JP2022014381A - Vessel - Google Patents

Abstract

To provide a vessel capable of improving propulsion performance while securing the number of load weight tons in a small domestic vessel.SOLUTION: A vessel 1 has the distance from a third partition wall 403 on a stern end side of an engine room 6 to stern perpendicular AP be approximately within 5% of the total length of a hull 101 and the distance from the stern perpendicular AP to the stern rear end in planned draft line Td to be within approximately 2% of the whole length of the hull. In addition, an expanding unit 12 having hull outer plates 105a, 105b of the hull 101 expanding outward from the hull 101 is formed so that the width of a gap 7 formed by right and left side walls 404a, 404b partitioning a cargo hold 5 and hull outer plates 105a, 105b of the hull 101 is partially wide over a prescribed range in the stern direction from a bow perpendicular FP of the hull 101.SELECTED DRAWING: Figure 1

Description

The present invention relates to a ship. More specifically, it relates to a small coastal vessel that can improve propulsion performance while ensuring a deadweight tonnage.

The tonnage that represents the size of a ship includes gross tonnage, deadweight tonnage, displacement tonnage, etc. Of these, the total volume inside the hull is used as the basis for calculating ship registration tax, port entry fee, etc. Is the "gross register tonnage" converted into tonnage by the legal formula. The ship-related law stipulates that the tax amount will increase each time the gross tonnage exceeds a predetermined gross tonnage such as 200 tons, 500 tons, and 750 tons.

In addition, Article 5, Paragraph 3 of the Law Concerning the Measurement of Tonnage of Vessels stipulates the calculation of the gross tonnage for double-deck vessels having a second deck below the upper deck, and is given preferential treatment over single-layer vessels. ing. In addition, the equipment required by the equipment regulations of the ship is different with the total ton number as a delimiter of 750 tons, and the double-layer deck ship with the total ton number less than 750 tons is widely adopted as a ship that can be economically constructed, and related technology. Has been published in large numbers (Patent Document 1 and Patent Document 2).

Japanese Unexamined Patent Publication No. 11-348892 Japanese Unexamined Patent Publication No. 2000-289687

By the way, due to the rise in fuel costs and the growing awareness of global warming in recent years, there is a demand for the development of fuel-efficient ships with low resistance during navigation. Here, resistances that hinder the navigation of ships include wave-making resistance, viscous resistance due to friction with water and vortices, and air resistance. Of these, wave-making resistance is mainly influenced by the bow shape, and viscous resistance is mainly influenced by the stern shape. In addition, propulsion performance other than resistance is mainly affected by the stern shape.

Therefore, when designing a fuel-efficient ship, it is necessary to fully consider the bow shape and stern shape, as well as the volume distribution between the central part, the bow part, and the stern part, which are important for securing the cargo capacity. Although it changes in a complicated manner due to various factors, in general, when the total length (Lоa) and total width (B) of the hull are taken, the smaller the Lоa / B and the faster the cruising speed with respect to the captain, the higher the wave-making resistance. It tends to grow.

In this regard, for example, in the above-mentioned small vessel having a total ton number of less than 750 tons, the sailing speed with respect to the captain is faster than that of the large vessel, so that the wave-making resistance during navigation inevitably increases and the fuel consumption per required horsepower is increased. It will be a large quantity ship. Further, in coastal vessels, it is necessary to secure a cargo area as much as possible for the purpose of improving transportation efficiency, so that the value of Lоa / B is smaller and the wave-making resistance is larger than that of large vessels.

On the other hand, in order to reduce the environmental load while ensuring the efficiency and economy of transportation, it is sufficient to suppress the decrease in the deadweight tonnage and then improve the propulsion performance of the hull. To achieve this, the hull should be made slender by making it longer than the width of the hull, but the gross tonnage is not the actual weight but the volume inside the hull calculated by a predetermined formula, so the hull is slender. If it is set to, the deadweight tonnage becomes small and the transportation rationality decreases.

Therefore, in a small vessel having a gross tonnage of less than 750 tons, it is desired to develop a fuel-efficient vessel capable of suppressing wave-making resistance during navigation while ensuring a deadweight tonnage.

The present invention has been devised in view of the above points, and an object of the present invention is to provide a vessel capable of improving propulsion performance while ensuring a deadweight tonnage in a small coastal vessel. It is a thing.

