Ship thrust booster

Abstract

The present invention provides a thrust booster that can actively convert wind pressure from the front of a vessel into propulsion while ensuring sufficient forward visibility for the vessel. [Solution] A superstructure 3 is provided on the forward portion of the upper deck 2 of the ship S. At the bow of the ship, a wind guide slope 7 that slopes downward toward the front is formed, and a lift generating plate 10 that generates upward and forward lift is installed on the upper surface of the upper deck 2 at the bow. The lift generating plate 10 has an airfoil cross-section and is positioned on the inclined deck 6 so that wind from the front of the ship flows above the superstructure 3. The lift generating plate 10 can convert the wind from the front into thrust for the ship S. Since the lift generating plate 10 is installed on the upper surface of the upper deck 2, its height can be kept low, and a wide field of view forward and downward from the bridge can be secured.

Description

Technical Field

[0001] The present invention relates to a thrust enhancing device for a ship. More specifically, the present invention relates to a thrust enhancing device that converts the wind pressure from the front to the rear of the ship into the thrust of the ship.

Background Art

[0002] Automobile carriers have a high freeboard and a large wind pressure area on the front of the hull. When a container ship loads a large number of containers, the wind pressure area becomes large. Large passenger ships with large superstructures also have a large wind pressure resistance on the water surface. For these large ships, various technologies for reducing wind pressure and saving energy have been developed.

[0003] As a device for reducing wind pressure in such general ships, there is the prior art of Patent Document 1. In this prior art, as shown in FIG. 9, a living area 110 is provided near the front of the upper deck 102 of the ship, and a bow windshield 120 is provided at the bow. The bow windshield 120 is configured to be lower than the upper end of the living area 110, and an intermediate layer windshield 121 is provided at the upper front side of the intermediate layer living area 111 in the living area 110. In this prior art, it is explained that the separation of the air flow that has collided with the living area can be adjusted by the intermediate layer windshield 121, thereby reducing the wind pressure resistance on the front surface of the living area 110.

[0004] However, in the above prior art, even if the wind pressure resistance can be reduced, the wind pressure cannot be converted into the thrust of the ship. In addition, there is a problem that the view when looking from the bridge at the front of the ship to the front of the bow is obstructed by the intermediate layer windshield 121 and the bow windshield 120 at the uppermost front of the living area 110. In this case, the sea surface near the bow cannot be visually recognized from the bridge, which hinders the safe operation of the ship.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2010-111209 [Overview of the project] [Problems that the invention aims to solve]

[0006] In view of the above circumstances, the present invention aims to provide a thrust enhancement device that can actively convert wind pressure from the front of a vessel into propulsion force and can ensure sufficient forward visibility for the vessel. [Means for solving the problem]

[0007] The thrust-enhancing device for a ship according to the first invention is characterized in that a superstructure is provided in the forward portion of the upper deck of the ship, aft of the bow, a wind-guiding slope that slopes downward toward the front is formed at the front end of the bow, and a lift-generating plate that generates an upward-forward lift is installed on the upper surface of the upper deck at the bow. The thrust-enhancing device for a ship according to the second invention is characterized in that, in the first invention, the lift-generating plate is provided on the upper surface of the upper deck in a position that directs wind from the front of the hull upwards to the superstructure. The third invention of a ship thrust-enhancing device is characterized in that, in the second invention, the lift-generating plate is installed on the upper surface of the upper deck, immediately behind the wind-guiding slope. The fourth invention is a ship thrust enhancement device, characterized in that, in the second invention, an inclined deck is formed in the forward portion of the bow between the rear end of the wind guide slope and the forward end of the bow, and the lift generating plate is installed on the upper surface of the inclined deck. The fifth invention, a thrust-enhancing device for a ship, is characterized in that, in the first, second, third, or fourth invention, the lift-generating plate is formed in the shape of an airfoil in cross-section. [Effects of the Invention]

