WO2015167263A1

WO2015167263A1 - Ship for reducing propeller cavitation-induced excitation force

Info

Publication number: WO2015167263A1
Application number: PCT/KR2015/004354
Authority: WO
Inventors: 이정훈; 김진학; 박형길; 이경준; 김윤식; 박지환; 전명호; 한재문; 허갑; 김부기
Original assignee: 삼성중공업 주식회사
Priority date: 2014-05-02
Filing date: 2015-04-29
Publication date: 2015-11-05
Also published as: CN106458307B; JP2017513768A; CN106458307A; JP6275872B2

Abstract

Disclosed is a ship for reducing propeller cavitation-induced excitation force. A ship for reducing propeller cavitation-induced excitation force according to one embodiment of the present invention comprises: a hull provided with a propeller; and a working gas receiving membrane pad which receives working gas at one side thereof and which is coupled to the hull, adjacent to the propeller, the working gas generating a reflective wave for causing destructive interference with an incident wave generated during the rotation of the propeller.

Description

Propeller Cavitation Organic Vibration Reduction Type Vessel

The present invention relates to a propeller cavitation organic vibration reduction type ship, and more particularly, to a propeller cavitation organic vibration reduction type ship with improved structure for vibration reduction.

When the propeller provided in the rear of the ship rotates in water, water flows to the wing surface of the propeller, generating a hydraulic pressure difference on the front and rear surfaces of the propeller wing surface, and the driving force is generated by the pressure difference. The driving force generated in this way can operate the ship at sea.

On the other hand, when a propeller is operated for the operation of a ship, that is, when the propeller is rotated in water, a fluctuation pressure is generated in the water due to the propeller as a rotating body, and the fluctuation pressure generated in this way increases the vibration force on the hull by increasing the vibration force to the hull. It acts as a factor in generating (including noise).

In particular, when cavitation is generated in the water by the propeller, vibration of the hull is severely generated because the vibration force is further increased.

This means that when the pressure in the water is low, the gas contained in the water escapes from the water and collects at the low pressure, thereby generating bubbles in the water. This is because the fluctuation pressure is generated.

In order to solve the problem of increasing the vibration force caused by the fluctuation pressure, the propeller wing itself is designed differently in shape or size, the shape of the ship's rear end is improved, or a separate reinforcement is added to block the noise and vibration, We have tried to apply or apply various methods such as attaching a guide device to guide the flow of water from the water, reducing the size of the propeller, etc., but it is effective to reduce the vibration force. It is difficult.

As such, vibration problems, including noise transmitted to the hull due to increased propulsion force during operation of the propeller, must be solved urgently in the case of ships intended for excursions such as cruise ships or ships that require quiet operation such as warships. It is.

Accordingly, the present applicant has applied for a number of techniques to the Korean Patent Office to reduce the vibration force by forming an air layer in the form of a certain amount of air bubbles on the surface of the hull adjacent to the propeller.

However, most of the prior arts that use the air layer, including the last filed technology, have to continuously inject air using a compressor to form the air layer, and thus, the installation and operation of the compressor and its related parts Problems such as the burden of energy consumption have been raised, so the research and development to solve this situation is urgent.

The technical problem to be achieved by the present invention is to prevent the vibration generated in the hull by increasing the vibration force during the operation of the propeller, in particular, the installation and operation of the associated parts, including the compressor, and energy consumption It is to provide a propeller cavitation organic vibration reduction type vessel that can fundamentally prevent the burden.

According to an aspect of the invention, the propeller is provided with a hull; And a work gas accommodating membrane pad coupled to the hull adjacent to the propeller, wherein a work gas generating a reflected wave for generating an incident wave and a destructive interference phenomenon generated during rotation of the propeller is accommodated on one side. Ships may be provided.

The working gas receiving membrane pad may be made of a material whose acoustic impedance is similar to that of water.

The material of the working gas receiving membrane pad may be rubber, and the working gas may be air.

The working gas receiving membrane pad, the pad body detachably coupled to the hull; And a working gas pocket formed on one side of the pad body to receive the working gas in a sealed manner.

The working gas receiving membrane pad may be coupled to the hull wall on the upper side of the propeller.

The working gas receiving membrane pad may be coupled to a plurality of wall surfaces of the hull adjacent to the propeller.

Working gas sizes of the working gas receiving membrane pads coupled to a plurality of wall surfaces of the hull may be provided differently.

When the propeller generates vibration components of N frequency bands (N is a natural number) and needs to be controlled, the N working gas receiving membrane pads may be attached to a wall of the hull adjacent to the propeller.

A volume of the work gas accommodated in the work gas accommodating membrane pad connected to the work gas accommodating membrane pad so as to variably control an excitation frequency band change due to a change in the rotational speed (RPM) of the propeller; It may further include a gas volume control unit.

