JP2013216325A - Air bubble holding device of ship - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air bubble holding device of a ship in which air bubbles are held even at the inclination of the ship which occurs depending on a ship navigation status and a ship status when, for example, the ship turns, and at a disturbance such as waves and flows, and which avoids to be a resistance hindering the progress of the ship.SOLUTION: An air bubble holding device of a ship comprises: gas injection ports 21, 22, 23, 24, 25 for injecting air bubbles along a ship bottom 3 formed at the ship bottom 3 of the ship 1; blowers 10, 11, 12, 13, 14 for air-sending gases to the gas injection ports 21, 22, 23, 24, 25; an electric motor for driving the blowers 10, 11, 12, 13, 14; and an air liquid separator 200 for sucking the injected air bubbles to the rear of at least the air injection ports 21, 22, 23, 24, 25 of the ship bottom 3.

Description

  The present invention relates to a ship bubble holding device, and more particularly to a ship bubble holding device that holds bubbles blown into water at the bottom of a ship for the purpose of reducing the frictional resistance of the hull.

  As a study of ship drag reduction, many achievements have been obtained for wave resistance, but friction resistance, which is said to account for about 80% of the total resistance of large ships, is related to complex turbulence phenomena. Until now, no outstanding results have been obtained. During the navigation of the ship, a turbulent boundary layer develops along the surface of the hull below the waterline, so that frictional resistance acts on the hull surface and reduces the propulsion performance of the ship. As a means to reduce the frictional resistance of the hull surface, the bubble jet type, which is reduced by injecting fine bubbles into the boundary layer along the surface, has recently attracted attention and researched as a promising measure for reducing frictional resistance. Is coming. The bubble jet type has a remarkable frictional resistance reduction effect, is relatively resistant to contamination, and has no problem of environmental pollution to the ocean or water system. It is considered a measure.

  However, this bubble jet type requires power because it generates bubbles by overcoming the water pressure from the bottom of the ship or from the bottom of the ship, and increases the net reduction effect considering both the frictional resistance reduction effect and the bubble generation power. Such consideration was necessary. In addition, ships navigating oceans and rivers are subject to various disturbances such as waves and currents, and are also affected by the state of cargo and navigation, how to effectively reduce frictional resistance. It was said. The research so far has mainly been research at the laboratory level and using model ships, and these studies have not been rigorous, taking into account these actual disturbances and navigational conditions.

  The inventors of the present application used an actual ship for the current state of research, equipped with a gas jetting device on this hull, and in a situation close to the actual situation such as a ship situation, a sailing condition, a sea condition, By investigating the relationship between the frictional resistance reduction effect and seeking to increase the net reduction effect, we have gained a lot of knowledge. In addition, research is being conducted on members, devices, and the shape of the bottom of the ship so that the gas ejected from the gas ejection device does not diffuse in the sea and does not leave the bottom of the ship.

  On the other hand, in the field of patents, for example, the measures shown in Patent Documents 1, 2, 3, and 4 have been taken in order not to escape such bubbles ejected from the ship.

  This patent document 1 forms a seawater intake part in front of the hull, jet flow generating means for blowing seawater entering the seawater intake part at the time of navigation to the bottom of the ship and injecting air to the bottom of the ship. And a regulating member that regulates the seawater blown to the bottom of the ship by the jet generating means and the air jetted by the air jetting means so as not to escape to the side of the hull. is there.

  Since such a configuration is adopted, air is injected from the center of the hull, and the effect of reducing the frictional force is limited. In addition, the regulating member itself becomes a resistor that hinders the propulsive force of the ship, reducing the net frictional resistance reduction effect by air. In addition, it is difficult to amplify the frictional resistance reduction effect due to the influence of water entering between the bottom surface of the ship and the air jetted from the air jetting means.

  Patent Document 2 describes a ship having a structure in which air is sent to the bottom of the ship. As a structure in which the bottom of the ship is substantially planar with respect to the flow, a large number of grooves are formed on the bottom of the ship, and air is introduced into the groove. It is structured to isolate the ship bottom and water by putting air.

  Since this structure is adopted, air is laid on the bottom of the ship, and air is attached to the bottom of the ship, but there are no members to hold the air. It is inevitable that the water pressure will diffuse to the lower water pressure and the amount of air attached to the bottom of the ship will decrease, and the friction reduction effect will also decrease. Further, as described above, it is difficult to amplify the frictional resistance reduction effect due to the influence of water entering between the bottom surface of the ship and the air.

  Patent Document 3 discloses that when gas is ejected from a submerged surface and bubbles and a gas layer are interposed in a boundary layer in contact with the submerged surface to reduce the frictional resistance of the submerged surface, A jet outlet for jetting pressurized gas into the water is arranged, and the inner wall of the jet outlet and the submerged surface are gently placed at a position downstream of the jet outlet and inward of the outer edge of the jet outlet. A connected guide surface is formed.

