KR20160000148A - A ship for reducing vibromotive force - Google Patents

Abstract

Disclosed is a ship for reducing propeller cavitation-induced excitation force. The ship for reducing propeller cavitation-induced excitation force according to one embodiment of the present invention comprises: a working gas receiving membrane pad having a plurality of working gas pockets wherein working gas, which generates an incident wave generated in rotation of a propeller and a reflected wave to cause destructive interference, is received, and having a pad body supporting the working gas pockets; a working gas supply unit connected to the working gas receiving membrane pad to supply the working gas to the working gas pockets; and a controller controlling operation of the working gas supply unit for the working gas to be supplied to the inside of at least one working gas pocket which is selected in the working gas pockets.

Description

A ship for reducing vibromotive force,

[0001] The present invention relates to a propeller cavitation organic exciter power reduction type ship, and more particularly, to a propeller cavitation propulsion system capable of variably controlling excitation frequency band variation according to RPM of a propeller, The present invention relates to a propeller cavitation-induced vibration reduction type vessel capable of performing precise control according to changes in intensity or position.

When the propeller provided at the rear of the ship rotates in water, the water flows to the propeller blade surface, causing a difference in hydraulic pressure between the front and back surfaces of the propeller blade surface. The propulsion generated in this way allows the ship to be operated at sea.

On the other hand, when the propeller is operated for the operation of the ship, that is, when the propeller is rotated in water, a fluctuating pressure is generated in the water due to the propeller as the rotating body. The fluctuating pressure thus generated increases the excitation force to the hull, (Including noise).

Particularly, when cavitation occurs in the water by the propeller, vibration of the hull is severely generated because the excitation force is further increased.

This is because when the pressure in the water is low, the gas contained in the water escapes from the water and collects at a low pressure. As a result, bubbles are generated in the water, and when the bubbles reach the high pressure part, Thereby generating a fluctuating pressure.

In order to solve the problem of increased excitation force due to such fluctuating pressure, it is necessary to design the shape and size of the propeller blade itself differently, to improve the shape of the rear of the ship, to attach a separate reinforcing material for preventing noise and vibration, Or by applying various methods such as attaching a guide device for guiding the flow of the water flowing in the propeller, reducing the size of the propeller, or the like. However, it is practically effective to reduce the excitation force it's difficult.

The vibration problem including the noise transmitted to the hull by the propeller is increased when the propeller is operated. For example, when the ship is a cruise ship, such as a cruise ship or a warship, .

Accordingly, the present applicant has filed with the Korean Intellectual Property Office (KIPO) a number of technologies for reducing the excitation force by forming an air layer in the form of an air bubble on the surface of the hull adjacent to the propeller.

However, most of the prior art attempts to use the air layer, including the last-filed technology, require air to be continuously injected using a compressor to form an air layer, so that due to the installation and operation of the compressor and its related components Energy consumption and so on.

Accordingly, it is an object of the present invention to prevent vibrations from occurring in the hull by increasing the excitation force at the time of operation of the propeller while fundamentally preventing the burden of energy consumption due to the installation and operation of the compressor and related parts, A method of applying a working gas containing membrane pad accommodated in one side to a hull can be considered.

However, when applying the working gas receiving membrane pad to the hull, only one frequency band corresponding to the specific rotational speed (RPM) of the corresponding propeller is controlled through one working gas receiving membrane pad It is urgent to develop a technique for performing precise control according to the change of the intensity or position of vibration by using a plurality of workpiece gas receiving membrane pads in a bundle unit.

Prior Art _1; Japanese Patent Application Laid-Open No. 8-188192 Prior Art _2; Japanese Unexamined Patent Application Publication No. 2009-274705

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above problems, and it is therefore an object of the present invention to provide a propulsion device for a propeller which is capable of preventing a vibration from being generated in a hull by increasing propulsion force during operation of a propeller while fundamentally preventing a burden of energy consumption, In particular, it is possible to perform variable control on changes in the frequency band of the propeller due to changes in the RPM of the propeller, as well as propeller cavitation organic excitation force And to provide a reduced ship.

