JP2008013128A - Hull frictional resistance reduction device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device capable of sufficiently performing reduction of friction resistance of a hull in navigation while accomplishing rationalization of feeding of a high pressure gas for bubble generation by dispersingly performing arrangement of a local gas chamber provided in a vessel width direction for jetting the bubble from a bubble jetting port in a hull outer plate surface of a vessel bottom part in a vessel longitudinal direction and by suitably performing feeding of the high pressure gas to respective division chambers in rolling of the hull by dividing the respective gas chambers to a plurality of division chambers over the vessel width direction. <P>SOLUTION: The gas chambers 2 formed in a vessel over a width direction of the vessel bottom part are arranged so as to be dispersed in the vessel longitudinal direction and are divided to the plurality of division chambers 2a over the width direction of the vessel bottom part. The bubble jet ports are formed on the hull outer plate portions corresponding to the respective division chambers 2a and jet the bubble of high pressure gas fed from a compressor. For uniformity of distribution of the bubble along the outer plate of the vessel bottom, feeding of the high pressure gas to the respective division chambers 2a is controlled based on information from a rolling sensor of the hull. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a device for reducing the frictional resistance of water along the outer surface of the bottom of a hull during navigation.

In navigating vessels, the submerged surface of the bottom of the ship generally receives frictional resistance of water, and in the case of large ships in particular, most of the hull resistance is occupied by the frictional resistance generated by the relative flow of outside water at the bottom of the ship. It has been.
Therefore, a technique for reducing the hull frictional resistance by covering the bottom of the ship with a bubble flow during navigation has been proposed for a long time.
Japanese Patent No. 3692398 JP 2002-68073 A

In general, a ship is likely to be shaken by wind and waves during navigation, so it is difficult to always wrap the bottom of the ship uniformly with bubbles for reducing frictional resistance. There is a problem that the bubbles are separated from the hull when they are tilted and lifted along with the rolling motion.
In addition, providing the bubble ejection port over the entire surface of the ship bottom causes a significant cost increase.
Therefore, the present invention performs the arrangement of the local gas chambers provided in the ship width direction in order to eject air bubbles from the hull outer plate surface of the bottom of the ship, and distributes each gas chamber in the ship width direction. In order to streamline the supply of high-pressure gas for generating bubbles, it is possible to appropriately supply high-pressure gas to each compartment when the hull rolls. It is an object of the present invention to provide an apparatus that can sufficiently reduce the frictional resistance of a hull.

  In the hull frictional resistance reduction device of the present invention, a plurality of gas chambers formed in the ship over the width direction of the ship bottom are arranged so as to be dispersed in the ship length direction, and the gas chamber extends over the width direction of the ship bottom. Divided into a plurality of compartments, a large number of bubble outlets are formed in the hull outer plate portion corresponding to the compartments, and a high-pressure gas supply pipe that leads to the plurality of compartments from the compressor via valves is provided in the ship. And is detected by the roll sensor of the hull and the roll sensor in order to equalize the distribution of the bubbles that are ejected from the bubble outlet during navigation and flow along the outer surface of the bottom of the ship. A high-pressure gas supply control system for controlling the high-pressure gas supply to the compartment based on the hull lateral inclination angle is provided.

  Further, in the hull frictional resistance reduction device according to the present invention, the high pressure gas supply control system is configured such that the chamber on the side where the draft becomes shallow due to the horizontal tilt of the hull based on the horizontal tilt angle of the hull detected by the roll sensor. It is characterized by controlling the opening degree of the valve so that the amount of high-pressure gas supplied to the water is reduced more than the amount of high-pressure gas supplied to the compartment on the deeper side of the draft.

  Further, in the hull frictional resistance reduction device of the present invention, the high-pressure gas supply control system is configured to stop the high-pressure gas supply to the branch chamber on the side where the draft is shallowest when the hull is tilted sideways. It is characterized by setting so that the said valve | bulb corresponding to may be closed.

