CN112272637B

CN112272637B - Small wind resistance ship

Info

Publication number: CN112272637B
Application number: CN201980037295.0A
Authority: CN
Inventors: 田中良和; 谷口豪; 木村校优; 池田刚大; 浅沼则道
Original assignee: MITSUI O S K TECHNO TRADE Ltd; Mitsui OSK Lines Ltd
Current assignee: MITSUI O S K TECHNO TRADE Ltd; Mitsui OSK Lines Ltd
Priority date: 2018-06-04
Filing date: 2019-05-27
Publication date: 2023-05-12
Anticipated expiration: 2039-05-27
Also published as: JP2019209821A; WO2019235281A1; KR20210006354A; JP6687673B2; CN112272637A; KR102438509B1

Abstract

A ship with small wind resistance is provided, wherein a sector area (Rα) is formed between a first inclined line (L1) extending at a first angle (alpha 1) of 50 degrees relative to a bow direction (Lc) in a front-back direction (X) and a second inclined line (L2) extending at a second angle (alpha 2) of 80 degrees in each horizontal section (Sh (z)) in a stern side first range (Rx 1) and an up-down first range (Rz 1) of structures (2), (20) on the water surface, and when a key virtual point (P2 (z)) of the sector area (Rα) moves back and forth along a hull center line Lc, the following virtual point (P2 (z)) exists: a contour line (Ls (Z)) having a length of 50% to 100% of the length of the contour line (Ls (Z)) of the horizontal cross section (Sh (Z)) enters the fan-shaped region (Rα). In this way, the influence of the oblique wind can be reduced, and the lift force can be generated by the hull or the upper structure and the structure on the water surface formed by the stacked cargo, and the thrust force can be obtained from the component of the lift force in the fore-and-aft direction of the hull, so that the propulsion performance of the ship can be improved.

Description

Small wind resistance ship

Technical Field

The present invention relates to a ship having a small wind resistance against oblique wind, and more particularly, to a ship having a reduced wind resistance against oblique wind by designing a shape of a stern side of an upper structure of a bridge, a living area, or the like.

Background

In almost all commercial vessels traveling on the water, there have been developed a reduction in resistance due to the design of the shape of the hull below the water surface of the vessel, an improvement in propulsion performance due to the relationship between the hull and the propeller, rudder, and the like, and a reduction in resistance in wave-making resistance, wave-breaking resistance, and reflected waves caused by waves near the water surface, and a reduction in resistance by the design of the bow shape and the stern shape.

On the other hand, there is also a demand for improvement of air resistance, that is, wind resistance, with respect to resistance caused by air on the water surface, and various efforts have been made. Particularly, an automobile carrier (a special automobile ship) having a high topside and a large wind pressure area, a container ship having an increased wind pressure area due to loading of cargo, a passenger ship having a large upper structure, and the like have a large wind pressure area on the water surface, and are thus susceptible to wind pressure, and reduction of wind resistance is expected to be associated with energy saving.

In connection with this, as described in japanese patent application laid-open No. 2011-57052, for example, there is proposed a ship with small wind resistance in which the shape of at least one of the stern side of an upper structure provided on an upper deck or the stern side of a hull on the water surface is formed as follows: in the shape of each cross section parallel to the water surface in the range of at least 0% to 50% of the range of the up-down direction of the above-water structure, a region outside an isosceles trapezoid having the stern-side rearmost part of the maximum width B as a lower side, the length B1 of the lower side as 0.9×b, the base angle θ1 as 40 degrees to 80 degrees, the length B2 of the upper side as 0.5×b, the isosceles triangle having the stern-side rearmost part of the maximum width B as a base, the length B3 of the base as 1.2×b, and the base angle θ2 as 40 degrees to 80 degrees is entered.

In the ship with small wind resistance, the following shapes are proposed for the purpose of reducing the influence of wind pressure of an automobile carrier, a container ship, a passenger ship, and the like, which are liable to be influenced by wind pressure, because of a large wind pressure area on the water surface, and improving the shipping performance of the ship: mainly, the generation of stagnation vortex and outflow vortex such as Kalman vortex generated in a dead water region is prevented in the rear of a structure on the water surface with respect to the windward from the front.

On the other hand, as described in japanese patent application laid-open No. 2014-501194, for example, there has been proposed a hull in which a hull on a water surface is formed into a symmetrical NASA wing-shaped air foil, and a rear edge on a stern side is cut to form a cross section perpendicular to a fore-and-aft direction of the hull so that the hull functions as a sail by generating aerodynamic lift in a ship traveling direction with relative wind. In this hull, the following wind tunnel test results are disclosed: the component of wind force acting in the direction of movement of the ship is obtained in a section of wind from about 13 degrees to 39 degrees.

In addition to this, it is important to reduce the wind resistance against oblique wind according to the weather conditions of the ship on the way and during sailing, in addition to the frontal wind from the direction of travel of the ship.