[0008] According to the first invention, wind from the front is converted into forward-upward lift by the lift-generating plate. This forward-upward lift can be converted into propulsion for the ship, thus achieving energy savings during navigation. According to the second invention, the wind coming from the front of the ship is rectified by the lift-generating plate and becomes a laminar flow that flows towards the superstructure, thereby reducing wind pressure resistance. Moreover, the lift-generating plate, located within the laminar flow, effectively generates a forward and upward lift force. According to the third invention, the wind guide slope formed at the front of the bow increases the airflow and directs the air above and below the lift generating plate, thereby effectively generating forward and upward lift. According to the fourth invention, since the inclined deck is shaped to be cut diagonally at the upper part of the bow, a large amount of air can be collected, and the height of the lift-generating plate to be installed can be reduced. As a result, a wide forward view from the bridge, especially the view to the forward and downward, can be secured. According to the fifth invention, since the lift-generating plate has an airfoil cross-section, it can generate high lift over a wide angle of attack range. [Brief explanation of the drawing]

[0009] [Figure 1] This is a perspective view showing the forward portion of a car carrier S equipped with a thrust enhancement device according to the first embodiment of the present invention. [Figure 2] This is a perspective view showing the state with the lift-generating plate 10 removed from Figure 1. [Figure 3] Figure 1 is an explanatory diagram of the lift generation operation of the lift generating plate 10. [Figure 4] This is a perspective view of the forward portion of a car carrier S equipped with a thrust enhancement device according to a second embodiment of the present invention. [Figure 5] Figure 4 is a plan view showing the forward portion of the car carrier S. [Figure 6] Figure 4 is a front view showing the forward portion of the car carrier S. [Figure 7] Figures 4-6 are explanatory diagrams illustrating the lift-generating action of the lift-generating plate 10. [Figure 8] This is an explanatory diagram of the forward view in the car carrier S of the present invention. [Figure 9] It is an explanatory view of a conventional wind resistance reduction structure.

Mode for Carrying Out the Invention

[0010] Next, embodiments of the present invention will be described based on the drawings. The following embodiments are applied to a car carrier among ships. The symbol S is used hereinafter to indicate the entire ship or the car carrier of the present embodiment. In the drawings shown below, dimensions, positional relationships, and shapes are shown as examples and are not limited to those shown.

[0011] (First Embodiment) In FIGS. 1 and 2, S is a car carrier, and 1 is a hull (in FIG. 1, the hull 1 is not shown in its entirety but only the front part including the bow). An upper structure 3 is provided at the front part of the upper deck 2 of the hull 1. This upper structure 3 is also called a living area, and generally, a bridge for controlling the ship is provided on the uppermost layer at its front end.

[0012] The bow 4 of the hull 1 is a vertical bow, and from the draft to the upper part (freeboard), it is formed in a square shape in plan view. Note that the part below the draft is thin at the bow tip to reduce the propulsion resistance and has a shape that gradually widens toward the rear.

[0013] FIG. 2 shows the bow in a state where the lift - generating plate 10 described later is removed. As shown in the figure, at the front end of the hull 1, that is, at the front end of the bow 4, a wind - guiding inclined surface 7 that slopes downward toward the front is formed. The upper deck 2 extends from the upper structure 3 to the upper - end edge (rear - end edge) on the wind - guiding inclined surface 7, and the upper - deck extension 2a of the part where the windshield 5 is not provided is horizontal and at the same height as the upper deck 2.

[0014] On the bow 4 of the hull 1, a windshield 5 is provided along its outer edge. This windshield 5 is an outer plate for wind protection stretched along the upper edge of the bow 4. However, as described above, the windshield 5 is not provided in the portion where the wind guiding slope 7 is formed.

[0015] As shown in FIG. 1, on the upper surface of the upper deck 2 at the bow, a lift generating plate 10 that generates an upward forward lift is installed. The installation position of the lift generating plate 10 is not particularly limited as long as it is on the upper surface of the upper deck and between the superstructure 3 and the bow 4. In the embodiment shown in FIGS. 1 and 3, the lift generating plate 10 is installed on the upper surface of the upper deck extension 2a of the upper deck 2, immediately behind the wind guiding slope 7. This position is also where the wind from the front of the hull flows above the superstructure 3. The thrust enhancing device of this embodiment is composed of the lift generating plate 10 and the wind guiding slope 7.

[0016] As shown in FIG. 3, the lift generating plate 10 is supported on the upper deck extension 2a by a support pedestal 11. The support pedestal 11 is not particularly limited in the length and shape of its legs, and any structure that can support the lift generating plate 10 on the posts erected on the upper surface of the upper deck extension 2a is acceptable. The lift generating plate 10 may be fixedly attached to the support pedestal, or may be attached in a manner that allows variable adjustment of the angle of attack of the lift generating plate 10. When the lift generating plate 10 is fixedly attached, it is easy to maintain high attachment strength. Also, with a structure that allows variable adjustment of the angle of attack, it becomes easy to adjust so that the generation of lift is maximized.