According to an aspect of the present invention, there is provided a plasma processing apparatus including a plurality of working gas pockets for accommodating a working gas for generating a reflected wave for generating a destructive interference phenomenon with incident waves generated upon rotation of a propeller, A working gas receiving membrane pad having a pad body; A working gas supply unit connected to the working gas receiving membrane pad to supply the working gas to the working gas pockets; And a controller for controlling the operation of the working gas supply unit such that the working gas is supplied into at least one working gas pocket selected from the working gas pockets.

The propeller rotational speed detector may further include a propeller rotational speed sensor for detecting the rotational speed of the propeller. The controller may control the operation of the working gas supplying unit based on information from the propeller rotational speed sensor.

The work gas supply unit includes a work gas receiver in which the work gas is stored; A work gas main line connected to the work gas receiver to deliver the work gas; A first valve provided on the working gas main line for selectively interrupting the flow of the working gas on the working gas main line; A plurality of working gas individual connection lines for individually connecting working gas pockets of the work gas main line and the working gas receiving membrane pads, respectively; And a plurality of second valves, each of which is provided on the working gas individual connection lines, for selectively interrupting the flow of the working gas on the working gas individual connection lines.

The working gas supply unit includes a regulator provided on the main line of the working gas main body to maintain a positive pressure with respect to the working gas supplied through the working gas receiver; A check valve provided on the working gas main line between the regulator and the first valve to prevent back flow of the working gas; A third valve provided on a working gas branch line which branches with respect to the working gas main line and selectively interrupts the flow of the working gas on the working gas branch line; And a pressure gauge provided on the working gas main line between the first valve and the working gas receiving membrane pad to measure a pressure of the working gas supplied to the working gas receiving membrane pad.

The anti-fouling paint may be applied to the outer surface of the working gas receiving membrane pad.

The working gas receiving membrane pads may be disposed between the 0.5 diameter D of the propeller in the fore direction and the 0.5 diameter D of the propeller in the stern direction relative to the propeller, May be disposed between a diameter D of the propeller in the starboard direction and a diameter D of the propeller in the port direction with respect to the axis of rotation of the propeller.

According to the present invention, it is possible to prevent vibrations from occurring in the hull by increasing the excitation force at the time of operation of the propeller while fundamentally preventing the burden of energy consumption and the like due to installation and operation of the related parts including the compressor. Particularly, it is possible not only to perform variable control on changes in the excitation frequency band according to the change of the RPM of the propeller, but also to perform precise control according to the change in intensity or position of vibration.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a structural view of a propeller area of a propeller cavitation propellant-reducing type propulsion vessel according to an embodiment of the present invention; FIG.
2 is an enlarged view of the area A in Fig.
3 is a plan structural view of the working gas receiving membrane pad of FIG.
Fig. 4 is a chart for measuring the impedance of water, rubber, and air.
5 is a view for explaining the principle of incident wave and reflected wave.
6 is a view of a working gas receiving membrane pad for illustrating equation (1).
Fig. 7 is a view showing a state where a working gas receiving membrane pad is installed in a region on the upstream side of the propeller, and shows a plurality of variable pressure measuring points.
Figure 8 is a graphical representation of the efficiency of a working gas receiving membrane pad relative to the frequency of the propeller.
Figure 9 is a graph summarizing the results of the 150 Hz band for the working gas receiving membrane pads corresponding to Figure 7;
10 is a schematic configuration diagram of a working gas supply unit.
11 is a control block diagram of the working gas supply unit.
FIG. 12 is a graph showing the measurement results of the vibration at transom according to the volume change of the working gas of the working gas supplying unit. FIG.

In order to fully understand the present invention, operational advantages of the present invention, and objects achieved by the practice of the present invention, reference should be made to the accompanying drawings and the accompanying drawings which illustrate preferred embodiments of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Like reference symbols in the drawings denote like elements.

FIG. 1 is a structural view of a propeller area of a propeller cavitation propulsion reducing type ship according to an embodiment of the present invention, FIG. 2 is an enlarged view of a region A of FIG. 1, and FIG. 3 is a cross- Fig.

Referring to these drawings, the propeller cavitation propulsion reduction type ship according to the present embodiment can prevent the burden of energy consumption and the like due to the installation and operation of the related parts including the compressor, It is possible to prevent the vibration of the hull 110 from being generated due to the increase of the exciting force.