In order to achieve the above object, the ship of the present invention has a hull, a first partition wall on the nose side of the center of the hull and extending in the width direction of the hull, and a stern side of the first partition wall. A second partition extending in the width direction of the ship, a cargo hold partitioned by a pair of side walls, and the second partition, which is on the stern side of the second partition and extends in the width direction of the ship. It is partitioned by a third partition wall and the pair of side walls, and is installed at a position where the distance between the engine room where the main engine is installed and the stern vertical line from the third partition wall is within approximately 5% of the total length of the hull. It includes a steering wheel, a propeller installed so as to substantially coincide with the stern vertical line of the steering wheel, and a propeller shaft that transmits the output of the main engine to the propeller.

Here, by providing a cargo hold divided by a first partition wall, a second partition wall, and a pair of side walls, a cargo hold consisting of a certain space is formed inside the ship, and a load amount corresponding to the total tonnage of the ship is provided. The tonnage can be secured.

Further, by providing a second partition wall, a third partition wall, and an engine room partitioned by the side wall on the stern side of the cargo hold, a main engine serving as a power source can be installed in the engine room. The main engine serving as a power source is composed of, for example, a diesel internal combustion engine, and can transmit the reciprocating motion of the internal combustion engine to the propeller via the propeller shaft described later.

Further, by providing a rudder installed at a position where the distance from the third bulkhead to the stern vertical line is within about 5% of the total length of the hull, the third bulkhead which is the stern side bulkhead for partitioning the engine room is provided. Can be located on the stern side compared to conventional ships.

This makes it possible to move the entire engine room and cargo hold to the stern side without changing the volume of the engine room and cargo hold as compared with a conventional ship. Furthermore, since it is not necessary to secure the volume of the cargo hold on the bow side, the degree of freedom in shape is increased, and the water line surface shape from both sides of the ship to the bow end is narrower than that of conventional ships. , Can be made into a sharper shape. Therefore, it is possible to reduce the wave-making resistance and improve the propulsion performance by reducing the displacement on the bow side of the hull and suppressing the wave-making generated from the bow.

In addition, by providing a propeller installed so as to substantially coincide with the stern line of the rudder, the hull can be moved forward and backward by the propulsive force of the propeller.

At this time, since the propeller is installed so as to substantially coincide with the stern vertical line of the rudder, the propeller is installed at a predetermined position between the bow side edge and the stern side edge of the rudder in the side view of the hull. Therefore, as described above, the distance from the third bulkhead to the stern vertical line can be shortened, and the engine room can be laid out on the stern side.

Further, by providing a propeller shaft that transmits the output of the main engine to the propeller, as described above, the reciprocating motion of the internal combustion engine that is the main engine can be converted into a rotational force, and the rotational force can be transmitted to the propeller that is the propulsion device. can.

In addition, the hull has an upper deck and a second deck, and a gap of a predetermined width is formed from the bottom of the hull to the upper deck between the left and right side walls of the cargo hold and the side walls of both the left and right sides of the hull. If so, a gap can be formed through which workers can pass in a so-called "two-deck deck ship" consisting of an upper deck and a second deck.

In addition, the hull outer panels on both starboard and starboard sides have a predetermined range in the vertical direction with the second deck as the base point, and are approximately 15% to 35% of the total length of the hull in the stern direction from the bow hanging line of the hull. If a bulge that bulges toward the outside of the hull is formed so that the width of the gap is predeterminedly wide over the range, the shape is sharp toward the bow end, while the gap is formed. It is possible to secure the minimum width for ensuring the passage of workers.

That is, in a double-deck ship, the minimum width of the gap between the side wall of the cargo hold and the outer panel of the hull is defined so that workers can pass through. As described above, if the bow shape is a sharp shape with a narrow beam width, a narrow gap portion that cannot partially satisfy this minimum width may be formed. In this respect, a bulge is formed in the vicinity of the height position of the second deck in a range of about 15% to 35% of the total length of the hull in the stern direction from the bow vertical line where the gap is narrow. As a result, the minimum width that workers can pass through can be secured.

