KR102209084B1 - A rudder for ship - Google Patents

Abstract

A ship rudder according to an embodiment of the present invention includes a rudder body for manipulating a ship by receiving a wake of a propeller in a ship rudder, and when the lower end of the rudder body is viewed from the side, it has a downwardly convex curved shape. It is characterized by having.

Description

A rudder for ship

The present invention relates to a ship rudder.

The present invention is derived from a study conducted as part of the industrial convergence source technology development project of the Ministry of Knowledge Economy and the Korea Institute of Industrial Technology Evaluation. [Task identification number: 10040060, Task name: Development of additional energy-saving devices for each ship type, improving resistance propulsion performance, and Apply solid line]

In general, in the case of a large ship, a method of advancing by using the flow of fluid generated when a propeller attached to the rear of the hull rotates is used. At this time, a rudder is attached to the rear of the propeller, and as the rudder rotates left and right, the direction of navigation is changed by adjusting the flow direction of the fluid.

In this way, in order to achieve a certain speed through rotation of the propeller, the engine must be driven using oil such as diesel. In this case, a large amount of oil is consumed and greenhouse gas is discharged, causing problems such as environmental destruction. .

Therefore, in recent years, various efforts have been made to reduce fuel consumption by reducing energy consumed during propulsion of a ship. In particular, IMO discussed ways to reduce GHG emissions during ship operation in 2010, and is in the process of debating the standards and directions for fuel economy regulations.

As shipping companies joined in this movement, shipping companies began to pay attention to fuel-saving ships that could reduce the burden of fuel costs. In response to the needs of shipping companies, shipbuilders have been continuously researching and developing fuel-saving technologies that can reduce fuel consumption and reduce greenhouse gas emissions.

As an example of fuel-saving technology, an energy saving device (ESD: Energy Saving Device) that saves fuel while increasing propulsion efficiency by improving the shape of a ship's tail, propeller, rudder, etc. It is receiving attention, and these energy-saving supplementary devices have already been applied and used in a significant number of ships.

It can be seen that the conventional ship rudder has an extended rudder 1 close to the lowermost tip portion of the propeller 2 as disclosed in FIG. 1 of Patent Document 1. In this case, due to the wake flow of the propeller 2, the conventional rudder 1 has a problem in that the propulsion performance of the ship is deteriorated due to the loss of lift and cavitation.

In order to solve this problem, the rudder 5 of Patent Document 1 is partially solving the above problem by applying the rudder 5 only to one side above the propeller shaft based on the propeller shaft, and the rudder 6 of Patent Document 2 is also a propeller. By providing the rudder 6 only above the lower part of the cab, some of the above problems are being solved.

However, in Patent Documents 1 and 2, the problem of reducing the occurrence of cavitation formed at the lower end of the rudder remains a problem as the rudder is manufactured by focusing only on the wake flow of the rudder.

Accordingly, in order to solve the problem of cavitation occurring in the lower part of the rudder, various solutions are proposed in Patent Documents 3 and 4.

Among them, in Patent Document 3, in order to prevent erosion and damage due to cavitation, the cross section of the rudder as a whole is maintained and the inclination of the lower part of the rudder is reduced to reduce the thickness of the lower section of the rudder. At this time, when the rudder of Patent Document 3 is viewed from the front, the lower end of the rudder is flat in a trapezoidal shape, and even when the rudder is viewed from the side, the lower end of the lower part of the rudder is at least partially formed flat. Has been.

In addition, in Patent Document 4, the shoulder portion 50 of the lower rudder 30 is formed so that both side surfaces 52 are inclined at an angle ranging from 45° to 55° in the direction of the bottom surface 54, and in the shoulder portion 50 By reducing the influence of the cavitation of the rudder, the cavitation generated in the lower part of the rudder has little influence on the floor surface 54 and is allowed to escape downstream. Even at this time, when the rudder of Patent Document 4 is viewed from the front, the lower end of the rudder has a trapezoidal shape laid down as in Patent Document 3, and the lowermost end is formed flat, and when the rudder is viewed from the side, At least part of the lower end is formed flat as in Patent Document 3.

As described above, the rudders of Patent Documents 3 and 4 are trying to partially solve the problem of cavitation with their lower shape, but only lateral flow analysis of the lower end of the rudder is considered, and the flow under the lower end of the rudder is There is a problem that does not effectively solve cavitation reduction because research has not been conducted.

