JPS6342073Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a ship in which breaking waves at the bow of the ship, particularly those generated on the side of the ship's bow, are reduced and hull resistance is reduced.

Conventionally, as shown in Figures 1 and 2, when a ship a with a small entrance angle θ sails on water, water forms a thin film along both sides of the bow slightly aft of the bow perpendicular b. This bulge (arrow d) eventually separates from each bow side c and falls onto the water surface at a steep angle, causing waves to break. At the falling part, turbulence on the water surface and a vortex f are generated, and this vortex f does not disappear and extends to the rear of the ship along the ship's side g, increasing the hull resistance. Air bubbles caused various problems such as sonar malfunction, reduced propeller efficiency, and cavitation.

The present invention was made in order to solve the above problems by reducing the generation of vortices, and the present invention is a rectifying plate that is sloped downwardly toward the outside and has a concave surface toward the top. is attached to both sides of the bow on the waterline slightly aft of the bow perpendicular with a gap between it and the hull, and the lower end of the current plate approaches a horizontal plane including the waterline. The current plate catches the water falling from the vessel and returns it to the water surface after changing the direction of the flow to a nearly horizontal direction, which prevents the generation of eddies.As a result, breaking wave resistance is reduced and hull resistance is reduced. It has the following advantages:

Hereinafter, embodiments of the present invention will be described based on the drawings. Figures 3 to 7 show an embodiment of the present invention, and in the figures, 1 is a hull having a small cutting angle θ, 2 is the center of the hull, 3 is a bow perpendicular, 4 is a bow valve, and 5 is a hull with a small cutting angle θ. A substantially rectangular rectifying plate 7 having an upwardly concave surface at a predetermined position on both sides 6, 6 of the bow on the water line slightly behind the bow perpendicular 3, that is, the position where water separated from the ship side falls. ,7
is attached to the hull 1 via struts 8,8.

Each of the current plates 7, 7 is inclined downwardly toward the outside as shown in FIG.
As shown in FIG. 6, the lower side 12 of the current plate is bent so as to circumscribe the water surface 13 located near the bow water line, as shown in FIG.

Next, the function of the current plate 7 will be explained with reference to FIG. While the hull 1 is moving forward, the water that has risen in a thin film along the bow side 6 rises diagonally rearward (arrow j) due to the flare provided at the bow and the hull surface.
Thereafter, it peels off from the hull surface and falls, and is caught by the current plate 7.

As shown in FIG. 6, the falling water has a horizontal velocity component u and a vertical velocity component v at a point k just before contacting the current plate 7, but it flows down this concave surface 10. When the direction changes, the velocity in the horizontal direction changes at the point where it leaves the current plate 7.
It has only u' and flows almost parallel to the water surface 13 and returns to the water surface 13. Therefore, the turbulence of the water surface on the side of the bow caused by the falling water film, which was observed in conventional ships, is alleviated.
The generation of vortices at the falling position is reduced.

It should be noted that the present invention is not limited to the above-described embodiments, and it goes without saying that various changes can be made without departing from the gist of the present invention.

Since the ship of the present invention has the above-described configuration, it exhibits the following excellent effects.

(i) Straightening plates attached to both sides of the bow are used to catch water falling from the side of the ship, and the concave surfaces of the plates change the direction of the water flow to almost horizontal before returning it to the water surface. It can reduce breaking waves, prevent the generation of vortices, and reduce hull resistance.

(ii) As a result of item (i), it is possible to prevent air bubbles from being drawn into the bottom of the ship due to vortices, and it is possible to eliminate problems such as sonar malfunction, reduced propeller efficiency, and cavitation.

(iii) It can be easily implemented not only for new ships but also for existing ships as part of modification work, and the current plate is installed on both sides of the ship on the waterline slightly aft of the bow perpendicular and in the gap between the ship and the ship. Since the current plate is installed with a berth, it is possible to reliably see the current plate, so when a ship approaches or leaves the quay, the vessel can be maneuvered to avoid damage due to contact with the current plate on the quay or other vessels. This can be done easily, and there is no risk of damaging the rectifying plate by the anchor when dropping or dropping the anchor.

[Brief explanation of the drawing]

Figures 1 and 2 are explanatory diagrams of breaking waves and vortices that occur on the bow side of conventional ships;
7 to 7 show an embodiment of the present invention, FIG. 3 is a partial side view of a hull with a sharp bow, and FIGS. 6 is an explanatory diagram of the cross-sectional shape of the current plate shown in FIG. 3, and FIG.
FIG. 2 is an explanatory diagram of the traveling state of the hull shown in the figure. In the figure, 6... bow side, 7... straightening plate, 10...
... Concave surface of the current plate, 12... Indicates the lower side of the current plate.

Claims (1)

[Scope of utility model registration request] A rectifying plate that is inclined downwardly toward the outside and has a concave surface facing upward is installed on both sides of the bow on the waterline slightly aft of the bow perpendicular, with a gap between it and the hull, and the lower end of the rectifying plate is attached to the waterline A ship characterized in that it is configured to approach a horizontal plane that includes.