a ship bottom between the skeg portions. The opening area of the outlet is formed larger than the opening area of the inlet,
The ship according to claim 1 or 2, wherein the channel is formed so as to become narrower from the inlet to the outlet. The ship according to any one of claims 1 to 3, wherein the fluid delivery means increases the delivery amount of the fluid as the navigation speed of the ship increases.

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