Particularly, the propeller cavitation organic exciter power reduction type ship according to the present embodiment is capable of variably controlling the excitation frequency band change according to the RPM of the propeller 120, A working gas receiving membrane pad 130 coupled to the hull 110 and having a plurality of working gas bladders 132 and a working gas receiving chamber 130 having a plurality of working gas bladders 132, A working gas supplying unit 150 connected to the membrane pad 130 to supply the working gas to the working gas bladders 132 and a controller 170 for controlling the operation of the working gas supplying unit 150.

In this embodiment, since at least one selected from the plurality of working gas bladders 132 on the working gas receiving membrane pad 130 can be used by using the working gas supplying part 150, the rotational speed of the propeller 120 The variable frequency band can be variably controlled according to the variation. That is, even if the number of revolutions of the propeller 120 changes during the operation of the ship, the vibration reduction effect can be provided for all frequency bands corresponding to the number of revolutions of the propeller 120. The vibration of the hull 110 can be reduced even if the number of revolutions of the propeller 120 is changed.

Hereinafter, the configuration of the present embodiment will be described. At the rear of the hull 110, a propeller 120 for propelling the hull 110 is provided. A propeller rotational speed detector 180 (see FIG. 11) is connected to the propeller 120 to detect the rotational speed RPM of the propeller 120.

A rudder 125 for adjusting the traveling direction of the ship is provided around the propeller 120. The rudder 125 may be a normal rudder or a bulb rudder.

For reference, the ship to which the present invention is applied may include all of marine vessels, warships, fishing vessels, carriers, drillships, cruise ships, special work ships, and the like, as well as floating marine structures. Therefore, the scope of right of the present embodiment can not be limited to a specific ship.

As described above, when the propeller 120 is operated, that is, when the propeller 120 is rotated in water, a fluctuating pressure is generated in the water due to the propeller 120 as a rotating body. ), Which causes vibration (including noise) in the hull.

The vibration transmitted to the hull 110 may be a serious problem, for example, as a cruise ship or a warship such as a warship, and should be prevented.

In other words, the vibrating force is increased due to the fluctuating pressure generated in the water during the operation of the propeller 120 to prevent the vibration of the hull 110 from being generated. For this purpose, in this embodiment, the working gas receiving membrane pad 130 ) Is applied.

As will be described in detail below, the working gas receiving membrane pad 130 applied to the vessel of the present embodiment has a completely different form from the structures forming the air layer, which is a conventional air bubble shape.

In other words, since the working gas receiving membrane pad 130 applied in the present embodiment is only a structure in which the air is confined, there is no need to install or operate the relevant parts including the compressor which should be used in the past .

Therefore, it is possible to fundamentally prevent the burden of installing and operating the compressor and related parts, and energy consumption.

The working gas receiving membrane pad 130 in this role is coupled to the hull 110 adjacent to the propeller 120 as shown in Figure 1 and is connected to the hull 110 as it is generated during rotation of the propeller 120, And has a shape in which a reflected wave is generated to cancel an incident wave, and a working gas is accommodated in one side.

In particular, the working gas receiving membrane pads 130 may be joined to the wall surface of the hull 110 on the upper side of the propeller 120. As an example, the work gas receiving membrane pads 130 are shown attached to the upper chamber of the propeller 120 in the figure.

2, the working gas accommodating membrane pad 130 includes a pad body 131 detachably coupled to the hull 110, and a working electrode 130 formed on one side of the pad body 131, And a plurality of working gas pockets (132) sealed and accommodated.

In this embodiment, a plurality of working gas pockets 132, in which a working gas for generating a reflected wave to cause a destructive interference phenomenon with respect to an incident wave generated when the propeller 120 rotates, Respectively.

In this embodiment, the working gas receiving membrane pads 130 are positioned between the 0.5 diameter D of the propeller 120 and the 0.5 diameter D of the propeller 120 in the aft direction with respect to the propeller 120, As shown in FIG. In other words, when the diameter of the propeller 120 is 50 cm, the working gas receiving membrane pad 130 may be disposed between the propeller 120 and the point 25 cm in the aft direction.