The work gas volume control unit, a work gas receiver (receiver) in which the work gas is stored; A working gas main line connecting the working gas receiver and the working gas receiving membrane pad; And a first valve provided on the work gas main line to selectively interrupt the flow of the work gas on the work gas main line.

The work gas volume adjusting unit may include a regulator provided on the work gas main line to maintain a constant pressure with respect to the work gas supplied through the work gas receiver; A check valve provided on the work gas mainline between the constant pressure and the first valve to prevent backflow of the work gas; A second valve provided at a work gas branch line branched from the main body of the work gas, the second valve selectively interrupting the flow of the work gas on the work gas branch line; And a pressure gauge provided on the work gas mainline between the first valve and the work gas accommodating membrane pad to measure the pressure of the work gas supplied to the work gas accommodating membrane pad.

The work gas volume control unit, a propeller rotation speed sensor for detecting the rotation speed of the propeller; And a controller configured to control operations of the work gas receiver, the first valve, and the second valve based on the information from the propeller rotation speed detector.

A bottom plug module including a bottom socket coupled to the hull and a bottom plug detachably coupled to the bottom socket may further include a bottom plug module. The membrane pad may be detachably coupled to the bottom plug module.

The bottom plug may include: a plug head coupled to a socket through portion of the bottom socket; And a threaded plug shaft connected to the plug head and exposed to the outer wall of the hull through the bottom socket, wherein the working gas receiving membrane pad is inserted into the threaded plug shaft of the bottom plug. The pad body hole may be provided.

A fixing nut fastened to the threaded plug shaft at an outer side of the hull to fix the work gas accommodating membrane pad; A sealing gasket having a gasket hole inserted into the screw plug shaft, the sealing gasket being in close contact with the screw plug shaft to seal the pad body hole; And a plate hole inserted into the threaded plug shaft, the reinforcing plate disposed between the sealing gasket and the fixing nut to reinforce the work gas accommodating membrane pad.

According to the present invention, it is possible to prevent vibration from occurring in the hull due to increased vibration force during the operation of the propeller, and in particular, the burden of energy consumption due to the installation and operation of the compressor and its related components, and the like. You can prevent it.

1 is a structural diagram of a propeller region of a propeller cavitation organic vibration reducing vessel according to a first embodiment of the present invention.

FIG. 2 is an enlarged view of region A of FIG. 1.

3 is a layout view between the propeller and the working gas receiving membrane pad.

FIG. 4 is a schematic rear view of the region A of FIG. 1 and not shown with a propeller.

5 is a diagram measuring the impedance of water, rubber and air.

6 is a view for explaining the principle of the incident wave and the reflected wave.

7 is a view of a working gas accommodating membrane pad for explaining [Equation 1].

FIG. 8 is a diagram showing a state where the working gas accommodating membrane pads are installed in the starboard region directly above the propeller, showing a plurality of fluctuation pressure measuring points.

9 is a graph showing the efficiency of the working gas receiving membrane pad based on the frequency of the propeller.

FIG. 10 is a graph summarizing the results of the 150 Hz band for the working gas accommodating membrane pad corresponding to FIG. 8.

11 is a graph showing the relationship between the optimum equivalent air volume according to the reduction target frequency.

12 is a rear structural diagram of a vibration reduction type ship according to a second embodiment of the present invention, in which working gas receiving membrane pads are installed at various positions.

FIG. 13 is a schematic configuration diagram of a work gas volume control unit in a propeller cavitation organic vibration reducing vessel according to a third embodiment of the present invention.

FIG. 14 is a control block diagram of the working gas volume adjusting unit of FIG. 13.

15 is an enlarged view illustrating main parts of a propeller cavitation organic vibration reduction type vessel according to a fourth embodiment of the present invention.

FIG. 16 is an enlarged structural diagram of region B of FIG. 15.

17 is an exploded view of FIG. 16.

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

Hereinafter, the present invention will be described in detail by explaining preferred embodiments of the present invention with reference to the accompanying drawings. Like reference numerals in the drawings denote like elements.

1 is a structural diagram of a propeller region of a propeller cavitation organic vibration reducing vessel according to a first embodiment of the present invention, FIG. 2 is an enlarged view of region A of FIG. 1, and FIG. Arrangement and FIG. 4 is a schematic rear view of the region A of FIG. 1, with the propeller not shown.

Referring to these drawings, the propeller cavitation organic vibration reduction type ship according to the present embodiment can increase the vibration force during operation of the propeller 120 to prevent the vibration generated in the hull, in particular, including the compressor It is to be able to fundamentally prevent the burden of energy consumption, such as the installation and operation of the relevant parts, and includes a hull 110, and the working gas receiving membrane pad 130 coupled to the hull (110).