In addition, on the water line surface on the second deck, the angle between the position of the water line on the stern side and the end of the bow, which is approximately 2.5% of the length between the bow and the line, and the angle between the lines passing through the center of the hull. When is in the range of about 10 to 15 degrees, by arranging the engine room and the cargo hull on the stern side as a whole, the water line surface is narrower and sharper than that of a conventional ship. Can be shaped. As a result, as described above, it is possible to reduce the displacement on the bow side of the hull and suppress the wave-making generated from the bow, thereby reducing the wave-making resistance and improving the propulsion performance.

Further, when the distance from the stern vertical line to the rear end of the stern in the planned draft is within about 2% of the total length of the hull, the overhang on the stern side in the planned draft can be shortened. Therefore, since the volume of the stern end under the water surface can be increased, a larger load amount can be secured.

If the rudder has a substantially cylindrical shape installed so as to house the propeller around the axis of the propeller, the installation position of the propeller and the rudder in the stern direction shall be approximately the same by the duct type rudder. Therefore, the engine room can be arranged on the stern side, and the overhang on the stern side in the planned draft can be shortened. In addition, the duct type can produce a rectifying effect on the stern flow, and the reduced flow can increase the rotational efficiency of the propeller and improve the propulsion performance.

Further, the rudder consists of a pair of rudders, and when the rudder is arranged on the side of the propeller, the installation position of the propeller and the rudder in the stern direction is substantially the same by the gate type rudder. As a result, the engine room can be arranged on the stern side, and the overhang on the stern side in the planned draft can be shortened. In addition, the gate type can produce a rectifying effect on the stern flow, and the reduced flow can increase the rotational efficiency of the propeller and improve the propulsion performance. Furthermore, at low speeds, the direction of the water flow of the propeller is changed to function as a thruster, so that the offshore and berthing performance can be improved.

The vessel according to the present invention is a small coastal vessel capable of improving propulsion performance while ensuring a deadweight tonnage.

It is a side view of the ship which concerns on embodiment of this invention. It is a front sectional view near the center of the hull of the ship which concerns on embodiment of this invention. It is an enlarged view of the stern side of the ship which concerns on embodiment of this invention. It is a front enlarged view of the propeller and the rudder of the ship which concerns on embodiment of this invention. It is an enlarged view of the stern side of a conventional ship. It is a comparison diagram of the horizontal cross-sectional line of the target ship and the comparison ship. It is a graph which shows the resistance increase in the wave of a ship. It is a graph which shows the required horsepower of a target ship and a comparison ship. It is a hull front view of the target ship.

Hereinafter, embodiments of the present invention will be described with reference to the drawings for the purpose of understanding the present invention. For convenience of explanation in each figure, the direction connecting the bow and the stern of the hull is the direction of the stern, and the direction orthogonal to the stern direction in the plan view is orthogonal to both the width direction, the stern direction, and the width direction. The direction of movement is called the vertical direction. In the stern direction, the bow side is called the front side, and the stern side is called the rear side. Further, in the width direction of the ship, the direction facing the outside of the hull is called the outside, and the direction facing the inside of the hull is called the inside.

First, the ship 1 according to the embodiment of the present invention will be described with reference to FIGS. 1 to 3. The hull 101 of the ship 1 assumed in the embodiment of the present invention has a total length (Loa) of 85 m or less, a ship width (B) of 15 m or less, and a planned draft (Td) of 6 m or less, and is located on the upper deck 102 and its lower layer. It is a double-deck ship with a second deck 103 and a total ton number of less than 750 tons. Note that Lpp in FIG. 1 indicates the length between perpendiculars of the bow vertical line FP and the stern vertical line AP.

Vessel 1 has a first partition wall 401 which is a partition wall 4 on the bow end side in the hull 101, a second partition wall 402 rearward from the center in the bow stern direction, and a stern rearward from the second partition wall 402. It is provided with a third partition wall 403 on the end side. The cargo hold 5 is partitioned by the first partition wall 401, the second partition wall 402, and the left and right side walls 404a and 404b, and the engine room is formed by the second partition wall 402, the third partition wall 403, and the left and right side walls 404a and 404b. 6 is formed in a section.

The left and right side walls 404a and 404b of the cargo hold 5 extend from the inner bottom plate 104 to the upper part of the upper deck 102, and are predetermined between the side walls 404a and 404b and the port and starboard outer plates 105a and 105b of the hull 101. It has a "double hull structure" in which voids 7 are formed. Further, the space sandwiched between the hull bottom plate 106 and the inner bottom plate 104, and the space below the second deck 103 and sandwiched between the hull outer plates 105a and 105b and the side walls 404a and 404b are allocated to the seawater ballast tank. Be done.

