Ships

Abstract

To reduce an in-wave resistance increase without increasing smooth underwater resistance in a vessel.SOLUTION: A vessel includes a pitch suppressing member provided in a vessel longitudinal direction more above in a height direction than a water surface rising position in smooth underwater navigation on a bow side in a port side and a starboard side of a hull and the pitch suppressing member has a portion arranged separated from the surface of the hull.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to marine vessels. [Background technology]

[0002] In the ocean, waves that are a mixture of wind waves and swells occur. The waves cause the bow of a ship sailing on the ocean to pitch up and down, increasing its navigation resistance. Conventionally, technologies for reducing the increase in navigation resistance of a ship when waves are occurring include those described in, for example, the following patent documents. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4889238 [Patent Document 2] Patent No. 5103687 [Patent Document 3] Japanese Patent Application Laid-Open No. 2001-247075 Summary of the Invention [Problem to be solved by the invention]

[0004] As mentioned above, one technique for reducing the increase in navigation resistance of a ship in calm water is to provide horizontal plate members along the length of the ship on both sides of the bow of the hull. However, there is a demand for further reduction in the increase in navigation resistance of a ship in rough waves.

[0005] The present disclosure is intended to solve the above-mentioned problems, and aims to provide a vessel that can reduce the increase in resistance in waves without increasing resistance in calm water. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the ship of the present disclosure has pitching suppression members provided on the bow sides of the port and starboard sides of the hull, along the length of the ship, at a height above the water surface rise position when sailing in calm water, and a portion of the pitching suppression member is positioned away from the surface of the hull. [Effects of the Invention]

[0007] According to the vessel of the present disclosure, the increase in resistance in waves can be reduced without increasing resistance in calm water. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic side view showing a ship according to the present embodiment. [Figure 2] FIG. 2 is a schematic plan view showing the bow of a ship. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5] FIG. 5 is a cross-sectional view showing a modified example of the pitching suppression member. [Figure 6] FIG. 6 is a side view showing the bow of a ship for explaining the function of the pitching suppressing member. DETAILED DESCRIPTION OF THE INVENTION

[0009] Preferred embodiments of the present disclosure will be described in detail below with reference to the drawings. Note that the present disclosure is not limited to these embodiments, and when there are multiple embodiments, the present disclosure also includes configurations that combine the embodiments. Furthermore, the components in the embodiments include those that can be easily imagined by a person skilled in the art, those that are substantially identical, and those that are within the so-called equivalent range.

[0010] <Ship> 1 is a schematic side view illustrating a ship according to an embodiment of the present invention.

[0011] The ship in this embodiment is preferably a high-speed vessel that travels at high speed, but may be any other type of ship, such as a patrol boat, a passenger ship (including a car ferry), a car carrier, a container ship, a bulk carrier, a very large oil tanker (VLCC, ULCC), an LNG carrier, or an LPG carrier.

[0012] As shown in Figure 1, the ship 10 has a hull 11. The hull 11 has a bow 12, a stern 13, a bottom 14, a port side 15, and a starboard side 16. In the following explanation, the fore-and-aft direction of the hull 11 will be referred to as the ship's length direction X, the left-right direction of the hull 11 as the ship's width direction Y, and the up-and-down direction of the hull 11 as the ship's height direction Z. In addition, the center position of the hull 11 in the ship's width direction Y will be referred to as the centerline CL, and the waterline indicating the loading limit of the hull 11 will be referred to as the load waterline WL.

[0013] The hull 11 is partitioned by a bulkhead 21 on the stern 13 side into an engine room 22, and a main engine (e.g., a diesel engine) 23 is disposed in the engine room 22. The main engine 23 has a propeller 25 connected to an output shaft 24 extending rearward in the longitudinal direction X of the ship. The propeller 25 is driven to rotate by the main engine 23, thereby obtaining propulsive force for the hull 11. Note that in this embodiment, the propulsion device is the main engine 23, the output shaft 24, the propeller 25, etc., but is not limited to this configuration and may be, for example, a water jet.

[0014] The hull 11 is provided with a rudder drive device 26 at the stern 13. In the rudder drive device 26, a rudder 28 is connected to a rudder stock 27 extending downward in the ship height direction Z. The rudder 28 is rotated by the rudder drive device 26, and the direction of travel of the hull 11 can be controlled.