The working gas receiving membrane pad 130 is disposed between the one diameter D of the propeller 120 in the starboard direction and the one diameter D of the propeller 120 in the port direction relative to the rotational axis of the propeller 120 . In other words, when the diameter of the propeller 120 is 50 cm, the working gas receiving membrane pad 130 can be disposed between the starboard and the 50 cm point in the port direction with respect to the rotational axis of the propeller 120.

In this position, the working gas receiving membrane pad 130 is coupled to the wall surface of the hull 110 to prevent the hull 110 from being vibrated.

In this embodiment, the material of the working gas receiving membrane pad 130 may be rubber, and the working gas may be air.

However, the scope of the rights of the present embodiment is not limited thereto. That is, if the material of the working gas receiving membrane pad 130 is a material similar to rubber, it is sufficient, and the working gas may be applied to various gases as long as it is not a liquid.

The pad body 131 forming the working gas receiving membrane pad 130 is a flat structure made of a rubber material and is utilized as a part detachably coupled to the hull 110.

The pad body 131 may be coupled to the hull 110 through a variety of structures and methods. For example, the pad body 131 can be coupled to the hull 110 in various manners such as a bolt-nut coupling method, a fitting method, and a welding method in which an insert metal plate is welded. Therefore, the scope of the right of the present embodiment can not be limited to the manner in which the pad body 131 is coupled.

In this embodiment, the pad body 131 may have a rectangular shape, but the shape of the pad body 131 may be rectangular, circular, triangular, or the like. Therefore, the right range of the present embodiment can not be limited to the shape of the pad body 131. [

The working gas bladders 132 are formed on one side of the pad body 131 and have a shape swollen to one side of the pad body 131.

Although the working gas pocket 132 has a circular shape in the present embodiment, the shape of the working gas pocket 132 may also be various polygonal shapes such as a triangle shape and a square shape. Therefore, Can not be.

As described above, the working gas bag 132 is filled with air as a working gas.

The working gas filled in the working gas pocket 132 is formed integrally with the working gas receiving membrane pad 130 when the working gas receiving pocket 132 is formed, It does not.

As described above, a plurality of work gas bladders 132 may be provided on one pad body 131. By the action of the work gas supplier 150, work gas is supplied to all of the work gas bladders 132 Or some or all of the selected workpieces may be charged and used. As a result, it is possible to perform variable control on a change in the excitation frequency band according to the change in RPM of the propeller 120, as well as to perform precise control according to the change in intensity or position of the vibration.

Hereinafter, the principle of reducing the exciting force due to the working gas receiving membrane pad 130 in which the working gas is hermetically sealed will be described in detail with reference to FIG. 4 to FIG.

Fig. 4 is a graph showing impedance of water, rubber and air, Fig. 5 is a view for explaining the principle of an incident wave and a reflected wave, Fig. 6 is a drawing of a working gas receiving membrane pad for explaining [Equation 1] 7 is a view showing a plurality of variable pressure measuring points in a state where the working gas receiving membrane pads are installed in the area immediately upstream of the propeller and Fig. 8 is a graph showing the efficiency of the working gas receiving membrane pads based on the frequency of the propeller And FIG. 9 is a graph summarizing the results of the 150 Hz band for the working gas receiving membrane pads corresponding to FIG.

Referring to these drawings, referring first to FIG. 4, an acoustic impedance (which means an acoustical resistance) of rubber, which is a material of the working gas receiving membrane pad 130 of the present embodiment, , While it is almost infinitely greater than air.

Typically, when sound waves propagate in a specific medium and a medium having a different impedance is encountered, a transmission phenomenon and a reflection phenomenon occur. Since the impedance of seawater and rubber is similar, only the reflection phenomenon occurs without reflection at the boundary between sea water and rubber.

For example, as shown in FIG. 5, the incident wave generated in the operation of the propeller 120 passes through the rubber layer, which is the wall surface of the working gas pocket 132, and then flows into the work gas filled in the working gas pocket 132, And is reflected by the phase opposite to the incident wave, that is, it is formed as a reflected wave. This reflected wave causes a destructive interference phenomenon with the incident wave, so that the incident wave generated in the operation of the propeller 120 is canceled. By such a phenomenon, the exciting force is reduced and the occurrence of vibration of the ship 110 can be reduced.