  Since this structure is adopted, air is attached to the guide surface as described above, but there is no member to hold the air, and the air is moved to a lower water pressure by tilting the ship due to disturbances such as waves and flows. As a result, the amount of air accompanying the ship bottom decreases and the friction reduction effect also decreases. Further, as described above, it is difficult to amplify the frictional resistance reduction effect due to the influence of water entering between the bottom surface of the ship and the air.

  Further, Patent Document 4 uses an energy efficiency device to reduce water friction generated in the hull of a ship, and the contact between the outer surface of the ship's hull and the water that is normally engaged with water covers the outer surface. It is reduced by the advantageous introduction of pressurized or compressed air or gas.

  Because of this configuration, vents or nozzles must be placed to be trapped in the grooves or channels to prevent compressed air from escaping beyond the vessel's bow profile, such as waves and flows. It was difficult to maintain the air corresponding to the inclination of the ship at the time of disturbance, and the friction reduction effect was also reduced.

Japanese Patent Laid-Open No. 5-116672 JP-A-6-191396 JP-A-9-150785 Special table 2001-524421 gazette

  The present invention solves the above-described problems of the prior art, and bubbles are also retained in the navigational state of the ship and the state of the ship, for example, the inclination of the ship that occurs when the ship is disturbed by waves or flows or when turning. And it aims at providing the bubble holding | maintenance apparatus of a ship which avoids becoming a resistor which obstructs advancing of a ship.

In order to achieve such an object, a gas holding device for a ship according to the present invention includes a ship, a gas jet for ejecting bubbles along the bottom of the ship provided on the bottom of the ship, and a gas to the gas jet. A plurality of end plates arranged in a longitudinal direction of the bottom of the ship at least at a substantially end of the bottom of the ship after the gas ejection port. Each of the end plates may be substantially symmetrical with a flat cross section, and may have a streamline shape at least at the rear end thereof and a shape in which the rear flat cross section opens outward.

  Here, the air supply means can secure an air supply amount effective for generating bubbles, a compressor driven by a blower or a turbine, an air pressure supply source pre-installed in a ship, an engine exhaust gas pressurized, etc. In particular, it is preferable that the amount of air supply is small even when the discharge side pressure fluctuates.

  In addition to an electric motor, an engine driven by liquid fuel or gas fuel, a driving device is a turbine that obtains rotational force using exhaust from a ship engine, a hydraulic motor driven by hydraulic pressure or pneumatic pressure, It refers to pneumatic motors.

  The end plate refers to a plate-like material formed from iron, steel, metal materials including steel, wood including cedar and cypress, materials such as FRP, etc., which are hard and rusted by the influence of moisture and the like. Those that are less likely to induce aging are preferred. It is more preferable to paint the surface of the material for rust prevention. Further, the method for arranging the end plate includes a method for joining and arranging the joining member to the ship bottom by a joining method including a screw, a nail, and an adhesive. It is preferable to dispose them by fitting and / or meshing with each other, or by welding. At the time of disposition, the disposing strength may be improved by using the joining member in a reinforcing manner.

  According to the above configuration, when the gas is ejected from the gas ejection port by the air supply means driven by the driving device, the plurality of end plates are arranged in the stern direction with respect to the gas ejection port as a substantial end of the ship bottom. By being disposed in the longitudinal direction in the section, the ejected bubbles can flow while being held on the ship bottom in water.

  Further, in addition to the above-described configuration, this apparatus has a gas holding device for a ship in which a plurality of the end plates are symmetrically arranged in accordance with the planar shape of the bottom of the ship, and the length of the front end plate is set to the rear. You may comprise so that it may become shorter than the length of an end plate.

  According to the above configuration, a plurality of pairs of end plates are arranged substantially symmetrically in accordance with the planar shape of the ship, so that the end plates (aggregates thereof) become resistors that obstruct the progress of the ship. Can be substantially avoided.

  Also, at this time, the length of the front end plate can be made shorter than the length of the rear end plate. Since the shape is approximated, the effect of retaining bubbles can be further enhanced.

  Further, in addition to the above-described configuration, the device has a configuration in which the end plate has a shape defined by a shape using a curve including a substantially triangular shape or a quadratic function curve whose cross section is the bottom side of the ship bottom. May be.

Here, the approximate triangle is not limited to a right triangle, an isosceles triangle, and an equilateral triangle, but includes all triangles having a certain angle and side length. Further, the quadratic function curve is a quadratic curve related to the basic equation (y = αx ² + βx + γ) of the quadratic function, and includes all of the predetermined variables α, β, and γ. Moreover, you may comprise a substantially triangle combining arbitrary curves.

  According to the configuration as described above, the end plate has a shape related to a shape using a curve such as a substantially triangular shape or a quadratic function curve with the bottom side at the bottom in a cross-sectional view. Since the effect of the plate (aggregate) substantially avoiding the resistance that hinders the progress of the ship is further promoted, the ejected bubbles can flow while being held at the bottom of the ship in water.