Here, the cargo hold 5 does not necessarily have to be partitioned by the first partition wall 401 and the second partition wall 402. A partition wall may be further provided between the first partition wall 401 and the second partition wall 402 to divide the cargo hold 5 into small sections.

Further, it is not always necessary that the cargo hold 5 and the engine room 6 are continuously formed with the second partition wall 402 as the partition wall. For example, a predetermined space may be formed between the cargo hold 5 and the engine room 6.

The engine room 6 houses a diesel engine as a main engine 8 that is a power source of the ship 1, a fuel tank (not shown) for supplying fuel to the diesel engine, and the like. When an electric motor is adopted as the main engine 8, a generator or the like related to the electric motor can be installed.

A propeller 10 is installed behind the engine room 6 via a propeller shaft 9. The reciprocating motion of the diesel engine as the main engine 8 is converted into rotary motion by the propeller shaft 9 and transmitted to the propeller 10. In this way, the propulsive force for moving the hull 101 back and forth can be obtained by the rotational force of the propeller 10 rotating via the propeller shaft 9.

A duct-type rudder 11 is installed around the propeller 10 so as to interior the entire propeller 10. The rudder 11 does not have to be a duct type, and the type of rudder is not particularly limited as long as the rudder 11 is laid out on the side surface of the propeller 10. For example, a gate-type rudder composed of a pair of rudders as shown in FIG. 4 may be installed on both the left and right sides when the propeller 10 is viewed from the front.

FIG. 5 shows the stern structure of the conventional ship 1 corresponding to FIG. 3 for comparison with the stern shape of the ship 1 according to the embodiment of the present invention. In the following description, the ship according to the embodiment of the present invention is defined as a “target ship”, and the conventional ship is defined as a “comparison ship”. In addition, the main specifications such as the total length, width, and planned draft of the comparison ship shall be the same as those of the target ship.

In a conventional ship, as shown in FIG. 5, the rudder 11 is arranged on the stern side of the propeller 10, so when the total length Loa is considered to be the same as the target ship, the partition wall on the stern side of the engine room 6 (the first). The distance l _ER2 between the partition wall 403) of 3 and the stern vertical line AP is inevitably long. Therefore, in order to secure a constant volume of the cargo hold 5 partitioned on the bow side of the engine room 6, the first bulkhead 401 (not shown), which is the bulkhead on the bow side of the cargo hold 5, is placed near the bow end. Need to be placed.

On the other hand, in the target ship, since the rudder 11 is arranged on the side surface of the propeller 10, the entire engine room 6 can be arranged behind the comparison ship while the volume of the engine room 6 remains the same. Therefore, the distance l _ER1 between the third bulkhead 403, which is the bulkhead on the stern side of the engine room 6, and the stern vertical line AP can be shortened as compared with the comparative ship (l _ER1 <l _ER2 ).

In the target ship, the distance between the third partition wall 403 and the stern vertical line AP is 4 m with respect to the total length of 85 m. That is, by adopting the layout of the rudder 11 and the propeller 10 of the target ship, the distance l _ER1 between the third partition wall 403 and the stern vertical line AP with respect to the total length Loa can be suppressed to within about 5% in the target ship. In this respect, in the comparative ship, the distance l _ER2 between the third partition wall 403 and the stern vertical line AP with respect to the total length Loa is about 6 to 7%.

As described above, in the target ship, the position of the engine room 6 can be moved toward the stern direction from the comparison ship while maintaining the volume of the engine room 6. Then, as the engine room 6 moves to the stern side, the cargo hold 5 partitioned in front of the engine room 6 can also move backward as a whole while keeping the volume constant.

In this way, if the cargo ship 5 of the target ship can be moved backward compared to the cargo ship 5 of the comparison ship, the first bulkhead 401, which is the partition wall on the bow side that divides the cargo ship 5, also moves backward. can do. Therefore, the shape of the bow side is less likely to be affected by the cargo hold 5, and the degree of freedom in design can be increased.