Patent document 1 Japanese patent application laid-open No. 2011-57052

Patent document 2 Japanese patent application laid-open No. 2014-501194.

The inventors of the present invention have obtained the following knowledge: when the speed of the ship itself is substantially equal to the speed of natural wind and considered in the relative wind direction during the navigation of the ship, the probability of the ship becoming obliquely incident is high. Further, the following knowledge is obtained from the results of wind tunnel experiments under oblique windward conditions, etc., and particularly, the shape in the stern has a large influence on wind resistance, and the shape of the external form of the structure on the water surface of the ship is designed, whereby the thrust can be obtained at the time of oblique windward without providing a special sail.

Disclosure of Invention

The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a ship with small wind resistance, which can reduce the influence of oblique wind in an automobile carrier, a passenger ship, a container ship, a wood carrier, or the like, which has a relatively large wind pressure area on the water surface and is easily influenced by wind pressure, and which can generate lift in an above-water structure formed by a ship body, an upper structure, and a stacked cargo 30 such as a container, and which can obtain thrust from a component of the lift in the fore-and-aft direction of the ship body, thereby improving the propulsion performance of the ship.

In order to achieve the above object, the present invention provides a low windage ship having a sailing speed of 0.13 to 0.30, wherein in at least one of a hull on a water surface and an upper structure provided on an upper deck, a point on a center line of the hull in a rearmost part of a stern side of a maximum width of the hull is set as a first position, a first range between the first position and a rearmost end of the hull is set as a stern side, a range of 50% or more and 100% or less in any continuous portion of the hull in an up-down direction of the hull is set as an up-down first range, a line extending from a virtual point on the center line of the hull at a first angle with respect to a bow direction of the hull in the forward-backward direction is set as a first inclined line, a second inclined line extending from the virtual point at a second angle with respect to the bow direction of the hull in the forward-backward direction of the hull is set as a second inclined line corresponding to a sector-shaped line, and a range of 50% or less is set as a first inclined line in a horizontal cross section parallel to the water surface in the up-down first range, and a sector-shaped region is set as a second inclined line extending from the virtual point at a first angle of the bow direction of the virtual point in the forward-backward direction of the hull at a first angle of the forward direction of the hull is set to be a sector-shaped region of the first inclined line in a range of between the first angle=40 = 80: a contour line having a length of 50% to 100% of a length of the contour line of the horizontal cross section enters the fan-shaped region.

Further, when the navigation speed is set to V (m/s),The length between the perpendicular lines is Lpp (m), and the gravitational acceleration is g (m/s) ² ) When fn=v/(lpp×g) ^1/2 . Here, the reason why the froude number Fn of the ship to be the object of the present invention is set to 0.13 to 0.30 is that in almost all high-speed ships in which the froude number Fn is greater than 0.30, the stealth technique for reducing radar reflection is sometimes used to cover and shield the entire hull, and therefore, the purpose is to distinguish it from such a stealth cover.

According to this structure, the stern shape of the hull on the water surface or the structure on the water surface of at least one of the upper structures provided on the upper deck is formed in a V-shape with a large opening having an angle α of 40 degrees to 80 degrees on the starboard side, and the flow of the stern is made similar to the flow of the rear end of the wing, so that a lift force can be generated when the ship is inclined to face the wind.

With this configuration, when the ship is inclined to face the wind, the wind at the stern passes through the ship more easily, the flow to the rear of the structure on the water surface is smoothed, and the local part of the structure on the water surface can function as a wing to generate lift force, so that the thrust of the ship can be obtained by using the component of the lift force in the fore-and-aft direction of the ship hull. The generation of the lift force and the thrust force was confirmed from the results of the wind tunnel experiment.

Further, there are advantages in that, by means of the shape of the stern side of the obtuse angle of the structure on the water surface, there is also the following: in the case of a ship having the same overall length, the volume increases, and the amount of accumulation increases accordingly.

In the above-described ship with small wind resistance, in the shape of each horizontal cross section in the upper and lower first ranges (Rz 1), the following effect can be obtained if the side wall portion of the stern-side first range is formed of a smooth curved portion having a width of the concavity and convexity of 5% or less of the maximum width of the above-water structure, or a straight portion having a width of the concavity and convexity of 5% or less of the maximum width of the above-water structure, or a combination of both.

According to this structure, the flow path is formed in a smooth curve or a straight line with less irregularities, and thus the occurrence of separation during flow in the curve or the straight line can be suppressed, thereby generating a large vortex.

In the above-described ship with small wind resistance, the following effect can be obtained if the side wall portion on the stern side of the above-water structure is formed so as to have an inclination angle of 30 degrees or more and 90 degrees or less with respect to the horizontal plane in the stern side first range and the upper and lower first ranges.

