JP2009255835A - Finned rudder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve propulsion performance by attaching a fin which generates thrust in the forward motion direction by utilizing rising, falling, and swirling flows near a rudder surface. <P>SOLUTION: This finned rudder 10 is disposed rearward of a screw propeller that rotates clockwise as viewed from a stern side during forward motion for changing the course of a ship 1 and provided with a first fin 12 and a second fin 14 in respective rudder surfaces 11, 13. One end of the first fin 12 is attached at a position higher than a center position of the screw propeller on a leading edge side of a central portion of the rudder surface 11, and one end of the second fin 14 is attached at a position lower than the center position of the screw propeller on the leading edge side of the central portion of the rudder surface 13. The other end of the first fin 12 extends at an upward inclination to a position inside the rotation radius of the screw propeller where the upward flow is strong, and the other end of the second fin 14 extends horizontally to a position inside the rotation radius of the screw propeller where the downward flow is strong. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a finned rudder that is mounted on a ship and changes the course direction of the ship.

Conventionally, in order to improve propulsion performance, a structure that changes the propeller rotational flow into a flow in the propulsion direction, for example, tilts from the center position of the rudder valve shaft to both sides, corresponding to the inflow angle that changes as the propeller shaft is separated The thing disclosed by the horizontal fin (patent document 1) which set the angle | corner (torsion angle) is known. Also, in order to improve propulsion performance, a valve is added to the rudder front edge near the propeller shaft center, and horizontal fins with the same left and right height integrated with the valve are added (Patent Document 2). Yes.
JP-A-6-305487 JP 11-139395 A

However, as a result of detailed analysis of the flow field around the rear rudder where the propeller of the uniaxial clockwise ship is operating, the present inventors have produced a water flow as shown in FIG. It was discovered that a water flow as shown in FIG. 13 occurs at the center position of the rudder shaft. That is, from FIG. 12 and FIG. 13, on the port side of the boat rudder R (right side in FIG. 12 and FIG. 13), it is on the inner side of the rotation radius P of the screw propeller and above the center position C of the screw propeller. It can be seen that the downward flow becomes stronger near the rudder R for the ship. On the starboard side of the rudder (left side in FIGS. 12 and 13), on the other hand, the downward flow is stronger inside the screw propeller and below the center position of the screw propeller, and in the vicinity of the ship rudder R. Then we can see that the downward flow is getting stronger.
Therefore, at the rudder shaft center position in the wake of the propeller, the flow and the strength of the flow are remarkably different above and below the center position C in the left and right side where the propeller rotation direction is different as described above. For this reason, as described in Patent Document 1 and Patent Document 2, the horizontal fins provided at the same height on both sides from the axial center position and the vicinity of the axial center efficiently improve the propulsion efficiency in the wake of the propeller. There is a problem that cannot be made.
The flow field analysis results at Reynolds number: 1080000 and screw propeller rotation speed: 7.8 rps are shown in FIG. 12 and FIG. 13 when moving forward as seen from the bow side. Seeing from the right is rotating. In the figure, the direction of the arrow indicates the direction of the flow in the plane, and the length of the arrow indicates the size of the flow. In particular, the downward flow is stronger below the propeller center line on the rudder starboard side.

  The present invention has been made in view of the above circumstances, and aims to improve the propulsion performance (propulsion efficiency) by increasing the wake gain by adjusting the flow of water behind the screw propeller more effectively. It is an object to provide a rudder with fins that can be used, and a ship equipped with the same.

In order to solve the above problems, the present invention employs the following means.
The first aspect of the finned rudder according to the present invention is arranged behind the screw propeller, changes the course direction of the ship, and has the first fin on the port side rudder surface and the starboard side rudder surface. When the screw propeller rotates clockwise as viewed from the stern side when moving forward, one end of the first fin is connected to the port side. A side control surface is attached above the center position of the screw propeller, and one end of the second fin is attached to the starboard side control surface below the center position of the screw propeller. When the screw propeller rotates counterclockwise when viewed from the stern side when moving forward, one end of the first fin is below the center position of the screw propeller on the port side control surface. The one end of the second fin is attached to the starboard side control surface above the center position of the screw propeller, and the other end of each fin is from the turning radius of the screw propeller. Also, it extends horizontally to a position where the upward or downward flow becomes strong.

