JP2006123849A - Rudder device for ship - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rudder device for a ship capable of improving a wake factor and a propeller efficiency ratio by improving a propeller surface flow field. <P>SOLUTION: Fins 14 are provided on both sides of a rudder horn 13 behind a propeller 12 rotatably supporting a rudder plate 11 to a hull. The fins 14 are used as forward moving blades, and made to have blade thicknesses thicker than a conventional one. Therefore, a flow on the propeller surface is made to be slow, and the wake factor and the propeller efficiency ratio is improved by improving the propeller surface flow field. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a marine rudder device, and aims to improve energy recovery of propeller rotating flow and improvement of propeller surface flow field, thereby improving wake ratio and propulsion device efficiency ratio.

  For the purpose of improving the propulsion performance of a ship, various ship rudder devices having fins on a rudder plate and a rudder column have been proposed in order to recover energy of a flow (propeller wake) generated by propeller rotation. Yes.

  For example, in the rudder disclosed in Patent Document 1, as shown in FIG. 5, fins 3 are provided on both side surfaces in the vicinity of the center of the vertical length of the rudder 2 disposed behind the propeller 1. The fin 3 on the side where the propeller blade rises with rotation has a positive angle of attack, and the fin 3 on the side where the propeller blade descends has a negative angle of attack.

    Further, in the ship propulsion performance improving device disclosed in Patent Document 2, as shown in FIG. 6, a small valve 4 is provided substantially on the propeller axis of the rudder 2 behind the propeller 1, and a wing is provided on the valve 4. A pair of left and right fins 5 having a cross-section are provided, thereby simplifying the configuration, and propulsion efficiency even with a fast stern flow such as a medium or high speed ship rather than an increase in load resistance. The improvement is getting bigger.

Furthermore, the technique regarding the rudder for ships which provided the fin in the rudder for ships of patent document 3, the rudder of patent document 4, the rudder apparatus of the ship of patent document 5, etc. is proposed.
JP 47-15895 A JP 11-139395 A JP 2002-178993 A Japanese Patent Laid-Open No. 58-1695 Japanese Patent Laid-Open No. 48-24494

However, in any proposal related to the rudder device for ships of Patent Documents 1 to 5, the energy behind the propeller is recovered as lift by the fins or fins provided on the rudder and boss, and the ship traveling direction component of lift is used as the thrust. It contributes to improving the thrust of the ship, and as a whole, energy saving and fuel efficiency are improved. As a result of further experiments and examinations on these conventional rudder devices with fins or fins, the energy of the propeller rotating flow Since recovery is the main purpose, it was found that the propeller surface flow field was not sufficiently improved, and there was room for improvement in the wake ratio and propulsion unit efficiency ratio.

  This invention is made in view of the subject of this prior art, and intends to provide the ship rudder apparatus which can improve a wake rate and a propulsion device efficiency ratio by the improvement of a propeller surface flow field. .

  In order to solve the above-described problems of the prior art, a marine rudder device according to claim 1 of the present invention has fins on both sides of a rudder horn or a rudder plate behind a propeller that rotatably supports a rudder plate on a hull. A marine rudder device provided, wherein the fin is a forward wing, and a blade thickness chord ratio of the fin is 15 to 40% at a blade root and 5 to 20% at a blade tip. To do.

According to this marine rudder device, the fins are made forward blades to bring the front edge of the fins closer to the propellers, and the fins are thick wings, thereby slowing the flow on the propeller surface, thereby propellers. The wake ratio and propulsion efficiency ratio can be improved by improving the surface flow field.

In the marine rudder device of the present invention, the fin is provided above 70% of the propeller radius from the propeller shaft center height, or the wing width of the fin is 50 to 100% of the propeller radius. Further, the chord length of the fin blade tip may be 40 to 90% of the blade root.

Here, the forward wing means that the angle between the midpoint of the chord length of the wing root and the midpoint of the chord length of the wing tip and the rudder center line on the horizontal plane is 90 degrees (right angle) or less. It refers to a wing having a certain planar shape (see FIG. 4).

According to the marine rudder device of the first aspect of the present invention, the fins provided on both sides of the rudder horn or the rudder plate are made to be forward wings so that the front edge of the fins can be brought close to the propeller, and the fins are thick wings. Thus, the flow on the propeller surface can be slowed down, and the wake ratio and the propulsion device efficiency ratio can be improved by improving the propeller surface flow field.

Further, according to the marine rudder device according to claims 2 to 4 of the present invention, the fins are effective by setting the fin mounting height, the fin wing width, and the chord length of the fin wing tip within a predetermined range. It is possible to slow down the flow on the propeller surface and improve the wake ratio and the propulsion unit efficiency ratio by improving the propeller surface flow field.

Furthermore, according to the marine vessel rudder apparatus combining a plurality of configurations described in the respective claims, the respective operational effects can be exhibited in combination.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
1 and 2 relate to an embodiment of a ship rudder device according to the present invention, FIG. 1 is a schematic front view and an enlarged AA sectional view, and FIG. 2 is an explanatory front view and part for defining a fin shape. It is an enlarged plan view.