According to this structure, by tilting the stern-side wall portion at 30 degrees to 90 degrees, both of which are included in the above-water surface structure, the vortex generated at the corner portion between the stern-side upper surface and the stern-side wall portion can be suppressed. Further, by providing a chamfer or a rounded corner at the corner of the stern side upper surface and the stern side wall portion, the vortex can be suppressed more effectively.

In the above-described low wind resistance ship, when the upper structure is a water surface structure, in the stern-side first range and the upper and lower first ranges, 50% or more of the side wall portion of the upper structure is formed as a straight line in each horizontal section, the average value in the upper and lower first ranges of the first angle with respect to the hull center line of the straight line is set to a first average angle αm, 20% or more of the side wall portion of the hull below the upper structure on the stern side of the front surface of the upper structure is formed as a straight line, and the average value in the topside range of the hull with respect to the upper and lower direction of the third angle with respect to the hull center line is set to a third average angle θm, and when the angle γ1 is set to 5 degrees, the relationship between the first average angle αm and the third average angle θm is set to (αm+γ1) as the relationship of (αm+γ1).

According to this structure, the flow in the up-down direction between the upper structure on the stern side and the topside of the hull is reduced, and the planar flow is maintained, so that the trailing end effect by the wing shape of each of the upper structure and the hull can be maintained, the increase in the wind resistance of the entire ship in the oblique windward direction can be suppressed, and the improvement in the propulsion performance due to the generation of the lift force can be achieved.

In the above-described low wind resistance ship, when the hull is used as the above-water structure, 30% or more of the stern side of the above-water structure is formed in a straight line in the stern side first range and in the upper and lower first ranges, an average value in a range of a topside of the hull with respect to the up and down direction with respect to a third angle with respect to the center line of the hull is set to a third average angle θm, an angle γ2 is set to 20 degrees, and θ1 is set to 50 degrees, and the third average angle θm is set to a relation of (θ1- γ2) +.θm+.ltoreq.θ1+γ2.

According to this structure, even in a ship in which an upper structure such as a container ship is arranged in front of or in the middle of the hull in the front-rear direction of the hull, the rear end effect of the wing shape can be exerted by the stern shape of the hull, and an increase in wind resistance of the entire ship in the oblique windward direction can be suppressed, and an improvement in propulsive performance due to lift generation can be achieved.

Further, according to the arrangement of the stacked cargo 30 such as a container on the upper deck, the shape of the entire cargo at the time of stacking is made to match or be similar to the stern shape of the hull, so that the wing-shaped rear end effect can be exerted in addition to the rear end effect of the wing shape on the stern side of the hull in the shape of the entire cargo at the time of stacking on the upper deck.

According to the ship with small wind resistance of the present invention, in an automobile carrier, a passenger ship, a container ship, a wood carrier, or the like, which has a large wind pressure area on the water surface and is easily affected by wind pressure, the influence of oblique windward can be reduced, and a lift force can be generated on the water surface structure formed by the ship body or the upper structure, the stacked cargo 30 of the container, or the like, and a thrust force can be obtained from a component of the lift force in the fore-and-aft direction of the ship body, and a thrust force that can improve the propulsion performance of the ship can be obtained, and the propulsion performance of the ship can be improved. As a result, fuel efficiency can be improved, and energy saving can be achieved.

Drawings

Fig. 1 is a view of a ship according to a first embodiment of the present invention as viewed from the rear obliquely above the port side.

Fig. 2 is a side view of the rear side of the hull of the above-water structure in the ship of fig. 1.

Fig. 3 is a plan view showing a stern side shape of a horizontal section of a hull as the above-water structure in the ship in fig. 1.

Fig. 4 is a right side view of a ship in a second embodiment of the invention.

Fig. 5 is a view of an upper structure, which is an above-water structure in the ship of fig. 4, viewed from obliquely above.

Fig. 6 is a right side view of the stern portion of the vessel of fig. 4.

Fig. 7 is a horizontal cross-sectional view of the stern portion of the vessel of fig. 4.

Fig. 8 is a schematic plan view showing an angular relationship between a side wall portion on the rear side of the upper structure of the ship in fig. 4 and a side wall portion of the hull in plan view.

Fig. 9 is a right side view of a ship in a third embodiment of the present invention.

Fig. 10 is a schematic plan view showing an angular relationship in a plan view of a side wall portion of a hull in the ship of fig. 9.

Detailed Description

Hereinafter, embodiments of the ship with low wind resistance according to the present invention will be described with reference to the accompanying drawings. Here, the first embodiment will be described with an example of an automobile carrier (a special purpose automobile ship), and the second embodiment will be described with an example of a cargo ship having an upper structure provided above an upper deck in a living area and a bridge. However, the present invention can be applied not only to an automobile carrier or a cargo ship but also to other ships such as a passenger ship. In order to exclude ships that cover the hull for stealth technology, the friedel Fn is 0.13 to 0.30, which is related to the navigation speed V of the ship. The distance between the bow vertical line f.p. and the stern vertical line a.p. is referred to as the line length Lpp.

