JPS62292591A - Ship trailing stream rectifying device - Google Patents

Abstract

PURPOSE:To prevent the resistance of a rectifying fin from increasing so that the propulsion efficiency is lowered, by providing a rotatable horizontal cylindrical nozzle in a propeller aperture section in a stern of a ship. CONSTITUTION:A ring-like nozzle 5 is rotatably provided in a propeller aperture section 2 in a stern to which a propeller 4 is attached. This nozzle 5 is arranged such that is may be disposed within the diametrical area of the propeller 4. Further, this nozzle 5 has a streamline cross-sectioned shape having a blade chord, and the flow inlet port thereof is a ring-like body greater than that of the flow outlet port thereof. That is, the streamline shape may increase the flow rate while it make the fluid resistance less. with this arrangement, the nozzle 5 may rectify a slow velocity stream within the propeller plane, and the revolving stream in the trailing stream of the propeller 4 may be reduced, thereby it is possible to enhance the gain of propeller wakes and to reduce the propeller vibration exciting force.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a stern rectifier for ships, and more specifically, it rectifies the flow of seawater flowing into the propeller surface. Ryu 1
This invention relates to a stern rectifying device that can improve the propeller loading and unloading force while reducing propeller loading and unloading force.

[Prior Art] Conventionally, there are the following three types of stern rectifiers that rectify the flow of seawater flowing into the propeller surface of a ship.

Type A As shown in Figures 4 and 5 (A-A sectional view in Figure 4), a plurality of small rectifying fins C are provided in upper and lower stages on both chord sides of the propeller b in the stern. There is. Each of the fins C is formed and arranged so that the flow of seawater flowing along the hull exterior plate a, which is relatively slow with respect to the hull exterior plate a, is evenly guided to the propeller surface. There is. Note that the shape and arrangement position of each fin C are set in accordance with the flow of seawater in a constant state (eg, empty state g).

The rectifying fins C configured as described above uniformly guide the relatively slow flow of seawater generated by the gap resistance with the hull outer plate a to the propeller surface in the above-described constant state. This allows the propeller b to recover the energy lost due to friction between the ship and the seawater, and also reduces the propeller excitation force.

Type B As shown in Figures 6 and 7 (B-B sectional view in Figure 6), a predetermined length is installed on both sides of the stern part of the hull shell a from just above the propeller b to the bow direction. The elongated fin d is notched by δ. The fin d has a substantially arcuate cross section and is formed to cover the upper part of the propeller b. The fins d configured in this way speed up the flow in the high wake zone j and reduce the propeller excitation force.

Type C As shown in FIG. 8, a stator Q having a plurality of rectifying fins f extending radially with respect to one plane is fixed coaxially with the propeller just in front of the propeller b.

The rectifying fins f are pitched so that the flow of seawater flowing into the propeller surface rotates in the opposite direction to the propeller b.

The stator Q configured as described above forces the flow of seawater flowing into the propeller surface to create a rotating flow in the opposite direction to the rotation of the propeller b. This rotational flow flows into propeller b and is canceled out, increasing the rotational component of the backward flow by 7.

Orui has two fins on the rudder plate as shown in Figure 9.
It is provided extending outward on both sides. The fins i are provided with gambers and angles of attack that are opposite to each other along the flow of seawater flowing on both sides of the rudder board.

The fin i configured in this manner operates as follows. When the rotational flow generated by propeller b flows into the rudder plate, it obtains a force on both sides thereof in a direction perpendicular to the diagonally upward or downward flow. The component of this force in the propulsion direction becomes part of the direction of movement.

[Problems to be Solved by the Invention; However, in the conventional stern rectifier, each of the above three types has had its own problems.

In the case of A type, the rectifier fin is C or fixed type.

Each fin C is
Because the shape and position of the vessel were fixed, it was difficult to deal with the flow of seawater near the hull outer plate a, which differs significantly between the loaded state and the unloaded state. As a result, the flow of seawater changes.

There was a problem in that this rectifying fin OL7') resistance increased and propulsion efficiency decreased.

In the case of Type B, the fin d is large and has a wide range, making it difficult to create a shape that matches the flow of Z ice cubes near the fin d, which changes depending on the cargo condition.

There was a problem that the resistance of the fin d increased and the propulsion efficiency decreased.

In case of C type, fin f provided at the front of propeller b
is large, and the fin 1 provided at the rear is attached to the rudder plate or rudder post, so attention must be paid to strength and vibration.

A.8. C each type! In both stations, there remains a rotational flow in the wake of propeller B, and this rotational flow (is not an advantage in terms of an odd 5-1 V flow for the propulsion force of the ship).
? There wasn't.

[Object of the Invention] The present invention was devised in order to effectively solve the problems in the conventional stern rectifier, and its purpose is to improve the wake gain as much as possible and reduce the propeller excitation force. The object of the present invention is to provide a stern rectifying device that can reduce energy consumption and enable energy-saving key navigation.

SUMMARY OF THE INVENTION 1 To achieve the above object, the present invention provides a horizontal cylindrical nozzle that is rotatably provided in a propeller aperture section in the stern section to which a propulsion propeller is attached.

and a nozzle driving means for driving and controlling the nozzle within the hull, and constantly rectifying the flow of seawater by moving the nozzle in accordance with the flow of seawater at the stern, which changes depending on the state of the cargo and the impact, etc. I made it possible.

[Example] An example according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a side view showing one embodiment of the present invention, and FIG. 2 is a side view showing one embodiment of the present invention.
3 is a cross-sectional view taken along the line A--A in FIG. 1.

