KR101607876B1 - A ship for reducing vibromotive force - Google Patents

Abstract

A propeller cavitation organic exciter-powered vessel is disclosed. In accordance with an aspect of the present invention, there is provided a propeller-cavitation-induced propulsion-reduction-type ship comprising: a ship having a propeller for generating a propulsion force; A bottom plug module including a bottom socket coupled to the hull and a bottom plug removably coupled to the bottom socket; And a working gas receiving membrane pad which is coupled to the bottom plug module and receives a working gas for generating a reflected wave for generating a destructive interference phenomenon with an incident wave generated when the propeller rotates.

Description

A ship for reducing vibromotive force,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a propeller cavitation organic exciter power reduction type ship, and more particularly, to a propeller cavitation organic exciter power reduction type propeller pump, Ship.

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 it is desired to apply the working gas receiving membrane pads to the hull, the installation or maintenance work of the working gas receiving membrane pads should be easy and convenient. The bottom plug module is installed in the hull. Considering the installation method of the working gas receiving membrane pads utilizing such a bottom plug module needs to be considered.

Prior Art _1; Japanese Patent Application Laid-Open No. 8-188192 Prior Art _2; Japanese Unexamined Patent Application Publication No. 2009-274705 Prior Art_3; Korean Intellectual Property Office Publication No. 20-2014-0000604

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, by employing a bottom plug module already applied to the hull, the working gas receiving membrane pads can be installed on the hull, so that the work gas receiving membrane pads can be installed or maintained easily and conveniently And to provide a propeller cavitation organic exciter force reduction type vessel which can be carried out.

According to an aspect of the present invention, there is provided a hull comprising: a hull to which a propeller generating thrust is coupled to the rear; A bottom plug module including a bottom socket coupled to the hull and a bottom plug detachably coupled to the bottom socket; And a working gas accommodating membrane pad which is coupled to the bottom plug module and receives a working gas for generating a reflected wave for generating a destructive interference phenomenon with an incident wave generated when the propeller rotates, An anti-vibration type ship can be provided.

The bottom plug includes: a plug head coupled to a socket penetration portion of the bottom socket; And a screw plug shaft connected to the plug head and exposed to an outer wall of the hull through the bottom socket.

The working gas receiving membrane pad may be detachably coupled to the threaded plug shaft of the bottom plug.

Wherein the working gas receiving membrane pad comprises: a pad body having a plurality of pad body holes inserted into the threaded plug shaft; And a working gas bag formed on one side of the pad body and sealed with the working gas.

And a fixing nut fastened to the screw-type plug shaft from the outside of the hull to fix the pad body.

And a sealing gasket having a gasket hole inserted into the threaded plug shaft and sealing the pad body hole in close contact with the screwed plug shaft.

And a reinforcing plate disposed between the sealing gasket and the fixing nut to reinforce the pad body, the plate plate having a plate hole inserted into the screw shaft.

The material of the working gas receiving membrane pad may be a rubber whose acoustic impedance is similar to water, and the working gas may be air.

The working gas receiving membrane pads may be arranged between the diameter (D) of the propeller in the forward direction and the diameter (D) of the propeller in the stern direction with respect to the propeller.

The working gas receiving membrane pads may be disposed between the one diameter D of the propeller in the starboard direction and the one diameter D of the propeller in the port direction on the basis of the rotational axis of the propeller.

According to the present invention, it is possible to prevent vibrations from occurring in the hull due to increased propulsive force when the propeller is operated, while preventing the burden of energy consumption due to installation and operation of the compressor, , The work gas receiving membrane pads can be installed on the hull by utilizing the bottom plug module already applied to the hull, so that the installation or maintenance work of the work gas receiving membrane pads can be easily and conveniently performed.

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.
FIG. 3 is a schematic rear view of the region A of FIG. 1, showing the state where the propeller is not shown.
4 is an enlarged structural view of a bolt-type pad attach / detachable portion which is a region B in FIG.
5 is an exploded view of Fig.
Fig. 6 is a chart for measuring the impedance of water, rubber and air.
7 is a view for explaining the principle of incident waves and reflected waves.
Figure 8 is a drawing of a working gas receiving membrane pad to illustrate (1).
Fig. 9 is a view showing a state in which a working gas receiving membrane pad is installed in a region on the upstream side of the propeller.
10 is a graphical representation of the efficiency of a working gas receiving membrane pad relative to the frequency of the propeller.
Figure 11 is a graph summarizing the results of the 150 Hz band for the working gas receiving membrane pads corresponding to Figure 9;