The second aspect of the finned rudder according to the present invention is arranged behind the screw propeller that rotates clockwise when viewed from the stern side when moving forward, and changes the course direction of the ship, and the 1 fin is a rudder with fins in which one second fin is provided on the starboard side control surface, and one end of the first fin is the port side control surface, and the screw It is attached above the center position of the propeller, and one end of the second fin is attached below the center position of the screw propeller on the starboard side control surface, and the other end of the first fin However, it extends obliquely upward to a position where the upward flow is strong inside the rotational radius of the screw propeller, and the other end of the second fin is larger than the rotational radius of the screw propeller. The side, and extends horizontally to a position where the downward flow is strong.
In addition, when arrange | positioning at the back of the screw propeller which rotates counterclockwise seeing from the stern side at the time of advance, the positional relationship of a 1st fin and a 2nd fin becomes right-and-left reverse.

According to the rudder with fins according to the present invention, since the fins having an appropriate angle of attack with respect to the descending, rising and turning flows near the rudder generate thrust, the hull resistance is reduced and the propulsion horsepower is reduced. can do. Also, the fin mounting horsepower reduction effect is increased by moving the fin mounting position up and down as shown in FIG. 7 or by tilting the mounting angle as shown in FIG. be able to.
In addition, as shown in FIG. 13, there is a case where the flow is close to the swirl flow in which the upward flow and the inward flow are combined above the port side of the control surface. When directed upward, the effect of thrust generation by the fins can be further increased.

  In the rudder with fins, a rudder valve made of a weight body is provided at a front edge portion facing the propeller boss of the screw propeller, and the front edge is in the inflow direction of the wake of the screw propeller. More preferably, they are twisted together.

According to such a finned rudder, the rudder valve causes the flow generated from the rear end of the propeller boss to flow along the surface of the rudder valve, which weakens the boss vortex, thus reducing vortex resistance. The propulsion performance (propulsion efficiency) can be further improved.
The front edge of the rudder with fins is twisted (twisted) in the opposite direction according to the inflow direction of the wake of the screw propeller, and there is a gap at the position of the propeller shaft center height. This gap is generated and causes cavitation, but this gap is eliminated by the rudder valve, and rudder cavitation generated from the front edge can be suppressed, preventing erosion of the rudder surface and peeling of paint from the rudder surface. Can do.
Furthermore, the other end of the front edge is connected to the top of the rudder valve, and one end of the front edge is connected to the bottom of the rudder valve. That is, since the other end of the front edge and one end of the front edge are connected via a rudder valve, the processing of the front edge can be facilitated, and the manufacturability can be improved. .

  In the above-mentioned rudder with fins, the first fin has an airfoil shape in cross section and is formed to have an upward camber, and the second fin has an airfoil shape in cross section and has a camber facing downward. More preferably,

According to such a rudder with fins, each fin is provided with a camber oriented to increase lift. And since the forward component of this lift becomes the thrust which pushes the ship's hull forward, this thrust acts on the hull and the hull resistance is reduced.
Thereby, propulsion performance (propulsion efficiency) can be further improved.

  According to the rudder with fins according to the present invention, the fins having an appropriate angle of attack with respect to the descending, rising, and turning flows in the vicinity of the rudder generate thrust, thereby reducing the hull resistance and reducing propulsion horsepower. can do.

  According to the rudder with fins according to the present invention, since the fins having an appropriate angle of attack with respect to the descending, rising and turning flows near the rudder generate thrust, the hull resistance is reduced and the propulsion horsepower is reduced , It has the effect of improving the fuel consumption.

Hereinafter, a first embodiment of a finned rudder according to the present invention will be described with reference to FIGS. 1 to 4.
FIG. 1 is a right side view of a stern portion of a ship equipped with a finned rudder according to the present embodiment when viewed from the starboard side, and FIG. 2 is a view of the stern portion of a ship equipped with the finned rudder according to the present embodiment from the port side. Left side view, FIG. 3 is a front view of the finned rudder according to this embodiment viewed from the bow side, and FIG. 4 is an experiment obtained by sailing a ship equipped with the finned rudder according to this embodiment. It is a graph which shows a result.