Korean Patent Publication No. 10-2011-0109306 Japanese Unexamined Patent Application Publication No. Hei 10-138998 Korean Utility Model Publication No. 20-0446855 Korean Patent Publication No. 10-1010998 Korean Patent Publication No. 10-1580404 Korean Patent Publication No. 10-2010-0086385 Korean Patent Publication No. 10-2014-0004717

The present invention has been created to solve the problems of the prior art as described above, and an object of the present invention is to provide a rudder for a ship that is optimized for a propeller wake flow and improves steering performance and propulsion performance of a ship.

A ship rudder according to an embodiment of the present invention includes a rudder body for manipulating a ship by receiving a wake of a propeller in a ship rudder, and when the lower end of the rudder body is viewed from the side, it has a downwardly convex curved shape. It is characterized by having.

Specifically, when viewed from the front, the lower end of the rudder body may have a curved shape that is convex downward.

Specifically, the rudder body, the top surface; Bottom side; And a side surface extending from the upper surface to the lower surface.

Specifically, the lower end may be formed extending downward from the lower surface of the rudder body.

Specifically, the lower end may have a maximum downward protrusion length of 0.02 to 0.07 of the propeller radius.

Specifically, the lower end may have a maximum downward protrusion length of 0.05 to 0.35 of the propeller shaft diameter.

Specifically, the lower end may be located within 20 to 40% of the point at which the maximum downward protrusion length is maximum in the front and rear direction from the front end of the lower end of the rudder body.

Specifically, the rudder body may have the lower end formed only up to a line at the lower end of the shaft of the propeller.

Specifically, the rudder body, the lower surface is located between the lower end line of the shaft of the propeller and the lower end line of the propeller, it may be provided closer to the lower end line of the shaft of the propeller.

Specifically, the rudder body may have the lower surface located within 0.5 vertical length of the propeller radius from the lower end line of the propeller shaft.

Specifically, the rudder body may have a length of less than 1.3 of a vertical length from the upper end of the rudder body to a line at the lower end of the shaft of the propeller.

Specifically, the rudder body may be provided in a region where the lower end surface is closer to the propeller shaft than the tip of the propeller based on an intermediate position of the propeller radius.

Specifically, the lower surface may be formed such that the rear surface has a curvature.

Specifically, the curvature may have a radius of 8m to 12m.

Specifically, the rear edge of the rudder body may extend from the top surface to an upper position of 45mm to 55mm upward from the maximum protruding point downward of the lower end.

Specifically, the lower surface may be formed so that the front surface has a curvature.

Specifically, the curvature may have a radius of 0.5m to 1m.

Specifically, it may further include a rudder bulb having a central axis formed on the same axis as the propeller shaft on the leading edge of the rudder body.

Specifically, the rudder bulb may be formed such that a maximum cross section is smaller than a maximum cross section of the propeller shaft.

Specifically, the rudder bulb may be formed such that the lower end is located in the lower end line of the shaft of the propeller.

Specifically, a current (Pre-swirl) pin formed on one side of the left or right side of the rudder may be further included.

The ship rudder according to the present invention has the effect of securing the ship's steering performance to the maximum by extending it to the lower line of the propeller shaft at a certain interval, while being optimized for the wake flow of the propeller to reduce drag generated in the rudder and improve lift. There is an effect of improving the propulsion performance of the ship.

In addition, since the ship rudder according to the present invention is optimized for the wake flow of the propeller by extending at a certain interval to the lower line of the propeller shaft, it is possible to actively cope with the occurrence of cavitation of the rudder, thereby improving the durability of the rudder.

In addition, the rudder for a ship according to the present invention has the effect of minimizing cavitation occurring in the rudder by making the lower rudder and the front part of the rudder in a round shape, thereby minimizing noise pollution and maximizing the propulsion performance of the ship. There is.