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 propeller according to an embodiment of the present invention, Fig. 2 is an enlarged view of area A in Fig. 1, Fig. 3 is a schematic view FIG. 4 is an enlarged structural view of a bolt-type pad attach / detachable portion which is a region B in FIG. 3, and FIG. 5 is an exploded view of 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 vibrations from being generated in the hull 110 due to an increase in the excitation force and in particular to prevent the vibration of the hull 110 by utilizing the bottom plug module 150 already applied to the hull 110, 130 attached to the hull 110 can be mounted on the hull 110 so that the installation or maintenance work of the work gas receiving membrane pads 130 can be easily and conveniently performed. A plug module 150, and a working gas receiving membrane pad 130.

In this embodiment, since the work gas receiving membrane pad 130 can be mounted on the hull 110 by utilizing the bottom plug module 150 already applied to the hull 110, the working gas receiving membrane pad 130 can be easily and conveniently carried out.

Thus, the cost associated with the installation or maintenance of the working gas receiving membrane pads 130 can be significantly reduced.

Particularly, since the bottom of the hull 110 is always immersed in water, it is difficult to install the working gas receiving membrane pad 130 on the bottom of the hull 110 while diving for a long time. The method of installing the working gas receiving membrane pads 130 on the bottom of the hull 110 in a simple and highly efficient structure is very important.

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 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 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. Although the drawing shows that the working gas receiving membrane pad 130 is attached to the upper chamber of the propeller 120, the scope of the scope of the present embodiment can not be limited to the drawings.

The working gas receiving membrane pad 130 includes a pad body 131 having a plurality of pad body holes 131a and a pad body 131 formed on one side of the pad body 131. [ And a working gas pocket 132 in which the working gas is sealed and accommodated.

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 different configurations and schemes, in the case of the present embodiment, coupled to the hull 110 via the bottom plug module 150.

Although the pad body 131 is formed in a rectangular shape, the pad body 131 may have a rectangular shape, a circular shape, a triangular shape, 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 bag 132 is formed inside the pad body 131 and has 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.

3 to 5, in the case of this embodiment, the work gas receiving membrane pad 130 may be coupled to the bottom plug module 150 of the hull 110, as described repeatedly.

The bottom plug module 150 is a structure installed in the hull 110. When the work gas receiving membrane pad 130 is coupled to the bottom plug module 150 as described above, There is an advantage that no separate structure or parts are required.

The bottom plug module 150 will first be discussed before describing the coupling structure of the working gas receiving membrane pads 130 to the bottom plug module 150.

The bottom plug module 150 is a part mounted on the wall surface of the hull 110 and serves as a cap for draining the water introduced into the hull 110. The bottom plug module 150 is not a part to be removed.

The bottom plug module 150 includes a bottom socket 160 coupled to the hull 110 and a bottom plug 170 detachably coupled to the bottom socket 160.

A socket coupling portion 111 for coupling the bottom socket 160 is formed on the hull 110 so that the bottom socket 160 is coupled to the corresponding position.

A first inclined surface 112 and a first horizontal surface 113 are formed on the outer wall of the socket coupling portion 111 and a second inclined surface 161 and a second horizontal surface 162 are formed on the bottom socket 160 do.

With this structure, the bottom socket 160 can be coupled to the socket coupling part 111. [ At this time, it may be advantageous in terms of preventing the bottom socket 160 from being easily separated from being screwed into the socket coupling part 111 or press-fit.

The bottom plug 170 is detachably coupled to the bottom socket 160. The bottom plug 170 includes a plug head 171 coupled to the socket penetration portion 163 of the bottom socket 160 and a plug head 171 connected to the plug head 171 and connected to the bottom end of the hull 110 via the bottom socket 160. [ And a threaded plug shaft 172 exposed to the outer wall.

The plug head 171 and the bottom socket 160 are formed with a plurality of first and second through holes 171a and 160a which are mutually communicated so that bolts are fastened.

On the other hand, in this structure, the working gas receiving membrane pad 130 can be detachably coupled to the threaded plug shaft 172 of the bottom plug 170.

The sealing gasket 182 and the reinforcing plate 183 or the like such that the pad body 131 of the working gas receiving membrane pad 130 is detachably coupled to the threaded plug shaft 172 Structures are required.

The fixing nut 181 serves to fix the pad body 131 of the working gas receiving membrane pad 130, the sealing gasket 182 and the reinforcing plate 183 in a state in which they are successively inserted into the threaded plug shaft 172 .