As shown in FIG. 1 or 2, the rudder rudder 10 according to the present embodiment has a rudder shaft 5 that extends vertically downward from the stern bottom 4 of the stern portion 3 located on the rear side (stern side) of the screw propeller 2. It is a plate-shaped member that rotates around the vertical axis together with the rudder shaft 5 and changes the course direction of the ship 1.
The screw propeller 2 is attached to the rear end portion (end portion on the stern side) of the propeller shaft 7 that passes through the boshing 6, and rotates together with the propeller shaft 7 clockwise (clockwise) when viewed from the stern side. Rotate counterclockwise (counterclockwise) when viewed from the stern side during reverse travel.

Now, the first fin 12 is provided on the port side rudder surface 11 of the finned rudder 10 according to the present embodiment, and the second fin 14 is provided on the starboard side rudder surface 13 of the finned rudder 10 one by one. It is provided (attached).
As shown in FIGS. 2 and 3, one end (base) of the first fin 12 is attached to a position higher than the center position C of the screw propeller 2 on the front edge side of the central portion of the control surface 11, and horizontally ( FIG. 3 is a small wing having an upward camber with a cross-sectional airfoil shape extending in a port-side direction in FIG. 3. Further, the other end (tip) of the first fin 12 extends to a position (region) inside the rotational radius P of the screw propeller 2 (see FIGS. 12 and 13) and where the upward flow becomes strong. Yes.

  As shown in FIGS. 1 and 3, one end (base) of the second fin 14 is attached to a lower side of the center position C of the screw propeller 2 on the front edge side of the central portion of the control surface 13, and horizontally ( FIG. 3 is a small wing having a camber pointing downward and extending in the direction of the port side in FIG. Further, the other end (tip) of the second fin 14 extends to a position (region) inside the rotational radius P of the screw propeller 2 (see FIGS. 12 and 13) and where the downward flow becomes strong. Yes.

According to the finned rudder 10 according to this embodiment, the first fin 12 is inside the rotation radius P of the screw propeller 2 generated in the vicinity of the rudder surface 13 and above the center position C of the screw propeller 2. The upward flow generated on the side of the screw propeller 2 is weakened (suppressed), and is located inside the rotation radius P of the screw propeller 2 generated in the vicinity of the control surface 13 by the second fin 14 and the center position C of the screw propeller 2 The downward flow and the downward flow generated on the lower side are weakened (suppressed).
Thus, the hull resistance can be reduced by rectifying the flow in the vertical direction in the vicinity of the control surface. In other words, the fins on the control surface can improve the propulsion performance (propulsion efficiency) by using the lift generated from the vertical flow.

FIG. 4 is a graph showing experimental results obtained by navigating a ship equipped with the finned rudder 10 according to the present embodiment, where the horizontal axis is the ship speed (kn: knot), and the vertical axis is the horsepower (kW). ). In addition, the broken line drawn from the lower left to the upper right in the figure is data obtained from the ship not equipped with the finned rudder 10 according to the present embodiment, and the solid line drawn from the lower left to the upper right in the figure is the main line. It is the data obtained from the ship equipped with the rudder 10 with a fin which concerns on embodiment.
As shown in FIG. 4, the ship equipped with the finned rudder 10 according to this embodiment needs less horsepower to obtain the same boat speed as the ship not equipped with the finned rudder 10 according to this embodiment. In addition, when the same horsepower as that of the ship not equipped with the finned rudder 10 according to the present embodiment is applied, the ship speed increases (increases). As a result, a fuel consumption reduction effect of about 2% is obtained compared to the conventional case, which is an effective experimental result as supporting the above-described operation effect by the finned rudder 10 according to the present embodiment.

Moreover, according to the rudder 10 with a fin which concerns on this embodiment, the fin 12 is attached with respect to the corresponding control surface 11 so that the front edge may be located below rather than a rear edge, and an upward camber is attached. The fins 14 are attached to the corresponding control surfaces 13 so that the front edges thereof are located above the rear edges, and are provided with a downward camber. Lift can be generated upward and downward. And since the forward component of this lift becomes the thrust which pushes the hull of the ship 1 in the forward direction, this thrust acts on the hull and the hull resistance is reduced.
Thereby, propulsion performance (propulsion efficiency) can be improved.

