WO2017169030A1 - Hull frictional resistance reduction device and ship - Google Patents

Abstract

Provided are a hull frictional resistance reduction device and a ship such that the frictional resistance of a hull can be effectively reduced while risks associated with bubbles flowing into a propeller are mitigated. This hull frictional resistance reduction device comprises: a plurality of bubble jetting units (36C, 36R, 36L) which are provided in the width direction forward of a propeller (16); an adjusting mechanism (35) which adjusts the amount of bubbles to be jetted from the bubble jetting units (36C, 36R, 36L); a control device (50); and a inflow information acquisition means for acquiring information relating to flow of bubbles (100) into the propeller (16). The control device (50) has an adjusting mechanism control unit (52), and upon acquiring the bubble inflow information from the inflow information acquisition means, the adjusting mechanism control unit (52) controls the operation of the adjusting mechanism (35) in such a manner that the amount of the bubbles (100) to be jetted to at least the bubble jetting unit (36C) disposed straight in front of the propeller (16) is reduced.

Description

Hull friction drag reduction device and ship

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a hull friction resistance reduction device that reduces hull friction resistance by covering the bottom of the hull with bubbly flow, and a vessel including the same.

There is known a technique for reducing the frictional resistance of the hull by generating a bubbly flow from the bow side to the stern side during sailing and covering the bottom of the vessel with the bubbly flow.
As such a technique, there is a technique disclosed in Patent Document 1, for example. The technology disclosed in Patent Document 1 includes a navigation condition determination unit (100) and a sea condition determination unit (120), and performs control on the ejection of air bubbles to the bottom (3) based on the current condition of the ship and the sea condition, for example When the wave height becomes equal to or more than a predetermined value, the ejection of air bubbles is stopped (see paragraphs [0079]-[0083], [0097], etc. Reference numerals in parentheses are used in Patent Document 1) Show the sign).

JP, 2009-248611, A

However, in the technology of reducing the frictional resistance of the hull by the bubbly flow, a portion of the bubbly flow may flow into the stern propeller, particularly when traveling at high speed. If air bubbles flow into the propeller, the propeller's propulsive force is reduced, the vibration of the hull is increased due to the propeller's oscillating force caused by the increase in propeller fluctuating pressure, and the propeller's erosion risk is increased.
According to the technology disclosed in Patent Document 1, various sensors are provided to judge the navigation condition and the sea state based on the detection results of these sensors, and control on the ejection of air bubbles is performed based on this judgment. And the inflow of air bubbles into the propeller is not recognized as a problem, and the problem can not be solved.

SUMMARY OF THE INVENTION The present invention was conceived in view of the above problems, and it is possible to effectively reduce the frictional resistance of the hull while suppressing the risk due to the inflow of air bubbles into the propeller. It aims at providing a reduction device and a vessel.

(1) In order to achieve the above object, a plurality of hull frictional resistance reduction devices according to the present invention are provided along the hull width direction ahead of the propellers at the bottom of the boat, and a bubble jetting unit that jets bubbles; It is a hull friction resistance reduction device provided with an adjustment mechanism which adjusts the amount of bubbles of a blowout unit, and a control device, and there is a possibility that the bubbles flow into the propeller or the bubbles flow into the propeller The inflow information acquiring means for acquiring air bubble inflow information indicating that, the control device has an adjusting mechanism control unit for controlling the operation of the adjusting mechanism, and the adjusting mechanism control unit is configured to receive the inflow information acquiring means When the air bubble inflow information is not acquired, the operation of the adjustment mechanism is controlled such that air bubbles of a predetermined amount are ejected from each of the plurality of air bubble ejection units, while When the air bubble inflow information is acquired from the inflow information acquiring means, at least the air bubble ejection unit disposed in front of the propeller in the plurality of air bubble ejection units has the predetermined amount of the air bubbles ejected. It is characterized in that the operation of the adjusting mechanism is controlled so as to be reduced more.

Here, in the case where there are a plurality of bubble jetting units arranged in front of the propeller, if at least one bubble jetting unit in front of the propeller is reduced with respect to the bubble jetting unit, then In the case of the bubble jetting unit disposed in front of the propeller, the amount of the bubble jetting is reduced to be smaller than a predetermined amount.

(2) Preferably, the inflow information acquisition means is an inflow detection means for detecting the inflow of the air bubbles into the propeller.

(3) When the adjustment mechanism control unit acquires the bubble inflow information from the inflow information acquisition unit, at least the bubble ejection unit disposed in front of the propeller in the plurality of bubble ejection units. Preferably, the ejection of the air bubbles is stopped.

(4) When the adjustment mechanism control unit acquires the air bubble inflow information from the inflow information acquisition unit, only the air bubble ejection unit in front of the propeller in the plurality of air bubble ejection units is It is preferable to reduce the amount of ejection more than the predetermined amount.

(5) The inflow detection means is provided in the imaging device for imaging the propeller and the control device, and whether or not the air bubble is inflowing to the propeller based on the image information imaged by the imaging device It is preferable to include a determination unit that performs the determination of

(6) It is preferable that the imaging device be directly attached to the bottom of the ship in front of the propeller.

(7) It is preferable that the imaging device be disposed just beside the propeller.

(8) Preferably, the imaging devices are arranged in a pair so as to sandwich the propeller from both sides in the width direction of the hull.

(9) The inflow detection means includes vibration detection means for detecting vibration or vibration of the propeller, and the controller, and the air bubble is sent to the propeller based on detection information of the vibration detection means. It is preferable to include a determination unit that determines whether or not there is inflow.

(10) Preferably, a plurality of the vibration detection means are provided along the hull width direction, and the determination unit performs the determination based on detection information of the plurality of vibration detection means.

(11) In the case where there is the vibration detection unit determined by the determination unit that the air bubble is flowing to the propeller based on the detection information, among the plurality of vibration detection units, the adjustment is performed. Preferably, the mechanism control unit reduces the amount of ejection of the air bubble to be smaller than the predetermined amount at least for the air bubble ejection unit in front of the vibration detection unit determined to have the air bubble flowing therein.

(12) Preferably, the vibration detection means is a pressure sensor in which at least the detection end is exposed to the outside of the propeller above the propeller.

(13) Preferably, the vibration detection means is an acceleration sensor disposed in the ship above the propeller.

(14) It is preferable that the propeller is provided at the center in the width direction of the hull, and the air bubble ejection unit in front of the front is disposed at the center in the width direction of the hull.

(15) A plurality of the propellers are arranged in parallel along the hull width direction, the air bubble ejection units are respectively disposed in front of the plurality of propellers, and the inflow information is acquired for each of the plurality of propellers Preferably means are provided.

(16) In order to achieve the above object, a ship of the present invention is characterized by including the hull friction resistance reduction device according to any one of (1) to (15).

According to the present invention, in the case where bubble inflow information indicating that air bubbles have flowed into the propeller or air bubbles may have flowed into the propeller is not acquired, a plurality of bubble jetting units provided along the hull width direction In the case where bubble inflow information is acquired from at least a bubble blowing unit disposed forward of the front of the propeller, the bubble blowing amount is reduced, so that the bubbles to the propeller are reduced. The friction resistance of the hull can be reduced while suppressing the risk due to the inflow of water.