First, a ship with low wind resistance (hereinafter referred to as a ship) according to the first embodiment will be described. As shown in fig. 1 to 3, the ship 1 according to the first embodiment is a ship, which is exemplified by an automobile carrier, and is transported from the bow to the stern of the hull 2, has a plurality of decks having a stepped structure, and is provided with a mast 4 and a chimney 5 on the upper deck 3 as the uppermost deck, but is not provided with a bridge, a living area, or other building. In the ship 1, both the bridge and the living area are provided below the upper deck 3, and the projection is not provided as much as possible above the upper deck 3, so that the wind resistance is reduced. For example, the bridge is provided at a bow portion having a good view below the upper deck 3, and the living area is provided at a stern side near an engine room having an engine.

A bow nose 2a is provided on the bow side and a propeller 6 and rudder 7 are provided on the stern side below the water surface. The ship 1 of fig. 1 is a one-axis one-rudder, but the present invention is not limited thereto, and may be a two-axis two-rudder multi-axis ship or the like.

In this structure, an upward inclined surface 3a is formed in the bow portion from the upper end of the leading edge of the bow toward the upper deck 3. The inclined surface 3a is formed so as to have an elevation angle of 20 degrees (angle) to 60 degrees, preferably 38 degrees, with respect to the horizontal plane. Thereby, when the wind current flows from the upper end of the bow front edge toward the upper deck 3, the occurrence of the vortex and the peeling in the portion of the upper deck 3 are suppressed, and the wind resistance is reduced.

A cut-out step 9 is provided at the corner of the upper deck 3 and the side portion 8 of the hull 2 across substantially the entire length from the bow to the stern. As shown in fig. 1, the cut-away step 9 is formed with a depth ds of 5 to 20% of the topside fb in the ballasted state obtained by subtracting the ballasted draft db from the depth D from the upper deck to the bottom (keel line) in the center of the hull, and a width bs. For example, the vehicle is formed by cutting a width of one or two vehicles to be loaded in a square shape.

By the step-cut portion 9, peeling and generation of vortex at the corner portion connecting the upper deck 3 and the side portion 8 with respect to oblique wind are suppressed, and drag, lateral force, and yaw moment due to wind pressure are reduced. The cut-out step 9 is effective if it is provided over substantially the entire length from the bow to the stern, but may be provided over a range from the bow to substantially the center of the hull.

In the structure of fig. 1, an opening for a gangway ramp for loading and unloading an automobile and a door 10 thereof are provided at the stern of a portion (on-water structure) on the water surface of the side portion 8 of the hull 2. Further, an opening for a gangway ramp for loading and unloading an automobile and a door thereof may be provided in the side portion 8 near the center portion of the hull 2.

As shown in fig. 1 to 3, in the above-water structure 2 as the above-water hull, a point on the hull center line Lc in the stern-side rearmost portion of the maximum width Bmax of the hull 2 is set as a first position P1, and a stern-side first range Rx1 is set between the first position P1 and the rearmost end Pa of the hull 2. The range of 50% to 100%, preferably 40% to 100%, of the arbitrary continuous portion in the vertical direction of the above-water structure 2 is defined as the vertical first range Rz1. The stern-side first range Rx1 and the upper-lower first range Rz1 of the above-water structure 2 are set as stern specific ranges Sa1 (cross-hatched portions in fig. 1 and 2). The water surface position is set to the lower end as the entire vertical range, and is set to the uppermost portion of the hull 2 except the mast 4, the chimney 5, and the like, when an upper structure (not shown) is provided.

In each horizontal cross section Sh (z) parallel to the water surface in the stern specifying range Sa1, a line extending at a first angle α1 from a virtual point P2 (z) on the hull center line Lc with respect to the bow direction (+x direction) of the fore-and-aft direction X of the hull 2 is defined as a first inclined line L1, and a line extending at a second angle α2 from the virtual point P2 (z) with respect to the bow direction (+x direction) of the fore-and-aft direction X of the hull 2 is defined as a second inclined line L2. Here, the first angle α1 is set to 50 degrees (degrees), preferably 55 degrees, and the second angle α2 is set to 80 degrees, preferably 65 degrees. Further, a fan-shaped region rα (z) is defined between the first inclined line L1 and the second inclined line L2.

Under the above conditions, when the virtual point P2 (z) is moved on the hull center line Lc and the sector region rα (z) is moved in the fore-and-aft direction of the hull, the following virtual point P2 (z) is located: the contour line Ls (z) of 50% to 100% of the length of the contour line Ls (z) of the horizontal cross section Sh (z) enters the fan-shaped region rα (z), and preferably 60% to 100% of the length of the contour line Ls (z). In other words, the following structure is provided: when the virtual point P2 (z) is provided at an appropriate position on the hull centerline Lc, the contour line Ls (z) having a length of 50% to 100% of the length of the contour line Ls (z) of the horizontal cross section Sh (z), preferably 60% to 100% of the length thereof, enters the inside of the fan-shaped region rα (z) having the virtual point P2 (z) as a vertex.