A finned rudder according to a second embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a right side view of a stern portion of a ship equipped with a finned rudder according to the present embodiment as viewed from the starboard side, and FIG. 6 is a view of the stern portion of a ship equipped with the finned rudder according to the present embodiment from the port side. The left side view seen, FIG. 7 is the front view which looked at the rudder with a fin which concerns on this embodiment from the bow side.
The finned rudder 20 according to the present embodiment includes a rudder valve 21 as shown in FIGS. 5 to 7, and the front edges 22 and 23 thereof have a vertical axis (vertical axis) as shown in FIG. Is different from that of the first embodiment described above in that it is inclined with respect to the first embodiment. Since other components are the same as those of the first embodiment described above, description of these components is omitted here.

Rudder valve 21 is a front edge of rudder-equipped rudder 20 and a weight provided at a position facing propeller boss 2a (see FIG. 1 or 2) of screw propeller 2 (see FIG. 1 or 2). As shown in FIG. 5 or FIG. 6, the diameter rapidly increases from the bow-side end surface facing the propeller boss 2a to the front edge of the finned rudder 20, and from the front edge of the finned rudder 20 to the rear edge side. The diameter is gradually reduced. As shown in FIG. 5, the second fin 14 is provided below the rudder valve 21 on the downstream side from the front edge of the rudder 20. Further, as shown in FIG. 6, the first fin 12 is provided above the rudder valve 21 on the downstream side from the front edge of the rudder 20. Thus, in consideration of the flow field in the vicinity of the rudder, the first fin 12 and the second fin 14 are provided in the vicinity of the rudder valve 21 on the downstream side of the front edge portion of the rudder 20 with fins, so that the thrust force is increased. Can be obtained most effectively. Moreover, as shown in FIG. 7, the cross-sectional shape of the rudder valve 21 is substantially circular, and this cross-section is the same at any position from the bow side to the stern side.
Such a rudder valve 21 suppresses the boss vortex generated from the rear end of the propeller boss 2a, that is, the flow generated from the rear end of the propeller boss 2a flows along the surface of the rudder valve 21. As a result, the boss vortex is weakened (collected) and the vortex resistance is reduced to improve the propulsion performance (propulsion efficiency).

As shown in FIG. 7, the front edge 22 located above the rudder valve 21, that is, above the rudder valve 21, has one end (upper end) that is the same as the center position C of the screw propeller 2 or the screw propeller 2. The other end (lower end) is located on the port side from the center position C, and the other end (lower end) is located on the port side from the center position C of the screw propeller 2, and is formed in a substantially straight line from one end to the other end. The other end of the front edge 22 is connected to the top of the rudder valve 21.
On the other hand, the front edge 23 located below the rudder valve 21, that is, below the rudder valve 21, has one end (upper end) located on the starboard side with respect to the center position C of the screw propeller 2, and the other end (lower end). ) Is the same as the center position C of the screw propeller 2 or on the starboard side of the center position C of the screw propeller 2, and is formed in a substantially straight line from one end to the other end. One end of the front edge 23 is connected to the bottom of the rudder valve 21.
That is, the front edges 22 and 23 are twisted (twisted) in accordance with the inflow direction of the wake of the screw propeller 2, whereby the inflow direction (inflow angle) of the finned rudder 20 to the screw propeller 2 is changed. The rudder cavitation generated from the front edges 22 and 23 of the finned rudder 20 is suppressed by reducing the rudder cavitation.