  In this marine vessel rudder device 10, fins 14 are provided on both sides of a rudder horn 13 behind a propeller 12 that rotatably supports a rudder plate 11 on a hull, and the fins 14 serve as forward wings. Thus, the flow on the propeller surface is slowed down, and the wake ratio and the propulsion efficiency ratio are improved by improving the propeller surface flow field.

The fins 14 may be provided not only on both sides of the ladder horn but also on both sides of the rudder plate 11.
In this marine vessel rudder device 10, fins 14 provided so as to protrude horizontally on both sides of the ladder horn 13 are formed so that the forward wing, that is, the receding angle is 0 degree, and the leading edge is orthogonal to the bow-stern direction.

By using such a fin 14 as an advancing wing having a receding angle of 0 degrees, the fin 14 can be brought closer to the propeller 12, the flow of the propeller surface is slowed, and the flow on the propeller surface is made uniform.
Moreover, in this marine vessel rudder apparatus 10, the blade thickness of the fin 14 is made thicker than before, and the blade thickness chord length ratio is 15-40% at the blade root and 5-20% at the blade tip.

  In the conventional fin, the blade thickness chord length ratio is about 10% at the blade root, and the fin 14 is about 2 to 4 times, preferably 3 to 4 times at the blade root. An effect can be obtained.

  By increasing the blade thickness of the fins 14 in this way, the fast flow of the propeller surface is slowed by the effect of eliminating the fins 14 and the flow is made uniform on the propeller surface, thereby improving the wake ratio and the thruster efficiency ratio. The

  Regarding the improvement of the wake ratio and thruster efficiency ratio of this fin with thick blades, the blade thickness chord length ratio of the blade root portion is set to 30% and the blade thickness chord length ratio of the blade root portion is set to 10%. The results of testing for thin blades are shown in FIG.

  This figure shows the improvement rate compared to the case where no fin is attached to the ladder horn. By increasing the blade thickness ratio, the wake ratio is significantly improved and the propulsion unit efficiency ratio is also improved compared to the thin blade. It can be seen that the required horsepower is improved by about 3%.

  Such a fin 14 is preferably attached at 0 to 70% above the propeller radius from the axial center height of the propeller 12. This is because a remarkable effect due to the installation of the fins 14 cannot be obtained at positions exceeding these ranges.

  Further, the blade width of the fin 14 is preferably 50 to 100% of the radius of the propeller 12. If the blade width is less than 50%, the effect of the fins 14 cannot be obtained, and an increase in the effect obtained even with a wide blade width exceeding 100% cannot be expected, causing problems such as an increase in manufacturing cost.

  Furthermore, it is preferable that the chord length of the blade tip of the fin 14 is 40 to 90% of the blade root. The fins 14 may be forward wings and may be provided with a receding angle at the trailing edge, so that the chord length of the wing tip is in the range of 40 to 90% of the blade root. If it is smaller than 40%, the fin effect at the blade tip becomes insufficient.

  As described above in detail, according to this boat rudder device 10, by using the fin 14 as a forward wing, the front edge of the fin 14 is brought closer to the propeller 12, and the blade chord length ratio of the fin 14 is increased. Since the blade root is 15-40% at the blade root and 5-20% at the blade tip compared to the conventional blade, the flow on the propeller surface can be slowed down, and the propeller surface flow field is improved. The flow rate and propulsion efficiency ratio can be improved.

1 is a schematic front view and an enlarged AA sectional view according to an embodiment of a ship rudder device of the present invention. It is the explanation front view and partial enlarged plan view for defining the fin shape concerning one embodiment of the ship rudder device of this invention. It is a graph which shows the test result which compared the thick wing | blade and thin wing | blade concerning one Embodiment of this invention's boat rudder apparatus as a performance improvement rate when not mounting | wearing with a fin. It is explanatory drawing of the definition of the advance wing concerning one embodiment of the ship rudder device of this invention. It is the schematic perspective view and left view of the conventional rudder apparatus for ships. It is the schematic front view and plane sectional view of the conventional rudder apparatus for ships.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Boat rudder 11 Rudder board 12 Propeller 13 Ladder horn 14 Fin

Claims (4)

A rudder horn behind a propeller that rotatably supports a rudder plate on a hull or a rudder device for a ship provided with fins on both sides of a rudder plate,
A marine rudder apparatus, wherein the fin is a forward wing, and the blade thickness chord ratio of the fin is 15 to 40% at the blade root and 5 to 20% at the blade tip.   The marine rudder device according to claim 1, wherein the fin is provided above the propeller shaft center height within 70% of a propeller radius.   The ship rudder device according to claim 1 or 2, wherein a blade width of the fin is 50 to 100% of the propeller radius. 4. The marine rudder device according to claim 1, wherein a chord length of a wing tip of the fin is 40 to 90% of a blade root.