  Further, in addition to the above configuration, the gas holding device for a ship according to the present invention may be configured such that the front end portion of the end plate has a streamlined shape.

  Here, the streamlined shape is a shape having a curve in order to minimize the resistance of water in the progression of the ship. For example, in order to avoid obstruction of the progression due to air resistance, at the head of an automobile, train, airplane, etc. Although the shape employ | adopted is included, it is not limited to these shapes.

  According to such a configuration, the end plate has a streamlined front end portion and / or rear end portion at the front and rear end portions thereof, thereby minimizing water resistance. Bubbles flow while being held at the bottom of the ship.

Further, a ship gas holding device according to the present invention includes a gas jet port for jetting bubbles along the bottom of the ship provided on the bottom of the ship, an air feeding means for feeding gas to the gas jet port, A driving device for driving the air means and a recess may be formed in the longitudinal direction at least on the bottom of the ship after the gas outlet.

  Here, the concave portion means a shape obtained by bending, forming, attaching or cutting a ship bottom itself of the ship into a shape related to the concave portion. The shape member related to the recess on the bottom of the ship may be disposed on the bottom of the ship by welding, including a screw, a nail, and an adhesive, or by welding, in the same manner as the end plate is disposed.

  According to the above configuration, when the gas is ejected from the gas ejection port by the air supply means driven by the driving device, the concave portion is formed in the longitudinal direction in the ship bottom in the stern direction with respect to the gas ejection port. As a result, the bubbles in the water related to the jetted air are retained and flowed until reaching the end of the recess on the bottom of the ship, thereby further promoting the effect of flowing.

  Further, a ship gas holding device according to the present invention includes a gas jet port for jetting bubbles along the bottom of the ship provided on the bottom of the ship, an air feeding means for feeding gas to the gas jet port, And a driving device that drives the air means, and is configured to form at least a concave-convex cross section having a cross-sectional width of one or more bases relative to a height in a longitudinal direction of the ship bottom after the gas ejection port. May be.

  Here, the concavo-convex cross section refers to a shape in which straight lines or curved lines bent at an arbitrary angle in a cross-sectional view are connected, and the number of concave portions and convex portions, the total area, and the gradient between the concave portions and the convex portions are not limited.

  According to the above configuration, when the gas is ejected from the gas ejection port by the air supply means driven by the driving device, the longitudinal direction is opposite to the traveling direction of the ship with respect to the gas ejection port. Since the cross-sectional width of the bottom is 1 or more with respect to the height, a bubble in the water related to the ejected air is attached to the concave portion due to its resistance, and at the end of the concave-convex cross section on the bottom of the ship. It is possible to flow while being held.

  Further, in addition to the above-described configuration, the ship gas holding device according to the present invention is configured such that the concavo-convex cross-section has a shape in which a substantially triangular shape is connected horizontally, and the height of the substantially triangular shape is a height sufficiently covered with bubbles (for example, 10 mm or less). ) You may comprise so that it may be formed below.

  Here, the substantially triangular shape is not limited to a right-angled triangle, an isosceles triangle, and an equilateral triangle, but includes all triangles having a predetermined angle and side length. Moreover, you may form a substantially triangular shape using arbitrary curves.

  According to the above configuration, the concavo-convex cross-section has a shape in which a substantially triangular shape is continuous side by side, and the height of the substantially triangular shape is less than or equal to a height sufficiently covered with the bubble, so that the bubble is actually caused by the resistance. Attached to the concave portion related to the substantially triangular shape, bubbles can be held and flow until reaching the end of the concave-convex cross section of the ship bottom.

  Further, the ship gas holding device of the present invention comprises a gas jet port for jetting bubbles along the ship bottom provided on the ship bottom, an air feed means for feeding gas to the gas jet port, A driving device for driving the air means, and at least a plurality of end plates provided at substantially end portions of the ship bottom after the gas ejection port, the end plates being adapted to serve as a stabilizing means for the ship. May be configured as a feature.

Here, ship stabilization means include bilge keels, fin stabilizers, anti-rolling tanks, etc., natural phenomena including large waves, side waves, cross winds, storms, gusts, typhoons, storms and thunderstorms during navigation, other ships, drift ice The concept includes a device, a machine, and an instrument for suppressing the rolling and rollover of the ship against a collision object including driftwood and fish, which are attached to the hull and bottom of the ship and a predetermined algorithm. The thing which concerns on the automatic control which has is included.

  By being configured as described above, when the gas is ejected from the gas ejection port by the air feeding means driven by the driving device, the gas jetting port is used as a reference in a direction opposite to the traveling direction of the ship. Since the plurality of end plates provided at the end also serve as a means for stabilizing the ship, the effect of suppressing the rolling and rollover of the ship due to natural phenomena and collision objects is more effective. It is possible to flow while being held until the end of the.

