JPH0129196Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a stern rectification structure provided to rectify the flow in the stern of a ship and introduce it to a propeller.

The conventional stern rectifying structure is shown in Fig. 1 (side view of the stern), Fig. 2 (longitudinal cross-sectional view along the hull centerline of the conventional stern rectifying structure), and Fig. 3 (- in Fig. 2).
As shown in the sectional view shown in FIG. 3, a shew piece 4 is installed between a rudder support member 5 that supports the rudder 3 and the lower end of the stern frame 2.

The show piece 4 includes a plurality of vertical plate members 6.
The front end of the plurality of vertical plate members 6 is fixed to the lower end of the stern frame 2, and the rear end is fixed to the rudder receiver 5.

Further, the plurality of rectifying plates 7 are installed between the vertical plate members 6 at appropriate mutual intervals, rising and tilting rearward, and are fixed to each of the vertical plate members 6 at a substantially right angle.

In a ship equipped with such a shew piece 4, when the screw propeller 1 rotates and the ship sails, the water near the shew piece 4 flows rearwards from below the stern bottom 2b. However, since the flow passes between the vertical plate member 6 and the straightening plate member 7, it flows into the screw propeller rotating surface almost undisturbed and without slowing down the flow velocity.

Therefore, the flow velocity distribution at the propeller position becomes more uniform than in the case where the show piece 4 is not formed to have a rectifying structure.

However, in the case of the conventional flow straightening structure as described above, the flow velocity is slowed down near the hull centerline C by the stern bottom portion 2b.

That is, FIG. 4 is a graph showing the results of measuring the flow velocity distribution at an arbitrary radius within the propeller rotation circle in a cross section of the screw propeller position of a ship. In the stern rectification structure, the flow velocity decreases directly below the propeller (at the center of the hull), which is directly above the shew piece.

In this way, according to the conventional stern shape,
The flow velocity is slowed down by the stern bottom 2b near the hull centerline C, and the flow velocity distribution within the cross section at the propeller 1 position becomes uneven, causing thrust and moment fluctuations in the propeller 1, causing propeller vibration. There is a problem in that it becomes a force and causes the hull to vibrate.

The present invention attempts to solve these problems by providing a recess in the center of the hull and stern frame near the shewpiece, which equalizes the flow velocity distribution at the propeller position and reduces the propeller excitation force. It is an object of the present invention to provide a stern rectifying structure that improves propulsion performance while reducing hull vibration by reducing vibration.

Therefore, the stern rectification structure of the present invention includes a plurality of vertical plate members arranged at appropriate intervals in the ship width direction to connect the lower rear end of the stern hull and the rudder receiver below the stern tube. and a plurality of straightening plates installed at appropriate mutual intervals between the same longitudinal plate members and raised and tilted rearward. A recess is provided in the hull, and the recess guides a flow inclined in a direction opposite to the rotational direction of the propeller to the propeller behind the stern tube,
It is characterized by being formed in a direction inclined to the hull centerline.

An embodiment of the present invention will be explained below with reference to the drawings. Figures 4 to 6 show a stern rectification structure as an embodiment of the present invention, Figure 4 is a graph showing its characteristics, and Figure 5 is the hull of the ship. FIG. 6 is a longitudinal sectional view taken along the center line, and FIG. 6 is a sectional view taken along the - arrow in FIG.

As shown in FIGS. 1, 5, and 6, below the stern tube 2a, an appropriate section is installed in the width direction to connect the lower part of the rear end of the stern frame 2 constituting the stern hull with the rudder receiver 5. A plurality of vertical plate members 6 are arranged at intervals.

That is, the front ends of the plurality of vertical plate members 6 are fixed to the lower rear end of the stern frame 2, and the rear ends are fixed to the rudder receiver 5.

A plurality of rectifier plates 7 are installed between the vertical plate members 6 at appropriate intervals.

This rectifying plate member 7 is provided so as to be inclined rearward, and is fixed to each vertical plate member 6 at a substantially right angle.
The flow below the stern bottom 2b is guided to the rotating surface of the propeller 1.

In this way, the show piece 4 is formed by the vertical plate member 6 and the rectifying plate member 7.
supports the rudder 3 attached to the rudder support member 5 and rectifies the flow flowing into the propeller 1.

On the other hand, in the stern frame 2 that constitutes the stern hull,
A recess 12 is provided near the hull center line C from near the bottom of the stern tube 2a to the bottom of the ship.