According to the finned rudder 20 according to this embodiment, the rudder valve 21 causes the flow generated from the rear end of the propeller boss 2a to flow along the surface of the rudder valve 21, thereby weakening the boss vortex. The vortex resistance can be reduced, and the propulsion performance (propulsion efficiency) can be further improved.
Further, the front edges 22 and 23 of the finned rudder 20 are twisted (twisted) in accordance with the inflow direction of the wake of the screw propeller 2, and thereby the wake of the screw propeller 2 wake to the finned rudder 20. Since the inflow direction (inflow angle) is reduced, rudder cavitation generated from the front edges 22 and 23 can be suppressed, and the erosion of the control surfaces 11 and 13 and the peeling of the paint from the control surfaces 11 and 13 can be suppressed. Can be prevented. In particular, high speed ships such as container ships may cause erosion due to rudder cavitation and peeling of paint, and when the present invention is applied to high speed ships such as container ships, the effect of suppressing rudder cavitation is Become prominent.
Furthermore, the other end of the front edge 22 is connected to the top of the rudder valve 21, and one end of the front edge 23 is connected to the bottom of the rudder valve 21. Such a reaction rudder has a problem that since the twist direction is reversed at the propeller shaft center, a step occurs at the rudder front edge, cavitation occurs from the step, and machining is difficult. However, in the present invention, since the other end of the front edge 22 and one end of the front edge 23 are connected via the rudder valve 21, a step at the rudder front edge does not occur, and cavitation occurs. In addition, the front edge portion can be easily processed and the manufacturability can be improved.
Other functions and effects are the same as those of the above-described first embodiment, and thus description thereof is omitted here.

A finned rudder according to a third embodiment of the present invention will be described with reference to FIG. FIG. 8 is a front view of the rudder with fins according to the present embodiment as viewed from the bow side.
The finned rudder 30 according to the present embodiment is different from that of the first embodiment described above in that a first fin 31 is provided instead of the first fin 12. Since other components are the same as those of the first embodiment described above, description of these components is omitted here.

  As shown in FIG. 8, the first fin 31 according to the present embodiment is obliquely attached at one end (base) to the front edge of the center portion of the control surface 11 and above the center position C of the screw propeller 2. A winglet extending in the upward direction (upper right direction in FIG. 8) having a cross-sectional airfoil shape and having an upward camber. Further, the other end (tip) of the first fin 31 extends to the position (region) where the upward flow is strongest inside the rotational radius P of the screw propeller 2 (see FIGS. 12 and 13). ing.

As shown in FIG. 13, there is a case where the upward flow and the inward flow are close to the swirl flow above the port side of the rudder surface. In such a case, the first flow according to the present embodiment is obtained. The effect of thrust generation by the fins can be increased by directing the mounting angle obliquely upward like the fins 31.
Other functions and effects are the same as those of the above-described first embodiment, and thus description thereof is omitted here.

A finned rudder according to a fourth embodiment of the present invention will be described with reference to FIGS. 9 to 11. FIG. 9 is a right side view of a stern portion of a ship equipped with a finned rudder according to the present embodiment as viewed from the starboard side, and FIG. 10 is a view of the stern portion of a ship equipped with the finned rudder according to the present embodiment from the port side. The left side view seen, FIG. 11 is the front view which looked at the rudder with a fin which concerns on this embodiment from the bow side.
The finned rudder 40 according to the present embodiment is different from that of the second embodiment described above in that a first fin 41 is provided instead of the first fin 12. Since other components are the same as those of the second embodiment described above, description of these components is omitted here.

  As shown in FIGS. 10 and 11, the first fin 41 according to the present embodiment has one end (base) attached to the top rear edge side of the rudder valve 21 and above the center position C of the screw propeller 2. And a winglet extending in an obliquely upward direction (upper right direction in FIG. 11) having an airfoil shape in cross section and having an upward camber. Further, the other end (tip) of the first fin 41 extends to a position (region) where the upward flow is strongest inside the rotational radius P of the screw propeller 2 (see FIGS. 12 and 13). ing.

  Since the effect of the finned rudder 40 according to this embodiment is the same as that of the above-described third embodiment, the description thereof is omitted here.

Since the flows shown in FIG. 12 and FIG. 13 are different for each ship, it is preferable to perform a flow field analysis for each ship and specify a region where the first fin and the second fin are effective. Further, the present invention is not limited to the above-described embodiment, and can be appropriately modified and changed as necessary without departing from the technical idea of the present invention.
The rudder with fins of the present invention is applied to general merchant ships such as ships, for example, gas carriers, tankers, container ships, ferries, RORO ships, car carriers, bulk carriers, passenger ships, etc. Can improve fuel efficiency and can be expected as an energy-saving ship.