  Further, in addition to the above-described configuration, the ship gas holding device may be configured by changing the performance of the stabilizing means for the contribution to the stabilizing function of the end plate.

  By being configured as described above, it is not necessary to separately provide stabilizing means, or the performance, function, and equipment of the stabilizing means can be minimized, so that the economic efficiency of the ship can be promoted. .

  Further, in addition to the above-described configuration, the ship gas holding device may be configured such that the stabilizing means also serving as the end plate is a bilge keel, and the end plate height is set smaller than the bilge keel height.

Here, bilge keels are generally thin plates that extend in the longitudinal direction from the bow to the bottom of the ship's bottom or to the joint between the ship's side and the bottom of the ship. Indicates the part that is being used.

  By being comprised as mentioned above, it becomes possible to control the equipment of a bilge keel, and since the height of an end plate is smaller than a bilge keel height, the resistance of the tidal current concerning a ship can be reduced.

  Further, the ship gas holding device of the present invention comprises a gas jet port for jetting bubbles along the ship bottom provided on the ship bottom, an air feed means for feeding gas to the gas jet port, And a driving device for driving the air means, and a step for attracting the bubbles ejected to the rear of the gas outlet at the bottom of the ship may be provided.

Here, the level difference means a structure in which a wing-like raised portion provided in a place where bubbles are separated and diffused from the bottom of the gas outlet and the bottom of the stern is formed in a stepped shape. It has the effect of attracting diffused bubbles to the bottom of the ship again due to the target action.

  According to the above configuration, the bubbles ejected from the gas ejection port by the air feeding means driven by the driving device are attached to the surface of the ship bottom by the fluid action related to the level difference and reach the end of the level difference on the level of the ship bottom. It is possible to flow until it is held.

  According to a first aspect of the present invention, there is provided a gas holding device for a ship, which includes a gas outlet that jets bubbles along the bottom of the ship and a gas that sends gas to the gas outlet. An air means, a driving device for driving the air supply means, and a bubble suction means for sucking the bubbles ejected at least behind the gas outlet on the bottom of the ship are provided.

  Here, the bubble suction means is a concept that means a device, a machine, or an instrument having a function of sucking bubbles present in water. For example, using a blower, a pump, an air compressor, etc. Also included is a structure for sucking.

  According to the above configuration, the air blowing means driven by the driving device makes it possible to suck the bubbles blown from the gas outlet through the bubble sucking means where the bubbles are separated from the ship bottom and start to diffuse. Can be avoided.

  Further, in addition to the above configuration, the gas holding device of the ship may be configured such that the bubbles sucked by the bubble sucking means are again ejected from the ship bottom.

According to the above configuration, it is possible that the bubbles in the bubble suction section where begin to diffuse away from the ship's bottom is written Sucking, by re-discharge the sucked air bubbles, more effectively friction throughout the hull Resistance can be reduced.

  According to the above configuration, when the gas is ejected from the gas ejection port, the plurality of end plates are arranged in the stern direction in the longitudinal direction at the stern direction with respect to the gas ejection port. The generated bubbles can flow along the bottom of the ship in the water, and the frictional resistance can be effectively reduced. In addition, the action of the end plate can prevent the bubbles from diffusing toward the lower water pressure even when the ship is inclined due to disturbances such as waves and flows, and the frictional resistance can be stably reduced.

  Further, according to the above configuration, since a plurality of end plates are arranged substantially symmetrically in accordance with the planar shape of the ship bottom, the end plates (aggregates thereof) serve as resistors that prevent the vessel from proceeding. This can be substantially avoided. In addition, it is possible to dispose the gas outlet to the forefront near the bow in accordance with the planar shape of the front part of the ship bottom, and the frictional resistance can be reduced over the entire ship bottom.

  Moreover, according to the said structure, since this end plate (the aggregate | assembly) is approximated to the planar shape of a ship bottom, it becomes possible to further improve the bubble holding effect.

  In addition, according to the above configuration, the end plate is defined as a shape using a curve such as a substantially triangular shape or a quadratic function curve with the bottom side at the bottom in a cross-sectional view. Compared with the case where it contacted, the contact area with water can be reduced and the frictional resistance by installing an end plate can be reduced. As a result, the effect of the end plate (aggregate) substantially avoiding the resistance that hinders the progress of the ship is further promoted, and the bubbles in the water related to the ejected air are effectively held along the ship bottom. Flowing.

  Further, according to the above configuration, since the front end and / or the rear end of the end plate has a streamlined shape at the front and rear end portions thereof, the resistance of water is minimized, so that the friction resistance by installing the end plate is reduced. Can be further reduced, and bubbles in the water related to the ejected air are effectively held along the ship bottom and flow.