The rear of the hull 110 is provided with a propeller 120 for the propulsion of the hull 110. In addition, a rudder 125 may be provided around the propeller 120 to adjust a traveling direction of the ship. The rudder 125 may be a general rudder or a bulb rudder.

For reference, the ship applied in the present embodiment may include all of the floating marine structures, including merchant ships, warships, fishing vessels, carriers, drillships, cruise ships and special working ships. Therefore, the scope of the present embodiment can not be limited to a specific vessel.

On the other hand, as described above, when the propeller 120 is operated, that is, when the propeller 120 is rotated in the water, the fluctuation pressure is generated in the water due to the propeller 120 as a rotating body, the generated fluctuation pressure is the hull 110 By increasing the vibration force of the furnace, it acts as a factor in generating vibration (including noise) in the hull.

As such, the vibration transmitted to the hull 110 should be prevented because it can be a big problem in the case of a ship that is intended to cruise or a quiet ship such as a warship, for example, a cruise ship.

In other words, due to the fluctuation pressure generated in the water during operation of the propeller 120, the vibration force is to be prevented from occurring due to the increase in vibration force in the ship body 110. In this embodiment, the working gas receiving membrane pad 130 ) Is applied.

As will be described later in detail, the working gas accommodating membrane pad 130 applied to the ship of the present embodiment has a completely different form from the structures that form an air layer, which is a conventional air bubble form.

That is, the working gas receiving membrane pad 130 applied in the present embodiment is only a tube-type structure in which air is trapped, and thus related components including a compressor, which had to be used when applying an air layer, were used. There is no need to install or operate.

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

The working gas receiving membrane pad 130 that plays this role is coupled to the hull 110 adjacent to the propeller 120, as shown in FIG. 1, and is generated when the propeller 120 rotates to face the hull 110. The reflection wave is generated to cancel the incident wave, but the work gas is accommodated on one side.

In particular, the working gas receiving membrane pad 130 may be coupled to the wall of the hull 110 on the upper side of the propeller 120.

As an example, the drawing shows that the working gas receiving membrane pad 130 is attached directly above the propeller 120.

In detail, when the rotation direction of the propeller 120 is counterclockwise as shown in FIG. 3 when the front side is viewed from the front side, the work gas accommodating membrane pad 130 is positioned within 0.5 R of the STBD area center standard of the propeller 120. Can be deployed. Here, R means the radius from the center line (CL) of the propeller 120 to the end of the propeller (120).

Similarly, when the rotational direction of the propeller 120 is counterclockwise, the work gas accommodating membrane pad 130 may be disposed within 0.5 R of the center of the PORT area directly above the propeller 120. Placement of the receiving membrane pad 130 may result in optimal efficiency.

On the other hand, the working gas receiving membrane pad 130 is a pad body 131 detachably coupled to the hull 110, the work gas pocket 132 is formed on one side of the pad body 131 is sealed to accommodate the working gas 132 ).

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

On the other hand, the pad body 131 forming the working gas receiving membrane pad 130 is a flat structure made of a rubber material, it is utilized as a portion detachably coupled to the hull 110.

The pad body 131 may be coupled to the hull 110 through various structures and methods. For example, the pad body 131 may be attached to the hull 110 in various ways, such as a bolt and nut coupling method, a fitting coupling method, a welding coupling method for internally welding an insert metal plate, and a coupling method using a bottom plug. Can be combined. The coupling method using the bottom plug is described below in the following embodiments.

In the drawing of the present embodiment, the pad body 131 has a square shape, but the shape of the pad body 131 may be various, including a square shape, a circular shape, and a triangular shape. Therefore, the right scope of the present embodiment is not limited to the shape of the pad body 131.

The work gas pocket 132 is formed inside the pad body 131 and has a shape inflated toward one side of the pad body 131.

In the present embodiment, the working gas bag 132 has a circular shape, but the shape of the working gas bag 132 may also be various polygonal shapes such as a triangular shape and a square shape, so the scope of the present invention is limited to the shape of the drawings. Can't be.

As described above, the working gas bag 132 may be filled with air as the working gas.

The work gas filled in the work gas bag 132 is formed to be integrally contained in the manufacture of the work gas accommodating membrane pad 130, and leaks in the work gas bag 132 unless the work gas bag 132 is incised. It doesn't work.

Hereinafter, the principle that the vibration force is reduced due to the work gas accommodating membrane pad 130 in which the work gas is sealed will be described in detail with reference to FIGS. 5 to 11.