  Further, the hull frictional resistance reduction device of the present invention is configured such that the high-pressure gas supply control system detects with a ship anemometer in order to control the amount of bubble ejection from the bubble ejection port according to the water speed of the hull during navigation. The high-pressure gas supply amount supplied to the compartment based on the ship speed is set so as to be adjusted by the opening of the valve.

  Furthermore, the hull frictional resistance reduction device of the present invention is based on the ship speed detected by the ship speedometer to control the amount of bubble ejection from the bubble ejection port according to the water velocity of the hull during navigation. A compressor control system for adjusting the amount of high-pressure gas supplied to the compartment by controlling the compressor is provided.

  In the hull frictional resistance reduction device of the present invention, gas chambers formed in the ship over the width direction of the ship bottom are arranged so as to be dispersed in the ship length direction, and each gas chamber is divided into a plurality of compartments over the width direction of the ship bottom. In addition to being divided, a large number of bubble outlets are formed in the hull skin corresponding to each compartment, and high pressure gas supply pipes that are connected to the respective compartments via valves are connected to each compartment, so that the hull in operation The outer surface of the ship bottom is appropriately covered with fine bubbles ejected from a number of bubble ejection ports formed in the hull outer plate corresponding to the compartment.

  The supply of the high-pressure gas to the compartment is controlled by the high-pressure gas supply control system based on the hull lateral inclination angle detected by the hull roll sensor, so that the hull greatly rolls during navigation in the waves. At the same time, the distribution of bubbles flowing from the bubble outlet and flowing along the outer surface of the bottom of the ship is made uniform.

  Further, the high-pressure gas supply control system determines the amount of high-pressure gas supplied to the compartment on the side where the draft becomes shallow due to the lateral inclination of the hull based on the horizontal inclination angle detected by the roll sensor. By controlling the opening of the valve so as to reduce the amount of gas supplied to the compartment on the other side, the distribution of bubbles for covering the bottom of the ship is appropriately performed without waste.

  Further, the high-pressure gas supply control system is set to close the valve corresponding to the branch chamber in order to stop the high-pressure gas supply to the branch chamber on the side where the draft is shallowest when the hull is inclined sideways. In this case, even when the hull is largely inclined at the time of turning of the marine vessel that is being navigated, the bubbles are appropriately distributed to the outer surface of the bottom of the vessel without waste.

  Also, when the water velocity of the ship is small, the frictional resistance due to the outside water of the hull is also reduced, so that the amount of bubble ejection from the bubble outlet can be controlled according to the water velocity of the hull during navigation. If the high-pressure gas supply control system is set so that the amount of high-pressure gas supplied to the compartment can be adjusted by the opening of the valve based on the ship speed detected by the ship speedometer, It is possible to reduce the amount of high-pressure gas supply by suppressing the ejection of bubbles.

  Further, the amount of high-pressure gas supplied to the compartment based on the ship speed detected by the ship speedometer so that the amount of bubble jet from the bubble outlet can be controlled according to the water velocity of the hull during navigation. Even when a compressor control system is provided for adjusting the air pressure by controlling the compressor, it is possible to reduce the amount of high-pressure gas supply by suppressing the ejection of bubbles when the boat speed is low.

  1 is a side view of a ship equipped with a hull frictional resistance reducing device as one embodiment of the present invention, FIG. 2 is a cross-sectional view of the hull taken along the line AA in FIG. 1, and FIG. FIG. 4 is a system diagram showing a control system of the above apparatus.

  As shown in FIGS. 1 and 2, in the bottom 1 of the ship as a large ship, the gas chambers 2 formed in the ship over the width direction as shown in FIG. 2 are dispersed in the ship length direction as shown in FIG. A plurality (four in this embodiment) are arranged.