  In addition, according to the above configuration, since the concave portion is formed in the ship bottom in the longitudinal direction in the stern direction with respect to the gas outlet, the bubbles in the water related to the jetted air are The effect of being held and flowed effectively along the bottom of the ship is further promoted until the end of the ship. Moreover, even if a ship inclines by disturbances, such as a wave and a flow, by the effect | action of a recessed part, it can prevent that a bubble is spread | diffused to the direction where water pressure is low, and can aim at reduction of frictional resistance stably.

  In addition, according to the above configuration, since the cross-sectional width of the base of the base is 1 or more with respect to the height in the longitudinal direction with reference to the gas outlet, bubbles in the water related to the ejected air are The resistance accompanies the concave portion and can flow while being held up to the end of the concave-convex cross section of the ship bottom.

  In addition, according to the above configuration, the concave and convex cross section has a shape in which a substantially triangular shape is connected sideways, and the height of the substantially triangular shape is less than or equal to a height that is sufficiently covered by the bubbles, so that the bubbles actually have the differential pressure. Accordingly, the bubbles can be retained and flow until they reach the end of the concavo-convex cross section of the ship bottom, accompanying the concave portion related to the substantially triangular shape. Moreover, since the substantially triangular shape is connected horizontally, there are a large number of substantially triangular vertices, which can be easily placed on the pedestal when entering the dock, and the work can be improved.

  In addition, according to the above configuration, since the plurality of end plates provided at the substantially end portion of the ship bottom also serve as a ship stabilization means in the stern direction with respect to the gas jet outlet, The effect of suppressing roll and rollover is further exerted, and the ejected bubbles can be held and flow in water until reaching the end of the ship bottom. In addition, due to the action of multiple end plates that also serve as stabilization means, even if there is a disturbance such as a wave or flow, the ship is difficult to tilt, and even if it is slightly tilted, the bubbles diffuse to the lower water pressure due to the action of the end plates. Therefore, the frictional resistance can be stably reduced.

  Moreover, according to the said structure, since there is no need to provide a stabilization means separately or the performance, function, and equipment of a stabilization means can be minimized, the economic efficiency improvement of a ship can be promoted.

  Moreover, according to the said structure, it becomes possible to control the installation of a bilge keel, and since the height of an end plate is smaller than a bilge keel height, the resistance of the tidal current concerning a ship can be reduced.

  Further, according to the above configuration, the air bubbles that are ejected from the gas ejection port by the air supply means driven by the driving device are attached to the surface of the ship bottom due to the fluid action of the step that attracts the air bubbles, and the entire ship bottom is covered. It becomes possible to flow while being held, and the effect of reducing frictional resistance can be increased.

  Further, according to the above configuration, the bubbles ejected from the gas outlet can be sucked by the bubble sucking means where the bubbles leave and diffuse from the ship bottom, and the diffusion of the bubbles in water can be avoided. Become.

  In addition, according to the present invention, bubbles are sucked in by the bubble sucking means, and bubbles can be sucked in by the bubble sucking means when they are separated from the ship bottom and diffused, and the sucked bubbles are re-discharged. In addition, the frictional resistance can be reduced more effectively over the entire hull.

(a) A side view of a ship to which the bubble holding device for a ship in one embodiment of the present invention is applied, (b) a top view of the ship, (c) a bottom view of the ship XX sectional view (of FIG. 1) of a hull 4 according to an embodiment of the present invention. XX sectional view (of FIG. 1) of a hull 4 according to another embodiment of the present invention. XX sectional drawing (of FIG. 1) of the hull 4 which concerns on another one Embodiment of this invention. The enlarged view of the dotted-line Y part of FIG. 2 which concerns on another one Embodiment of this invention. XX sectional drawing (of FIG. 1) of the hull 4 which concerns on another one Embodiment of this invention. XX sectional drawing (of FIG. 1) of the hull 4 which concerns on another one Embodiment of this invention. The conceptual diagram which shows the bubble holding | maintenance state at the time of arrangement | positioning of the end plates 5 and 5 'which concern on one Embodiment of this invention. The conceptual diagram which shows the bubble flow state during the ship navigation at the time of arrangement | positioning which concerns on the end plates 5 and 5 'which make the front part and rear part which concern on one Embodiment of this invention into a streamline type The cross-sectional conceptual diagram which shows the bubble holding | maintenance state which concerns on another one Embodiment of this invention, and the ship bottom 3 is made into the uneven | corrugated shape which concerns on a triangle by sectional view. The cross-sectional conceptual diagram which shows the bubble holding | maintenance state which concerns on another one Embodiment of this invention during the ship navigation of the ship made into the structure which has a wing | blade cross-section type mound by cross-sectional view in the ship bottom 3. The cross-sectional conceptual diagram which shows the bubble holding | maintenance state which concerns on another one Embodiment of this invention, and has the structure which has the gentle level | step difference toward the rear part in the ship bottom 3 by sectional view. Sectional drawing for demonstrating the structure of the gas-liquid separator 200 in the bubble holding | maintenance apparatus which concerns on the 2nd Embodiment of this invention. The conceptual diagram which shows the usage method of the gas-liquid separator 200 in the bubble holding | maintenance apparatus which concerns on the 2nd Embodiment of this invention. The conceptual diagram which shows the usage method of the gas-liquid separator 200 in the bubble holding | maintenance apparatus which concerns on the 2nd Embodiment of this invention. The situation figure which concerns on use of the gas-liquid separator 200 in the bubble holding | maintenance apparatus which concerns on the 2nd Embodiment of this invention.