According to this structure, the stern shape of the above-water structure of the above-water hull 2 can be formed in a V-shape with a large opening, in which the angle α of the single side is 40 degrees to 80 degrees, preferably 55 degrees to 65 degrees. In this stern shape, the flow of the stern is similar to the flow of the rear ends of the wings, and the flow is similar to the wings when the wind is inclined, so that lift can be generated.

That is, with the hull 2 having this stern shape, the passage of the stern wind is improved when the stern is inclined to the wind, the flow of the wind to the rear of the above-water structure 2 is smoothed, and the local part of the above-water structure 2 functions as a wing, so that the lift force can be generated. The thrust of the ship 1 can be obtained by the component of the lift in the fore-and-aft direction X of the hull 2. The generation of the lift force and the thrust force was confirmed from the results of the wind tunnel experiment.

In a ship in which the portion on the water surface is shaped like a hull 2 extending upward from the water surface as in the case of an upper structure such as an automobile carrier or a passenger ship, the portion on the water surface is hardly erected on the exposed deck, and the portion from the bow to the stern is shaped like a wing, so that the shape of the stern is shaped to have substantially the same function as the rear end of the wing, whereby the lift force generated in the oblique windward direction can be increased, and the thrust from the lift force can be obtained.

Further, according to this structure, since the passage of wind on the stern side of the hull 2 is improved with respect to the oblique windward direction, the generation of vortex flow in the stern portion of the hull 2 is reduced, the wind force in the transverse direction Y of the hull due to the wind in this portion can be reduced, and the rotational moment due to the wind acting on the hull 2 can be reduced. This can reduce the steering angle for canceling the rotational moment, and from this point of view, the propulsion efficiency can be improved, and the operability can be improved.

Further, the stern side shape of the obtuse angle of the hull 2 is utilized, and there are the following advantages: in the case of a ship having the same overall length, the volume increases, and the amount of accumulation increases accordingly.

In addition, in the shape of each horizontal cross section Sh (z) of the upper and lower first ranges Rz1, it is preferable that the side wall portion (side portion) 8 of the stern specific range Sa1 forming the stern side of the above-water structure 2 is formed of a smooth curved portion having a concave-convex width of 5% or less of the maximum width Bmax of the hull 2, a straight portion having a concave-convex width of 5% or less of the maximum width Bmax of the hull 2, or a combination of both. By adopting this structure, the occurrence of separation in the flow at the curved portion or the linear portion can be suppressed, and the occurrence of a large vortex can be suppressed.

In the stern-side first range Rx1 and the upper and lower first ranges Rz1, if the stern-side wall portion 8 forming the above-water structure 2 is formed to have an inclination angle β of 30 degrees or more and 90 degrees or less with respect to the horizontal plane, it is possible to suppress the occurrence of eddy currents in the corner portions of the upper deck 3 and the sidewall portion 8 forming the stern-side upper surface of the above-water structure 2. In addition, it may be set as follows: if the entire or a part of the side wall 8 on the water surface is formed in a curved surface shape protruding outward, the air flow flowing on the upper side of the structure 2 on the water surface (the upper surface of the deck, the bridge, or the like) can be lowered along the curved surface of the side wall 8, and an increase in resistance due to the occurrence of vortex or the like can be suppressed. In this case, the angle formed by the tangential plane at each point on the curved surface and the horizontal plane is set to be the inclination angle β.

If the inclination angle β is set to be smaller than 30 degrees, the lower portion of the stern side portion extends largely in the stern direction, and if it is too large to be larger than 90 degrees, it becomes impractical. Further, by providing chamfers or fillets at the corners of the upper deck 3 and the side wall 8, the vortex flow can be more effectively suppressed.

Next, a ship with low wind resistance (hereinafter referred to as a ship) according to the second embodiment will be described. As shown in fig. 4 to 8, the ship 1A according to the second embodiment is a stern bridge ship in which an upper structure 20 is disposed above an upper deck 3 at the stern, and the upper structure 20 includes a bridge 21 and a living area 22, taking a cargo ship (bulk cargo ship in this case) as an example. As the cargo ship, a bulk cargo ship, a tanker, a general cargo ship, or the like having a living area at the stern is exemplified. The upper surface of the upper structure 20 is provided with a mast 4 and a chimney 5, and navigation wings (evades) 21a which are part of the deck of the marine bridge and which extend out on the sides of the bridge 21 are provided on both sides.