  Each gas chamber 2 is divided into a number of compartments 2a over the width direction of the ship bottom 1, and a large number of bubble outlets 1b are formed in the hull outer plate portion 1a corresponding to each compartment 2a as shown in FIG. Has been. In addition, you may make it employ | adopt a porous board for this ship bottom outer plate part 1a. In particular, when a stainless sintered wire mesh as a porous plate obtained by laminating and sintering a large number of stainless steel wire meshes is used for the ship bottom outer plate portion 1a, sufficient strength and durability can be ensured.

  As shown in FIGS. 3 and 4, high-pressure gas supply pipes 3 leading to the respective compartments 2a are arranged in the ship, and each gas supply pipe 3 has a valve 5 and a flow meter 6 as shown in FIG. The main pipe 3A is connected to a compressor (in this embodiment, an air compressor) 8 through a main plug 7.

  Then, as shown in FIG. 4, as shown in FIG. 4, the roll sensor 9 of the hull and the roll of the hull can be made uniform so that the distribution of the bubbles b flowing from the bubble outlet 1 b and flowing along the outer surface of the ship bottom 1 can be made uniform. A high-pressure gas supply control system 10 is provided for controlling the amount of high-pressure gas supplied to the compartment 2 a based on the hull lateral inclination angle detected by the sensor 9.

  That is, the high-pressure gas supply control system 10 determines the amount of high-pressure gas supplied to the compartment 2a on the side where the draft becomes shallower when the hull is tilted based on the detection information from the roll sensor 9 on the side where the draft becomes deeper. The opening degree of the valve 5 can be controlled so as to reduce the amount of the high-pressure gas supplied to the compartment 2a.

  Further, the high-pressure gas supply control system 10 is based on the detection information from the roll sensor 9 so as to stop the high-pressure gas supply to the compartment 2a on the side where the draft is the shallowest when the hull is inclined. The valve 5 corresponding to 2a is set to be closed.

  Further, the high-pressure gas supply control system 10 moves to the compartment 2a based on the ship speed detected by the ship speedometer 11 so that the amount of bubble injection from the bubble outlet 1b can be controlled according to the water velocity of the hull during navigation. The high-pressure gas supply amount to be supplied is set so as to be adjusted by the opening degree of the valve 5.

  In addition, the high-pressure gas supply supplied to the compartment 2a based on the ship speed detected by the ship speedometer 11 so that the amount of air bubbles ejected from the air bubble outlet 1b can be controlled according to the water speed of the hull during navigation. A compressor control system 12 for adjusting the amount by controlling the compressor 8 is also provided.

  In the above-described hull frictional resistance reduction device of the present embodiment, the gas chambers 2 formed in the ship over the width direction of the ship bottom portion 1 are arranged so as to be dispersed in the ship length direction. While being divided into a plurality of compartments 2a over the width direction, a large number of bubble jets 1b are formed in the hull outer plate portion 1a corresponding to each compartment 2a, and each compartment 2a is connected to each compartment 2a via a valve 5 respectively. Since the high-pressure gas supply pipe 3 is connected, the outer surface of the ship bottom 1 of the sailing hull has fine bubbles b ejected from a number of bubble outlets 1b formed in the hull outer plate 1a corresponding to the compartment 2a. Will be covered properly.

  The supply of the high-pressure gas to the compartment 2a is controlled by the high-pressure gas supply control system 10 on the basis of the hull lateral inclination angle detected by the hull roll sensor 9, so that the hull greatly sways during navigation in the waves. Even when shaking, the distribution of bubbles flowing from the bubble outlet 1b and flowing along the outer surface of the bottom of the ship is made uniform.

  Further, the high-pressure gas supply control system is 10, and based on the hull lateral inclination angle detected by the roll sensor 9, the high-pressure gas supply amount to the compartment 2a on the side where the draft becomes shallower due to the horizontal inclination of the hull becomes deeper. By controlling the opening of the valve 5 so as to reduce the amount of gas supplied to the side compartment 2a, the distribution of bubbles for covering the bottom of the ship can be appropriately performed without waste.

