JPS6226197A - Device for improving marine propulsive performance - Google Patents

Abstract

PURPOSE:To reduce increase of resistance of each for improved propulsive performance of a ship by disposing at obliquely lower front positions with respect to the fin boss of a reaction fin straightening propellers rotating in the opposite direction of the propeller to generate forward thrust. CONSTITUTION:When straightening propellers 8a, 8b are rotated in the direction shown by arrows m1, m2 and opposite to the rotation of the propeller 6, the straightening propellers 8a, 8b generate rotating flow which causes water flow in the stern portion to be bent in the direction opposite to the rotation of the propeller 6 and sent to fins 7a-7f, and the water flow in further bent by the fins 7a-7f in the same direction as the rotation of the propellers 8a, 8b to be sent into the propeller 6, so that the resistance of each fin 7a-7b itself is reduced. Furthermore, as the propellers 8a, 8b are disposed at obliquely lower front positions with respect to the fin boss 3, on the blade-rising side of the propeller 6 bilge swirl in the same direction as the rotation is weakened by the propeller 8a, and on the blade-lowering side bilge swirl in the opposite direction to the rotation is promoted by the propeller 8b, resulting in smooth operation and improved propulsive performance.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a device for improving the propulsion performance of a ship, and in particular to a device for improving the propulsion performance of a ship, which is equipped with a reaction fin and a rectifying propeller in front of a stern propeller. Regarding a propulsion performance improvement device.

[Conventional technology]

Conventionally, as a device to improve the propulsion performance of ships,
Figure 6 (stern side view) and fjtJ7 figure (■ in Figure 6)
As shown in (cross-sectional view), a fin boss 3 is fixed to the stern frame 2 in front of the propeller 6 at the stern of the hull 1, and a plurality of fins 7n, 7b protrude radially from the fin boss 3.

Reaction fins consisting of 7c, 7d, 7e, and 'N are used.

Each of the fins 7a to 7f is tilted or twisted so as to bend the flow of water in a direction opposite to the direction of rotation of the propeller 6.

In addition, the reference numeral 4 in FIGS. 6 and 7 indicates a shoe piece, and 5 indicates a propeller shaft.

With the above-mentioned configuration, when the propeller 6 is rotated by the inboard main engine (not shown) and the hull 1 is sailing, the flow of water at the stern is opposite to the rotating direction of the propeller 6 due to the action of the fins 7a to 7F. It is bent in the same direction and sucked into the propeller 6.

Therefore, the rotational flow generated behind the propeller 6 in the same direction as the propeller rotation direction is reduced.

Originally, the rotational flow generated behind the propeller 6 is generated due to the rotation of the propeller 6, and is energy that is not used for propulsion of the hull 1. Therefore, a decrease in the rotational flow is due to the propulsion This will improve efficiency.

[Problem that the invention seeks to solve]

In this way, in the reaction fin, each fin 7a~
7f bends the water flow in the opposite direction to the rotation direction of the propeller 6 and sends it to the propeller 6, improving propulsion efficiency. On the other hand, when each fin 7a to 7r bends the water flow, each fin There is a problem in that the hull resistance increases due to the resistance of the hulls 7a to 7f themselves, which hinders the improvement of the propulsion performance of the hull 1 by that much.

The flow of water along the lower surface of the ship's bottom turns into a bilge vortex at the bilge (the curved part of the ship's bottom) and heads toward the propeller 6, so especially on the side of the ship where the propeller lift rises, the fins 7n
, 7b, and 7c become large, and the resistance of the fins themselves becomes significantly large, resulting in a problem that the propulsion performance of the hull 1 is not sufficiently improved.

The present invention aims to solve these problems, and by installing a rectifying propeller in front of the reaction fin while taking into consideration the influence of bilge vortices, the increase in resistance of each fin of the reaction fin is reduced. It is an object of the present invention to provide a propulsion performance improving device for a ship, which can sufficiently improve the propulsion performance of a ship.

[Means for solving problems]

Therefore, the ship propulsion performance improving device of the present invention includes a fin boss fixed to a stern frame in front of the stern propeller, and a fin boss that projects radially from the fin boss to bend the flow of water in the opposite direction to the rotational direction of the propeller. The propeller is provided with a reaction fin consisting of a plurality of fins tilted or twisted in such a manner that the propeller rotates diagonally below and in front of the fin boss, at least on the side where the blades of the propeller rise when the ship is moving forward. It is characterized by a rectifying propeller that rotates in the opposite direction to generate forward thrust.

[Effect]

In the ship propulsion performance improvement device of the present invention described above, with the operation of the rectifying propeller that rotates in the opposite direction to the rotation direction of the stern propeller, the water flow is bent in the opposite direction to the rotation direction of the propeller, and a reaction occurs. The flow of water flows into each fin of the fins, and the flow of water, which is further bent by these fins in the direction opposite to the direction of rotation of the propeller, flows into the same propeller, causing rotation in the wake of the propeller. The flow component will be sufficiently reduced.