[0017] There is no particular limitation on the material of the lift generating plate 10, but it is preferable to use a material with sufficient strength and excellent workability, such as steel or FRP (fiber reinforced resin material). Among FRPs, CFRP (resin material with carbon fiber as the reinforcing material) is more preferable because of its high rigidity and high strength.

[0018] The lift-generating plate 10 is preferable if it has an airfoil cross-section, as this generates a large amount of lift. The airfoil shape can be any shape, as long as the pressure decreases on the upper surface and increases on the lower surface. However, among the various airfoil cross-sections, the NACA4418 airfoil is particularly preferred. The No. 4418 airfoil, defined by NACA (National Advisory Committee for Aeronautics), is known to have a high lift-to-drag ratio over a wide angle of attack range.

[0019] As shown in Figure 3, the wind guide slope 7 is inclined downward toward the front end of the bow section 4, so that it can collect wind from the front, increase the airflow, and further direct the wind above and below the lift generating plate 10. As a result, the wind from the front of the ship S is straightened into a laminar flow as it passes between the lift generating plate 10 and the upper deck extension 2a, and at the same time, the wind on the upper surface of the lift generating plate 10 is also straightened.

[0020] The lift-generating plate 10 described above has an airfoil cross-section, and when placed in a laminar flow Fl, it generates a lift force Df. This lift force Df is very large because it is generated by the synergistic effect of the lift-generating plate 10, which has a high lift-to-drag ratio cross-sectional shape, and the airflow being laminar flow Fl. The vertical component of this lift force Df provides buoyancy to the vessel S, and the horizontal component (forward) provides thrust to the vessel S. Therefore, energy savings can be achieved while the vessel S is in motion.

[0021] In this invention, as shown in Figure 3, the air rectified by the lift-generating plate 10 flows above the superstructure 3, thereby reducing the wind pressure on the superstructure 3. The distance D between the front wall of the superstructure 3 and the center of the lift-generating plate 10 is set so that the lift-generating plate 10 directs the airflow over the superstructure 3.

[0022] The bottom surface of the lift generating plate 10 may be installed parallel to the upper surface of the upper deck extension 2a, or it may be inclined relative to the upper deck extension 2a so that the front end of the lift generating plate 10 is lowered and the rear end is raised. In that case, it becomes easier to direct the wind upwards over the superstructure 3.

[0023] (Second Embodiment) The thrust enhancement device of the second embodiment will be described based on Figures 4 to 7. In this embodiment, a sloping deck 6 is formed at the bow of the vessel S, sloping downward from the forward area toward the front end of the bow. In other words, in this invention, the upper part of the tip of the bow is shaped as if it were cut at an angle. Furthermore, a wind guide slope may or may not be provided following the front end of the sloping deck 6.

[0024] A lift-generating plate 10 that generates upward and forward lift is installed on the inclined deck 6 described above. The thrust-enhancing device of this embodiment consists of this lift-generating plate 10 and the inclined deck 6.

[0025] As shown in Figure 7, when the lift generating plate 10 is installed on the inclined deck 6, the wind coming from the front of the ship S is straightened into a laminar flow as it passes between the lift generating plate 10 and the inclined deck 6. At the same time, the wind on the upper surface of the lift generating plate 10 is also straightened. In addition, the lift generating plate 10 functions to direct the wind blowing from the front to the rear of the ship on the inclined deck 6 upwards towards the superstructure 3.

[0026] In this embodiment as well, when the lift generating plate 10 is placed in a laminar flow Fl, a lift force Df is generated. This lift force Df is higher when the lift generating plate 10 has an airfoil cross-section. In this embodiment, a synergistic effect occurs due to the high lift-to-drag ratio of the lift generating plate 10 and the laminar flow Fl of the airflow, resulting in a very large lift force Df. This lift force Df provides buoyancy to the vessel S through its vertical component and thrust to the vessel S through its horizontal component (forward). Therefore, energy savings can be achieved during the vessel S's navigation.