1A is a bottom perspective view of a ship rudder of the present invention.
Figure 1b is a bottom view of the ship rudder of the present invention.
Figure 1c is a front view of the ship rudder of the present invention.
Figure 1d is a side view of the ship rudder of the present invention.
Figure 1e is a bottom front cross-sectional view of the ship rudder of the present invention.
Figure 2a is a side view of a ship rudder according to an embodiment of the present invention.
2B is a cross-sectional view of a ship rudder according to an embodiment of the present invention.
2C is a bottom perspective view of a ship rudder according to an embodiment of the present invention.
3 is a side view of a ship rudder according to another embodiment of the present invention.
4 is a comparison diagram of a conventional ship rudder and a ship rudder of the present invention.
5A is a side view of a ship rudder according to another embodiment of the present invention.
5B is a detailed view of a lower front edge (A) of a ship rudder according to another embodiment of the present invention.
6 is a side view of a ship rudder according to another embodiment of the present invention.
7 is a cavitation experiment diagram for a wake of a propeller of a conventional ship rudder without a round shape at the lower end.
8 is a cavitation experiment diagram for a wake of a propeller of a ship rudder of the present invention having a round shape at a lower end thereof.
9A is an experimental diagram of whether cavitation occurs according to the amount of change in the length of the lower end of the rudder of the present invention separated from the lower end of the rudder.
9B is a view showing examples of variations in the length of the lower end round shape of the ship rudder of the present invention separated from the lower end of the rudder.
9C is an energy reduction result table according to the amount of change in the length of the lower end of the rudder of the present invention separated from the lower end of the rudder.
9D is a first view of CFD showing whether cavitation occurs according to the amount of change in the length of the lower end of the rudder of the present invention separated from the lower end of the rudder.
9E is a second view of CFD showing whether cavitation occurs according to the amount of change in the length of the lower end of the rudder of the present invention separated from the lower end of the rudder.
10A is a diagram illustrating a rudder torsional moment according to any one of the longitudinal positions of the lower end of the rudder in the round shape of the lower end of the rudder of the present invention.
Figure 10b is a view showing any one embodiment of the longitudinal position of the lower end of the rudder of the present invention in the form of a rounded lower end of the rudder.
10C is a table showing a result of a rudder twisting moment according to any one of the longitudinal positions of the lower end of the rudder in the form of a lower end round of the rudder of the present invention.

Objects, specific advantages and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments associated with the accompanying drawings. In adding reference numerals to elements of each drawing in the present specification, it should be noted that, even though they are indicated on different drawings, only the same elements are to have the same number as possible. In addition, in describing the present invention, when it is determined that a detailed description of related known technologies may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 1a is a bottom perspective view of the ship rudder of the present invention, Figure 1b is a bottom view of the ship rudder of the present invention, Figure 1c is a front view of the ship rudder of the present invention, Figure 1d is a side view of the ship rudder of the present invention, Figure 1e is A lower front cross-sectional view of a ship rudder of the present invention, FIG. 2A is a side view of a ship rudder according to an embodiment of the present invention, FIG. 2B is a cross-sectional view of a ship rudder according to an embodiment of the present invention, and FIG. 2C is an embodiment of the present invention. A bottom perspective view of a ship rudder according to an example, FIG. 3 is a side view of a ship rudder according to another embodiment of the present invention, FIG. 4 is a comparison view of a conventional ship rudder and a ship rudder of the present invention, and FIG. 5A is another embodiment of the present invention. A side view of a ship rudder according to an example, FIG. 5B is a detailed view of a lower front edge (A) of a ship rudder according to another embodiment of the present invention, and FIG. 6 is a side view of a ship rudder according to another embodiment of the present invention.

1 to 6, the rudder 1 for a ship includes a rudder body 10, a lower end 20, a rudder skeg 30, a propeller, and a rudder bulb 50. Hereinafter, the configurations will be described in detail with reference to the drawings.

The rudder body 10 is located at the rear of the propeller and extends downward from the rudder skeg 30 formed in the stern 2 of the hull (not shown), and receives the wake of the propeller to the ship (not shown). ) To control the navigation direction.

Specifically, the rudder body 10 is formed surrounded by the left side of the rudder 11, the right side of the rudder 12, the top side 15 and the bottom side 16, and the front edge of the rudder body receiving the wake of the propeller first ( 13) and a rear edge portion 14 of the rudder body that finally flows the wake of the propeller.

The left side of the rudder 11 and the right side of the rudder 12 are faces formed on the left and right sides of the rudder body 10, and are left from the upper face 15 to the lower face 16 in contact with the rudder skeg 30, respectively. It may be formed by extending downward or downward to the right.