1A and 1B are schematic views showing the entire structure of a ship according to a first embodiment of the present invention, FIG. 1A is a side view, and FIG. 1B is a bottom view. FIG. 2 is a schematic view of the configuration of the hull friction resistance reduction device according to the first embodiment of the present invention. FIG. 3A and FIG. 3B are schematic diagrams for explaining the determination method by the determination unit according to the first embodiment of the present invention, and showing an example of an image of a propeller captured by a surveillance camera. FIGS. 4A and 4B are schematic views showing the configuration of the main part of a ship according to a second embodiment of the present invention, FIG. 4A is a side view of the rear of the ship, and FIG. 4B is a rear view (the rudder is omitted). FIG. 5A and FIG. 5B are schematic diagrams for explaining the determination method by the determination unit according to the second embodiment of the present invention, showing an example of an image of a propeller captured from the side by the monitoring camera. is there. 6A and 6B are schematic views showing the configuration of the main part of a ship according to a third embodiment of the present invention, FIG. 6A is a side view of the rear of the ship, and FIG. 6B is a rear view (the rudder is omitted). FIG. 7 is a schematic view of a hull friction resistance reduction device according to a third embodiment of the present invention. 8A, 8B, 8C and 8D are schematic views for explaining the determination method by the determination unit according to the third embodiment of the present invention, and FIG. 8A shows an example of pressure fluctuation above the propeller FIG. 8B, FIG. 8C and FIG. 8D are diagrams showing an example of the frequency spectrum of the fluctuating pressure above the propeller. FIG. 9 is a schematic rear view showing the main configuration of a ship according to a fourth embodiment of the present invention (the rudder is omitted). FIG. 10 is a schematic view of a hull friction resistance reduction device according to a fourth embodiment of the present invention. 11A and 11B are schematic diagrams for explaining the determination method by the determination unit according to the fourth embodiment of the present invention, in which the propeller is on the coordinates with the horizontal axis as the width direction and the vertical axis as the fluctuating pressure It is a figure which shows an example of upper fluctuation pressure distribution. 12A and 12B are schematic bottom views showing the configuration of a ship according to a modification of the present invention. FIGS. 13A and 13B are schematic bottom views showing the configuration of the stern side which is the main part of the ship of the modified example of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, each embodiment shown below is only an illustration to the last, and there is no intention which excludes the application of the various deformation | transformation and technology which are not specified by each following embodiment. The configurations of the following embodiments can be variously modified and implemented without departing from the scope of the invention.
In the following description, the bow 11 side (advancing direction) of the ship 1 is forward, the stern 12 is backward, the left and right are defined on the basis of forward, the direction of gravity is downward, and the opposite is upward. . In addition, a direction orthogonal to the longitudinal direction of the hull (hereinafter referred to as "longitudinal direction") X is taken as a hull width direction Y (hereinafter referred to as "width direction" or "ship width direction"). The side is an inside, and conversely, the side away from the center line CL is an outside.
Further, in the description of the devices and parts mounted on the ship 1, the vertical direction, the left and right direction, and the front and back direction are determined based on the state in which the devices and parts are mounted on the ship 1.

[1. First embodiment]
[1-1. Overall configuration of the ship]
The entire configuration of a ship according to a first embodiment of the present invention will be described with reference to FIGS. 1A and 1B.
1A and 1B are schematic views showing the entire configuration of a ship according to a first embodiment of the present invention, FIG. 1A is a side view, and FIG. 1B is a bottom view. It is a figure showing a figure collectively.
As shown in FIGS. 1A and 1B, the boat 1 includes a hull 10 which is a main body of the boat 1, a control room 20 in which various controls of the boat 1 are performed, and a hull friction resistance reduction device 30. Although the ship 1 is not limited to this, it is a flat bottom ship in which the bottom 13 is flat.
On the hull 10, one or more (one in this embodiment) propellers 16 for propelling the hull 10 are installed at the rear portion (closer to the stern 12), and further, behind the propellers 16 the traveling direction of the hull 10 is A rudder 17 to be determined is installed. The rotational center C0 of the propeller 16 and the rudder 17 are both positioned on the center line CL in plan view.
The hull frictional resistance reduction device 30 ejects air from the bottom 13 to generate a bubble flow (hereinafter, also referred to as a bubble) 100 at the boundary between the bottom 13 and water, and the bubble flow 100 covers the bubble layer covering the bottom 13. By forming it, the frictional resistance of the hull 1 to be navigated is reduced.

[1-2. Ship Frictional Resistance Reduction Device]
[1-2-1. Overall Configuration of Ship Frictional Resistance Reduction Device]
The entire configuration of the hull frictional resistance reduction device 30 will be further described with reference to FIGS. 1A, 1B and 2. FIG.
FIG. 2 is a schematic view of the configuration of the hull frictional resistance reduction device 30, including a block diagram showing a control configuration of the control device 50. As shown in FIG.
As shown in FIG. 1B and FIG. 2, the hull frictional resistance reduction device 30 includes an air supply source 31 configured by, for example, a blower or a compressor, an air supply passage 32 connected at one end to the air supply source 31, and an air supply. A flow control valve 33 installed in the passage 32, a plurality (six in this case) of branch supply pipes 34 branched from the other end side of the air supply passage 32, and a shut valve installed in each branch supply pipe 34 Mechanism) 35, air bubble jet parts 36C, 36L, 36R connected to the branch ends of the respective branch supply pipes 34, a monitoring camera (imaging apparatus) 40 for monitoring the propeller 16, and a control unit arranged in the control room 20 And 50.
Hereinafter, when not distinguishing foam | bubble ejection part 36C, 36L, 36R, it describes with the foam | bubble ejection part 36. FIG.

Each bubble spouting portion 36 is disposed at the front of the bottom 13. In the width direction Y, the bubble jetting portion 36C is disposed on the center line CL, the bubble jetting portion 36L is disposed on the port 14 side, and the bubble jetting portion 36R is disposed on the starboard 15 side. The 36 </ b> R is disposed over substantially the entire width of the bottom 13. With respect to the front-rear direction X, the bubble ejection portion 36C is disposed at the frontmost position, and the bubble ejection portions 36L and 36R are disposed at the same position behind the bubble ejection portion 36C. The bubble jetting parts 36C, 36L, 36R may be arranged side by side.

Further describing the position of the bubble jetting portion 36C, the bubble jetting portion 36C is located in front of and in front of the propeller 16. Being positioned forward of the front of the propeller 16, the bubbles 100 jetted from the bubble jet portion 36 C move relatively to the rear of the hull 1 and flow into the propeller 16 as the boat 1 runs. The position of the part 36 is said. Therefore, in the present embodiment, the respective center lines in the ship width direction Y of the bubble jet portion 36C and the propeller 16 coincide with the center line CL of the hull 1 in plan view (that is, the bubble jet portion 36C Centerline in the widthwise direction Y and the centerline in the widthwise direction Y of the propeller 16), the centerline in the widthwise direction Y of the air bubble jet portion 36C, and the widthwise direction Y of the propeller 16 It is not essential to match the centerline.
For example, that the bubble jet portion 36C is positioned forward of the front of the propeller 16 is that the bubble jet portion 36C is positioned so that at least a part is included in the upstream region A of the propeller 16 as shown in FIG. It can be defined that the bubble jetting part 36C is positioned so that at least a part thereof is present on the center line of the propeller 16, but it is not limited thereto.