[0027] In this embodiment, as shown in Figure 7, it is preferable to set the inclination angle θ of the inclined deck 6 (the intersecting surface with the upper deck 2) based on the distance D from the front wall of the superstructure 3 to the center of the lift generating plate 10. The fore-aft width d of the inclined deck 6 decreases as it approaches the bow 4 and increases as it moves away from the bow 4. Since the magnitude of this fore-aft width d is a factor that determines the fore-aft width of the lift generating plate 10 to be installed, i.e., the magnitude of the lift Df, the optimal value should be set based on the magnitude of the lift Df to be obtained.

[0028] The bottom surface of the lift generating plate 10 may be installed parallel to the top surface of the inclined deck 6, or the lift generating plate 10 may be tilted relative to the inclined deck 6, with its front end positioned higher than its rear end. In this case, a larger volume of air can be straightened by the lift generating plate 10 and the inclined deck 6.

[0029] (Effects of the present invention) 1: Wind pressure reduction effect Wind tunnel tests conducted with the invention of the applicant's prior application (Japanese Patent Application No. 2023-71626) (a structure in which a lift-generating plate is installed on the forward deck of the superstructure) confirmed that the airfoil-shaped lift-generating plate 10 reduces the wind pressure resistance acting on the model ship due to wind from the front of the hull by approximately 3 to 8% compared to a lift-generating plate of the same size with a rectangular cross-section.

[0030] As described above, wind resistance can be reduced by equipping the airfoil-shaped lift-generating plate 10. Moreover, the lift Df generated by the lift-generating plate 10 can be converted into the propulsion force of the ship S.

[0031] 2. Improved forward visibility In this invention, the lift generating plate 10 is installed on the upper deck extension 2a at the tip of the upper deck 2, or on the inclined deck 6, so that the height of the upper surface of the lift generating plate 10 can be reduced. As a result, as shown in Figure 8, the line of sight L (solid line) visible from the bridge is lowered. In other words, the angle at which it intersects the horizon becomes deeper. As a result, a wider forward view, especially a forward and downward view, can be secured. This effect is the same in both the first and second embodiments described herein.

[0032] In Figure 8, the lift generating plate 10', indicated by the dashed line, is installed on the forward deck of the superstructure 3, as adopted in the applicant's prior application (Japanese Patent Application No. 2023-71626). In this configuration, the installation height of the lift generating plate 10' is increased, so the line of sight L' (dashed line) visible from the bridge is also increased (the angle of intersection with the horizon becomes shallower), and the field of view reaching the front of the bow becomes further away. In the prior art shown in Figure 9, the height of the intermediate layer windscreen 121 is high and its mounting position is close to the bridge, so it is thought that securing forward visibility was not considered. In contrast to the above, the thrust enhancement device of the present invention has the effect of providing a good forward view. [Industrial applicability]

[0033] The thrust enhancement device of the present invention can be applied to container ships and large passenger ships other than car carriers S, and furthermore, it can be applied to all kinds of vessels. [Explanation of Symbols]

[0034] 1. Hull 2 Upper deck 3 Superstructure 4 Fore part 6 Sloped deck 10 Lift generating plate

Claims

1. The upper deck of a ship, in the forward portion and aft of the bow, is equipped with a superstructure. The forward end of the aforementioned bow section is formed with a wind-guiding slope that slopes downward toward the front. A lift-generating plate that generates upward and forward lift is installed on the upper surface of the upper deck at the bow of the ship. A thrust-enhancing device for ships characterized by the following:

2. The lift-generating plate is located on the upper surface of the upper deck, in a position that directs wind from the front of the hull upwards to the superstructure. The thrust enhancement device for a ship according to claim 1, characterized in that it is a ship.

3. The lift generating plate is installed on the upper surface of the upper deck, immediately behind the wind guide slope. The thrust enhancement device for a ship according to claim 2, characterized in that it is a ship.

4. In the forward portion of the bow, a sloping deck is formed between the aft end of the wind-guiding slope and the forward end of the bow. The lift-generating plate is installed on the upper surface of the inclined deck. The thrust enhancement device for a ship according to claim 2, characterized in that it is a ship.

5. The lift-generating plate is formed in the shape of an airfoil in cross-section. A thrust booster for a ship according to claim 1, 2, 3, or 4, characterized by the features described above.

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