It is the right view which looked at the stern part of the ship equipped with the rudder with a fin which concerns on 1st Embodiment of this invention from the starboard side. It is the left view which looked at the stern part of the ship equipped with the rudder with a fin which concerns on 1st Embodiment of this invention from the port side. It is the front view which looked at the rudder with a fin which concerns on 1st Embodiment of this invention from the bow side. It is a graph which shows the experimental result obtained by navigating the ship equipped with the rudder with a fin which concerns on 1st Embodiment of this invention. It is the right view which looked at the stern part of the ship equipped with the rudder with a fin which concerns on 2nd Embodiment of this invention from starboard side. It is the left view which looked at the stern part of the ship equipped with the rudder with a fin which concerns on 2nd Embodiment of this invention from the port side. It is the front view which looked at the rudder with a fin concerning 2nd Embodiment of this invention from the bow side. It is the front view which looked at the rudder with a fin which concerns on 3rd Embodiment of this invention from the bow side. It is the right view which looked at the stern part of the ship equipped with the rudder with a fin which concerns on 4th Embodiment of this invention from the starboard side. It is the left view which looked at the stern part of the ship equipped with the rudder with a fin which concerns on 4th Embodiment of this invention from the port side. It is the front view which looked at the rudder with a fin which concerns on 4th Embodiment of this invention from the bow side. It is the figure which looked at the flow of the water in the rudder board front edge position of the ship equipped with the conventional finned rudder from the bow side. It is the figure which looked at the flow of the water in the center position of a rudder axis of the ship equipped with the conventional finned rudder from the bow side.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ship 2 Screw propeller 2a Propeller boss 10 Rudder with fin 11 Rudder surface (rudder side rudder surface)
12 First fin 13 Control surface (control surface on starboard side)
14 Second fin 20 Rudder with fin 21 Rudder valve 22 Front edge 23 Front edge 30 Rudder with fin 31 First fin 40 Rudder with fin 41 First fin C Center position of screw propeller P Radius of rotation of screw propeller R Ship Rudder

Claims (5)

With fins that are arranged behind the screw propeller, change the course of the ship, and have one fin on the port side rudder surface and one second fin on the starboard rudder surface A rudder,
When the screw propeller rotates clockwise as viewed from the stern side when moving forward, one end of the first fin is on the front edge side of the central portion of the rudder-side control surface than the center position of the screw propeller. It is attached above, and one end of the second fin is attached below the center position of the screw propeller on the front edge side of the central part of the starboard side control surface,
When the screw propeller rotates counterclockwise when viewed from the stern side when moving forward, one end of the first fin is on the front edge side of the central portion of the rudder surface on the port side, and more than the center position of the screw propeller. It is attached below, and one end of the second fin is attached above the center position of the screw propeller on the front edge side of the central portion of the starboard side control surface,
A finned rudder characterized in that the other end of each fin extends horizontally to a position inside the radius of rotation of the screw propeller and where the upward or downward flow becomes strong. It is arranged behind the screw propeller that rotates clockwise as viewed from the stern side when moving forward, and changes the course of the ship, and the first fin is on the port side control surface and the second fin is on the starboard side control surface. A finned rudder with one fin each,
One end of the first fin is attached above the center position of the screw propeller on the front edge side of the center side of the port side control surface, and one end of the second fin is connected to the starboard side control surface Is attached below the center position of the screw propeller on the front edge side of the center portion of
The other end of the first fin extends obliquely upward to a position inside the rotation radius of the screw propeller and to a position where the upward flow becomes strong,
The finned rudder, wherein the other end of the second fin extends horizontally to a position inside the rotation radius of the screw propeller and where the downward flow becomes strong.   A rudder valve made of a bulged body is provided at the front edge portion of the screw propeller facing the propeller boss, and the front edge is twisted in accordance with the inflow direction of the wake of the screw propeller. A finned rudder according to claim 1 or 2.   The first fin has an airfoil shape in cross section and is formed to have an upward camber, and the second fin is airfoil shape in cross section and has a camber facing downward. The finned rudder according to any one of claims 1 to 3.   A ship comprising the finned rudder according to any one of claims 1 to 4.

Images