The bubble jetting portion 36C is configured by a plurality of (here, two) bubble jetting units 36C-1 and 36C-2 arranged in parallel along the width direction Y of the vessel. Similarly, the bubble jetting portion 36L is configured of a plurality (two in this case) of bubble jetting units 36L-1 and 36L-2 arranged in parallel along the width direction Y, and the bubble jetting portion 36R is a width of the ship. A plurality of (two in this case) bubble ejection units 36R-1 and 36R-2 are arranged in parallel along the direction Y. Hereinafter, the bubble ejection units 36C-1 to 36R-2 will be referred to as bubble ejection units 36-u when not distinguished.

Each bubble jetting unit 36-u is composed of an air chamber 36 a disposed inside the bottom 13 and a plurality of jet holes 36 b penetrating the bottom 13. The air chamber 36a is in the form of a rectangular box having an open bottom and is disposed inside the bottom 13 with its longitudinal direction oriented in the width direction Y. The ejection holes 36b are surrounded by the air chamber 36a in the front, rear, left, right, and upper sides.
The opening degree of the flow rate adjustment valve 33 is controlled by the controller 50. By controlling the opening degree of the flow rate adjustment valve 33, the bubble ejection amount from each of the bubble ejection portions 36C, 36L, 36R is simultaneously controlled.
A branch supply pipe 34 is connected to each bubble injection unit 36-u, and a shut valve 35 is installed in each branch supply pipe 34. The shut valve 35 is an on / off valve, and is controlled by the controller 50 to be fully open or fully closed. That is, when the shutoff valve 35 is controlled to be fully opened by the control device 50, air bubbles are ejected from the corresponding bubble ejection unit 36-u, and when the shutoff valve 35 is controlled to be fully closed by the control device 50. The ejection of air bubbles from the corresponding air bubble ejection unit 36-u is stopped. The shut valve 35 also functions as a check valve that prevents seawater from flowing back from the air bubble jet unit 36-u in the stopped state and entering the branch supply pipe 34.

The surveillance camera 40 is installed at the rear of the bottom 13 of the boat and is submerged while traveling to monitor the inflow of air bubbles into the propeller 16. The surveillance cameras 40 are disposed in a pair diagonally in front of the propellers 16 so as to sandwich the propellers 16 from both outer sides, and form a pair to image the entire propellers 16.
In addition, if the surveillance camera 40 can image the whole propeller 16, the installation location and number are not limited to said thing.

1-2-2. Control Configuration of Ship Frictional Resistance Reduction Device]
A control configuration of the control device 50 of the hull frictional resistance reduction device 30 will be described with reference to FIGS. 2, 3A and 3B.
FIGS. 3A and 3B are schematic diagrams for explaining the determination method by the determination unit 51 according to the first embodiment of the present invention, and are diagrams showing an example of an image of the propeller 16 captured by the monitoring camera 40. is there. In addition, since the surveillance camera 40 images the propeller 16 from diagonally forward, in fact, the image imaged by the surveillance camera 40 becomes a perspective image of the propeller 16 and a part of the hull 1 is reflected, but In 3A and 3B, for convenience, the front image of the propeller 16 is used and the hull 1 is omitted.
As shown in FIG. 2, the control device 50 controls the operation of the shutoff valve 35 based on the determination result of the determination unit 51 that determines whether air bubbles are flowing into the propeller 16 and the determination unit 51. And a control unit (adjustment mechanism control unit) 52.

The determination unit 51 acquires image information captured by each monitoring camera 40 as exemplified in FIGS. 3A and 3B, analyzes the image information, and binarizes the image based on, for example, lightness. The bubble 100 is identified, and it is determined whether the bubble 100 flows into the bubble detection area R. The air bubble detection area R is an area defined as a space between air bubble detection lines L1 and L2 set above and below the propeller 16. In the present embodiment, the air bubble detection lines L1 and L2 are defined as positions separated vertically from the rotation center C0 of the propeller 16 by the propeller radius r.
As described above, although front images of the propellers 16 are described for convenience in FIGS. 3A and 3B, in fact, since the surveillance camera 40 images the propellers 16 from both the left and right sides, Only the left and right sides can be imaged sufficiently. Therefore, the determination unit 51 analyzes the image information of both monitoring cameras 40, and the image information of any of the monitoring cameras 40 does not flow into the bubble detection area R as shown in FIG. 3A. When it is shown, it is determined that the bubble flow 100 has not flowed into the propeller 16, and the image information of one of the monitoring cameras 40 indicates that the bubble is flowing into the bubble detection area R as shown in FIG. 3B. When shown, it is determined that the bubbly flow 100 is flowing into the propeller 16.

The air bubble detection lines L1 and L2 may be defined as positions separated vertically from the rotation center C0 of the propeller 16 by r ′ (= r + Δr, Δr> 0) obtained by adding the margin Δr to the propeller radius r. In this case, the determination unit 51 determines that the bubble stream 100 does not flow into the propeller 16 when the air bubbles do not flow into the air bubble detection region R, and that the air bubbles flow into the air bubble detection region R When this is the case, it is determined that the bubble stream 100 is flowing into the propeller 16 or the bubble stream 100 may be flowing into the propeller 16.

As described above, the bubble flow 100 is flowing into the propeller 16 by the determination unit 51 based on the image information of the monitoring camera 40, so the inflow detection means of the present invention is configured by the monitoring camera 40 and the determination unit 51. Further, since detecting the inflow of the bubble flow 100 is to acquire bubble inflow information indicating that the bubble flow 100 has flowed in, the inflow information acquiring means of the present invention is obtained by the monitoring camera 40 and the determination unit 51. Is configured.

The shut valve control unit 52 fully opens all the shut valves 35 when acquiring information indicating that the bubble flow 100 has not flowed into the propeller 16 from the determination unit 51 (hereinafter, also referred to as a normal time). That is, the bubble jetting parts 36C, 36L, and 36R are brought into the operating state. On the other hand, when the shutoff valve control unit 52 obtains information (bubble inflow information) indicating that the bubble flow 100 is flowing into the propeller 16 from the determination unit 51, the bubble injection unit 36C located in front of the propeller 16 The shutoff valve 35 of the branch supply pipe 34 connected to (the bubble jetting unit 36C-1, 36C-2) is fully closed, and the jetting of the bubble 100 from the bubble jetting unit 36C is stopped (in other words, the bubble jetting unit 36C The amount of bubbles from the air bubbles 100 is reduced than usual. That is, the bubble ejection part 36C is brought into the stop state.