As shown in fig. 4 to 8, in the upper structure 20 provided on the upper deck 3, that is, in the above-water structure 20, a point on the hull center line Lc in the stern-side rearmost part of the maximum width Bmax of the upper structure 20 is set as a first position P1, and a first stern-side range Rx1 is set between the first position P1 and the rearmost end Pa of the hull 2. The range of 50% to 100%, preferably 40% to 100%, in the vertical direction of the above-water structure 20 is set to the vertical first range Rz1. The entire vertical range extends from the lower end of the upper structure 20, i.e., the upper surface of the upper deck 3, to the uppermost portion of the upper structure 20 excluding the mast 4, the chimney 5, and the like.

The stern-side first range Rx1 and the upper-lower first range Rz1 of the above-water structure 20 are set as the stern specific range Sa1 (cross-hatched portions in fig. 4 to 6). In each horizontal cross section Sh (z) parallel to the water surface in the stern specifying range Sa1, a line extending at a first angle α1 from a virtual point P2 (z) on the hull center line Lc with respect to the bow direction (+x direction) of the fore-and-aft direction X of the hull 2 is defined as a first inclined line L1, and a line extending at a second angle α2 from the virtual point P2 (z) with respect to the bow direction (+x direction) of the fore-and-aft direction X of the hull 2 is defined as a second inclined line L2. Here, the first angle α1 is set to 50 degrees (degrees), preferably 55 degrees, and the second angle α2 is set to 80 degrees, preferably 65 degrees. Further, a fan-shaped region rα (z) is defined between the first inclined line L1 and the second inclined line L2.

Under the above conditions, when the virtual point P2 (z) is moved on the hull center line Lc and the sector region rα (z) is moved in the fore-and-aft direction X of the hull 2, the following virtual point P2 (z) is located: the contour line Ls (z) of 50% to 100% of the length of the contour line Ls (z) of the horizontal cross section Sh (z) enters the fan-shaped region rα (z), and preferably 60% to 100% of the length of the contour line Ls (z). In other words, the following structure is provided: when the virtual point P2 (z) is provided at an appropriate position on the hull centerline Lc, the contour line Ls (z) having a length of 50% to 100% of the length of the contour line Ls (z) of the horizontal cross section Sh (z), preferably 60% to 100% of the length, enters the inside of the fan-shaped region rα (z) having the virtual point P2 (z) as the apex.

According to this structure, the stern shape of the structure 20 on the water surface of the upper structure 20 can be formed in a V-shape opened widely, with the angle α of the single side being 40 degrees (degree) to 80 degrees, preferably 55 degrees to 65 degrees. In this stern shape, the flow of the stern is similar to the flow of the rear ends of the wings, and the lift force can be generated in the same manner as the wings when the wings are inclined into the wind.

That is, with the upper structure 20 having the stern shape, the passage of the stern wind is improved when the stern is inclined to the wind, the flow to the rear of the above-water structure 20 is smoothed, and the local part of the above-water structure 20 functions as a wing, thereby generating lift. The thrust of the ship 1 can be obtained by the component of the lift in the fore-and-aft direction X of the hull 2. The generation of the lift force and the thrust force was confirmed from the results of the wind tunnel experiment.

In the ship having the upper structure 20 at the stern portion as in the ship 1A according to the second embodiment, the container (cargo) 30 is stacked on the upper deck 3 in the container ship, and the wood or the like is stacked on the upper deck 3 in the wood transfer ship, whereby the shape above the upper deck 3 is formed into an elongated shape as a whole. In such a ship, the upper structure 20 and the deposited cargo 30 from the bow to the stern are shaped like wing shapes, and therefore, the stern side shape of the upper structure 20 is shaped to have substantially the same function as the rear ends of the wings, whereby the lift force generated in the oblique windward direction can be increased, and the thrust force can be obtained from the lift force.

Further, according to this structure, the wind passing through the stern side of the upper structure 20 is better than the oblique windward, so that the generation of the vortex in the stern side portion can be reduced to reduce the wind force in the horizontal direction Y of the hull due to the wind in the portion, and the rotational moment due to the wind acting on the upper structure 20 can be reduced. This can reduce the steering angle for canceling the rotational moment, and from this point of view, the propulsion efficiency can be improved, and the operability can be improved. The effect of the rotational moment can be exerted even in a state where the stacked cargo 30 is not stacked on the upper deck 3 in front of the upper structure 20, and the propulsion efficiency and operability can be improved.

Further, the stern side shape of the upper structure 20 at an obtuse angle has the following advantages: in the case of a ship having the same overall length, the volume increases, and the amount of accumulation increases accordingly.

In addition, in the shape of each horizontal cross section Sh (z) of the upper and lower first ranges Rz1, the side wall portion (wall surface of the upper structure 10) 28 of the stern first range Rx1 forming the stern side of the above-water structure 20 is preferably formed of a smooth curved portion having a concave-convex width of 5% or less of the maximum width Bmax of the upper structure 20, or a straight portion having a concave-convex width of 5% or less of the maximum width Bmax of the upper structure 20, or a combination of both. By forming this structure, the occurrence of separation during flow and the generation of large vortex can be suppressed in the curved portion or the linear portion.