The rudder body leading edge 13 and the trailing edge 14 are formed on the front and rear sides of the rudder body 10, and the rudder body leading edge 13 is the first It is received, and the rear edge portion 14 of the rudder body may finally flow the wake of the propeller from the rudder body 10.

2A, the rudder body leading edge 13 and the rudder body trailing edge 14 are formed only up to the propeller shaft lower end line L1 (in this case, the rudder bottom line L2 is the propeller shaft lower end line L1). )), and looking at FIG. 3, it may be formed to extend by a predetermined length past the line L1 at the lower end of the propeller shaft. (In this case, the rudder body leading edge 13 and the rudder body trailing edge 14 may be formed up to the bottom line L2 of the rudder.)

The ship rudder 1 of the present invention disclosed in FIG. 3 further includes a rudder body lower front edge 131 and a rudder body lower rear edge 141, and a detailed description thereof will be described later.

The upper surface 15 and the lower surface 16 are surfaces formed on the upper and lower sides of the rudder body 10, and the upper surface 15 abuts the rudder skeg 30, and the lower surface 16 will be described later. It may be formed to be in contact with the lower end 20 to be done.

The lower surface 16 may have at least a portion of the front curvature R1, where the front curvature R1 is a curvature of the lower front edge of the rudder body, and at least a portion of the lower front edge 131 and the lower end 20 of the rudder body Can include. The curvature R1 of the lower leading edge of the rudder body may preferably have a radius of 0.5m to 1m (see FIGS. 5A and 5B).

Through this, the ship rudder 1 of the present invention can smoothly connect the front where the lower end 20 and the lower surface 16 are connected in a streamlined manner, so that the occurrence of a step that causes cavitation is prevented and thus the ship rudder ( Cavitation generated in the lower part of 1) can be more effectively reduced.

In addition, the lower surface 16 may have at least a portion of the rear curvature R2, where the rear curvature R2 is a curvature of the lower rear edge of the rudder body, and the rear of the lower rear edge 141 and the lower end 20 of the rudder body It may include at least some (see FIG. 6).

The curvature (R2) of the lower trailing edge of the rudder body may have a radius of 8m to 12m, and it extends from the top surface 15 to the upper position of 45mm to 55mm from the maximum downward protrusion point (D _LS ) of the lower end 20 Can be.

Through this, the ship rudder 1 of the present invention can smoothly connect the rear, where the lower end 20 and the lower end 16 are connected, in a streamlined manner, and thus prevent the occurrence of a step that causes cavitation to occur, thereby preventing the ship rudder ( Cavitation generated in the lower part of 1) can be more effectively reduced.

The rudder body 10 may have a lower end 16 formed up to a lower end line L1 of the propeller shaft. At this time, the rudder body 10 is not provided with the lower front edge 131 of the rudder body and the lower rear edge 141 of the rudder body (see Fig. 2A).

Through this, the ship rudder 1 of the present invention has the effect of implementing an increase in propulsive power by not receiving a wake that causes a decrease in propulsion during the downward flow of the propeller wake.

In addition, the rudder body 10, unlike this, can be formed up to the rudder lower surface line L2 by extending the lower end 16 by a predetermined length past the lower end line L1 of the propeller shaft. )

Specifically, the rudder body 10 is located between the lower end line (L1) of the propeller shaft and the lower end line of the propeller, that is, between the lower end line (L1) of the propeller shaft and the propeller tip (411). , It may be provided closer to the lower end of the propeller shaft line (L1). That is, the rudder body 10 may be provided in an area where the lower surface 16 is closer to the propeller shaft 44 than the propeller tip 411 based on the intermediate position of the propeller radius PR.

These results were derived through a study in which the flow of the lower end of the propeller shaft from the line (L1) at the lower end of the propeller shaft rather than the vertical length of 0.5 of the propeller radius (PR) lowered the propulsion performance of the ship. .

In other words, not all of the flow after the lower end line (L1) of the propeller shaft in the wake of the propeller degrades the propulsion performance of the ship, so it is known that there is room for further downward extension from the lower end line (L1) of the propeller shaft. I put it out.

