JPS6152039B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a ship's shoe piece that makes the flow flowing into a screw propeller at the stern part uniform.

Conventionally, the show piece provided to support the rudder provided at the stern of the ship has been made of cast metal, or
Otherwise, it is a watertight structure constructed of steel.

When the screw propeller rotates and the ship sails, the flow of water at the stern becomes very complicated and flows into the screw propeller. In particular, the flow at the bottom of the ship is upward from the bottom and has a relatively high speed, so when it hits the shew piece, it is significantly disturbed and the flow speed becomes very slow. When the screw propeller rotates and the ship sails in such a flow field, the thrust and moment generated from the propeller blades fluctuate violently, causing vibration of the ship.

It also causes cavitation of the propeller.

Figure 1 is a side view of the stern, where 01 is the screw propeller, 02 is the stern frame, 03 is the rudder installed behind the screw propeller 02, and 04 is the
This is a shoe piece that is provided at the lower end of the stern frame 02 and supports the rudder 03 from below.

Figure 2 is a detailed view of the vicinity of Shew Piece 04, and the arrows indicate the direction of water flow when the ship is sailing.

Figure 3 shows the flow velocity distribution at an arbitrary radius within the propeller rotation circle in the cross section of the screw propeller 01 position when a conventional shoe piece is installed. hits the bottom of the piece 04.

In this case, the screw propeller 01 rotates,
When the ship is sailing, the flow of water near Shew Piece 04 is fast and flows upward from the bottom of the ship, as shown by the arrow in Figure 2. However, when a conventional show piece is installed, the flow is similar to the show piece 04.
The flow becomes extremely turbulent and very slow. Such a flow is Screw Propeller 01
The flow velocity distribution at the screw propeller 01 position fluctuates significantly and becomes extremely complicated.

As a result, there are disadvantages in that the thrust and moment of the propeller vary significantly, making it more likely that ship vibration will occur, and propeller cavitation will be more likely to occur.

The present invention was proposed for the purpose of eliminating such drawbacks, and the present invention has been proposed below the propeller, with one end attached to the lower end of the stern frame of the ship and the other end attached to the rudder support member supporting the rudder. A ship for use in a ship, characterized in that a plurality of vertical plate members arranged at equal distances from the longitudinal center of the ship are connected, and a plurality of reinforcing straightening plates tilting rearward upward are installed in a lattice shape between the vertical plate members. Provide you peace.

When the shew piece of the present invention is provided, the flow flowing upward from the bottom of the ship in the vicinity of the shew piece while the ship is sailing passes through the space between the vertical plate member and the reinforcing straightening member, so that almost no disturbance occurs at the shew piece. The liquid flows into the screw propeller without being blocked or slowing down.

As a result, the flow velocity distribution at the propeller position is made uniform, and fluctuations in propeller thrust and moment are reduced, reducing ship vibration due to the propeller excitation force. The occurrence of tachion is reduced.

Further, since the show piece is constructed by assembling the vertical plate member and the reinforcing rectifying member, the space through which the flow passes can be easily enlarged, and the show piece is also easy to manufacture.

Next, one embodiment of the device of the present invention will be described based on the drawings.

4 and 5 are a vertical side view and a vertical plan view of the show piece according to this embodiment. In the figure, 2
4 is a stern aggregate, 4 is a shoe piece attached to the lower end of the stern aggregate 2, and 5 is a rudder receiver provided at the tip of the shoe piece 4. 6, the rear end is the rudder receiving material 5
The front end is a plurality of vertical plates fixed to the lower end of the stern frame 2 and arranged at appropriate intervals in the width direction of the ship. Reference numeral 7 denotes a reinforcing rectifying plate installed between each vertical plate 6 at a substantially right angle to each vertical plate, and these reinforcing rectifying plates are fixed to the vertical plate 6 obliquely upward at the rear.

In a ship equipped with such a shew piece, when the screw propeller rotates and the ship sails, water near the shew piece flows upward from the bottom of the ship as shown by the arrow in FIG. However, since the flow passes between the vertical plate 6 and the reinforcing straightening plate 7, it flows into the screw propeller almost undisturbed and without slowing down the flow velocity.

Therefore, the flow velocity distribution at the propeller position becomes nearly uniform.

FIG. 6 is a diagram 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 equipped with the present show piece. In the diagram, the part directly below the propeller (center of the hull) is directly above the shew piece.

Comparing FIG. 6 with FIG. 3 which shows the flow velocity distribution when a conventional show piece is installed, it can be seen that the flow velocity directly below the propeller in FIG. 6 is increased and the flow velocity is made uniform.

In this way, according to this device, the flow flowing into the propeller is made more uniform than in the case of using a conventional show piece, and therefore the thrust of the propeller and
This has the advantage that moment fluctuations are reduced, hull vibration is reduced, and propeller cavitation is less likely to occur. Furthermore, since the show piece is manufactured by assembling the vertical plate and the reinforcing straightening plate, the space through which the flow passes can be easily made large, and the show piece is also easy to manufacture.

[Brief explanation of the drawing]

Figure 1 is a side view showing the stern of the ship, Figure 2 is an enlarged view of the vicinity of the shew piece in Figure 1, and Figure 3 is a side view showing the stern of the ship.
The figure is a diagram showing the flow velocity distribution within the rotation circle of the screw propeller when a conventional showpiece is provided, and FIGS. 4 and 5 show an embodiment of the device of the present invention,
Figure 4 is a vertical sectional side view taken along line - in Figure 5, Figure 5 is a longitudinal sectional plan view taken along line - in Figure 4, and Figure 6 is a screwdriver of a ship equipped with the above equipment. FIG. 2 is a diagram showing flow velocity distribution within a propeller rotation circle. 01... Screw propeller, 02, 2... Stern frame, 03... Rudder, 04, 4... Sew piece, 5... Rudder receiving material, 6... Vertical plate, 7... Reinforced straightening plate.

Claims (1)

[Claims] 1. Below the propeller, a plurality of vertical plate members are disposed equidistantly from the longitudinal center of the ship, with one end at the lower end of the stern frame of the ship and the other end at the rudder support member supporting the rudder. 1. A ship piece, characterized in that a plurality of reinforcing rectifier plates are connected to each other and are installed in a lattice shape between the vertical plate members and inclined rearwardly upward.