That is, the fixing nut 181 is fastened to the threaded plug shaft 172 at the outside of the hull 110 and is fixed to the pad body 131 of the working gas receiving membrane pad 130, the sealing gasket 182, and the reinforcing plate 183 ).

It is preferable that the fixing nut 181 is applied as a nut having a loosening preventing function that is not loosened.

The sealing gasket 182 has a gasket hole 151a to be inserted into the threaded plug shaft 172 and closely contacts the threaded plug shaft 172 to seal the pad body hole 131a.

The sealing gasket 182 may be made of a somewhat resilient rubber material.

The reinforcing plate 183 has a plate hole 183a to be inserted into the threaded plug shaft 172 and is disposed between the sealing gasket 182 and the fixing nut 181 to reinforce the pad body 131 do.

The screw plug shaft 172 of the bottom plug 170 is exposed in advance to the outer wall of the hull 110. This makes it possible to prevent the hull 110 from being damaged, The operation is difficult because the pad body 131, the sealing gasket 182, and the reinforcing plate 183 are successively inserted into the screw-type plug shaft 172 and then closed with the fixing nut 181 even if the floor is immersed in water not. If the working gas pocket 132 is torn to replace the working gas receiving membrane pads 130, then work in the reverse order described above to remove the torn working gas receiving membrane pads and place the new working gas receiving membrane pads in place So it is not difficult to work.

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. 6 to FIG.

FIG. 6 is a graph showing the impedance of water, rubber and air, FIG. 7 is a view for explaining the principle of an incident wave and a reflected wave, FIG. 8 is a drawing of a working gas receiving membrane pad, 9 is a view showing a state in which a working gas receiving membrane pad is installed in a region immediately upstream of the propeller, and FIG. 10 is a graph showing the efficiency of the working gas receiving membrane pad based on the frequency of the propeller And FIG. 11 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. 6, 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.

7, 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 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.

On the other hand, such a reduction performance is limited to a specific frequency band of the propeller 120 as expressed by [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 indicate 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. 9, one working gas receiving membrane pad 130 having a reducing effect in the frequency band of 150 Hz was designed (or attached) on 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,

10, 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. 11 summarizes the results of the 150 Hz band. Referring to FIG. 11, the fluctuation 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.

As described above, by utilizing the bottom plug module 150 in applying or installing the working gas receiving membrane pad 130 to the hull 110, which can prevent vibration from occurring in the hull 110, The installation or maintenance work of the work gas receiving membrane pads 130 can be easily performed even if the bottom of the work gas receiving membrane 110 is immersed in water.

As described above, according to the present embodiment, the propulsion force is increased when the propeller 120 is operated, while preventing the burden of energy consumption and the like due to the installation and operation of the compressor, The work gas receiving membrane pad 130 can be installed on the hull 110 by utilizing the bottom plug module 150 already applied to the hull 110 and the working gas receiving membrane The installation or maintenance work of the pad 120 can be easily and conveniently performed.

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 131a: Pad body hole
132: Working gas pocket 150: Bottom plug module
160: bottom socket 161: second inclined surface
162: second horizontal plane 163: socket penetration part
170: bottom plug 171: plug head
172: Screw-type plug shaft 181: Fixing nut
182: sealing gasket 182a: gasket hole
183: reinforcing plate 183a: plate hole

Claims (10)

A hull in which a propeller generating thrust is coupled to the rear;
A bottom socket coupled to the hull, a plug head coupled to the socket penetration 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 A bottom plug module including a bottom plug;
A pad body having a plurality of pad body holes inserted into the threaded plug shaft and a working gas bag formed at one side of the pad body to receive and seal the working gas tightly, A working gas receiving membrane pad on one side of which a working gas for generating a reflected wave for causing a destructive interference phenomenon is accommodated;
A fixing nut fastened to the screw shaft from the outside of the hull to fix the pad body;
A sealing gasket having a gasket hole inserted into the screw type plug shaft, the sealing gasket being in close contact with the screw type plug shaft to seal the pad body hole; And
And a reinforcing plate disposed between the sealing gasket and the fixing nut to reinforce the pad body, the plate having a plate hole inserted into the screw type plug shaft. delete delete delete delete delete delete The method according to claim 1,
The material of the working gas receiving membrane pad is a rubber whose acoustic impedance is similar to that of water,
Wherein the working gas is an air propeller. The method according to claim 1,
Wherein the working gas receiving membrane pads are disposed between a diameter (D) of the propeller in the forward direction and a diameter (D) of the propeller in the stern direction with respect to the propeller. The method according to claim 1,
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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