[1-3. Action / Effect]
According to the hull friction resistance reduction device 30 and the ship 1 as the first embodiment of the present invention, the determination unit 51 determines whether the bubble flow 100 has flowed into the propeller 16 based on the image information captured by the monitoring camera 40 A determination is made, and the determination result is output to the shutoff valve control unit 52.
When the determination result indicates that the bubble flow 100 has not flowed into the propeller 16, the shut valve control unit 52 fully opens all the shut valves 35, as shown in FIG. 1B. All bubble injection units 36C-1 to 36R-2 are operated. Thereby, most of the area of the bottom 1 can be covered by the air bubbles 100.
On the other hand, when the determination result of the determination unit 51 is the determination that the bubble flow 100 is flowing into the propeller 16, the shut valve control unit 52, as shown in FIG. The shut valve 35 provided for the air bubble ejection units 36C-1 and 36C-2 located forward is fully closed, and the other air bubble ejection units 36L-1, 36L-2 and 36R-1 and 36R-2 are closed. The shut valve 35 provided is fully opened.

All or most of the air bubbles 100 flowing into the propeller 16 are air bubbles ejected from air bubble ejection units 36C-1 and 36C-2 disposed in front of the propeller 16. Therefore, the shutoff valve 35 provided for the bubble jetting units 36C-1 and 36C-2 is fully closed to stop the bubble jetting units 36C-1 and 36C-2, whereby the inflow of the bubbles 100 to the propeller 16 is caused. Can be suppressed. As a result, it is possible to suppress a decrease in propulsive force due to the inflow of the air bubbles 100 into the propeller 16, an increase in ship vibration due to the propeller excitation force, and an increase in erosion risk. In addition, since the bubble jetting units 36L-1, 36L-2, 36R-1, and 36R-2 are operated so that the bubbles 100 do not flow into the propeller 16, many regions of the bottom 1 can be covered with the bubbles 100.
Therefore, it is possible to reduce the frictional resistance of the hull 1 while suppressing the risk due to the inflow of the air bubbles 100 into the propeller 16 particularly at the time of high speed running where the air bubbles 100 easily flow into the propeller 16.

[2. Second embodiment]
A hull friction resistance reduction device and a ship as a second embodiment of the present invention will be described with reference to FIGS. 4A, 4B, 5A and 5B. The same components as those of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.
4A and 4B are schematic views showing the configuration of the main part of a ship according to a second embodiment of the present invention, FIG. 4A is a side view of the rear of the ship, and FIG. 4B is a rear view (the rudder 17 is omitted). .
FIG. 5A and FIG. 5B are schematic diagrams for explaining the determination method by the determination unit according to the second embodiment of the present invention, showing an example of an image of a propeller captured from the side by the monitoring camera. is there.

[2-1. Constitution]
The hull friction resistance reduction device and the ship of the present embodiment are different from the first embodiment in the arrangement of the monitoring camera 40.
Specifically, as shown in FIGS. 4A and 4B, the monitoring cameras 40 are arranged in a pair on the outer sides of the propeller 16 in the boat width direction Y. In the present embodiment, the monitoring camera 40 is disposed just beside the propeller 16 (that is, at the same position in the longitudinal direction X), but if it is outside the propeller 16 in the boat width direction Y, the front or rear It may be located at
Each surveillance camera 40 is supported by a pair of brackets (support members) 40 a depending from the outer edge of the lower surface of the stern 12. If it is possible to secure the attachment point to the hull 1, each monitoring camera 40 may be directly attached to the hull 1 respectively.

Since the surveillance camera 40 is disposed in proximity to the propeller 16, particularly in the submerged state while traveling, particularly when the bubble flow 100 flows into the propeller 16 (that is, when imaging by the surveillance camera 40 is most needed) It is conceivable that the bubble flow 100 flows into the monitoring camera 40 as well. In such a case, there is a concern that the surveillance camera 40 itself may be in the bubble flow 100, and the propeller 16 may not be imaged as clearly as image analysis is disturbed by the bubble flow 100.
Therefore, by arranging the monitoring camera 40 on the outer side in the width direction Y of the propeller 16, the monitoring camera 40 is removed from the traveling path of the bubble flow 100 flowing into the propeller 16.

In addition, although the risk that the bubble flow 100 from the bubble injection part 36C installed on the center line CL flows in only by arrange | positioning the surveillance camera 40 to the outer side of the propeller 16, it installs in the both sides of the bubble injection part 36C. There remains a risk that the bubbly flow 100 from the bubbly jet parts 36L, 36R will flow. For this reason, it is preferable to arrange the monitoring camera 40 at the outer edge of the hull 1 as in the present embodiment so as to be out of the downstream region of all the bubble jetting portions 36 including the bubble jetting portions 36L and 36R.

The image information as shown in FIGS. 5A and 5B captured from the side by the monitoring camera 40 is image-analyzed by the determination unit 51 (see FIG. 2) as in the first embodiment. That is, the determination unit 51 analyzes the image information of both monitoring cameras 40, and as for the image information of any monitoring camera 40, as shown in FIG. 5A, when the air bubble 100 does not flow into the air bubble detection area R, the propeller When it is determined that the bubble flow 100 has not flowed into 16, and the image information of any one of the monitoring cameras 40 shows that the bubble is flowing into the bubble detection area R, as shown in FIG. It is determined that the stream 100 is flowing.
Since the other configuration is the same as that of the first embodiment, the description will be omitted.

[2-2. Action / Effect]
According to the hull friction resistance reduction device and the ship as the second embodiment of the present invention, since the monitoring camera 40 is suppressed from entering the bubble flow 100, clear image information without the influence of the bubble flow 100 can be obtained. It can be acquired by the surveillance camera 40. Therefore, the detection accuracy of the inflow of the bubble flow 100 into the propeller 16 can be improved based on the clear image information, and the hull body while suppressing the risk due to the inflow of the bubble 100 into the propeller 16 more effectively. The frictional resistance of 1 can be reduced.

[3. Third embodiment]
A hull friction resistance reduction device and a ship according to a third embodiment of the present invention will be described with reference to FIGS. 6A, 6B, 7, 8A and 8B. In addition, about the component same as said each embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.
6A and 6B are schematic views showing the configuration of the main part of a ship according to a third embodiment of the present invention, FIG. 6A is a side view of the rear of the ship, and FIG. Is omitted).
FIG. 7 is a schematic view of a hull friction resistance reduction device 30A according to a third embodiment of the present invention, including a block diagram showing a control configuration of the control device 50A.
8A, 8B, 8C and 8D are schematic views for explaining the determination method by the determination unit according to the third embodiment of the present invention, and FIG. 8A shows an example of pressure fluctuation above the propeller FIG. 8B, FIG. 8C and FIG. 8D are diagrams showing an example of the frequency spectrum of the fluctuating pressure above the propeller.