Therefore, in the ship rudder 1 of the present invention, numerically preferably, the lower end surface 16 of the rudder body 10 can be located within 0.5 vertical length of the propeller radius PR from the lower end line L1 of the propeller shaft. have. In the case of a general rudder, compared with the lower surface 16 of the rudder body 10 located at 0.9 vertical length or more of the propeller radius PR from the lower end line L1 of the propeller shaft, the rudder body 10 of the present invention is The lower surface 16 is provided much closer to the lower end line L1 of the propeller shaft.

In addition, numerically, preferably, the rudder body 10 may have a length of less than 1.3 of the vertical length from the top surface 15 of the rudder body 10 to the lower end line L1 of the propeller shaft.

At this time, the rudder body 10 may have a lower rudder body leading edge 131 and a rudder body lower trailing edge 141, each of the rudder body lower leading edge 131 and the rudder body lower trailing edge 141 The downward length of is the length from the lower end of the propeller shaft line (L1) to the lower end of the rudder line (L2).

With the additional lower extension of the ship rudder 1 shown in FIG. 3 as described above, the ship rudder 1 in FIG. 3 may have a wider side area than the ship rudder 1 in FIG. 2A. This difference is that while the ship rudder 1 in FIG. 3 can have the effect of improving the propulsion performance of the ship like the ship rudder 1 in FIG. 2A, it is improved than the steering performance of the ship rudder 1 in FIG. 2A. There is an additional effect of being.

Through this, the rudder for a ship of the present invention (1; the rudder shown in Fig. 3) is a rudder (the rudder shown in Fig. 2a) in which the lower end surface 16 of the rudder body 10 is formed to the lower end line L1 of the propeller shaft. In the same way as ), it has the effect of realizing an increase in propulsive power by not receiving a wake that causes a decrease in propulsive power during the downward flow of the propeller wake, and at the same time increasing the lateral area of the ship's rudder (1) to ensure sufficient steering capability of the ship. It works.

The ship rudders of the present invention and the conventional ship rudders described above are easy to compare at a glance when looking at FIG. 4.

In Figure 4 (a) is a conventional ship rudder, the lower end of the rudder body is located between the propeller shaft lower end line and the propeller tip, but is provided closer to the propeller tip.

On the other hand, (c) is a ship rudder 1 according to an embodiment of the present invention, and the lower end 16 is formed to the lower end line L1 of the propeller shaft.

And, (d) is a ship rudder (1) of another embodiment of the present invention, the lower surface 16 is located between the propeller shaft lower end line (L1) and the propeller tip 411, but the propeller shaft lower end line ( It is provided closer to L1).

The lower end 20 is formed extending downward from the lower surface 16, and may have a shape of a downwardly convex curve when viewed from the side and a downwardly convexly curved shape when viewed from the front. For example, the lower end 20 may be seen in a form protruding downward from the lower end 16 of the rudder body 10.

In the embodiment of the present invention, due to the geometrical shape of the lower end 20 as described above, it is possible to very effectively reduce cavitation generated under the ship rudder 1, so that vibration noise generated from the ship rudder 1 Can be reduced very effectively.

This can be easily seen visually by looking at Figs. 7 and 8, so this will be described while looking at Figs. 7 and 8.

7 is a cavitation experiment diagram for a propeller wake of a conventional ship rudder without a round shape at the lower end. Specifically, Figures 7 (a) and (c) are views showing the results of the experiment by generating a propeller wake in a conventional ship rudder that has no round shape at the lower end, and Figure 7 (b) is a lower end It is a diagram showing the results of the experiment by generating a propeller wake in a conventional ship rudder that does not have a round shape.

7 (a) to (c), it can be clearly seen that cavitation occurs on both sides because there is no round shape at the lower end. For this reason, in the conventional ship rudder, vibration noise is largely generated due to cavitation, and the rudder is damaged and the propulsion performance of the ship is deteriorated.

8 is a cavitation experiment diagram for a wake of a propeller of a ship rudder of the present invention having a round shape at a lower end thereof. Specifically, Figure 8 (a) is a view of the experiment result by generating a propeller wake on the ship rudder of the present invention having a round shape at the lower end, and looking at the result of the experiment from the front right side, and Figure 8 (b) is at the lower end. It is a diagram showing the results of the experiment by generating a propeller wake in the ship rudder of the present invention having a round shape from the front left.