I will explain this again. The spherical pressure wave generated by the cavitation during the operation of the propeller 120, that is, the incident wave, can be propagated omnidirectionally.

In this case, when the working gas receiving membrane pads 130 filled with air are installed on the surface of the hull 110 around the propeller 120, the working gas pockets 132 of the working gas receiving membrane pads 130 The incident incident wave passes through the rubber layer, which is the wall surface of the working gas pocket 132, but is reflected by the working gas filled in the working gas pocket 132, i.e., air, in a phase opposite to that of the incident wave.

When the incident wave is formed as a reflected wave that is reflected by the opposite phase and strikes against the air, the reflected wave meets an incident wave incident on the workpiece receiving membrane pad 130, causing a destructive interference phenomenon with the incident wave.

As a result, the fluctuating pressure transmitted from the outside of the working gas receiving membrane pad 130 to the hull 110 is reduced, and when the fluctuating pressure is reduced, the exciting force is reduced. Therefore, 110 are reduced.

Such a reduction performance is limited to a specific frequency band of the propeller 120 as shown in Equation (1) below. In other words, it is limited to the specific frequency band corresponding to the specific number of revolutions (RPM) of the propeller 120.

[Equation 1]

Here, f is the propeller of a reduced _{frequency, c a (= 340m / s} ) and c _w (= 1500m / s), respectively for air and water sound speed _{ρ a (= 1.02 kg / m} 3), ρ w (= 1024kg / m ³ ) denote the density of air and seawater, and a and b mean the inner diameter and outer diameter of the working gas receiving membrane pads 130a to 130c, respectively, when they are regarded as equivalent spheres.

A model test was carried out to verify these items. That is, as shown in FIG. 7, one working gas receiving membrane pad 130 having a reducing effect in the frequency band of 150 Hz is designed (or attached) to the wall surface of the hull 110 on the STBD region side, P2, P3, and P4, as well as vibrations were measured in the transom region, which is a steel plate supporting above the stern of the hull 110. In addition,

8, the horizontal axis (x axis) refers to the frequency corresponding to the RPM of the propeller 120, and the vertical axis (y axis) refers to the frequency at which the work gas accommodating membrane pad 130 is attached The change in pressure and vibration after the installation of the working gas accommodating membrane pad 130 before the working gas accommodating membrane pad 130 is increased, but the reduction effect is remarkably observed in the vicinity of the design frequency of 150 Hz.

FIG. 9 summarizes the results of the 150 Hz band. Referring to FIG. 9, the fluctuating pressures at the positions P2, P3 and P4 located outside the working gas receiving membrane pad 130 are reduced by an average of about 70% As a result, the vibration level is also remarkably reduced by 70% or more.

Referring again to Equation 1 and FIG. 6, it can be seen that the reduction frequency band f of the propeller 120 is inversely proportional to the air volume (radius, a), and also the working gas receiving membrane pad 130) can be applied to only one frequency band.

However, there are often two or more frequency bands that need to be controlled when operating a ship.

Since RPM of the propeller 120 must be constantly changed in operating a ship, there is a high need to control N frequency bands (N is a natural number) instead of one frequency band.

In this case, since only one specific frequency band can be controlled through only one working gas receiving membrane pad 130, the working gas receiving membrane pad 130 of this embodiment is required to control the N frequency bands. A working gas receiving membrane pad 130 of the present embodiment in which a plurality of working gas pockets 132 are provided on one pad body 131 is required.

However, as described above, since all of the working gas bladders 132 may be filled with the working gas, or some or all of the working gas bladders 132 may be filled with the working gas, it is necessary to control the working gas bladders 132. For this, A controller 150, and a controller 170 are used.

When the work gas supply unit 150 controlled by the controller 170 is applied as in the present embodiment, the change in the excitation frequency band according to the change in the number of revolutions of the propeller 120 can be variably controlled. Therefore, even if the propeller 120 is rotated at any rotation speed, the vibration generated in the hull 110 can be reduced.

The structure and operation of the working gas supply unit 150 will be described with reference to FIGS. 10 to 12. FIG.