5 is a diagram measuring the impedance of water, rubber and air, Figure 6 is a view for explaining the principle of the incident wave and reflected wave, Figure 7 is a view of the working gas receiving membrane pad for explaining [Equation 1], Figure 8 is a diagram showing a working gas accommodating membrane pad in a starboard region directly above the propeller, showing a plurality of pressure measuring points, and FIG. 9 is a graph showing the efficiency of the working gas accommodating membrane pad based on the propeller frequency. FIG. 10 is a graph summarizing the results of the 150 Hz band for the work gas accommodating membrane pad corresponding to FIG. 8, and FIG. 11 is a graph showing the relationship between the optimum equivalent air volume according to the reduction target frequency.

Referring to these drawings, first, referring to FIG. 5, the acoustic impedance (rubber) of rubber, which is a material of the working gas accommodating membrane pad 130 of the present embodiment, is different from that of water. While roughly similar, it can be seen that it is infinitely larger than air.

In general, when a sound wave progresses in a specific medium and encounters a medium having different impedances, a transmission phenomenon and a reflection phenomenon occur. Since the impedance of seawater and rubber is similar, only a transmission phenomenon occurs without reflection at the interface between seawater and rubber.

For example, as shown in FIG. 6, the incident wave generated during operation of the propeller 120 passes through the rubber layer, which is a wall surface of the work gas bag 132, and then is filled in the work gas, ie, air, filled in the work gas bag 132. As a result, the light is reflected in a 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, thereby canceling the incident wave generated during operation of the propeller 120. Due to this phenomenon, the vibration force can be reduced to reduce the occurrence of vibration of the hull 110.

This will be explained again. When the propeller 120 operates, spherical pressure waves generated by cavitation, that is, incident waves, may propagate omnidirectionally.

At this time, when installing the working gas receiving membrane pad 130 filled with air on the surface of the hull 110 around the propeller 120 as in this embodiment, to the working gas pocket 132 of the working gas receiving membrane pad 130 The incident incident wave passes through the rubber layer, which is the wall surface of the work gas bag 132, but is reflected by the work gas filled in the work gas bag 132, ie, air, in a phase opposite to the incident wave, that is, formed as a reflected wave.

When the incident wave is formed as a reflected wave that is reflected in the opposite phase by hitting the air, the reflected wave meets the incident wave incident toward the working gas accommodating membrane pad 130 to cause an incident wave and a destructive interference phenomenon.

As a result, the fluctuation pressure transmitted to the hull 110 from the outside of the working gas accommodating membrane pad 130 due to this action is reduced, and when the fluctuation pressure is reduced, the vibration force is reduced to form the hull naturally ( The vibration generated in 110 will be reduced.

On the other hand, such a reduction performance is limited to a specific frequency band of the propeller as shown in Equation 1 below.

[Equation 1]

Where f is the propeller's reduced frequency band, c _a (= 340 m / s) and c _w (= 1500 m / s), respectively, for air and sea sound speeds ρ _a (= 1.02 kg / m ³ ), ρ _w (= 1024 kg / m ³ ) denotes the density of air and seawater, and a and b denote inner diameter and outer diameter when the working gas receiving membrane pads 130a to 130c are equivalent spheres as shown in FIG. 10.

Model tests were performed to verify these issues. That is, as shown in Figure 8, on the wall surface of the hull 110 toward the STBD region, one working gas receiving membrane pad 130 having a reduction effect in the 150Hz frequency band was designed (or attached), and then, P1, The fluctuation pressures were measured at the positions P2, P3, and P4, as well as the vibrations were measured in the transom region, which is a steel plate supporting the upper part of the stern portion of the hull 110.

In the measurement result shown in FIG. 9, the horizontal axis (x-axis) represents frequency, and the vertical axis (y-axis) represents the amount of increase and decrease after the attachment before the work gas accommodating membrane pad 130 is attached. It can be seen that the fluctuation pressure and vibration increase after the installation compared to the installation of the working gas accommodating membrane pad 130, but a significant reduction effect occurs in the vicinity of the design frequency 150 Hz band.

FIG. 10 summarizes the results of the 150 Hz band. Referring to FIG. 10, the fluctuation pressures at positions P2, P3, and P4 located outside the work gas accommodating membrane pad 130 are reduced by about 70% on average. As a result, it can be seen that the vibration level is also significantly reduced by more than 70%.

11 is a graph showing the relationship between the optimum equivalent air volume according to the reduction target frequency. Referring to this, for example, when the target frequency is 6 Hz, the optimum work bag pocket 132 of the receiving membrane pad 130 is optimal. The volume may be about 1500L (Liter), and as long as it satisfies such a volume condition, the shape of the working gas bag 132 may be circular or rectangular.

According to the present embodiment having the structure and action as described above, the vibration force may be prevented from occurring when the propeller 120 is operated to prevent the vibration from occurring in the hull 110, in particular, the compressor and its related parts. It is possible to fundamentally prevent obstacles such as the installation of parts and the burden of energy consumption due to operation.