Further, in the target ship, since the distance l _ER1 between the third partition wall 403 and the stern hanging line AP with respect to the total length Loa can be shortened, the distance from the stern hanging line AP to the rear end of the stern at the planned draft Td (stern overhang l). _AE1 ) can also be shortened (target ship is approximately 2m). When the stern overhang l _AE1 is shortened, the volume of the stern end below the water surface can be increased, so that a larger load can be secured. In the embodiment of the present invention, the stern overhang l _AE1 with respect to the total length Loa of the target ship can be suppressed to within about 2%.

Next, the bow shapes of the target ship and the comparison ship will be compared. FIG. 6 is a diagram showing a comparison between the horizontal cross-sectional lines of the bow shape of the target ship and the comparison ship at the height position of the second deck 103 (the horizontal cross-sectional line of the target ship is the solid line S1 and the horizontal cross section of the comparison ship). The line is indicated by the broken line S2).

As described above, in the target ship, since the first bulkhead 401 can be moved to the rear of the position of the comparison ship, as shown in FIG. 6, the sharpness with a short beam width from both sides of the ship to the bow end. Can be shaped like this. On the other hand, in the comparative ship, in order to secure a constant volume of the cargo hold 5, the first partition body 401 is located closer to the bow end than the target ship, so that water from both sides of the ship to the bow end. The line surface shape is a shape that projects to the outside of the hull (in FIG. 6, only the cargo bow 5 of the target ship is shown).

In addition, on the water line surface on the second deck 103 of the target ship and the comparison ship, the position of the water line approximately 2.5% behind the perpendicular length Lpp from the bow vertical line FP, the line connecting the bow end, and the hull center. When the angle formed by the line passing through the ship is measured, the target ship is in the range of θ1 = about 10 to 15 degrees, and the comparison ship is in the range of θ2 = about 20 to 25 degrees. That is, since the target ship can have a sharp bow shape with a shorter bow width than the comparative ship, it is possible to reduce the displacement on the bow side and suppress the wave-making resistance Rw. can.

Here, as a general definition, the total resistance Rt that a ship receives from water is expressed as the sum of the resistance R in plain water and the resistance increase Raw in waves. Further, the resistance in plain water is the sum of the wave-making resistance Rw and the viscous resistance Rv. That is, Rt = R + Raw and R = Rw + Rv.

Further, the viscous resistance Rv is the frictional resistance Rf of a flat plate (equivalent flat plate) having the same area as the hull, and the resistance such as a vortex generated by the viscosity due to the hull having a bulge, as K · Rf using the shape influence coefficient K. It can be expressed as Rv = Rf (1 + K).

As shown in FIG. 7, it is known that these components change depending on the ratio of the wavelength λ of the wave and the length between perpendiculars Lpp. In the wave resistance increase Raw (0) based on the hull motion, λ / Lpp at which the wavelength λ and the perpendicular length Lpp almost coincide with each other becomes the largest near 1. From this, the increase in resistance decreases regardless of the length of the wavelength. On the other hand, the resistance increase Raw (1) based on the reflected wave from the bow increases as the wavelength λ becomes shorter and decreases as the wavelength λ becomes longer. Therefore, when λ / Lpp is around 1, the resistance increase due to this component is almost the same. Does not occur.

From the above, in the target ship, the wave-making resistance Rw on the bow side decreases, but the displacement on the stern side increases, so the viscous resistance Rv and the shape influence coefficient K increase. However, in the target ship, when the displacement is moved to the stern side to this extent, the reduction of the wave-making resistance Rw is larger, so that the total resistance Rt is considered to be reduced.

More specifically, by making the shape of the bow end sharp, the incident angle of the water line at the bow end at the planned draft Td is reduced by reducing the displacement, and the resistance increase Raw during waves is reduced. Can be done. The smaller the waterline incident angle at the bow end, the smaller the resistance increase Raw (0) based on the hull motion and the resistance increase Raw (1) due to the reflection of the wave by the hull. When the increase in resistance during waves becomes small, the fuel consumption during operation decreases.