[0015] The hull 11 is provided with a bulb (bulbous bow) 29 at the bottom of the bow 12. The bulb 29 can reduce the wave-making resistance of the hull 11. The bulb 29 is provided below the load waterline WL. However, the hull 11 does not necessarily need to be provided with a bulb 29.

[0016] Additionally, the hull 11 is provided with a pitching suppression member 30 on the bow 12 side. The pitching suppression member 30 has a V-shape in plan view and is provided so as to extend from the bow 12 toward the port side 15 and starboard side 16. The bow 12 of the hull 11 and the pitching suppression member 30 are symmetrical with respect to the centerline CL.

[0017] <Configuration of pitching suppression member> 2 is a schematic plan view showing the bow of the ship, FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2, FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 2, and FIG. 5 is a cross-sectional view showing a modified example of a pitching suppression member.

[0018] 1 to 4, the pitching suppression members 30 are provided on the port side 15 and starboard side 16 of the hull 11, on the bow 12 side, above the load waterline WL in the ship height direction Z and along the ship length direction X. Specifically, the pitching suppression members 30 are positioned higher than the rising water surface that occurs when the ship 10 is sailing in calm water, i.e., a waveless state, at a navigation speed set at the time of design, which is a typical speed of the ship 10.

[0019] The pitching suppression member 30 has a V-shape in plan view (see FIG. 2). One end of the pitching suppression member 30 in the longitudinal direction X is fixed to the bow 12, the other end in the longitudinal direction X is fixed to the surface 11a of the hull 11, and the middle part in the longitudinal direction X is spaced apart from the surface 11a of the hull 11.

[0020] That is, the pitching suppression member 30 has a port side member 31 arranged on the port side 15 side and a starboard side member 32 arranged on the starboard side 16 side, and one end 31a of the port side member 31 and one end 32a of the starboard side member 32 are connected by a connecting part 33 so as to form a V shape. The pitching suppression member 30 has one end in the longitudinal direction X, that is, the connecting part 33, fixed to the bow 12 by a first support member 34.

[0021] In addition, the other end 31b of the port-side member 31 in the longitudinal direction X of the pitching suppression member 30 is fixed directly to the surface 11a of the hull 11 on the port side 15, and an intermediate portion of the port-side member 31 in the longitudinal direction X is fixed to the surface 11a of the hull 11 on the port side 15 by a second support member 35. In the pitching suppression member 30, the other end 32b of the starboard-side member 32 in the longitudinal direction X is fixed directly to the surface 11a of the hull 11 on the starboard side 16, and an intermediate portion of the starboard-side member 32 in the longitudinal direction X is fixed to the surface 11a of the hull 11 on the starboard side 16 by a second support member 36. In this case, the other end 31b of the port-side member 31 and the other end 32b of the starboard-side member 32 are smoothly connected to the surface 11a of the hull 11 without any steps.

[0022] As a result, a gap S is formed between the surface 11a of the hull 11 and the inner surface 30a of the pitch suppression member 30. The gaps S include gaps S1 and S2 between the surface 11a of the hull 11 on the port side 15 and the port-side member 31, and gaps S3 and S4 between the surface 11a of the hull 11 on the starboard side 16. Gap S1 is located between the first support member 34 and the second support member 35, and gap S2 is located between the second support member 35 and the other end 31b. Gap S3 is located between the first support member 34 and the second support member 36, and gap S4 is located between the second support member 36 and the other end 32b.

[0023] The pitching suppression member 30 preferably has a rectangular cross-sectional shape, and its length in the ship's width direction Y is preferably longer than its length in the ship's height direction Z. However, the cross-sectional shape of the pitching suppression member 30 is not limited to a rectangular shape, and it may also have a polygonal, circular, or elliptical cross-sectional shape. The pitching suppression member 30 preferably has an outward projection length Wa from the surface 11a of the hull 11 in the ship's width direction Y in the range of 0.2% to 1.0% of the ship's length L, and the gap length Wb of the gap S between the surface 11a of the hull 11 and the pitching suppression member 30 in the ship's width direction Y in the range of 20% to 50% of the projection length Wa. Furthermore, the gap length Wb is preferably in the range of 0.04% to 0.5% of the ship's length L. However, the projection length Wa and the gap length Wb are not limited to the above ranges and may be set appropriately depending on the type of ship 10, the shape of the hull 11, and other factors.

[0024] Furthermore, the projection length Wa and gap length Wb of the pitching suppression member 30 are preferably constant in the ship's longitudinal direction X, but may be gradually increased toward the rear in the ship's longitudinal direction X. Note that, because the other ends 31b, 32b of the pitching suppression member 30 smoothly connect with the surface 11a of the hull 11 without any steps, the projection length Wa and gap length Wb become smaller at the other ends 31b, 32b.