In the stern-side first range Rx1 and the upper and lower first ranges Rz1, if the stern-side wall portion 28 forming the above-water structure 20 is formed to have an inclination angle β of 30 degrees or more and 90 degrees or less with respect to the horizontal plane, it is possible to suppress the occurrence of vortex at the corner portions of the stern-side upper surface 27 and the sidewall portion 28 forming the stern-side of the above-water structure 20. In addition, it is preferable that the entire or upper part of the side wall 28 on the water surface is formed in a curved surface shape protruding outward, and in this case, an angle formed by a tangential plane at each point on the curved surface and the horizontal plane is set to be an inclination angle β.

If the inclination angle β is set to be smaller than 30 degrees, the lower portion of the stern side portion extends largely in the stern direction, and if it is too large to be larger than 90 degrees, it becomes impractical. Further, by providing chamfers or fillets at the corners of the stern-side upper surface 27 and the side wall portion 28, the vortex can be suppressed more effectively.

In the cargo ship 1A in which the upper structure 20 is the above-water structure 20, the following configuration is also preferable in the stern-side first range Rx1 and the upper and lower first ranges Rz1.

That is, as shown in fig. 8, 50% or more of the side wall portion 28 of the upper structure 20 is formed as a straight line L3 (Z) in each horizontal cross section, and the average value in the first vertical range Rz1 of the first angle α (Z) of the straight line L3 (Z) with respect to the vertical direction Z with respect to the hull center line Lc is set as the first average angle αm. Further, 20% or more, preferably 30% or more, more preferably 40% or more of the side wall portion (freeboard) 8 of the hull 2 below the upper structure 20 on the stern side than the front surface of the upper structure 20 is formed in a straight line L4 (z).

The average value in the range of the topside 8 of the hull 2 in the up-down direction Z at the third angle θ (Z) with respect to the hull center line Lc of the straight line L4 (Z) is set to the third average angle θm, and the angle γ2 is set to 5 degrees. At this time, the relation between the first average angle αm and the third average angle θm is set to be (αm—γ2) +.θm+.ltoreq.αm+γ2.

As a result, since there is no large difference between the first average angle αm and the third average angle θm in plan view between the upper structure 20 on the stern side and the topside 8 of the hull 2, the possibility of disturbance due to the upward and downward flow of the upper structure 20 and the hull 2 is reduced, and the planar flow is easily maintained, so that the rear end effect due to the wing shape of each of the upper structure 20 and the hull 2 can be exhibited, the increase in the windage of the entire ship 1A in oblique windward direction can be suppressed, and the improvement in propulsive performance due to the generation of lift force can be achieved.

It becomes possible to suppress the vortex.

Next, a ship with small wind resistance (hereinafter referred to as a ship) according to a third embodiment will be described, and as shown in fig. 9 and 10, a ship 1B according to the third embodiment is a ship with a stern shape defined by the ship 1 according to the first embodiment. Fig. 9 is an example of a container ship.

The vessel 1B is mainly a vessel such as a container vessel, and has an upper structure 20 above the upper deck 3, and the upper structure 20 includes a bridge 21 and a living area 22, but the upper structure 20 is disposed not on the stern side but on the bow side and at an intermediate position with respect to the fore-and-aft direction X of the hull.

In the ship 1B using the hull 2 as the above-water structure 2, similarly to the ship 1 of the first embodiment, the stern-side first range Rx1 and the upper and lower first ranges Rz1 are provided, and the stern shape at the portion is formed as follows with the stern-side first range Rx1 and the upper and lower first ranges Rz1 being the stern-specific range Sa 1.

That is, 30% or more of the stern side of the hull (structure on water) 2 is formed by a straight line L4 (Z), the average value of the third angle θ (Z) of the straight line L4 (Z) with respect to the hull center line Lc in the up-down direction (Z) is set to a third average angle θm, the angle γ2 is set to 20 degrees, preferably 10 degrees, more preferably 5 degrees, and when θ1 is set to 50 degrees, the third average angle θm is set to a relationship that (θ1- γ2) +.θm+.o (θ1+γ2).

According to this structure, even in a ship 1B such as a container ship in which the upper structure 20 is arranged in the front or middle in the fore-and-aft direction Z of the hull, the rear end effect of the wing shape can be easily exerted by the stern shape of the hull 2, and the improvement of the propulsion performance due to the generation of lift can be achieved while suppressing the increase of the wind resistance of the whole ship in the oblique windward direction.

Further, according to the arrangement of the cargo 30 such as a container on the upper deck 3, the shape of the entire cargo at the time of stacking can be matched with or made similar to the stern shape of the hull 2, and the wing-shaped rear end effect can be exerted in addition to the rear end effect of the wing shape of the stern side of the hull 2 in the shape of the entire cargo 30 at the time of stacking on the upper deck 3.