Since vibration can be effectively prevented from occurring in the hull 110 as described above, therefore, in the case of a ship intended for excursion, such as a cruise ship, or a ship to which a quiet operation such as a warship is to be assumed, it causes the vessel. It is possible to appropriately solve the vibration problem including noise.

In particular, the same structure as the present embodiment, the propeller 120, the shape or size of the wing itself differently as in the prior art, to improve the shape of the ship's tail, or to add a separate reinforcement for blocking noise and vibration, or bow In addition to the improvement of the noise and vibration problems by reducing various losses such as attaching a guide device to guide the flow of water from the water or reducing the size of the propeller 120, etc. Technically differentiate In addition, since the present technology provides a margin for eliminating vibration constraints in the propeller design by shielding the vibration force, it may be helpful to improve the propulsion efficiency, such as to greatly increase the size of the propeller 120. It is expected.

Referring to this figure, but with reference to [Equation 1] and Figure 7 described above, it can be seen that the reduced frequency band f is inversely proportional to the air volume (radius, a), and also the working gas accommodating membrane pads 130a to 130c. It can be seen that it is applicable to only one frequency band per one.

However, when operating an actual ship, there are many cases where there are two or more frequency bands to be controlled. That is, when operating a ship, it is sometimes necessary to control the vibration component of the frequency band of N or more (N is a natural number) rather than one frequency band according to the rotation speed (rpm) of the propeller 120. Here, the vibration component (or excitation component) is transmitted to the hull 110 during the rotation of the propeller 120 to vibrate the hull 110, the size of the vibration component may vary for each frequency.

In this case, since only one work gas accommodating membrane pad 130a to 130c cannot control N different frequency bands, the work gas accommodating membrane pads 130a to 130c are applied by the number N of frequency bands applied thereto. Must be used.

In other words, when N frequency bands are to be controlled, N working gas receiving membrane pads (not shown) may be attached to the wall of the hull 110 adjacent to the propeller 120.

For example, FIG. 12 illustrates that three working gas receiving membrane pads 130a to 130c are coupled to a plurality of wall surfaces of the hull 110 adjacent to the propeller 120 to control three frequency bands such as 130 Hz, 140 Hz, and 150 Hz. Indicates a situation.

At this time, the size of the work gas of the work gas receiving membrane pads 130a to 130c coupled to a plurality of wall surfaces of the hull 110, that is, the sizes of the work gas pockets 132a to 132c may be provided differently.

As a result, the work gas receiving membrane pads 130a to 130c can significantly reduce the vibration force of the hull 110 by the offset interference principle, whether one or a plurality is installed.

That is, even if a plurality of working gas accommodating membrane pads 130a to 130c are applied as in this embodiment, the vibration force may be prevented from occurring when the propeller 120 operates to prevent vibration from occurring in the ship body 110. It can fundamentally prevent obstacles such as the installation of compressors and related parts, and the burden of energy consumption due to operation.

FIG. 13 is a schematic block diagram of a work gas volume adjusting unit in a propeller cavitation organic vibration reducing vessel according to a third embodiment of the present invention, and FIG. 14 is a control block diagram of the work gas volume adjusting unit of FIG. 13.

Referring to these drawings, the propeller cavitation organic vibration reduction type vessel according to the present embodiment is connected to the work gas accommodating membrane pad 330, and adjusts the volume of the work gas accommodated in the work gas accommodating membrane pad 330 The working gas volume adjusting unit 350 may be further provided.

In the present embodiment, since the volume of the working gas on the working gas receiving membrane pad 330 can be adjusted using the working gas volume adjusting unit 350, one working gas containing membrane is attached to the hull 110 (see FIG. 1). Even if the pad 330 is applied, it is possible to variably control the change in the excitation frequency band according to the change in the rotation speed of the propeller 120 (see FIG. That is, even if the rotational speed of the propeller 120 changes during the operation of the ship, it is possible to provide an effect of reducing vibration for all the frequency bands corresponding to the rotational speed of the changed propeller 120. Easily represented, even if the rotational speed of the propeller 120 is changed, the vibration of the hull 110 can be reduced.

The rear end of the hull 110 is provided with a propeller 120 for the propulsion of the hull 110, in this embodiment the propeller rotation speed sensor 370 is connected to the propeller 120 is the number of revolutions of the propeller 120 ( RPM).

Meanwhile, referring back to Equation 1 and FIG. 7, the reduced frequency band f of the propeller 120 may be in inverse proportion to the air volume (radius, a). 330) It can be seen that only applicable to one frequency band per one.

However, when operating an actual ship, there are many cases where there are two or more frequency bands to be controlled.