3-1. Constitution]
The hull friction resistance reduction device 30A and the ship 1A of the present embodiment use a pressure sensor (vibration detection means) 41 instead of the monitoring camera 40 for the hull friction resistance reduction device 30 and the ship 1 of the first embodiment. Then, the inflow of the bubbly flow 100 to the propeller 16 is detected. That is, while the inflow information acquisition means and the inflow detection means of the present invention are configured by the monitoring camera 40 and the determination section 51 in the first embodiment, the pressure sensor 41 and the determination section 51A are the present invention. The inflow information acquisition means and the inflow detection means of

Specifically, as shown in FIGS. 6A, 6B and 7, the pressure sensor 41 is installed vertically above the propeller 16 in the boat 1A of the present embodiment. The pressure sensor 41 is inserted and fixed in a mounting hole formed on the bottom wall of the stern 12, and the detection end 411 is exposed to the outside of the boat to face above the propeller 16.
As shown in FIG. 7, the hull frictional resistance reduction device 30A includes the air supply source 31, the air supply passage 32, the flow rate adjustment valve 33, the branch supply pipe 34, the shut valve 35, and the bubble jetting parts 36C and 36L. 36R, the pressure sensor 41, and a control device 50A disposed in the control room 20 [see FIG. 1A].

The control device 50A controls the operation of the shutoff valve 35 based on the determination result of the determination unit 51A that determines whether air bubbles are flowing into the propeller 16 based on the detection result of the pressure sensor 41 and the determination unit 51A. And a shut valve control unit 52A.
The determination unit 51A obtains the pressure P above the propeller 16 at a predetermined cycle from the pressure sensor 41, and grasps time-series data Pp in which the pressure P and the time t are associated as shown in FIG. . Then, the determination unit 51A periodically acquires the frequency spectrum of the fluctuation pressure ΔP as shown in FIGS. 8B, 8C, and 8D by performing FFT analysis on the time-series data. The fluctuating pressure ΔP is correlated with the vibration, and the vibration becomes large as the fluctuating pressure ΔP is large. Therefore, the vertical axis in FIGS. 8B, 8C and 8D can be considered as the vibration.
Here, FIG. 8B shows the case where the ship frictional resistance reduction device 30A is stopped, FIG. 8C shows the case where the ship frictional resistance reduction device 30A is in operation but the bubbly flow 100 does not flow into the propeller 16, FIG. This is an example of the frequency spectrum of the fluctuating pressure ΔP when the hull frictional resistance reduction device 30A is in operation and the bubbly flow 100 flows into the propeller 16.

In the example shown in FIG. 8B, since the hull frictional resistance reduction device 30A is stopped, the bubbly flow 100 does not exist around the propeller. Then, for the NZ frequency F1 defined by the rotational frequency N and the number of blades Z of the propeller 16 and the high-order components F2, F3 and F4 of the NZ frequency F1, peak values ΔP1, ΔP2 and ΔP3 of the fluctuation pressure ΔP, respectively. , ΔP4 has occurred. The high-order component F2 is a frequency twice as high as the NZ frequency F1, the high-order component F3 is a frequency three times as high as the NZ frequency F1, and the high-order component F4 is a frequency four times as high as the NZ frequency F1. In the example shown in FIG. 8B, the peak value ΔP1 at the NZ frequency F1 indicates the highest fluctuation pressure.

In the example shown in FIG. 8C, only the peak value ΔP1 occurs at the NZ frequency F1, which is because the hull frictional resistance reduction device 30A is operating, that is, as shown in FIGS. 6A and 6B Since the flow 100 intervenes between the propeller 16 and the vessel bottom 13 immediately above and near the propeller 16, the bubbly flow 100 provides high-order components F2, F3, F4 of the NZ frequency F1 as shown in FIG. 8B. It attenuates and only the peak value ΔP1 is detected as the fluctuating pressure ΔP.
That is, the bubbly flow 100 between the propeller 16 and the bottom 13 directly above and near the top of the propeller 16 functions as a damper, and the peak values ΔP2, ΔP3, ΔP4 of the high-order components F2, F3, F4 of the NZ frequency F1. Decreases, and only the peak value ΔP1 of the NZ frequency F1 remains at the same level as the peak value ΔP1 in FIG. 8B.

In the example shown in FIG. 8D, since the bubbly flow 100 flows into the propeller 16 and cavitation on the blade surface of the propeller 16 is increased, the peak value .DELTA.P1 at the NZ frequency F1 is shown in FIG. In the example where the drag reduction device 30A is in operation, but the bubbly flow 100 does not flow into the propeller 16, the peak value ΔP1 of the example is increased. The peak values ΔP2, ΔP3 and ΔP4 of the high-order components F2, F3 and F4 of the NZ frequency F1 are the example shown in FIG. 8C (the ship frictional resistance reduction device 30A is operating, but the bubble flow 100 corresponds to the propeller 16). The damper function of the bubbly flow 100 dampens the same as in the example of not flowing).

The alarm line La set in advance is stored in the determination unit 51A. The alarm line La is a level at which the bubble flow 100 is likely to flow into the propeller 16 when the fluctuation pressure ΔP exceeds this level. Therefore, when the fluctuation pressure ΔP is equal to or less than the alarm line La as shown in FIG. 8C, the determination unit 51A judges that the bubble flow 100 does not flow into the propeller 16 and changes the fluctuation pressure ΔP as shown in FIG. 8D. When it exceeds the alarm line La, it is determined that the bubbly flow 100 is flowing into the propeller 16.
The shut valve control unit (adjustment mechanism control unit) 52A is configured in the same manner as the shut valve control unit 52 of the first embodiment, and the information that the bubble flow 100 does not flow into the propeller 16 is determined from the determination unit 51A. When acquired, all the shut valves 35 are controlled to be fully open, and when information indicating that the bubble flow 100 is flowing into the propeller 16 is acquired from the determination unit 51A, the bubble ejection portion 36C located in front of the propeller 16 in front And shut the shutoff valve 35 of the branch supply pipe 34 connected thereto.
Since the other configuration is the same as that of the first embodiment, the description will be omitted.

[3-2. Action / Effect]
According to the hull friction resistance reduction device 30A and the ship 1A as the third embodiment of the present invention, the pressure sensor 41 directly detects the vibration caused by the inflow of the air bubble 100 into the propeller 16 as the fluctuation pressure ΔP. The inflow of the bubble flow 100 to the propeller 16 can be detected more accurately than in the case where the monitoring camera 40 is used as in the first and second embodiments. That is, in the detection using the monitoring camera 40, when the area around the propeller 16 is dark as in the nighttime or when the transparency of the water is low, the identification accuracy of the bubble flow 100 decreases and the bubble flow 100 flows into the propeller 16 The detection accuracy of H may also decrease. However, in the case of detection based on the fluctuating pressure ΔP, it is possible to accurately detect the inflow of the bubble flow 100 to the propeller 16 even in such a case.

[3-3. Other]
In the above, the pressure sensor 41 installed vertically above the propeller 16 was used as the vibration detection means, but instead of the pressure sensor 41, an acceleration sensor installed vertically above the propeller 16 is used as the vibration detection means It is also good. When the acceleration sensor is used as the vibration detection means, since the vibration of the hull 1 is detected, it is not necessary to expose the detection end to the outside. Therefore, as in the case of using the pressure sensor 41, it is not necessary to process the mounting hole on the hull, and the mounting becomes easy.
The location where the pressure sensor 41 is installed does not have to be strictly above the propeller 16 and vertically out of the vertical direction from the vertical upper side of the propeller 16 within a range where the inflow of the bubble flow 100 to the propeller 16 can be detected as a fluctuating pressure. Good.