  The best mode for carrying out the present invention will be described below with reference to the drawings. In the following, the range necessary for the description for achieving the object of the present invention is schematically shown, and the range necessary for the description of the relevant part of the present invention will be mainly described. Are according to known techniques.

(First embodiment)
FIG. 1 shows an example in which a bubble holding device according to an embodiment of the present invention is applied to a ship used in the ocean. 1 (a) shows a side view of the ship, FIG. 1 (b) shows a top view thereof, and FIG. 1 (c) shows a bottom view. Let me express.

  On the deck 2 of the ship 1, blowers 10, 11, 12, 13, and 14 as air supply means are installed side by side. These blowers 10, 11, 12, 13, 14 are installed on the deck 2 in a hangar in order to avoid splashing tides crushed at the bow. Is taken from the opposite side of the direction of travel of the hull.

  These blowers 10, 11, 12, 13, and 14 are Roots type positive displacement blowers, and two rotors inside the blower are rotated via a belt by an inverter type electric motor 60 (not shown) as a driving device. The air taken in between the blower inner wall and the rotor is compressed and supplied as the rotor rotates (not shown). Since the blowers 10, 11, 12, 13, and 14 are of the positive displacement type, they can supply a fixed amount of air stably even if there is a pressure fluctuation. In addition, unlike the piston type, this Roots type blower has almost no pulsation because air is pressurized almost continuously unlike the piston type, and it is possible to eliminate tanks for pressure smoothing. is there. Furthermore, since the rotation is smooth and there is little vibration and noise, even if the blowers 10, 11, 12, 13, and 14 are arranged on the deck 2, resonance sound is hardly generated in the lower cabin.

  Air taken into the blowers 10, 11, 12, 13, and 14 is pressurized, passes through the air supply pipes 16, 17, 18, 19, and 20 having bent portions, and is installed near the ship bottom 3 It is guided to the ejection ports 21, 22, 23, 24, 25. In this embodiment, the gas outlets 21, 22, 23, 24, and 25 are arranged in a substantially line in a substantially plane with respect to the plane center line CL of the hull 4 on the front plane of the ship bottom 3. . The provision of the gas ejection ports 21, 22, 23, 24, 25 on the bottom 3 is for the purpose of prolonging the stay of the ejected bubbles on the bottom 3 and mitigating pressure fluctuations caused by waves or the like. Is provided for the purpose of allowing the ejected bubbles to stay on the bottom 3 as much as possible.

  In addition, the arrangement of the gas outlets 21, 22, 23, 24, 25 in approximately one line simplifies the configuration, and the blowers 10, 11, 12, 13, 14 and the air supply pipes 16, 17, provided correspondingly are arranged. This is for facilitating the arrangement of 18, 19, 20 and the like. In this example, the air outlets 21, 22, 23, 24, and 25 are an odd number of five, so the middle one (the air outlet 23) is brought on the plane center line CL. Thus, it is possible to realize one-point ejection of bubbles while the ship 1 has the straight traveling property. In this case, the air outlets 21, 22, 23, 24, and 25 are configured to be arranged so as to be substantially symmetrical with respect to the plane center line CL of the hull 4 and along the front plane shape of the ship bottom 3. It is possible.

  The ship bottom 3 has end plates 5, 5 ′, 6, 6 ′, 7, 7 ′ for guiding the air bubbles so as not to escape the air bubbles ejected from the air outlets 21, 22, 23, 24, 25. Are arranged symmetrically with respect to the plane center line CL of the hull 4. The end plates 6, 6 'and 7, 7' are drawn with substantially the same dimensions in the figure, but the end plates 7, 7 'may be shorter than the end plates 6, 6'. The numbers are not limited to those shown in FIG. In addition, the ship bottom 3 is provided with shear force sensors 50, 51, 52, 53, 54 on the stern side, which are shear force detectors for detecting the shear force acting on the hull 4 due to seawater or bubbles.

  In addition, relative speed sensors 55 and 56, which are relative speed detectors, are provided on the stern side. Another relative speed sensor 57 is provided on the ship side 8. These relative velocity sensors 55 and 56 are provided away from the air jets 21, 22, 23, 24, and 25, or the relative velocity sensor 57 is provided at a location where there is no influence of air bubbles on the ship side 8 even when close. . In particular, the relative speed sensor 57 is installed below the ship side 8 so as not to be affected by waves. These relative velocity sensors 55, 56, and 57 employ an ultrasonic method, can be used in water, and are less affected by waves and tides.