According to the

vessels

1, 1A, 1B having the above-described structure, in the case of the automobile carrier, the passenger ship, the container ship, the wood carrier, and the like, which are susceptible to the influence of wind pressure because the wind pressure area on the water surface is relatively large, the influence of oblique wind can be reduced, and the lift force can be generated in the

water surface structures

2, 20 formed by the hull 2 or the stacked cargo 30 such as the upper structure 20 and the container, and the thrust force can be obtained from the component of the lift force in the fore-and-aft direction X of the hull 2, and the propulsion performance of the

vessels

1, 1A, 1B can be improved. As a result, fuel efficiency can be improved, and energy saving can be achieved.

Reference numerals

1. 1A, 1B vessel

2. Boat hull (Water structure)

3. Upper deck

8. Side portion

20. Upper structure

21. Ship bridge

22. Residential area

30. Goods stack (Container)

AP. stern plumb line

Maximum width of Bmax

F.P. bow plumb line

L1 first inclined line

L2 second inclined line

Lc hull centerline

Lpp interline length

Contour line of Ls (z) horizontal section

P1 first position

P2 virtual point

The rearmost end of the PA hull

Rx1 stern side first range

First upper and lower ranges of Rz1

Rα (z) sector

Sa1 stern specific range

Horizontal cross section in specific range of Sh (z) stern

Fore-aft direction of X hull

Left-right direction of Y-shaped ship body

Up and down direction of Z hull

Angle of alpha single side

α1 first angle

Alpha 2 second angle

Beta tilt angle

And a third angle theta.

Claims

1. A ship with small wind resistance is a ship with a sailing speed of 0.13-0.30 Froude number, and is characterized in that,

in at least one of a hull on the water surface and an upper structure provided on an upper deck,

a point on the center line of the hull at the rearmost part of the stern side of the maximum width of the above-water structure is set as a first position, a first range between the first position and the rearmost part of the hull is set as a stern side first range, a range of 50% to 100% at any continuous part in the up-down direction of the above-water structure is set as an up-down first range,

in each horizontal section parallel to the water surface in the stern-side first range of the above-water structure and in the upper-lower first range,

when a line extending from a virtual point on a hull center line at a first angle with respect to a bow direction of a hull in a fore-and-aft direction is set as a first inclined line, a line extending from the virtual point at a second angle with respect to the bow direction of the hull in the fore-and-aft direction is set as a second inclined line, the first angle is set to 50 degrees, the second angle is set to 80 degrees, a sector area is set between the first inclined line and the second inclined line, and the virtual point is moved on the hull center line to move the sector area in the fore-and-aft direction of the hull,

a position where a contour line having a length of 50% to 100% of a length of the contour line of the horizontal cross section enters the virtual point such as the fan-shaped region,

when the upper structure is used as an above-water structure,

in the stern-side first range and the upper and lower first ranges,

in each horizontal section, 50% or more of the side wall portion of the upper structure is formed as a straight line, the average value in the first vertical range of the first angle relative to the hull center line of the straight line is set as a first average angle αm,

in the case where 20% or more of the side wall portion of the hull below the upper structure on the stern side than the front surface of the upper structure is formed in a straight line, the average value in the range of the topside of the hull in the up-down direction at a third angle with respect to the hull center line of the straight line is set to a third average angle θm, and the angle γ1 is set to 5 degrees,

the relation between the first average angle αm and the third average angle θm is a relation of (αm- γ1) +.θm+.ltoreq.αm+γ1.

2. A ship with small wind resistance is a ship with a sailing speed of 0.13-0.30 Froude number, and is characterized in that,

in the case where the hull is used as an above-water structure,

in the stern-side first range and the upper and lower first ranges,

the above-mentioned structure on the water surface is formed in a straight line at 30% or more of the stern side, the average value of the straight line with respect to the up-down direction of the third angle with respect to the hull center line is set to the third average angle θm, the angle γ2 is set to 20 degrees, and when θ1 is set to 50 degrees,

the third average angle θm is set to be equal to or smaller than (θ1- γ2) +.θm+.gtoreq.θ1+γ2.

3. The low wind resistance ship according to claim 1 or 2, wherein the side wall portion of the stern-side first range is formed by a smooth curved portion having a width of the concavity and convexity of 5% or less of the maximum width of the above-water structure, a straight portion having a width of the concavity and convexity of 5% or less of the maximum width of the above-water structure, or a combination of both, in the shape of each horizontal cross section of the upper and lower first ranges.

4. The low wind resistance ship according to claim 1 or 2, wherein the side wall portion on the stern side of the above-water structure is formed so as to have an inclination angle of 30 degrees or more and 90 degrees or less with respect to the horizontal plane in the stern side first range and the upper and lower first ranges.