Furthermore, the propulsion efficiency changes by moving the displacement on the bow side to the stern side. Here, the propulsion efficiency η ^D is composed of the propeller efficiency η ^o , the propeller efficiency ratio η ^r obtained from the water tank test using the model ship, the thrust reduction coefficient 1-t, and the wake-up coefficient 1-w. It is expressed as.
η ^D = η ^о・ η ^r・ (1-t) / (1-w)
The required horsepower PD at a ship speed of V (m / s) can be expressed as the following equation.
PD = R _t · V / η ^D

Based on the above, FIG. 8 shows the results estimated from the results of the water tank test by the model ship for the required horsepower of the target ship and the comparison ship. As is clear from the results of FIG. 8, since the target ship can run at the same speed as the comparison ship with less horsepower, it can be seen that the target ship has improved running performance as compared with the comparison ship. ..

In the case of a two-deck ship, the side walls 404a and 404b of the cargo hold 5 and the outside of the hull are located near the height position of the second deck 103 and near the first partition 401, which is the partition on the bow side. The minimum width of the gap for the purpose of allowing workers to pass between the plates 105a and 105b is determined to be one frame interval.

On the other hand, if the bow shape from both sides of the hull 101 to the bow is a sharp shape with a short beam width and a narrowed tip like the target ship, the above-mentioned minimum width may not be secured. Therefore, as shown in FIG. 9, the target ship has a height of about 2 m in the upward direction and about 1.5 m in the downward direction with the second deck 103 as the base point, and is in the stern direction from the bow hanging line FP. A bulging portion 12 is formed in which the hull outer plates 105a and 105b partially bulge outward from the hull over a range of about 15% to 35% of the total length Loa of the hull 101.

With the bulging portion 12, the width of the gap 7 of the second deck 103 of the target ship can secure the above-mentioned minimum width. The bulging portion 12 has a shape that partially bulges in the front cross-sectional line of the target ship, but as shown in FIG. 6, it has a smooth curve in the horizontal cross-sectional line, so that it has resistance during ship running. It has a shape that does not have a large effect on.

As described above, the vessel according to the present invention can improve the propulsion performance of a small coastal vessel while ensuring the deadweight tonnage.

1 Ship 101 Hull 102 Upper deck 103 Second deck 104 Inner bottom plate 105a, 105b Hull outer plate 106 Hull bottom plate 4 Partition 401 First partition 402 Second partition 403 Third partition 404a, 404b Side wall 5 Cargo rudder 6 engine Room 7 Void 8 Main engine 9 Propeller shaft 10 Propeller 11 Rudder 12 Swelling part

Claims (6)

With the hull,
A first bulkhead that is on the bow side of the center of the hull and extends in the width direction of the hull, a second bulkhead that is on the stern side of the first bulkhead and extends in the width direction of the hull, and a pair of side walls. With the compartmentalized cargo hull,
The second partition wall, the third partition wall on the stern side of the second partition wall and extending in the width direction of the ship, and the engine room partitioned by the pair of side walls and where the main engine is installed.
A rudder installed at a position where the distance from the third bulkhead to the stern vertical line is within approximately 5% of the total length of the hull.
A propeller installed so as to substantially coincide with the stern line of the rudder,
A ship comprising a propeller shaft that transmits the output of the main engine to the propeller. The hull has an upper deck and a second deck.
A gap having a predetermined width is formed between the side wall of the cargo hold and the hull outer plates on both the starboard and starboard sides of the hull from the bottom of the hull to the upper deck.
The hull outer plates on both the left and right sides of the hull are within a predetermined range in the vertical direction with the second deck as the base point, and are approximately 15% of the total length of the hull in the stern direction from the bow hanging line of the hull. The ship according to claim 1, wherein a bulge portion that bulges toward the outside of the hull is formed so that the width of the gap is predeterminedly wide over a range of a length of 35%. On the water line surface on the second deck, a line segment connecting the position of the water line approximately 2.5% behind the length between perpendiculars of the hull and the bow end, and a line segment passing through the center of the hull. The vessel according to claim 2, wherein the angle is in the range of approximately 10 to 15 degrees. The ship according to any one of claims 1 to 3, wherein the distance from the stern vertical line to the rear end of the stern on the planned waterline is within approximately 2% of the total length of the hull. The ship according to any one of claims 1 to 4, wherein the rudder has a substantially cylindrical shape installed so as to incorporate the propeller around the axis of the propeller. The ship according to any one of claims 1 to 4, wherein the rudder is composed of a pair of rudders and the rudders are arranged on the side of a propeller.

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