8(a) to (b), it can be clearly seen that there is a round shape at the lower end, so that cavitation does not occur at all on both sides. For this reason, in the ship rudder 1 of the present invention, the occurrence of cavitation is dramatically minimized, so that vibration and noise are not generated, and the propulsion performance of the ship is maximized.

In addition, the applicant of the present invention has obtained the following numerical characteristics by studying the geometric characteristics of the lower end 20 of the ship rudder 1 described above in more detail.

That is, in the embodiment of the present invention, the lower end 20 has a lower maximum protrusion length (D _RS ) of 0.05 to 0.35 of a propeller shaft diameter (D) or a lower maximum protrusion length (D _RS ) of a propeller radius (PR). It may be from 0.02 to 0.07.

In addition, the lower end 20 in the embodiment of the present invention, the lower projection length up to the point (D _LS) is located within the 20% to 40% in the longitudinal direction from the bottom surface 16 the front end of the rudder body (10) can do.

The test results that derive the effect due to these numerical limitations will be described with reference to FIGS. 9 to 10C.

First, in an embodiment of the present invention, look at FIGS. 9A to 9E in order to explain in detail the result that the lower maximum protrusion length (D _RS ) of the lower end 20 is from 0.05 to 0.35 of the propeller shaft diameter (D). Let's see.

9A to 9E are experimental diagrams showing whether cavitation occurs according to the amount of change in the length of the lower end of the ship rudder of the present invention separated from the bottom surface, showing examples, energy reduction result table, cavitation generation Figures 1 and 2 show whether or not CFD.

9A to 9E, the ship rudder 1, which is the standard of the experiment, is disclosed in FIG. 9A, and the round shape of the lower end 20 has a length (D _RS ) separated from the lower surface 16 by 0.1 Classified as D, 0.2D, 0.3D, 0.4D, 0.5D, 0.7D, and 1.0D, respectively (see Fig. 9B; where D is the diameter of the propeller shaft, and D _RS is the lower end of the rudder lower end line L2). It is the horizontal length to the protruding point line (L3).)

The results of the experiment for each of the lengths D _RS spaced apart from the bottom surface 16 in the round shape of the lower end 20 are shown in FIG. 9C, and a CFD diagram can be seen in FIGS. 9D and 9E.

Referring to FIG. 9C, it can be seen that the output reduction effect is calculated at the highest (about 4.80% to about 4.83%) in 0.1D to 0.3D, which is clearly revealed as CFD in FIGS. 9D and 9E.

That is, through FIGS. 9A to 9E, the maximum downward protrusion length (D _RS ) of the lower end 20 of the ship rudder 1 of the present invention is optimally reduced in output from 0.05 to 0.35 of the propeller shaft diameter (D). It is derived that the effect occurs and the occurrence of cavitation is minimized.

When this is converted numerically with respect to the propeller radius PR, the maximum downward protrusion length D _RS becomes 0.02 to 0.07 of the propeller radius PR. Accordingly, the experimental result may be shared with a numerical limitation based on the propeller radius PR.

Next, the point (D _LS ) of the maximum downward protrusion length of the lower end 20 of the present invention is a value located within 20% to 40% in the front and rear direction from the front end of the lower end 16 of the rudder body 10 In order to describe the derived results in detail, FIGS. 10A to 10C will be described.

10A to 10C are diagrams showing examples of rudder torsion moment experiments according to any one of the longitudinal positions of the lower end of the rudder in which the maximum protruded position of the lower end of the ship rudder of the present invention is in the longitudinal direction, and a rudder torsion moment result table. .

10A to 10C, the ship rudder 1, which is the standard of the experiment, is disclosed in FIG. 10A, and the point D _LS where the downward protrusion length of the lower end 20 is the maximum is 0.125C, 0.250C, It was classified into AP, 0.375C, 0.500C, 0.625C, 0.750C, and 0.875C, respectively (see Fig. 10B; where C is the anteroposterior length (C) of the lower surface 16 of the rudder body 10)

The results of the experiment for each point (D _LS ) where the downward protrusion length of the lower end 20 is the maximum are shown in FIG. 10C, and looking at this, the degree of comparison of the rudder torsion moment at 0.20C to 0.40C is calculated to be the lowest (about 2% to about 9%).