FIG. 10 is a schematic block diagram of the working gas supplying unit, FIG. 11 is a control block diagram of the working gas supplying unit, and FIG. 12 is a graph showing the vibration at transom measuring result according to the volume change of the working gas in the working gas supplying unit .

Referring to these drawings, a working gas supply unit 150 applied to a ship of the present embodiment is connected to a working gas receiving membrane pad 130 and serves to supply work gas to the working gas bladders 132.

The working gas supply unit 150 includes a working gas receiver 151, a regulator 152, a check valve 153, first to third valves 154, 161 and 155, and a pressure gauge 158 .

The work gas receiver 151 stores work gas and serves to supply work gas stored by the controller 170. [ The working gas receiver 151 can be connected to a compressor (not shown).

The work gas receiver 132 of the work gas receiver 151 and the work gas receiving membrane pad 130 are connected to the work gas main line 156.

One side of the working gas main line 156 is connected to a working gas branch line 157 which intersects the working gas main line 156.

And a plurality of working gas individual connecting lines 162 are provided on the other side of the working gas main line 156. A plurality of working gas individual connection lines 162 are lines connecting the working gas main lines 156 and the work gas pockets 132 of the working gas receiving membrane pads 130, respectively.

A regulator 152 is provided on the working gas main line 156 and serves to maintain a positive pressure with respect to the working gas supplied through the working gas receiver 151.

The check valve 153 is provided on the working gas main line 156 between the regulator 152 and the first valve 154 and serves to prevent backflow of the working gas.

A first valve 154 is provided on the working gas main line 156 and serves to selectively control the flow of working gas on the working gas main line 156.

A second valve 161 is provided on each of the work gas individual connection lines 162 and serves to selectively intercept the flow of working gas on the work gas individual connection lines 162.

A third valve 155 is provided in the working gas branch line 157 that branches against the working gas main line 156 and serves to selectively intercept the flow of working gas on the working gas branch line 157 .

A pressure gauge 158 is provided on the working gas main line 156 between the first valve 154 and the working gas pocket 132 of the working gas receiving membrane pad 130 to provide a working gas receiving membrane pad 130 And serves to measure the pressure of the working gas supplied to the gas bag (132).

The propeller rotational speed detector 180 detects the rotational speed RPM of the propeller 120. The propeller speed sensor 180 may be wireless or wired.

Finally, the controller 170 controls the operation of the work gas supply unit 150 based on the information of the propeller rotation speed sensor 180. [

Referring to the graph of FIG. 12, the frequency at which the vibration reducing effect is exhibited is shifted to the 170 Hz, 155 Hz, and 145 Hz bands according to the volume increase of the work gas as the working gas pockets 132 of the work gas receiving membrane pads 130 are used together. It can be seen that it is moving. In other words, as the number of the working gas bladders 132 of the working gas receiving membrane pad 130 is used, the frequency at which the abrasion performance appears is shifted to the lower frequency band (or the corresponding number of revolutions of the propeller 120) .

Therefore, in the case of the present embodiment, the controller 170 controls the operation of the working gas bag 132 so that the working gas is supplied into at least one working gas bag 132 selected from among the working gas bags 132 based on the information of the propeller- And controls the operation of the supply unit 150.

The controller 170 performing such a role may include a central processing unit 171 (CPU), a memory 172 (MEMORY), and a support circuit 173 (SUPPORT CIRCUIT) as shown in Fig.

The central processing unit 171 controls the operation of the working vessel so that the working gas is supplied into at least one working gas pocket 132 selected from among the working gas pockets 132 on the basis of the information of the propeller- And may be one of a variety of computer processors that are industrially applicable to control the operation of the gas supply unit 150.

The memory 172 (MEMORY) is connected to the central processing unit 171. The memory 172 may be a computer readable recording medium and may be located locally or remotely and may be any of various types of storage devices such as, for example, a random access memory (RAM), a ROM, a floppy disk, At least one or more memories.

The support circuit 173 (SUPPORT CIRCUIT) is coupled with the central processing unit 171 to support the typical operation of the processor. Such a support circuit 173 may include a cache, a power supply, a clock circuit, an input / output circuit, a subsystem, and the like.