  Video cameras 58 and 59 for monitoring the state of the jetted bubbles are provided at the rear and front of the ship bottom 3. The images taken by the video cameras 58 and 59 are monitored by a person and used to analyze the bubble ejection state.

  FIG. 2 is a cross-sectional view taken along the line XX (of FIG. 1) of the hull 4 according to one embodiment of the present invention. As shown in the figure, end plates 5, 5 'and bilge keels 101, 101' are provided. In this way, for example, a bilge keel is usually provided at the joint (bilge part) between the ship bottom 3 and the ship side 8 in order to stabilize the ship on the ship. Thereby, the ship can suppress rolling and rollover against natural phenomena such as waves and tidal currents and collision objects. Further, the end plates 5 and 5 'according to the present invention can be disposed separately from the bilge keels 101 and 101'. The arrangement position is preferably on the inner side with respect to the plane center line CL rather than the bilge keels 101, 101 ′.

  On the other hand, the end plates 5, 5 ′ can also be used to stabilize the ship. In this case, the performance relating to the stabilization of the bilge keels 101 and 101 ′ can be changed by the amount of the end plates 5 and 5 ′ responsible for the stabilization function. In that case, it is preferable to design in consideration of the structure, dimensions and arrangement positions of the end plates 5 and 5 'and the bilge keels 101 and 101' so as not to hinder the ship's ship. In addition, since the original purpose concerning the end plates 5 and 5 'is to flow while holding the bubbles on the ship bottom 3, the design of the end plates 5 and 5' and the bilge keels 101 and 101 'with sufficient consideration thereof. And

  FIG. 3 is a cross-sectional view taken along the line XX (of FIG. 1) of the hull 4 according to another embodiment of the present invention. The figure shows an aspect in which the cross-sectional shape of the end plate is configured as a substantially triangular shape. As shown in the figure, the end plates 5a, 5'a have a shape that is a substantially triangular shape with the bottom 3 as a base. Since the end plates 5 and 5 'according to FIG. 2 are different from each other only in the shape, the other detailed description is omitted.

  Here, when the cross-sectional shape of the substantially triangular shape is compared with the contact area with water in the case where the flat end plate 5 or 5 ′ is used, the sum of the two sides of the triangle is longer than one side. By doing so, the contact area with water becomes small, and the frictional resistance by installing the end plate can be reduced. The increase in the frictional resistance of the end plate can be reduced by the end plates 5a and 5'a having a substantially triangular shape.

  FIG. 4 is a cross-sectional view taken along the line XX (of FIG. 1) of the hull 4 according to still another embodiment of the present invention. The figure shows a mode in which the cross-sectional shape of the end plate is a curve such as a quadratic function curve. As shown in the figure, the end plates 5b and 5'b have a shape that is a curve such as a quadratic function curve with the bottom 3 as a base. Since the end plates 5 and 5 'according to FIG. 2 are different from each other only in the shape, the other detailed description is omitted. With the end plates 5a and 5'a having a shape such as a quadratic function curve, an increase in frictional resistance of the end plates can be reduced.

  FIG. 5 is an enlarged view of a dotted line Y portion of FIG. 2 according to still another embodiment of the present invention. The figure shows a mode in which the front part of the end plate is streamlined. As shown in the figure, the end plate 5 preferably has a streamlined shape with respect to the plane center line CL as a reference, and needs to be designed in consideration of not hindering the ship's navigation. Specifically, the tip of the end plate 5 preferably has a shape similar to the shape that the sword has in order to slightly change the angle of the surface like the tip of the sword and make it easier to cut an object. When the end plate 5 is already provided on the ship bottom 3, a streamlined member may be attached to the end plate 5. Also, the rear part of the end plate is preferably streamlined (not shown).

  FIG. 6 is a cross-sectional view taken along the line XX (of FIG. 1) of the hull 4 according to still another embodiment of the present invention. In the figure, a mode in which a concave portion is formed in the ship bottom 3 is shown. As shown in FIG. 2, instead of the end plates 5 and 5 ′ shown in FIG. 2, the end portions 5c and 5′c are left, and other portions are cut, or the end portions 5c and 5′c are provided. A configuration in which the shape member related to the recess is disposed, a configuration in which the end portions 5c and 5'c are attached to the existing ship bottom 3, or a configuration in which the ship bottom 3 itself has a recess. The front portions of the end portions 5c and 5'c may be streamlined as shown in FIG. Note that the end portions 5 and 5 'according to FIG. 2 are different only in that their shapes are different, and thus other detailed descriptions are omitted. Due to the end portions 5c and 5'c and the concave portion sandwiched between the end portions, it becomes possible to flow the air bubbles while holding them on the ship bottom.