That is, through FIGS. 10A to 10C, the point (D _LS ) where the downward protrusion length of the lower end 20 of the ship rudder 1 of the present invention is the maximum is at the front end of the lower end surface 16 of the rudder body 10 It can be seen that the minimum rudder torsional moment is generated at a position within 20% to 40% in the anteroposterior direction, so that the occurrence of cavitation is minimized.

Through the above experimental results, the lower end 20 in the embodiment of the present invention has a lower maximum protrusion length (DRS) of 0.05 to 0.35 of the propeller shaft diameter (D) (down maximum protrusion length (DRS) is a propeller radius ( PR) of 0.02 to 0.07), and the point where the downward protrusion length is maximum (DLS) may be designed to be located within 20% to 40% in the front and rear direction from the front end of the lower end surface 16 of the rudder body 10 .

Through this, the rudder 1 for a ship of the present invention does not generate any cavitation at the bottom due to the lower end 20, so that vibration and noise do not occur at all, and the propulsion performance of the ship is maximized.

The ship rudder 1 of the present invention has not been produced at all in the shipbuilding industry and has a form that cannot be found in the literature, so that novelty is very strong and cavitation can be very effectively reduced.

The rudder skeg 30 may protrude downward from the stern 2 to be integrally formed with the stern 2, and is provided between the stern 2 and the rudder body 10 to provide a ship rudder 1 to the stern ( It serves to directly or indirectly fix on 2), and is provided with at least one on the stern (2) (preferably one (short axis) or two (twin axis) installations) to help secure the straightness of the ship. Can give.

The rudder skeg 30 may be connected to the rudder body 10 by inserting a rudder shaft (not shown), and the cross section may have a curved front end and a sharp rear end.

Here, the cross section of the rudder skeg 30 is formed to be the same or similar to the cross section of the rudder body 10 so that the shape of the rudder skeg 30 and the shape of the rudder body 10 are continuously matched. By smoothly connecting the discontinuous surface of the rudder body 10 with the 30, the effect of minimizing the resistance caused by the discontinuous surface can be expressed.

Propellers are provided at the rear of the hull, generate propulsion in the ship, and may be provided in plurality (for example, two propellers in a twin-axle).

Specifically, the propeller is fastened to the propeller blade 41, the propeller cap 42 provided at the rear of the propeller shaft 44, and the propeller shaft 44 that push the fluid with rotational force to generate a propulsive force in reaction thereto. Includes a propeller hub 43 that transmits the power received from the shaft 44 to the propeller blades 41, and a propeller shaft 44 that receives power generated from a propulsion engine (not shown) from the drive shaft of the propulsion engine. do.

Here, the propeller may be a screw propeller that is generally widely used as an electric wheel, and the propeller blade 41 may be provided with a three-leaf or four-leaf blade, for example.

The rudder bulb 50 is formed on the rudder body leading edge 13 on the same axis as the center line L4 of the propeller shaft 44 to appropriately rectify the wake of the propeller, thereby enhancing the propulsion force of the ship. , Maximizes straightness, and can increase energy efficiency.

Here, the rudder bulb 50 is formed such that the maximum cross-section (a cross-sectional area perpendicular to the sea level) is smaller than the maximum cross-section of the propeller shaft 44 (for example, a cross-sectional area perpendicular to the sea level of the propeller cap 42). I can.

Through this, in the present invention, the rudder bulb 50 can effectively reduce the drag generated by being mounted on the ship rudder 1 and at the same time properly rectify the wake of the propeller, resulting in an increase in efficiency of 1.0% to 2.0%. I can.

Of course, it goes without saying that the rudder bulb 50 of the present invention may be formed such that the maximum cross section is larger than the maximum cross section of the propeller shaft 44.

In addition, the rudder bulb 50 may be formed such that the lower end of the rudder bulb is located on the lower end line L1 of the propeller shaft 44. Through this, the rudder bulb 50 has the effect of maximizing the propulsion performance of the ship by securing the steering performance than the conventional rudder bulb and at the same time rectifying the propeller wake very appropriately.

The thrust pin 60 may be provided on one side or the other side of the rudder bulb 50, and may improve the propulsion power of the ship by rectifying the wake of the propeller to generate lift. Here, the thrust pin 60 may be provided not only on the rudder bulb 50 but also on the left side of the rudder 11 or the right side of the rudder 12.