Since the number of revolutions (RPM) of the propeller 120 is constantly changing in operating a ship, it is highly necessary to control N frequency bands (N is a natural number) instead of one frequency band.

In this case, only one specific frequency band can be controlled through only one working gas receiving membrane pad 330.

Therefore, in order to control the N frequency bands, the work gas accommodating membrane pad 330 may be attached by using the number N of the frequency bands applied as shown in FIG. 12, or the work gas volume adjusting part 350 may be used as in this embodiment. The volume of the working gas on the working gas receiving membrane pad 330 may be adjusted.

When the working gas volume adjusting unit 350 is applied as in the present embodiment, even if one working gas accommodating membrane pad 330 is applied, it is possible to variably control the variation of the excitation frequency band according to the rotational speed of the propeller 120. have. Therefore, even if the propeller 120 is rotated at any rotational speed it can reduce the vibration formed in the hull 110.

The working gas volume adjusting unit 350 applied to the ship of the present embodiment is connected to the working gas receiving membrane pad 330 and works to variably control the excitation frequency band according to the rotational speed of the propeller 120. It serves to adjust the volume of the working gas accommodated in the working gas bag 332 of the gas receiving membrane pad 330.

The work gas volume control unit 350 is a work gas receiver 351, a receiver, a regulator (352), a check valve (353), the first and second valves (354, 355, valve), a pressure gauge (358), And a propeller rotation speed detector 370 and a controller 360.

The work gas receiver 351 (receiver) stores the work gas and serves to supply the stored work gas by the control of the controller 360. The work gas receiver 351 may be connected to a compressor (not shown).

The work gas receiver 351 and the work gas pocket 332 of the work gas accommodating membrane pad 330 are connected to the work gas main line 356.

One side of the work gas main line 356 is connected to the work gas branch line 357 intersecting with the work gas main line 356.

The regulator 352 is provided on the work gas main line 356 and serves to maintain a constant pressure with respect to the work gas supplied through the work gas receiver 351.

The check valve 353 is provided on the work gas main line 356 between the pressure regulator 352 and the first valve 354 to prevent backflow of the work gas.

The first valve 354 is provided on the work gas main line 356 and serves to selectively interrupt the flow of the work gas on the work gas main line 356.

The second valve 355 is provided in the work gas branch line 357 branched with respect to the work gas main line 356 and serves to selectively interrupt the flow of the work gas on the work gas branch line 357. .

The pressure gauge 358 is provided on the work gas main line 356 between the first valve 354 and the work gas pocket 332 of the work gas accommodating membrane pad 330 to work on the work gas accommodating membrane pad 330. It serves to measure the pressure of the working gas supplied to the gas bag (332).

The propeller rotation speed sensor 370 detects the rotation speed (RPM) of the propeller 120. The propeller rotation speed sensor 370 may be wireless or wired.

The controller 360 controls the operation of the work gas receiver 351, the first valve 354, and the second valve 355 based on the information of the propeller rotation speed sensor 370.

Referring to the graph of FIG. 9 described above, the frequency in which the vibration reduction effect is exhibited is in the range of 160 Hz, 155 Hz, and 145 Hz as the volume of the working gas accommodated in the working gas bag 332 of the working gas accommodating membrane pad 330 is increased. You can see that it is moving. In other words, as the size of the work gas bag 332 of the work gas accommodating membrane pad 330 increases, the frequency at which the reduction performance is exhibited moves to a low frequency band (or a corresponding number of revolutions of the propeller 120). You can see that.

Therefore, in this embodiment, the controller 360 is to increase or decrease the volume of the work gas bag 332 of the work gas accommodating membrane pad 330 according to the rotational speed of the propeller 120 (work gas receiver ( 351, the operations of the first valve 354 and the second valve 355 are controlled.

The controller 360 performing this role may include a central processing unit 361 (CPU), a memory 362 (MEMORY), and a support circuit 363 (SUPPORT CIRCUIT).

The central processing unit 361 is industrially used to control the operation of the work gas receiver 351, the first valve 354 and the second valve 355 based on the information of the propeller rotation speed sensor 370 in this embodiment. It may be one of various computer processors that can be applied to.

The memory 362 is connected to the central processing unit 361. The memory 362 may be installed locally or remotely as a computer readable recording medium, and may be readily available, such as, for example, random access memory (RAM), ROM, floppy disk, hard disk, or any digital storage form. At least one or more memories.

The support circuit 363 (SUPPORT CIRCUIT) is combined with the central processing unit 361 to support typical operation of the processor. Such support circuits 363 may include caches, power supplies, clock circuits, input / output circuits, subsystems, and the like.