This recessed portion 12 has both rear ends 14,
The depth from 14 to the front end 13 is formed to gradually increase from the lower part of the stern tube 2a to the bottom of the ship.

Further, the recessed portion 12 is formed such that its vertical center plane is inclined toward the starboard side toward the rear with respect to the hull centerline C.

That is, the flow passing through the recess 12 is given a velocity component toward the starboard side by the inner peripheral surface of the recess 12, and becomes a flow tilted in the opposite direction to the rotation direction of the propeller 1 (clockwise in this embodiment). It is designed so that it is guided by the plane of one revolution of the propeller.

Furthermore, both rear end portions 14, 14 of the recessed portion 12 are also twisted toward the starboard side toward the rear.

As a result, the flow along the stern hull is also given a velocity component toward the starboard side, and is guided to the plane of rotation of the propeller.

Since the stern rectification structure of the present invention is configured as described above, when the hull 10 is sailing, the stern bottom part 2
The flow near b flows through both outside sides of the shew piece 4 and the vertical plate member 6 and rectifying plate member 7 inside the shew piece 4.
is guided along the plane of one revolution of the propeller.

Further, a part of the flow passes through the recess 12 and is guided to the rotating surface of the propeller 1 without reducing the flow velocity.

Since the recess 12 is provided near the hull center line C, the flow passing through the recess 12 is
It is mainly guided directly below the propeller 1.

Therefore, the distribution of flow velocity within the rotating plane of the propeller 1 becomes uniform as shown by the broken line B in FIG. 4.

Further, the flow guided to the rotation surface of the propeller 1 described above is guided to the rotation surface of the propeller 1 with a speed component directed toward the starboard side added to the shape of the inner circumferential surface of the recess 12 and the outer surface of the stern hull.

As the propeller 1 rotates clockwise, the speed component toward the port side generated in the flow near the bottom of the rotating surface of the propeller 1 and the speed component toward the starboard side described above cancel each other out, and the speed component toward the starboard side described above is canceled out. The rotational flow that was occurring during this period is reduced.

This improves propeller efficiency and improves propulsion performance.

In this embodiment, the recess 12 is provided in the stern hull of a ship having the shew piece 4, but the same effect as described above can be obtained by providing a similar recess 12 in a ship that does not have the shew piece 4. be able to.

As detailed above, according to the stern rectification structure of the present invention, the stern tube is arranged at an appropriate interval in the width direction to connect the lower rear end of the stern hull and the rudder receiver below the stern tube. A shew piece is provided, which is made up of a plurality of vertical plate members and a plurality of rectifier plates installed at appropriate intervals between the longitudinal plate members and raised and tilted rearward, and extends from near the bottom of the stern tube to the bottom of the ship. A recess is provided in the stern hull near the centerline, and the recess is inclined with respect to the hull centerline in order to guide a flow inclined in a direction opposite to the rotational direction of the propeller to the propeller behind the stern tube. With a simple configuration in which the propeller is formed in the direction of
This has the advantage of reducing hull vibration and improving propulsion performance.

[Brief explanation of the drawing]

Figure 1 is a side view of the stern of a ship;
Figures 2 and 3 show the conventional stern rectification structure.
Figure 2 is a longitudinal sectional view taken along the centerline of the hull, Figure 3 is a sectional view taken along the - arrow in Figure 2, and Figures 4 to 6 show a stern rectifying structure as an embodiment of the present invention. Figure 4 is a graph showing its characteristics, Figure 5 is a longitudinal cross-sectional view along the hull center line, and Figure 6 is a graph showing its characteristics.
It is a sectional view taken along the - arrow in the figure. DESCRIPTION OF SYMBOLS 1... Propeller, 2... Stern aggregate, 2a... Stern tube, 2b... Stern bottom, 3... Rudder, 4... Shew piece, 5... Rudder receiving material, 6... Vertical plate member, 7
... Rectifier plate material, 10 ... Hull, 12 ... Recess, 1
3...Front end of the recess, 14...Rear end of the recess, C...
Hull centerline.

Claims (1)

[Scope of utility model registration request] Below the stern tube, a plurality of vertical plate members are arranged at appropriate intervals in the ship width direction to connect the lower rear end of the stern hull and the rudder receiver, and appropriate distances are provided between the longitudinal plate members. A shoe piece is provided, which is made up of a plurality of straightening plates installed at mutual intervals and raised and tilted rearward. is formed in a direction inclined with respect to the hull centerline so as to guide a flow inclined in a direction opposite to the rotating direction of the propeller to the propeller behind the stern tube.