At this time, the angle of the flow of water flowing into each fin of the action fins (angle of attack) can be smaller than in the case without a rectifying propeller, so the resistance due to the fins themselves is reduced.

In particular, in the device of the present invention, since the rectifying propeller is provided obliquely below and in front of the fin boss at least on the rising side of the propeller blade, when the ship is traveling forward,
Bilge vortices in the same direction as the propeller's rotational direction are attenuated in advance before they flow into the reaction fins, making it easier for the action fins to twist the water flow in the opposite direction to the propeller's rotational direction. The resistance of the fin itself will be significantly reduced after the first step.

〔Example〕

Hereinafter, embodiments of the present invention will be explained with reference to the drawings.
1 to 3 show a ship propulsion performance improving device as a first embodiment of the present invention, and FIG. 1 is a side view thereof, Ptf
Figure J2 is a sectional view taken along the ■-■ arrow in Figure 1, and Figure 3 (a) t(
b) is an explanatory diagram showing the state of water inflow into the port side fin and starboard gA fin, respectively, in comparison with the conventional case, and Fig. 415 is a ship propulsion performance improving device as a second embodiment of the present invention. Fig. 4 is a side view, and Fig. 5 is a side view.
The figure is a sectional view taken along the line ■-■ in FIG. 4.

In the case of the first embodiment of the present invention, as shown in FIGS. 1 and 2, there is a fin boss 3 fixed to the stern frame 2 in front of the propeller 6 at the stern of the hull 1, and a fin boss 3 that projects radially from the fin boss 3. multiple fins 7nt7b, 7
A reaction fin consisting of c, 7dt7e+7f is provided.

Each of the fins 7a to 7f is tilted or twisted so as to bend the flow of water in a direction opposite to the direction of rotation of the propeller 6.

In addition, numeral 4 in the diagram @1.2 indicates a sea piece, 5 indicates a propeller shaft, and the propeller 6 rotates clockwise as shown by arrow n to generate forward thrust.

In the device of the present invention, furthermore, on the side where the blades of the propeller 6 rise, the blades of the propeller 6 rotate diagonally downward and in front of the fin boss 3 in the opposite direction (the direction shown by the arrow 1) to the rotational direction of the propeller 6 (the direction shown by the arrow n). A rectifying propeller 8a that generates forward thrust is disposed.

Also, on the side where the blades of the propeller 6 descend, a rectifying propeller 8b is provided diagonally below and in front of the fin boss 3, and rotates in a direction opposite to the rotational direction of the propeller 6 (direction shown by arrow L112) to generate a forward thrust. is installed.

The rectifying propeller 8b is rotatably driven by a motor (not shown) inside the ship through a shaft 9b, and the reference numeral 10L+ in FIG. 1 indicates a bossing fixed to the hull 1.

Note that the commutating propeller 8a is also provided with a shaft 7)1 motor and a bossing similar to those of the above-mentioned commutating propeller 8b.

Since the propulsion performance improvement f & position of a ship as the first* embodiment of the present invention is configured as described above, the propeller 6 is rotated in the direction of the arrow n by the main engine (not shown), and the ship body 1 is sailed. When the fins 78 to 7f work, the flow of water at the stern part is bent in the opposite direction to the rotation direction of the propeller 6 and sent to the propeller 6, so that the rotation direction of the propeller 6 generated behind the propeller 6 is The rotational flow in the same direction is reduced, and the propulsion efficiency is improved.

On the other hand, the rectifying propeller 8 at 8 b is indicated by the arrow lIIIg
When the propeller 6 is rotated by a motor (not shown) in the opposite direction to the rotation direction of the propeller 6, as shown in FIG. I-style propeller 8
The same rectifying propellers 8a, 8 generated from a, 8b
Due to the action of the rotational flow in the same direction as the rotational direction of the propeller 6, the flow of water at the stern part is bent in the opposite direction to the rotational direction of the propeller 6 and is sent to the fins 7 (1 to 7f),
It is further bent in the same direction as the rectifying propeller 8 at 8 b (that is, in the opposite direction to the rotational direction of the propeller 6) by f, and is fed into the propeller 6.

Therefore, it flows into the propeller 6 (that is, the fins 7a to 7
Figure 3(a) showing the inflow of water into the port side fins 7a-7C and the inflow of water into the starboard 11111 fins 7d-7f when the rotational flow component of the flow (outflowing from f) is the same as the conventional one. As is clear from FIG. 3 (11) showing the flow angle α1. of the water flowing into each of the fins 7a to 7f. α2
are now smaller than the angles α1' and α2' in the conventional case without rectifying propellers 8n and 8b,
The resistance of each fin 78-71 itself is reduced. Note that the reference numbers in FIG. 153 (aL(b)) indicate reference lines parallel to the propeller shaft 5.

In particular, in this device, each rectifying propeller 8 a, 8 b is
It is located diagonally below and in front of the fin boss 3, so
On the rising side of the blade of propeller 6, there is a bilge vortex in the same direction as the rotation direction of propeller 6! ! Reduce with flow propeller 8a,
On the descending side of the blades of the propeller 6, the rectifying propeller 8b promotes the bilge vortex in the direction opposite to the direction of rotation of the propeller 6, so that the above-mentioned action can be carried out smoothly and efficiently.