[4. Fourth embodiment]
A hull friction resistance reduction device and a ship as a fourth embodiment of the present invention will be described with reference to FIGS. 9, 10, 11A and 11B. In addition, about the component same as said each embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.
FIG. 9 is a schematic rear view showing the main configuration of a boat 1B according to a fourth embodiment of the present invention (the rudder 17 is omitted).
FIG. 10 is a schematic view of a hull friction resistance reduction device 30B according to a fourth embodiment of the present invention, including a block diagram showing a control configuration of the control device 50B.
11A and 11B are schematic diagrams for explaining the determination method by the determination unit 51B according to the fourth embodiment of the present invention, in which coordinates in which the horizontal axis is the ship width direction Y and the vertical axis is the fluctuation pressure ΔP It is a figure which shows an example of the fluctuation pressure distribution above propeller 16 above. On the coordinates, the propeller 16 and the bubble jetting parts 36C, 36R, 36L are virtually shown with the position in the width direction Y aligned with the horizontal axis.

[4-1. Constitution]
The hull friction resistance reduction device 30B and the ship 1B of the present embodiment are propellers using a plurality of pressure sensors (vibration detection means) 41a to 41g with respect to the hull friction resistance reduction device 30A and the ship 1A of the third embodiment. The inflow of the bubbly flow 100 to 16 is detected. That is, while in the third embodiment the inflow information acquisition means and the inflow detection means of the present invention are configured by one pressure sensor 41 and the determination unit 51A, in the present embodiment, determination is made with a plurality of pressure sensors 41a to 41g. The inflow information acquisition means and the inflow detection means of the present invention are configured by the part 51B.

Specifically, in the ship 1B of the present embodiment, as in the pressure sensor 41 of the third embodiment shown in FIG. 6A, the pressure sensors 41a to 41g respectively installed vertically above the propeller 16 in side view As shown in FIG. 9 and FIG. 10, a plurality of sets are installed along the width direction Y of the ship. In the present embodiment, pressure sensor pressure sensors 41a to 41g are juxtaposed over substantially the entire width of the hull 10 including immediately above (vertically above) the propeller 16.
As shown in FIG. 10, the hull frictional resistance reduction device 30B includes the air supply source 31, the air supply passage 32, the flow rate adjustment valve 33, the branch supply pipe 34, the shut valve 35, and the bubble jetting parts 36C and 36L. , 36R, the plurality of pressure sensors 41a to 41g, and a control device 50B disposed in the control room 20 (see FIG. 1A).

The control device 50B determines whether or not air bubbles are flowing into the propeller 16 based on the detection results of the plurality of pressure sensors 41a to 41g, and the control unit 50B determines the shut valve 35 based on the determination results of the determination unit 51B. And a shutoff valve control unit (adjustment mechanism control unit) 52B that controls the operation.
The determination unit 51B obtains the pressure P from each of the pressure sensors 41a to 41g at a predetermined cycle, and obtains the maximum peak value ΔP7 to ΔP13 of the fluctuation pressure ΔP for each of the pressure sensors 41a to 41g. The maximum peak value refers to the maximum peak value among the peak values in the frequency spectrum. For example, in the examples shown in FIGS. 8B, 8C and 8D used in the description of the third embodiment, the peak value ΔP1 is the maximum peak It becomes a value. Then, from the positional information on the width direction Y of each pressure sensor 41a to 41g and the maximum peak values ΔP7 to ΔP13, the determination unit 51B determines the plurality of maximum peaks as shown in FIGS. 11A and 11B. The peak distribution Wp in the width direction Y is obtained by complementing the values ΔP7 to ΔP13. Then, the determination unit 51B sets the alarm region Ra [shown hatched in FIGS. 11A and 11B] exceeding the alarm line La of the peak distribution Wp as the region where the bubble flow 100 is flowing into the propeller 16 and the shut valve. It outputs to the control part 52B.

In the shut valve control unit 52B, the predetermined shut valve 35 is fully closed to stop the bubble jetting unit 36-u in front of the alarm area Ra, and the other bubble jetting units 36-u are operated. In the example shown in FIG. 11A, the ejection of the air bubble 100 from the air bubble ejection units 36C-1 and 36C-2 located in front of the alarm area Ra (that is, in front of the propeller 16 where the air bubbles 100 flowed) is stopped Bubbles 100 are jetted from the other bubble jetting units 36R-1, 36R-2, 36L-1, and 36L-2. In the example shown in FIG. 11B, the bubble ejection unit 36C-2 located in front of the alarm area Ra (ie, in front of the propeller 16 into which the air bubbles 100 flow) is stopped, and the other bubble ejection units 36R-1 and 36R -2, 36C-1, 36L-1, 36L-2 are operated.

The determination unit 51B outputs the pressure sensors 41a to 41g whose maximum peak values ΔP7 to ΔP13 of the fluctuation pressure ΔP exceed the alarm line La to the shut valve control unit 52B without using the peak distribution Wp or the alarm area Ra. The shut valve control unit 52B may stop the air bubble ejection unit 36-u in front of and in front of the pressure sensors 41a to 41g exceeding the alarm line La.
Note that the air bubble ejection unit 36-u located in front of the alarm area Ra in detail is the air bubble ejection unit 36-u located in front of the alarm area Ra in plan view. This refers to a bubble jetting unit 36-u at least a part of which overlaps with the alarm area Ra with respect to Y. Similarly, the air bubble ejection unit 36-u located in front of the pressure sensors 41a to 41g exceeding the alarm line La specifically refers to air bubbles located in front of the pressure sensors 41a to 41g exceeding the alarm line La in plan view. In other words, the ejection unit 36-u refers to a bubble ejection unit 36-u at least partially overlapping in the width direction Y with the pressure sensors 41a to 41g crossing the alarm line La.
As in the third embodiment, an acceleration sensor may be used instead of the pressure sensor.
Since the other configuration is the same as that of the third embodiment, the description will be omitted.

[4-2. Action / Effect]
According to the hull friction resistance reduction device 30B and the vessel 1B as the fourth embodiment of the present invention, the same effect as the third embodiment can be obtained, and the air bubble 100 is stopped according to the peak distribution Wp of the fluctuating pressure ΔP. The bubble ejection unit 36-u to be set can be set more finely, and the friction resistance of the hull 1 can be reduced while suppressing the risk due to the inflow of the bubbles 100 to the propeller 16 more effectively.

[4-3. Other]
(1) In the above, the operation of the air bubble ejection unit in front of the alarm area Ra is stopped, or the air bubble ejection unit 36-u in front of the front of the pressure sensors 41a to 41g exceeding the alarm line La is stopped. However, when the alarm area Ra occurs or when there is only one pressure sensor that exceeds the alarm line La, the air bubble ejection portion 36C (air bubble ejection unit 36C-1, 36C-2 located in front of the propeller 16) ) May be stopped.