The controller 170 of the ship according to the present embodiment is configured to detect the operation speed of the worker's hand such that the working gas is supplied into at least one working gas pocket 132 selected from among the working gas pockets 132 based on the information of the propeller- And controls the operation of the gas supply unit 150. At this time, the controller 170 controls the working gas supply unit 150 to supply the working gas into at least one working gas pocket 132 selected from among the working gas pockets 132 based on the information of the propeller rotation speed sensor 180, A series of processes and the like for controlling the operation of the memory 172 may be stored in the memory 172. [ Typically, a software routine may be stored in memory 172. The software routines may also be stored or executed by other central processing units (not shown).

Although processes according to the present invention are described as being performed by software routines, it is also possible that at least some of the processes of the present invention may be performed by hardware. As such, the processes of the present invention may be implemented in software executed on a computer system, or in hardware such as an integrated circuit, or in combination of software and hardware.

As described above, according to the present embodiment, the propulsion force is increased during operation of the propeller 120 while preventing the burden of energy consumption and the like due to installation and operation of the compressor, It is possible to variably control the change of the excitation frequency band according to the change of the RPM of the propeller 120. [

Although the description has been omitted in the above embodiments, in order to prevent fouling of foreign matter or the like from adhering to the workpiece accommodating membrane pad 130 during long-time ship operation, the working gas accommodating membrane pads 130, An anti-fouling paint (or an anode) may be applied.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Accordingly, such modifications or variations are intended to fall within the scope of the appended claims.

110: Hull 120: Propeller
125: rudder 130: working gas receiving membrane pad
131: Pad body 132: Working gas pocket
150: Working gas supply unit 151: Working gas receiver
152: Regulator 153: Check valve
154: first valve 155: third valve
156: Working gas main line 157: Working gas branch line
158: Pressure gauge 161: Second valve
162: Working gas individual connection line 170: Controller
180: Propeller speed detector

Claims (6)

A plurality of working gas pockets for accommodating a working gas for generating a reflected wave for causing a destructive interference phenomenon with incident waves generated when the propeller rotates; and a pad body for supporting the plurality of working gas pockets Receiving membrane pads;
A working gas supply unit connected to the working gas receiving membrane pad to supply the working gas to the working gas pockets; And
And a controller for controlling the operation of the working gas supply unit so that the working gas is supplied into at least one working gas pocket selected from the working gas pockets. The method according to claim 1,
Further comprising a propeller rotational speed sensor for sensing the rotational speed of the propeller,
Wherein the controller controls the operation of the working gas supply unit based on information from the propeller rotational speed sensor. The method according to claim 1,
The working gas supply unit,
A work gas receiver for storing the work gas;
A work gas main line connected to the work gas receiver to deliver the work gas;
A first valve provided on the working gas main line for selectively interrupting the flow of the working gas on the working gas main line;
A plurality of working gas individual connection lines for individually connecting working gas pockets of the work gas main line and the working gas receiving membrane pads, respectively; And
And a plurality of second valves, each of which is provided on the working gas individual connection lines, for selectively interrupting the flow of the working gas on the working gas individual connection lines. The method of claim 3,
The working gas supply unit,
A regulator provided on the main line of the working gas main body to maintain a positive pressure with respect to the working gas supplied through the working gas receiver;
A check valve provided on the working gas main line between the regulator and the first valve to prevent back flow of the working gas;
A third valve, provided on a working gas branch line that branches off with respect to the working gas main line, for selectively interrupting the flow of the working gas on the working gas branch line; And
And a pressure gauge provided on the working gas main line between the first valve and the working gas accommodating membrane pad for measuring the pressure of the working gas supplied to the working gas accommodating membrane pad, Ship. The method according to claim 1,
And a fouling preventing paint is applied to the outer surface of the working gas containing membrane pad. The method according to claim 1,
The working gas receiving membrane pads are arranged between the diameter D of the propeller in the fore direction and the diameter D of the propeller in the stern direction in relation to the propeller,
Wherein the working gas receiving membrane pad is disposed between a diameter D of the propeller in the starboard direction and a diameter D of the propeller in the port direction on the basis of the rotation axis of the propeller, Ship.

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