[0025] The length La of the pitching suppression member 30 in the ship's longitudinal direction X is in the range of 3% to 7% of the ship's length L. In this case, the pitching suppression member 30 is configured by connecting the port side member 31 and the starboard side member 32 via the connecting portion 33, but the port side member 31 and the starboard side member 32 may also be configured as separate members. Furthermore, the port side member 31 and the starboard side member 32 may also be configured from multiple members. In other words, the pitching suppression member 30 may be provided continuously or intermittently along the ship's longitudinal direction X. Furthermore, the positions of the first support member 34 and the second support members 35, 36 are not limited to those described above.

[0026] Furthermore, the pitching suppression member 30 is disposed so that its protrusion direction from the surface 11a of the hull 11 in the ship's width direction Y is along a first line L1 that is parallel to the load waterline WL. However, the direction in which the pitching suppression member 30 protrudes from the surface 11a of the hull 11 is not limited to the first line L1. For example, as shown in Figure 5, the pitching suppression member 30 may be disposed along a second line L2 that protrudes outward and is perpendicular to the surface 11a of the hull 11.

[0027] That is, it is preferable that the direction in which the pitching suppression member 30 protrudes from the surface 11a of the hull 11 in the ship's width direction Y is set at an angle θ between a first line L1 protruding from the surface 11a of the hull 11 in the ship's width direction Y and a second line L2 protruding outward and perpendicular to the surface 11a of the hull 11. However, the angle of the pitching suppression member 30 does not necessarily have to be set within this angle θ range, and can be set appropriately depending on the type of ship 10, the shape of the hull 11, etc.

[0028] The pitching suppression member 30 is disposed so that its direction along the ship's longitudinal direction X is parallel to the load waterline WL. However, if necessary, the pitching suppression member 30 may be inclined so that its rear end is positioned higher in the ship's height direction Z than its front end. In this case, the pitching suppression member 30 may be linear in the ship's longitudinal direction X, or may have a bent or curved shape that protrudes downward. Furthermore, the pitching suppression member 30 may have a tapered or curved portion at the lower end of the inner surface 33a so that the width of the gap S widens downward.

[0029] <Function of pitching suppression components> FIG. 6 is a side view showing the bow of a ship for explaining the function of the pitching suppressing member.

[0030] 6, when the ship 10 is sailing in calm water with no waves, the water surface swell W1 does not reach the underside of the pitching suppression member 30, and the pitching suppression member 30 does not create resistance to sailing. On the other hand, when the ship 10 is sailing through rough waves, seawater affected by the waves collides with the underside of the pitching suppression member 30, reducing the pitching of the hull 11.

[0031] That is, seawater affected by waves travels along the surface 11a of the hull 11 and reaches the underside of the pitching suppression member 30. Some of the seawater W2 collides with the underside of the pitching suppression member 30 and descends, while some of the seawater W3 rises through the gap S in the pitching suppression member 30. As the seawater W3 passes through the gap S in the pitching suppression member 30, its flow speed increases, and resistance between the seawater W3 and the surface 11a of the hull 11 and the inner surface 30a of the pitching suppression member 30 increases. This damping effect attenuates pitching, which is the up and down movement of the bow 12 of the hull 11. As a result, pitching of the bow 12 of the ship 10 is suppressed, even when the ship 10 is sailing through rough waves, enabling stable sailing.

[0032] [Effects of this embodiment] The vessel according to the first embodiment has a hull 11 with a port side 15 and a starboard side 16 on the bow 12 side. The vessel has a pitching suppression member 30 that is provided along the longitudinal direction X, above the water surface rise position during calm water navigation (ship height direction Z), and a portion of the pitching suppression member 30 is positioned away from the surface 11a of the hull 11.

[0033] With the ship according to the first aspect, waves traveling through waves travel along the surface 11a of the hull 11 to the pitching suppression member 30, and some of the waves pass through the gaps S in the pitching suppression member 30 and rise. As seawater passes through the gaps S in the pitching suppression member 30, the flow speed increases and resistance increases, which damps the pitching of the bow 12 of the hull 11 due to a damping effect. As a result, the increase in resistance in waves can be reduced without increasing the resistance of the ship 10 in calm water.