In this embodiment, the controller 360 controls the operation of the work gas receiver 351, the first valve 354, and the second valve 355 based on the information of the propeller rotation speed sensor 370. At this time, a series of processes in which the controller 360 controls the operation of the work gas receiver 351, the first valve 354, and the second valve 355 based on the information of the propeller rotation speed sensor 370 is a memory. 362 may be stored. Typically software routines may be stored in memory 362. Software routines may also be stored or executed by other central processing units (not shown).

Although the process according to the invention has been described as being executed by software routines, at least some of the processes of the invention may be performed by hardware. As such, the processes of the present invention may be implemented in software running on a computer system, in hardware such as integrated circuits, or by a combination of software and hardware.

As described above, when adjusting the volume of the working gas on the working gas receiving membrane pad 330 by using the working gas volume adjusting unit 350, even if one working gas receiving membrane pad 330 is Even if it is applied, it is possible to variably control the change in the excitation frequency band according to the rotational speed (RPM) of the propeller 120.

15 is an enlarged view illustrating main parts of a propeller cavitation organic vibration reduction type vessel according to a fourth embodiment of the present invention, FIG. 16 is an enlarged structural diagram of region B of FIG. 15, and FIG. 17 is an exploded view of FIG. 16.

Referring to these drawings, in the present embodiment, the working gas receiving membrane pad 430 may be coupled to the bottom plug module 450 of the hull 410.

The bottom plug module 450 is a structure installed in the hull 410. When the bottom plug module 450 is coupled to the work gas accommodating membrane pad 430, the coupling of the work gas accommodating membrane pad 430 is performed. The advantage is that no separate structure or component is required.

Before describing the coupling structure of the working gas receiving membrane pad 430 to the bottom plug module 450, the bottom plug module 450 will be described.

The bottom plug module 450 is a component mounted on the wall surface of the hull 410, and serves as a stopper for draining the water introduced into the hull 410. The bottom plug module 450 is not a component to be removed.

The bottom plug module 450 includes a bottom socket 460 coupled to the hull 410, and a bottom plug 470 detachably coupled to the bottom socket 460.

In order to couple the bottom socket 460 to the corresponding position, the hull 410 is provided with a socket coupling part 411 for coupling the bottom socket 460.

The first inclined surface 412 and the first horizontal surface 413 are formed on the outer wall of the socket coupling part 411, and the second inclined surface 461 and the second horizontal surface 462 are also formed in the bottom socket 460. do.

By this structure, the bottom socket 460 may be coupled to the socket coupling part 411. At this time, the bottom socket 460 may be advantageous in that it is not assembled or screwed into the socket coupling portion 411 is not easily separated.

The bottom plug 470 is a structure detachably coupled to the bottom socket 460. The bottom plug 470 is connected to the plug head 471 and the plug head 471 coupled to the socket through part 463 of the bottom socket 460, and the bottom of the hull 410 through the bottom socket 460. A threaded plug shaft 472 is exposed to the outer wall.

The plug head 471 and the bottom socket 460 are provided with a plurality of first and second through holes 471a and 160a which communicate with each other so that the bolt is fastened.

On the other hand, in such a structure, the working gas receiving membrane pad 430 may be detachably coupled to the threaded plug shaft 472 of the bottom plug 470.

In order to detachably couple the pad body 431 of the work gas accommodating membrane pad 430 to the threaded plug shaft 472, the fixing nut 481, the sealing gasket 482, and the reinforcing plate 483 may be used. A structure is required.

The fixing nut 481 fixes the pad body 431, the sealing gasket 482, and the reinforcing plate 483 of the work gas accommodating membrane pad 430 to the threaded plug shaft 472. Do it.

That is, the fixing nut 481 is fastened to the threaded plug shaft 472 on the outside of the hull 410 so that the pad body 431, the sealing gasket 482, and the reinforcing plate 483 of the membrane pad 430 for the work gas are accommodated. ) Is fixed.

Fixing nut 481 is preferably applied to a nut having a loosening prevention function that is not released.

The sealing gasket 482 has a gasket hole 451a inserted into the threaded plug shaft 472 and is in close contact with the threaded plug shaft 472 to seal the pad body hole 431a.

The sealing gasket 482 may be made of a rubber material that is slightly elastic.

The reinforcement plate 483 has a plate hole 483a inserted into the threaded plug shaft 472 and is disposed between the sealing gasket 482 and the fixing nut 481 to reinforce the pad body 431. do.

As described above, in the present embodiment, since the threaded plug shaft 472 of the bottom plug 470 is previously exposed to the outer wall of the hull 410 in the structure of the bottom plug 470, Even if the bottom is submerged in water, it is difficult to insert the pad body 431, the sealing gasket 482, and the reinforcing plate 483 into the threaded plug shaft 472 and finish with the fixing nut 481. not.