Note that when the commutating propellers 8 a and 8 b on both sides have the same diameter as shown in the figure, it is desirable that the rotation speed of the commutating propeller 8 a on the port side is higher than that of the commutating propeller 8 b on the starboard side. When 8a and 8b have the same rotational speed, it is desirable that the port rectifier propeller 8n has a larger diameter than the starboard rectifier propeller 8b.

In this way, the reaction fin and rectifying propeller 8
According to this device that includes both a and 8b, the propulsion performance of the hull 1 can be further improved compared to the conventional case that includes only reaction fins.

Next, in a second embodiment of the present invention shown in FIGS. 4 and 5, the rectifying propeller 8b on the starboard side is omitted compared to the first embodiment described above.

That is, in this second embodiment, only on the side where the blades of the propeller 6 rise, there is a rotation direction opposite to the rotational direction of the propeller 6 (the direction indicated by the arrow I+) (the direction indicated by the arrow m1) diagonally downward and in front of the fin boss 3. I rotates to generate forward thrust! ! i. A flow propeller 8a is provided, and the flow rectification propeller 8a is attached to a shaft 9n that protrudes from a bossing 10a that is integral with the hull 1.

In the flow of water at the stern, when the propeller 6 is clockwise, the flow velocity component in the same direction as the rotation direction of the propeller 6 is originally large on the port side and small on the starboard side due to the influence of the bilge vortex. On the starboard side, the flow velocity component in the direction opposite to the rotational direction of the propeller 6 is large.

Therefore, the fins 7d to 7f on the starboard side have a small angle of attack with respect to the water flow, and the fins 7a to 7c on the port side have a large angle of attack with respect to the water flow.

Therefore, on the starboard side, the effect of reducing the angle of attack of the fins 7d to 7f due to the action of the rectifying propeller 81) of the first embodiment is small. Therefore, the energy required to reduce the resistance of the fins 7d to 7r may be less than the energy required to drive the commutating propeller 8b, and as in this Pt52 embodiment, the commutating propeller 8b on the starboard side described above is May be omitted.

〔Effect of the invention〕

As detailed above, according to the ship propulsion performance improving device of the present invention, the fin boss is fixed to the stern frame in front of the propeller at the stern, and the fin boss projects radially from the fin boss in a direction opposite to the rotational direction of the propeller. A rear axle fin is provided with a plurality of fins that are tilted or twisted so as to bend the flow of water. It has a simple structure in which a rectifying propeller is placed in the lower front that rotates in the opposite direction to the rotation direction of the propeller to generate forward thrust, which greatly reduces the resistance of the rear axle fin itself. This has the effect of sufficiently improving the propulsion performance of the hull.

[Brief explanation of the drawing]

1 to 3 show a ship propulsion performance improving device as a first embodiment of the present invention, and FIG. 151 is a side view thereof, and FIG.
The figure is a sectional view taken along the ■-■ arrow in Figure 1, and Figures 3 (a) and (b).
are explanatory diagrams showing the state of water inflow into the port side fin and the starboard side fin, respectively, in comparison with the conventional case, and Figures 4 and 5 are illustrations showing improvement in the propulsion performance of a ship as a second embodiment of the present invention. This shows the device, and Figure 4 is its side view, rjSs
The figure is a sectional view taken along the ■-V arrow in Figure 4, and Figures 6 and 7 show a conventional ship propulsion performance improvement device, with Figure 6 being a side view and Figure 7 being 0's6. It is a sectional view taken along the line ■-■ in the figure. 1... Hull, 2... Stun frame, 3... Fin boss, 4... Shoe piece, 5... Propeller shaft, 6... Propeller, 7a+7b+7ct7cL7e+7f'' Fin, 8a, 8b... Rectifying propeller, 9a, 9b... - Shaft, 10a, 10b... Bossing, L - Reference line parallel to the propeller axis, 1... Arrow indicating the rotation direction of the commutating propeller 8a, +112... Arrow indicating the rotating direction of the commutating propeller 8b, n... an arrow indicating the rotation direction of the propeller 6;
α2. α2... Angle of attack in the case of the present invention, α1', α2'
...Angle of attack 6 in the conventional case Yoshihiko Iinuma, patent attorney Figure 2 Figure 3 (b)

Claims (1)

[Claims] A fin boss fixed to a stern frame in front of the stern propeller, and a plurality of fins projecting radially from the fin boss and tilted or twisted so as to bend the flow of water in the opposite direction to the rotational direction of the propeller. A rectifier is provided with a reaction fin that rotates in a direction opposite to the rotational direction of the propeller and generates a forward thrust at least on the side where the blade of the propeller rises when the ship is traveling forward, diagonally below and in front of the fin boss. A device for improving the propulsion performance of a ship, characterized by being equipped with a propeller.