[0034] In the ship according to the second aspect, one end of the pitching suppression member 30 in the longitudinal direction X is fixed to the bow 12, the other end in the longitudinal direction X is fixed to the surface 11a of the hull 11, and the middle part in the longitudinal direction X is separated from the surface 11a of the hull 11. This allows a gap S to be formed between the hull 11 and the pitching suppression member 30 at an appropriate position.

[0035] In the ship according to the third aspect, the pitching suppression member 30 has a V-shape in plan view, with one end in the ship's longitudinal direction X fixed to the bow 12 by a first support member 34, and the other ends in the ship's longitudinal direction X fixed to the surface 11a of the hull 11 on the port side 15 and starboard side 16 by second support members 35, 36. This allows a gap S of an appropriate width to be formed between the hull 11 and the pitching suppression member 30, and also allows the pitching suppression member 30 to be fixed to the hull 11 with appropriate strength.

[0036] In a ship according to the fourth aspect, the projection length Wa of the pitching suppression member 30 from the surface 11a of the hull 11 in the ship's width direction Y is in the range of 0.2% to 1.0% of the ship's length L, and the gap length Wb in the ship's width direction Y between the surface 11a of the hull 11 and the pitching suppression member 30 is in the range of 20% to 50% of the projection length Wa. This gives the pitching suppression member 30 an appropriate width, enabling effective damping of the pitching of the bow 12 of the hull 11.

[0037] In a vessel according to the fifth aspect, the pitching suppression member 30 is provided at an angle θ between a first line L1 that protrudes from the surface 11a of the hull 11 in the ship's width direction Y and a second line L2 that protrudes outward and is perpendicular to the surface 11a of the hull 11. This provides an appropriate angle for the pitching suppression member 30, enabling effective damping of the pitching of the bow 12 of the hull 11.

[0038] In the ship according to the sixth aspect, the length of the pitching suppression member 30 in the ship's longitudinal direction X is in the range of 3% to 7% of the ship's length L. This gives the pitching suppression member 30 an appropriate length, enabling the pitching of the bow 12 of the hull 11 to be effectively damped. [Explanation of symbols]

[0039] 10 ships 11 Hull 11a surface 12 Bow 13 Stern 14 Ship's Bottom 15 port side 16 starboard 30 Pitching suppression member 31 Port side member 31a One end 31b Other end 32 Starboard side member 32a One end 32b Other end 33 Connecting part 34 First support member 35, 36 Second support member S, S1, S2, S3, S4 gap X Captain direction Y transverse direction Z Ship height direction CL Center Line WL Load Line Captain L Wa Extension length Wb Gap length θ angle

Claims

1. The vessel has pitch suppression members provided on the bow sides of the port and starboard sides of the hull along the length of the vessel, at heights above the water surface rise position when the vessel is sailing in calm water, a portion of the pitching suppression member is disposed spaced apart from the surface of the hull; One end of the pitch suppression member in the ship's longitudinal direction is fixed to the bow, the other end is fixed to the surface of the hull, and an intermediate portion in the ship's longitudinal direction is spaced apart from the surface of the hull. ship.

2. The pitching suppression member has a V-shape in plan view, and one end in the ship's longitudinal direction is fixed to the bow by a first support member, and each of the other end in the ship's longitudinal direction is fixed to the surface of the hull on the port side and the starboard side by a second support member.

2. The watercraft of claim 1.

3. The vessel has pitch suppression members provided on the bow sides of the port and starboard sides of the hull along the length of the vessel, at heights above the water surface rise position when the vessel is sailing in calm water, a portion of the pitching suppression member is disposed spaced apart from the surface of the hull; The pitching suppression member has a protrusion length that protrudes from the surface of the hull in the ship's width direction within a range of 0.2% to 1.0% of the ship's length, and the gap length in the ship's width direction between the surface of the hull and the pitching suppression member is within a range of 20% to 50% of the protrusion length. ship.

4. The vessel has pitch suppression members provided on the bow sides of the port and starboard sides of the hull along the length of the vessel, at heights above the water surface rise position when the vessel is sailing in calm water, a portion of the pitching suppression member is disposed spaced apart from the surface of the hull; The pitching suppression member is provided at an angle within a range between a first line protruding from the surface of the hull in the ship's width direction and a second line protruding outward perpendicular to the surface of the hull. ship.

5. The length of the pitch suppression member in the longitudinal direction of the ship is in the range of 3% to 7% of the ship length. A vessel according to any one of claims 1 to 4.

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