(2) In the fourth embodiment, as shown in FIG. 9, in addition to the pressure sensors 41c, 41d and 41e located vertically above the propeller 16, the pressure located outside the propeller 16 in the width direction W Sensors 41a, 41b, 41f and 41g were used. On the other hand, only the pressure sensors 41c, 41d and 41e located vertically above the propeller 16 may be installed.
In this case, the determination unit 51B determines the inflow of the bubble flow 100 based on the maximum peak value obtained from the detection results of the pressure sensors 41c, 41d, and 41e, and outputs the determination result to the shutoff valve control unit 52B. . Alternatively, the determination unit 51B outputs, to the shutoff valve control unit 52B, the pressure sensors 41c to 41e whose maximum peak value of the fluctuation pressure ΔP exceeds the alarm line La.

[5. Other]
(1) Modification 1
In the first embodiment and the second embodiment described above, the operator may be able to view an image captured by the monitoring camera 40 by the monitor installed in the control room 20, and further, control the imaging direction of the monitoring camera 40 The adjustment may be made from the room 20 by remote control.
In addition, when the operator who was monitoring by the monitor performs “determination that the bubble flow 100 has flowed into the propeller 16 or the bubble flow 100 may have flow into the propeller 16” (hereinafter referred to as bubble flow determination) Alternatively, a manual switch may be provided to stop the bubble jetting unit 36 by the manual operation of the operator. In this case, the manual switch corresponds to the inflow information acquisition means of the present invention.

(2) Modification 2
In each of the above embodiments, the shut valve 35 is fully closed as one mode of reducing the ejection amount of the bubble 100 from the bubble ejection portion 36C compared to the normal time when the judging portions 51, 51A, 51B make the bubble inflow judgment. And the ejection of the air bubble 100 by the air bubble ejection portion 36C is stopped (in other words, the adjustment mechanism of the present invention is configured by the shut valve 35), but the ejection amount of the air bubble 100 from the The aspect to which it is made to be not limited to this. For example, when the adjustment mechanism of the present invention is replaced by the shutoff valve 35 and constituted by a control valve capable of adjusting the opening degree continuously or in stages, the judgment units 51, 51A, 51B make bubble inflow judgment. The opening degree of the control valve may be set smaller than that at the normal time (when the judgment units 51, 51A, 51B do not make the bubble inflow judgment). In this case, even if the determination units 51, 51A, and 51B still make the bubble inflow determination even after the opening degree of the control valve is narrowed, the opening degree of the control valve may be further narrowed.

(3) Modification 3
In the above embodiments, when the judgment units 51, 51A and 51B make the bubble inflow judgment, the ejection of the air bubbles 100 is stopped only for the air bubble ejection portion 36C, but the ejection of the air bubbles 100 in the air bubble ejection portion 36C is stopped (or the ejection In addition to the volume reduction), the ejection stop (or the ejection amount reduction) of the bubble 100 may be performed on at least one of the bubble ejection portion 36L and the bubble ejection portion 36R.

Alternatively, even if the ejection stop or the ejection amount reduction of the air bubble 100 of the air bubble injection portion 36C is performed, if the judging portions 51, 51A, 51B still make the air bubble inflow judgment (inflow of the air bubble 100 into the propeller 16 is eliminated In the case of not being performed, the ejection stop or the ejection amount reduction of the bubble 100 may be additionally performed for at least one of the bubble ejection portion 36L and the bubble ejection portion 36R. Alternatively, in the case where the judgment units 51, 51A, 51B continuously perform the bubble inflow judgment, the order of the bubble ejection portion 36C, the bubble ejection portion 36L, and the bubble ejection portion 36R (or the bubble ejection portion 36C, the bubble ejection portion 36R , And may be sequentially added to the bubble ejection portion 36L in this order).

(4) Modification 4
This modification will be described with reference to FIGS. 12A and 12B.
12A and 12B are schematic bottom views showing the configuration of the ship of the present modification. The same components as those in each embodiment are denoted by the same reference numerals, and the description thereof is omitted.
In each of the above-mentioned embodiments, although one propeller 16 is provided on the center line CL as the ship 1 is illustrated, the present invention is not limited to this, for example, the center line CL as shown in FIGS. 12A and 12B. The propellers 16L and 16R can be used on the vessels 1C and 1D provided on both sides of the propellers 16L and 16R, respectively.
In the vessel 1C shown in FIG. 12A, the rear portion of the bottom 13 is divided into two rear portions 13L and 13R, and propellers 16L and 16R are respectively installed on these rear portions 13L and 13R. On the other hand, in the ship 1D shown in FIG. 12B, the propellers 16L and 16R are installed so as to project rearward from the left and right sides (both sides in the width direction) of the rear of the single bottom 13.

In the example shown in FIG. 12A and FIG. 12B, detection of inflow of bubble flow (here, detection by inflow information acquisition means using the monitoring camera 40 is not limited thereto, and pressure sensors and acceleration sensors are also used. Control of the air bubble jet parts 36C, 36L, 36R is performed individually for each of the propellers 16L, 16R, for example, when the inflow of the bubble flow is detected for the left propeller 16L, When the ejection stop (or the ejection amount decrease) of the air bubble 100 is performed by the air bubble ejection unit 36L located in the front on the front, and the inflow of the air bubble flow is detected for the propeller 16R on the right, The ejection stop (or the ejection amount reduction) of the bubble 100 by a certain bubble ejection unit 36R is performed.

Furthermore, when three or more propellers 16 are installed on the hull along the ship width direction Y, bubble flow inflow detection means are provided for each propeller 16, and air bubbles in the propeller 16 are detected by the bubble flow inflow detection means. When the inflow of the air bubble is detected, the ejection stop (or the ejection amount decrease) of the air bubble 100 by the air bubble ejection unit 36 located in front of the front of the propeller 16 where the inflow of air bubbles is detected may be performed.

(5) Modification 5
This modification will be described with reference to FIGS. 13A and 13B.
13A and 13B are schematic bottom views showing the configuration of the stern side which is the main part of the ship of the present modification. The same components as those in each embodiment are denoted by the same reference numerals, and the description thereof is omitted.
In each of the above-mentioned embodiments, although one propeller 16 is provided on the center line CL as the ship 1 is exemplified, the present invention is not limited to this, for example, the center line CL as shown in FIGS. 13A and 13B. It can also be used for ships 1E and 1F provided with a plurality of (two in this modification) propellers on the front (or on a plurality of lines along the center line CL).
In the ship 1E shown in FIG. 13A, a pod pusher 18 is provided at the rear of the propeller 16. The pod propulsion unit 18 is provided with a propeller 18 a so as to face the front propeller 16, and the propeller 16 is driven by the built-in electric motor to generate propulsion. The propeller 18 a of the pod propeller 18 is disposed on the center line CL together with the propeller 16.
In the ship 1F shown in FIG. 13B, propellers 16A and 16B are provided on the center line CL back and forth, and the propellers 16A and 16B are rotationally driven in opposite directions from each other by a drive shaft consisting of an inner shaft and an outer shaft. .