Specifically, the thrust pin 60 may have one end attached to the rudder bulb 50 fixed to the front, and may be curved upward or downward from one end to the other end. Accordingly, the thrust pin 60 can maximize the propulsion efficiency of the ship by properly rectifying the wake of the propeller by appropriately using the wake pressure generated by the propeller. That is, the thrust pin 60 is a component for the reaction of the lifting force and drag force generated by using the propeller wake flow, and can maximize the straightness of the ship and improve the propulsion of the ship. have.

In addition, the thrust pin 60 may have a shape in which the front and rear widths are the same or variable as the distance from the rudder bulb 50 increases, and the angle of attack of the leading edge (not shown) of the thrust pin 60 is a propeller It can be configured to suit the wake flow of.

As described above, the effects on the ship rudder 1 of the present invention through the above configurations are summarized below, and the ship rudder 1 according to the present invention is lowered at a certain interval from the lower end line L1 of the propeller shaft 44 As it extends to maximize the ship's steering performance, it is optimized for the wake flow of the propeller to reduce drag generated in the rudder 1 and improve lift, thereby improving the propulsion performance of the ship.

In addition, since the ship rudder 1 according to the present invention is optimized for flow after the propeller by extending from the lower end line L1 of the propeller shaft 44, it is possible to actively cope with the occurrence of cavitation of the rudder 1, and thus Due to this, there is an effect of improving the durability of the rudder 1.

In addition, the ship rudder 1 according to the present invention has the effect of minimizing cavitation occurring in the rudder 1 by making the lower end 20 of the rudder in a round shape, thereby minimizing vibration noise and There is an effect of maximizing propulsion performance.

In addition, since the ship rudder 1 of the present invention has not been produced at all in the shipbuilding industry and has a form that cannot be found in the literature, novelty is very strong and cavitation can be very effectively reduced.

Although the present invention has been described in detail through specific examples, this is for describing the present invention in detail, and the present invention is not limited thereto, It would be clear that the transformation or improvement is possible.

All simple modifications to changes of the present invention belong to the scope of the present invention, and the specific scope of protection of the present invention will be made clear by the appended claims.

1: ship rudder 2: stern
10: rudder body 11: left side of rudder
12: rudder right side 13: rudder body leading edge
131: lower front edge of the rudder body 14: rear edge of the rudder body
141: lower rear edge of the rudder body 15: upper surface
16: lower surface 20: lower end
30: rudder skeg 41: propeller wing
411: propeller tip 412: propeller tip
42: propeller cap 43: propeller hub
44: propeller shaft 50: rudder bulb
60: thrust pin
L1: Line at the lower end of the propeller shaft L2: Line at the lower end of the rudder
L3: Line of the maximum protrusion point at the lower end L4: Center line of the propeller shaft
C: Length before and after rudder bottom surface D: Propeller shaft diameter
PR: Propeller radius D _RS : Maximum protruding length at the lower end
D _LS : Maximum position of the lower end R1: Curvature of the lower edge of the rudder body
R2: Curvature of lower trailing edge of rudder body

Claims (7)

In the ship rudder installed on the twin axis,
It includes a rudder body that controls the ship by receiving the wake of the propeller,
The rudder body,
Ship rudder, characterized in that the lower end has a curved shape convex downward when viewed from the side, and a front curvature and a rear curvature are formed. The method of claim 1, wherein the front curvature is
Ship rudder, characterized in that the radius is formed in the range of 0.5m to 1m. delete The method of claim 1, wherein the posterior curvature is
Ship rudder, characterized in that the radius is formed larger than the radius of the front curvature. The method of claim 4, wherein the rear curvature is
Ship rudder, characterized in that the radius is formed in the range of 8m to 12m. The method of claim 1, wherein the posterior curvature is
A ship rudder, characterized in that the rear end is formed from a point where the lower protruding length of the lower end is maximum to a point of 45mm to 55mm vertically upward. The method of claim 1, wherein the rudder body,
A ship rudder, characterized in that the lower end has a curved shape that is convex downward when viewed from the side and the bottom surface is viewed as a whole to reduce cavitation generated under the rudder body.

Images