If the work gas bag 432 is torn and the work gas accommodating membrane pad 430 needs to be replaced, the work gas accommodating membrane pad may be removed in the reverse order as described above, and the new work gas accommodating membrane pad may be put back into place. It is not difficult to work.

As described above, when the working gas receiving membrane pad 430 is installed on the hull 410 by utilizing the bottom plug module 450 already applied to the hull 410 as in this embodiment, the working gas receiving membrane pad ( Installation or maintenance work of the 420 can be easily and conveniently performed.

As described above, the present invention is not limited to the described embodiments, and various modifications and changes can be made without departing from the spirit and scope of the present invention, which will be apparent to those skilled in the art. Therefore, such modifications or variations will have to be belong to the claims of the present invention.

The present invention is applied to ships including all floating marine structures, including merchant ships, warships, fishing vessels, carriers, drillships, cruise ships and special working ships to be used to prevent the occurrence of vibration in the hull Can be.

Claims

A hull provided with a propeller; And

A vessel including a work gas accommodating membrane pad coupled to the hull adjacent to the propeller, the work gas generating a reflected gas for generating an incident wave and a destructive interference phenomenon generated during rotation of the propeller is accommodated on one side. .
The method of claim 1,

The material of the working gas receiving membrane pad is a vessel in which the acoustic impedance (Acoustic impedance) is similar to seawater (water).
The method of claim 1,

The work gas receiving membrane pad is made of rubber (rubber),

The working gas is a ship (air).
The method of claim 1,

The working gas receiving membrane pad,

A pad body detachably coupled to the hull; And

And a work gas pocket formed on one side of the pad body to accommodate the work gas in a sealed manner.
The method of claim 1,

And the working gas receiving membrane pad is coupled to the hull wall on the upper side of the propeller.
The method of claim 1,

The work gas receiving membrane pad is coupled to a plurality of wall surface of the hull adjacent to the propeller.
The method of claim 6,

And a working gas size of the working gas receiving membrane pads coupled to a plurality of wall surfaces of the hull.
The method of claim 6,

When the propeller generates a vibration component of the N frequency band (N is a natural number) to control this, the N working gas receiving membrane pad is attached to the wall surface of the hull adjacent to the propeller.
The method of claim 1,

A volume of the work gas accommodated in the work gas accommodating membrane pad connected to the work gas accommodating membrane pad so as to variably control an excitation frequency band change due to a change in the rotational speed (RPM) of the propeller; Propeller cavitation organic vibration reduction type vessel further comprising a gas volume control unit.
The method of claim 9,

The working gas volume control unit,

A work gas receiver in which the work gas is stored;

A working gas main line connecting the working gas receiver and the working gas receiving membrane pad; And

A propeller cavitation organic vibration reduction vessel provided on the work gas mainline, the valve comprising a first valve for selectively controlling the flow of the work gas on the work gas mainline.
The method of claim 10,

The working gas volume control unit,

A regulator provided on the main body of the working gas and maintaining a constant pressure with respect to the working gas supplied through the working gas receiver;

A check valve provided on the work gas mainline between the constant pressure and the first valve to prevent backflow of the work gas;

A second valve provided at a work gas branch line branched from the main body of the work gas, the second valve selectively interrupting the flow of the work gas on the work gas branch line; And

A propeller cavitation organic vibration suppression type further includes a pressure gauge provided on the work gas mainline between the first valve and the work gas accommodating membrane pad to measure the pressure of the work gas supplied to the work gas accommodating membrane pad. Ship.
The method of claim 1,

The working gas volume control unit,

A propeller rotation speed sensor for sensing the rotation speed of the propeller; And

And a controller for controlling the operation of the work gas receiver, the first valve and the second valve based on information from the propeller rotation speed detector.
The method of claim 1,

And a bottom plug module including a bottom socket coupled to the hull, and a bottom plug detachably coupled to the bottom socket.

The work gas accommodating membrane pad is propeller cavitation organic vibration reduction vessel, characterized in that detachable coupling to the bottom plug module.
The method of claim 13,

The bottom plug,

A plug head coupled to the socket through portion of the bottom socket; And

A screw plug shaft connected to the plug head and exposed to the outer wall of the hull through the bottom socket;

And the work gas accommodating membrane pad has a plurality of pad body holes inserted into the threaded plug shaft of the bottom plug.
The method of claim 14,

A fixing nut fastened to the threaded plug shaft at an outer side of the hull to fix the work gas accommodating membrane pad;

A sealing gasket having a gasket hole inserted into the screw plug shaft, the sealing gasket being in close contact with the screw plug shaft to seal the pad body hole; And

And a reinforcing plate arranged between the sealing gasket and the fixing nut and reinforcing the work gas accommodating membrane pad, the plate hole being inserted into the threaded plug shaft.