As shown in the figure, an annular nozzle 5 is rotatably provided in a propeller aperture section 2 at the stern section to which a propeller 4 is attached.

This nozzle 5 is arranged so as to fit approximately within the diameter 9 of the propeller 4. That is, the nozzle 5 is connected to the propeller 4
It is provided with a size of 1/2 or less of the diameter of. Furthermore, the nozzle 5 has a substantially streamlined cross-sectional shape and a chorded shape (also referred to as an "aerofoil type" or "airplane wing type"), and the inlet has an annular shape slightly larger than the outlet. No body.

It has a shape that accelerates flow velocity and has low fluid resistance.

Further, the annular nozzle 5 is integrally formed with support shafts 6a and 6b at the upper and lower portions of the substantially central portion. The support shaft 6a engages with a nozzle driving means 7 provided inside the hull and is rotatably driven so that the nozzle 5 can be rotated from side to side in a substantially horizontal direction. It is pivotally supported on the upper part of the valve part 3.

Further, the nozzle driving means 7 controls the rotation speed of the propeller 4.

The nozzle driving means 7 is automatically activated and rotates the nozzle 5 by receiving data signals related to ship operation such as ship speed and tidal current.

Note that 8 indicates a stern frame, and 10 indicates a propeller shaft.

Next, the operation of the present invention will be explained.

The following relationship exists between the flow velocity va in the plane of the propeller, the ship speed Vs, and the wake coefficient ω. Namely.

Va=Vs (1-ω) becomes.

If the flow of seawater that is slowed down relative to the hull shell 1 due to the resistance with the hull shell 1 (hereinafter referred to as "slow flow") is collected within the plane of the propeller, Va in the above equation will be reduced.

In other words, VS (1-ω) becomes smaller, and as a result, the horsepower (DHP) required for propulsion of the ship becomes smaller.

Further, since the propeller 4 rotates in one direction, a rotational flow remains behind the propeller. Since this rotational flow does not serve as a propulsion force for the ship, the energy loss can be reduced by giving the flow a rotational component in the opposite direction to the rotation of the propeller 4. This means that due to the frictional resistance between the hull outer plate 1 and the seawater, part of the energy wasted in the seawater is recovered by the propeller 4 as propulsive force (wake gain).

For this reason, the nozzle 5 configured as described above can rectify the slow flow within the plane of the propeller, and the rotational flow in the wake of the propeller 4 can be reduced.

That is, since the propeller 4 rotates in one direction (usually clockwise when viewed from the rear), a component of the rotating flow in the opposite direction should be generated in advance.

By adjusting the rotation of the nozzle 5, the rotational flow in the wake of the propeller 4 can be reduced.

For example, in the case of a clockwise propeller 4, rotation adjustment is made so that the nozzle 5 faces to the right (the rear end of the nozzle faces to the left) when viewed from above.

In addition, by directing the rotation of the propeller 4 in a direction that increases the flow component in the opposite direction to suppress the rotation of the propeller, or by increasing the rotation of the propeller in the opposite direction, the propeller 4 can be prevented from becoming dirty.
This is because it can contribute to adjusting the load on the main engine due to changes over time, sea conditions, etc.

Enables energy-saving operation.

As described above, the present invention uses a nozzle to rectify the flow of seawater so that it flows uniformly onto the propeller surface.

Since a flow component in the direction opposite to the rotation of the propeller 4 is generated and the rotational flow in the wake of the propeller 4 is reduced, the wake gain is improved and the propeller excitation force is reduced.

It will become possible to operate ships in an energy efficient manner.

[Effects of the Invention] As described above, the two stern rectifiers of the present invention exhibit various excellent effects as described below.

(1) The nozzle is rotatably installed in the aperture part of the stern, so it can respond to a variety of seawater flows that change depending on conditions such as stuttering, ship speed, and sea conditions.

It is possible to rectify the flow of seawater so that it always flows evenly onto the propeller surface.

<2> Since the slow flow against the hull outer plate is rectified toward the propeller surface, the wake gain is improved as much as possible, greatly contributing to the propulsion efficiency of the ship, and enabling energy-saving operation.

(3) Since the flow of seawater can be evenly rectified toward the propeller surface, the propeller excitation force can be reduced as much as possible.

(4) Navigation performance can be improved by measuring the diagonal flow caused by the ship's turning or tidal current using an appropriate method and correcting the diagonal flow using the nozzle.

[Brief explanation of drawings]

FIG. 1 is a side view showing an embodiment of the present invention, FIG. 2 is a sectional view of FIG. 1, FIG. 3 is a sectional view taken along line A-A in FIG.
9 to 9 are diagrams showing conventional examples. In the figure, 1... Hull outer plate, 2... Propeller aperture part, 3... Stun valve part, 4... Propeller, 5...
... Nozzle, 6a, 6b... Support shaft, 7... Nozzle drive means. 8...Scoon frame, 9...Propeller diameter, 1
0... Indicates propeller shaft. Patent applicant Ishikawajima-Harima Heavy Industries Co., Ltd. Figure 1 A - A Figure 4 Figure 5 Figure 2 Figure 3, S j, B Figure 5 Figure 7 Figure 8

Claims (1)

[Claims] The vessel is characterized by comprising: a horizontal cylindrical nozzle rotatably provided in a propeller aperture portion of the stern portion to which a propulsion propeller is attached; and a nozzle drive means for driving and controlling the nozzle within the hull. Stern rectifier.