JPH0437039Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a device for reducing vortices generated in the bilge section of a ship's hull.

[Conventional technology]

Generally, as shown in Figures 3 and 4, a ship in which the side of the central part of the hull 1 is formed as a parallel hull part 2, and the stern bottom part 4 behind the parallel hull part 2 gradually becomes thinner. is often used.

In addition, in FIGS. 3 and 4, reference numeral 8 indicates a main screw propeller, and reference numeral 9 indicates a rudder.

[Problem that the invention attempts to solve]

In such a ship, bilge vortices 5a and 5b generated in the rear parts of the left and right hull parallel parts 2 and the bilge part 3 of the bottom side part 4, respectively, when sailing, cause the bilge vortices 5a and 5b to flow into the stern shell plates 4a and 4b of the bottom side part 4. It flows backwards while developing along the .

The bilge vortex 5a generated on the starboard side has a counterclockwise rotational component when viewed from the rear of the hull, and the bilge vortex 5b generated on the port side has a clockwise rotational component when viewed from the rear of the hull. Since the bilge vortices 5a and 5b as described above increase the hull resistance of the hull 1, there is a problem that the propulsion performance of the marine vessel is reduced.

This invention aims to solve the above-mentioned problems, and by canceling out the bilge vortices generated in the bilge part of the ship's hull during cruising with a rotating flow in the opposite direction to the rotational direction of the bilge vortices, the ship's resistance is increased. An object of the present invention is to provide a bilge vortex reduction device for a ship, which reduces the vortex and improves the propulsion performance of the ship.

[Means for solving problems]

For this reason, the ship bilge vortex reduction device of the present invention is
In order to reduce the bilge vortex that occurs along the thin outer surface of the hull behind the rear end of the bilge in the parallel part of the hull, by generating a flow that rotates in the opposite direction to the rotation direction of the bilge vortex, the starboard side and A starboard rectifier propeller and a port rectifier propeller are provided near the rear end of each bilge part on the port side, and the starboard rectifier propeller is provided to rotate clockwise when viewed from the rear of the hull, and the port side rectifier propeller is provided so as to be driven to rotate clockwise. It is characterized by a rectifying propeller that is rotated counterclockwise.

[Effect]

In the ship bilge vortex reduction device of the present invention described above,
The rectifying propellers provided on both sides of the bottom of the stern rotate in a direction opposite to the rotating direction of the bilge vortex, thereby canceling out and reducing the bilge vortex.

〔Example〕

Hereinafter, a bilge vortex reduction device for ships as an embodiment of the present invention will be explained with reference to the drawings.
The figure is a front view of the stern of a vessel equipped with the device, and FIG. 2 is a side view of the stern of the vessel.

As shown in Figures 1 and 2, in a ship where the side of the central part of the hull 1 is formed as a parallel hull part 2, and the stern bottom part 4 behind the parallel hull part 2 gradually becomes thinner. , a main screw propeller 8 is provided at the center rear end of the stern section.

At the stern bottom part 4 forward of the main screw propeller 8, the bilge parts 3 on its starboard and port sides
Propeller shafts 7a and 7b are provided to protrude rearward from the stern shell plates 4a and 4b near the rear end, respectively.
A starboard rectifying propeller 6a and a port rectifying propeller 6b are respectively attached to the rear end of the propeller b.

The starboard side rectifying propeller 6a is rotated clockwise when viewed from the rear of the hull by a drive device (not shown) inside the hull, and the port side rectifying propeller 6b is driven by a drive device (not shown) inside the hull. It is designed to rotate counterclockwise when viewed from the rear of the hull. As a result, the rectifying propellers 6a, 6b on the starboard side and the port side, respectively,
It will be rotated in the opposite direction to the direction of rotation. In addition, in FIGS. 1 and 2, the reference numeral 9 indicates a rudder.

Since the bilge vortex reduction device for a ship according to the present invention is configured as described above, when the ship body 1 is sailing,
Near the rear end of the bilge section 3, a drive device (not shown) drives the rectifying propellers 6a, 6 on the starboard side and the port side.
b are rotated in the opposite direction to the bilge vortices 5a and 5b generated in the bilge portion 3, so
Bilge vortex 5a,
The rotational component of 5b is canceled out.

In this way, the bilge vortex 5 included in the flow along the stern outer plates 4a and 4b of the stern bottom 4 of the hull 1
Since the rotational components caused by a and 5b are eliminated or significantly reduced, the hull resistance is reduced and the propulsion performance of the ship is significantly improved.

[Effect of idea]

As described in detail above, according to the bilge vortex reduction device of the present invention, the bilge vortex generated along the thin outer surface of the hull behind the rear end of the bilge in the parallel part of the hull can be reduced by the rotation of the bilge vortex. In order to reduce it by generating a flow that rotates in the opposite direction,
A starboard rectifier propeller and a port rectifier propeller are provided near the rear end of each bilge part on the starboard side and port side, respectively, and the starboard rectifier propeller is provided so as to be driven to rotate clockwise when viewed from the rear of the hull, With a simple configuration in which the port side rectifying propeller is installed to rotate counterclockwise, the bilge vortex generated in the bilge part of the hull is transferred to the starboard and port sides, which rotate in the opposite direction to the bilge vortex. Since it is reliably canceled by the rectifying propeller, the rotational component of the flow included in the flow along the outer surface of the hull at the bottom of the stern is eliminated or significantly reduced, reducing hull resistance and improving the propulsion performance of the vessel. Significantly improved.

This also has the advantage of reducing fuel consumption required for sailing the ship, and significantly reducing costs associated with its operation.

[Brief explanation of the drawing]

Figures 1 and 2 show a bilge vortex reduction device for a ship as an embodiment of the present invention. Figure 1 is a stern front view of a ship equipped with the device, and Figure 2 is a stern side view of the same ship. FIGS. 3 and 4 show the stern of a conventional ship, with FIG. 3 being a front view thereof and FIG. 4 being a side view thereof. 1... Hull, 2... Parallel part of the hull, 3... Bilge part, 4... Stern bottom, 4a, 4b... Stern outer plate, 5a, 5b... Bilge vortex, 6a... Starboard rectifying propeller, 6b...Port side rectifying propeller, 7
a, 7b... propeller shaft, 8... main screw propeller, 9... rudder.

Claims (1)

[Scope of utility model registration request] In order to reduce the bilge vortex that occurs along the thin outer surface of the hull behind the rear end of the bilge in the parallel part of the hull, by generating a flow that rotates in the opposite direction to the rotation direction of the bilge vortex, the starboard side and A starboard rectifier propeller and a port rectifier propeller are provided near the rear end of each bilge portion on the port side, and the starboard rectifier propeller is provided so as to be driven to rotate clockwise when viewed from the rear of the hull,
A bilge vortex reduction device for a ship, characterized in that the port side rectifying propeller is provided so as to be driven to rotate counterclockwise.