  Further, the high-pressure gas supply control system 10 is set so as to close the valve 5 corresponding to the same compartment 2a in order to stop the supply of the high-pressure gas to the compartment 2a on the side where the draft becomes the shallowest when the hull is inclined sideways. In this case, even when the hull is largely tilted when the vessel is turning, the air bubbles b are appropriately distributed to the outer surface of the bottom of the vessel without waste.

  Further, since the frictional resistance of the hull is reduced when the water velocity of the ship is low, the high-pressure gas supply control is performed so that the amount of bubble ejection from the bubble outlet 1b can be controlled according to the water velocity of the hull during navigation. If the system 10 is set so that the amount of high-pressure gas supplied to the compartment 2a can be adjusted by the opening of the valve 5 based on the ship speed detected by the ship speedometer 11, bubbles are generated when the ship speed is low. The amount of high-pressure gas supply can be reduced by suppressing the ejection of gas.

  Further, a high-pressure gas supply supplied to the compartment 2a based on the ship speed detected by the ship speedometer 11 so that the amount of bubble injection from the bubble outlet 1b can be controlled according to the water velocity of the hull during navigation. Even when the compressor control system 12 for adjusting the amount by the control of the compressor 8 is provided, it is possible to reduce the amount of high-pressure gas supply by suppressing the ejection of bubbles when the boat speed is low.

It is a side view of the ship provided with the hull frictional resistance reduction apparatus as one Example of this invention. FIG. 2 is a transverse cross-sectional view of the hull taken along line AA in FIG. 1. It is an enlarged view of the B section of FIG. It is a systematic diagram which shows the control system of the said apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ship bottom part 1a Hull outer plate part 1b Bubble outlet 2 Gas chamber 2a Branch 3 High pressure gas supply pipe 3A Main pipe 5 Valve 6 Flow meter 7 Main plug 8 Compressor 9 Roll sensor
10 High-pressure gas supply control system
11 Ship speedometer
12 Compressor control system b Air bubbles

Claims (5)

  A plurality of gas chambers formed in the ship over the width direction of the ship bottom are disposed so as to be dispersed in the ship length direction, and the gas chamber is divided into a plurality of compartments over the width direction of the ship bottom, A large number of bubble jets are formed in the hull outer plate corresponding to the compartment, and a high-pressure gas supply pipe that leads from the compressor to each of the compartments via a valve is arranged in the ship, and In order to make uniform the distribution of the bubbles ejected from the spout and flowing along the outer surface of the bottom of the ship, to the compartment based on the roll sensor of the hull and the hull lateral inclination angle detected by the roll sensor And a high-pressure gas supply control system for controlling the high-pressure gas supply of the ship.   The high-pressure gas supply control system is configured such that, based on the hull lateral inclination angle detected by the roll sensor, the amount of high-pressure gas supplied to the compartment on the side where the draft becomes shallow due to the horizontal inclination of the hull becomes the side where the draft becomes deeper. The hull frictional resistance reduction device according to claim 1, wherein the opening degree of the valve is controlled so as to be less than the amount of high-pressure gas supplied to the compartment.   The high-pressure gas supply control system is set to close the valve corresponding to the same compartment in order to stop the high-pressure gas supply to the compartment on the side where the draft is shallowest when the hull is inclined sideways. The hull frictional resistance reduction device according to claim 2, wherein   The high-pressure gas supply control system is supplied to the compartment based on the ship speed detected by the ship speedometer in order to control the amount of bubble injection from the bubble outlet according to the water speed of the hull during navigation. The hull frictional resistance reduction device according to any one of claims 1 to 3, wherein the high-pressure gas supply amount is set so as to be adjusted by the opening degree of the valve.   In order to control the amount of air bubbles ejected from the air bubble outlet according to the water velocity of the hull during navigation, the compressor supplies the amount of high-pressure gas supplied to the compartment based on the ship speed detected by the ship speedometer. The hull frictional resistance reduction device according to any one of claims 1 to 4, further comprising a compressor control system for adjustment by the control.

Images