JP3090368U - Skeg on top of rudder - Google Patents

Abstract

(57) [Summary] [Problem] The intersection of the leading edge of the skeg and the stern aggregate is substantially at a right angle, and there is a problem that a vortex is generated at a stagnation point, resulting in pressure resistance. SOLUTION: The height of a skeg 5 is a dimension to fill a gap between a rising line of a stern aggregate 4 and an upper surface of a rudder plate 2, and the height thereof is set to a front upper surface of the rudder plate 2 and the front edge thereof. The stern aggregate 4 immediately above the stern 5 is indicated by a height a, and the length is substantially the length of the rudder plate 2 with the front edge of the skeg 5 having a smooth warp and extended. From the base to the extended base. Therefore, when viewed from the side, the shape of the inverted trapezoid has a warp on one side of the front side, and the cross-sectional shape is a streamlined water drop like a front fertilizer.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 This invention relates to a structure of a skeg provided on an upper part of a rudder of a ship.

[0002]

[Prior art]

 Conventionally, as shown in FIG. 2, a propeller 31 is provided at the stern of a hull S, and a rudder plate 32 is provided behind the propeller 31, and the rudder plate 32 is supported by a rudder shaft 33, as shown in FIG. .

In recent years, the rudder plate 32 has been reduced in rudder area by adopting a lift rudder or the like, a gap has been increased between the upper surface of the rudder plate 32 and the stern aggregate 34, and protection and pressure resistance of the rudder shaft 33 have been increased. A skeg 35 was provided to alleviate this.

A height direction of the skeg 35 is a dimension to fill a gap between a line rising from the tail of the stern aggregate 34 and an upper surface of the rudder plate 32, and a length direction substantially corresponds to a length of the rudder plate 32. The shape in side view was an inverted trapezoid, and the cross-sectional shape was a streamlined water drop like a front fertilizer.

[0005] The hull S is advanced by the rotational energy of the propeller 31. A streamline 36 is formed above the propeller 31 of the hull S, and the streamline 36 is directed upward to the rear of the hull S. The skeg 35 itself has a streamlined shape. A vortex 38 was generated at the stagnation point 37 at the intersection of the leading edge of the skeg 35 and the stern aggregate 34.

[0006]

[Problems to be solved by the invention]

 Although the skeg itself has a streamlined shape as described in the prior art, the intersection of the skeg's leading edge and the stern aggregate is almost at a right angle, and a vortex occurs at the stagnation point, resulting in pressure resistance. Had the problem that

[0007] The present invention has been made in view of such inadequate points of the prior art, and the purpose thereof is to provide a smooth warp at the leading edge of the skeg and to reduce the stagnation point. The purpose is to make the water flow flow behind the hull, and thus to reduce the pressure loss.

[0008]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention is directed to a skeg provided in a gap between the upper surface of the rudder plate and the stern aggregate, wherein the height of the skeg is determined by the rising line of the stern aggregate and the upper surface of the rudder plate. The length is approximately the length of the rudder plate with a smooth warp from the leading edge of the rudder plate to the leading edge of the skeg. It has a streamlined shape.

[0009] The shape of the skeg in a side view has a warp on one front side of an inverted trapezoid, and the shape of the extension of the skeg has an extension length longer than a front height of the skeg and an extension length. Is not more forward than just above the tip of the propeller.

[0010]

【Example】

 As shown in FIG. 1, the propeller 1 is provided at the stern of a hull S, and a rudder plate 2 is provided behind the propeller 1. The rudder plate 2 is supported by a rudder shaft 3.

The downsized rudder plate 2 has a gap between the upper surface of the rudder plate 2 and the stern aggregate 4, and a skeg 5 is provided for protecting the rudder shaft 3 and reducing pressure resistance. I have.

The height of the skeg 5 is a dimension that fills the gap between the rising line of the stern aggregate 4 and the upper surface of the rudder plate 2. The stern aggregate 4 immediately above the stern 5 is indicated by the height a, and the length is approximately the length of the rudder plate 2 with the front edge of the skeg 5 extended with a smooth warp. It is indicated by the length b from the base to the base extended. Therefore, when viewed from the side, the shape of the inverted trapezoid has a warp on one side of the front, and the cross-sectional shape is a streamlined water drop like a front fertilizer.

Therefore, if the shape of the extension of the skeg 5 is expressed by a mathematical expression, b / a> 1 and b is not forward of the position immediately above the tip of the propeller 1.

The hull S is advanced by the rotational energy of the propeller 1, and a streamline 6 is formed above the propeller 1 of the hull S in an upward direction behind the hull S. Even if the flow reaches the stagnation point 7, The line 8 flows along the skeg 5 to the rear of the hull.

[0015]

[Effect of the invention]

 Since the present invention is configured as described above, the following effects can be obtained. This idea is to make the front edge of the skeg have a smooth warp and to make the water flow at the stagnation point flow to the rear of the hull, thus reducing the pressure loss.

[Brief description of the drawings]

FIG. 1 is a schematic side view of the stern of the present invention.

FIG. 2 schematically shows a conventional hull stern in a side view.

[Explanation of symbols]

 Reference Signs List 1 propeller 2 rudder plate 3 rudder shaft 4 stern aggregate 5 skeg 6 streamline 7 stagnation point 8 streamline S hull

Claims (2)

[Utility model registration claims] A skeg provided in a gap between the upper surface of the rudder plate and the stern aggregate, the height of the skeg is a dimension to fill a gap between a line rising from the tail of the stern aggregate and the upper surface of the rudder plate. Yes, the length is approximately the length of the rudder plate, with a smooth warp from the leading edge of the rudder plate to the leading edge of the skeg, and the cross-sectional shape is a streamlined water drop like a front fertilizer A skeg on the upper part of the rudder that is a feature. 2. The shape of the skeg when viewed from the side has a warp on one front side of an inverted trapezoid, and the shape of the extension of the skeg is longer and longer than the front height of the skeg. The length is not forward than immediately above the tip of the propeller.
The skeg above the rudder.