In the example shown in FIG. 13A and FIG. 13B, detection of inflow of bubble flow (here, detection by inflow information acquiring means using the monitoring camera 40 is not limited to this, and a pressure sensor or an acceleration sensor is also used) Is performed for the forward propellers 16 and 16A, but may be performed for at least one of the two propellers so that detection of inflow of bubble flow is performed for the rearward propellers 16B and 18a. You may

(6) As exemplified in the above-described modified examples (4) and (5), the arrangement of the propeller 16 and the number of the propellers 16 installed are not limited at all.

(7) In the first and second embodiments, the bubble jetting units 36C-1 and 36C-2 in front of the front of the propeller 16 are integrally controlled based on the image information acquired by the two monitoring cameras 40. However, the bubble jetting units 36C-1 and 36C-2 may be separately controlled for each piece of image information acquired by each monitoring camera 40.
That is, when the inflow of the air bubble 100 to the propeller 16 is detected based on the image information of the monitoring camera 40 on the right eye 15 side of the propeller 16, the air bubble ejection unit 36 C-1 on the right eye 15 side is stopped and the propeller 16 is In the case where the inflow of the air bubble 100 into the propeller 16 is detected based on the image information of the monitoring camera 40 on the left side 14 side, the air bubble ejection unit 36C-2 on the left side 14 may be stopped.
In this case, for example, the inflow of the air bubble 100 into the propeller 16 is detected based on the image information of the monitoring camera 40 on the starboard side 15, while the air bubble to the propeller 16 is detected based on the image information of the monitoring camera 40 on the port side 14 When the inflow of 100 is not detected, the air bubble ejection unit 36C-1 on the starboard 15 side is stopped, and the air bubble ejection unit 36C-2 on the port 14 side is operated.

1, 1A, 1B, 1C, 1D, 1E, 1F Vessel 10 Hull 11 Bow 12 Stern 13 Bottom 16,16A, 16B, 16L, 16R Propeller 18 Pod Propeller 18a Pod Propeller 18 Propeller 20 Control Room 30, 30A, 30B Hull friction drag reduction device 32 air supply passage 34 branch supply pipe 35 shut valve (adjustment mechanism)
36C, 36L, 36R bubble ejection part 36C-1 to 36R-2 bubble ejection unit 40 surveillance camera (imaging device)
40a Bracket (supporting member)
41, 41a to 41 g Pressure sensor (vibration detection means)
411 Detection end 50, 50A, 50B Control device 51, 51A, 51B Judgment unit 52, 52A, 52B Shut valve control unit (adjustment mechanism control unit)
100 Bubbly Flow CL Centerline for Hull 1, 1A, 1B, 1C, 1D, 1E, 1F

Claims (16)

1. A plurality of bubble discharge units are provided along the width direction of the ship ahead of the propeller at the ship bottom, and include a control unit and an adjustment mechanism that adjusts the amount of bubble discharge of the bubble discharge unit, and a control device. A resistance reduction device,
   The propeller includes an inflow information acquisition unit that acquires bubble inflow information indicating that the bubble has flowed into the propeller or that the bubble may flow into the propeller.
   The control device includes an adjustment mechanism control unit that controls the operation of the adjustment mechanism.
   The adjustment mechanism control unit
   When the air bubble inflow information is not acquired from the inflow information acquisition means, the operation of the adjustment mechanism is controlled so that a predetermined amount of air bubbles are ejected from each of the plurality of air bubble ejection units,
   In the case where the bubble inflow information is acquired from the inflow information acquiring means, at least the bubble ejection unit of the plurality of bubble ejection units arranged in front of the propeller in front of the propeller, A hull friction resistance reduction device characterized by controlling operation of said adjustment mechanism so that it may reduce rather than a fixed quantity.
2. The hull friction resistance reduction device according to claim 1, wherein the inflow information acquisition means is an inflow detection means for detecting the inflow of the air bubbles into the propeller.
3. When the adjustment mechanism control unit acquires the air bubble inflow information from the inflow information acquisition unit, at least the air bubble ejection unit disposed in front of the propeller in the plurality of air bubble ejection units is the air bubble injection unit. The hull friction resistance reduction device according to claim 1 or 2, characterized in that ejection of air bubbles is stopped.
4. When the adjustment mechanism control unit acquires the air bubble inflow information from the inflow information acquisition unit, only the air bubble ejection unit in front of the propeller among the plurality of air bubble ejection units is the ejection amount of the air bubbles. The hull friction resistance reduction device according to any one of claims 1 to 3, wherein the reduction amount is smaller than the predetermined amount.
5. The inflow detection means is
   An imaging device for imaging the propeller;
   The control device is provided with a determination unit that determines whether the air bubble is flowing into the propeller based on the image information captured by the imaging device. The hull friction resistance reduction device according to claim 3 or 4 which cites 2 or claim 2.
6. 6. The hull friction resistance reduction device according to claim 5, wherein the imaging device is directly attached to the bottom of the boat in front of the propeller.
7. 6. The hull friction resistance reduction device according to claim 5, wherein the imaging device is disposed just beside the propeller.
8. The hull friction resistance reduction device according to any one of claims 5 to 7, wherein the imaging devices are arranged in a pair so as to sandwich the propellers from both sides in the width direction of the hull.
9. The inflow detection means is
   Vibration detection means for detecting a vibration or a parameter correlated with the vibration of the propeller;
   3. The apparatus according to claim 2, further comprising: a determination unit provided in the control device to determine whether the air bubble is flowing into the propeller based on the detection information of the vibration detection means. Or, the hull friction resistance reduction device according to claim 3 or 4 which refers claim 2.
10. A plurality of the vibration detection means are provided along the hull width direction;
    10. The hull friction resistance reduction device according to claim 9, wherein the determination unit makes the determination based on detection information of the plurality of vibration detection means.
11. Among the plurality of vibration detection means, when there is the vibration detection means determined by the determination unit that the air bubbles are flowing into the propeller based on the detection information, the adjustment mechanism control unit 11. The apparatus according to claim 10, characterized in that, for at least a bubble jetting unit in front of the vibration detecting means determined that the bubble is flowing, the amount of jetting of the bubble is reduced more than the predetermined amount. The hull friction resistance reduction device of description.
12. The ship body frictional resistance reduction device according to any one of claims 9 to 11, wherein the vibration detection means is a pressure sensor in which at least a detection end is exposed to the outside of the propeller above the propeller. .
13. The hull friction resistance reduction device according to any one of claims 9 to 11, wherein the vibration detection means is an acceleration sensor disposed in the ship above the propeller.
14. 14. The propeller according to claim 1, wherein the propeller is provided at the center in the width direction of the hull, and the air bubble jetting unit at the front of the front is disposed at the center in the width direction of the hull. The hull friction resistance reduction device according to Item.
15. A plurality of the propellers are arranged in parallel along the hull width direction, the air bubble ejection units are respectively disposed in front of the plurality of propellers, and the inflow information acquiring unit is provided in each of the plurality of propellers. The hull friction resistance reduction device according to any one of claims 1 to 13, characterized in that
16. A vessel comprising the hull friction resistance reduction device according to any one of claims 1 to 15.
    

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