  FIG. 7 is a cross-sectional view taken along the line XX (of FIG. 1) of the hull 4 according to still another embodiment of the present invention. In the figure, a mode in which a concave portion is formed in the ship bottom 3 is shown. As shown in the figure, instead of the end plates 5 and 5 'shown in FIG. 2, the end portions 5d and 5'd are left, and other portions are cut, or the end portions 5d and 5'd are provided. The shape member related to the concave portion is disposed or the end portions 5d and 5'd are attached to the existing ship bottom 3. The shapes of the end portions 5c and 5c ′ according to FIG. The front portions of the end portions 5d and 5'd may be streamlined as shown in FIG. Note that the end portions 5 and 5 'according to FIG. 2 are different only in that their shapes are different, and thus other detailed descriptions are omitted. Due to the end portions 5d and 5'd and the concave portion sandwiched between the end portions, it becomes possible to flow the air bubbles while holding them on the ship bottom.

  Next, operation | movement and the usage method of the bubble holding | maintenance apparatus which concern on one Embodiment of this invention are demonstrated using a conceptual diagram.

  FIG. 8 is a conceptual diagram showing a bubble holding state when the end plates 5 and 5 ′ according to the embodiment of the present invention are arranged. In the same figure, the holding | maintenance state of the bubble when a ship inclines is demonstrated. In this case, in the XX cross section of FIG. 1, a differential pressure is generated at both ends of the bottom 3 due to the inclination of the ship, and the bubbles move toward the lower pressure. As a result, the bubbles diffuse out of the range of the ship bottom 3, and the friction reducing effect by the bubbles is reduced. On the other hand, in the present application, by disposing the end plates 5 and 5 ′ at both ends of the ship bottom 3, the bubble diffusion is suppressed. Specifically, the bubbles move from the higher pressure to the lower pressure, and cannot move from the lower pressure to the higher pressure. Therefore, in order for the bubbles to move to the lower pressure side, it is necessary to bypass the barrier on the end plate 5, and for that purpose, it is necessary to move to the higher pressure side. Is held on the bottom 3 of the ship. The same applies when the slope is reversed. Even if there is no tilt as much as the figure, the bubbles sense a minute differential pressure due to subtle rolls while navigating, and the bubbles move to the lower pressure in the same way. The diffusion due to the movement of the bubbles is suppressed by 5 and flows while being held up to the end point of the end plate 5. As a result, the bubbles are retained even in the case of disturbance such as waves and flows or when the ship is tilted, and the frictional resistance can be effectively reduced.

  FIG. 9 is a conceptual diagram showing a bubble flow state during marine vessel navigation at the time of disposition related to the end plates 5 and 5 ′ having streamlined front and rear portions according to one embodiment of the present invention. In the figure, it is as much as possible that the end plates 5 and 5 'become resistors that prevent the ship from navigating by making the front portions of the end plates 5 and 5' symmetrical with respect to the center line. Can be avoided. Further, the rear part of the end plates 5 and 5 ′ has a streamline shape that has a gentle curve or inclination from the rear part of the deeper water depth with respect to the center line and terminates the rear part of the shallower water depth, The air bubbles are not suddenly released from the end point at the rear part of the end plates 5 and 5 ', but are released from the end of the end plates 5 and 5' at the start point of the gentle curve or inclination according to the rear part. Since the dimensions are reduced and the shape of the bubbles is gradually released by this shape, the bubbles gradually diffuse into the water. In addition, by forming the rear part to open, the air bubbles that have sufficiently flown over the bottom of the ship become a flow toward the outside, eliminating the entrainment of air bubbles in the propeller (not shown) provided at the stern, and the propulsive force Can be prevented from falling.

  FIG. 10 is a conceptual cross-sectional view showing a bubble holding state during the navigation of a ship according to still another embodiment of the present invention. In the same figure, when the cross-section of the ship bottom 3 is a concavo-convex shape related to a triangle, the bubbles are formed with a gradient in the first triangular shape and the second triangular shape, which are adjacent to the bottom 3 of the concavo-convex cross section, Due to the differential pressure generated at such a gradient, the bubbles move to a lower pressure. In addition, since the air bubbles trapped in one triangular cross section have resistance to get over the apex of the triangle, they flow toward the stern along the longitudinal direction with less resistance. Accordingly, the movement and diffusion of the bubbles are suppressed and the bubbles are held on the bottom 3 even by the differential pressure generated by the inclination of the hull generated during the navigation of the ship or the slight differential pressure caused by the slight roll. While flowing. The height of the triangle with the bottom 3 as the base is preferably 10 mm or less based on the bottom 3, but the basis of this concept is that the height of the triangle is less than the height that is sufficiently covered with bubbles. It is to be done. That is, the height dimension of the triangle with the bottom 3 as the base is not limited to 10 mm or less with respect to the bottom 3 as long as it is sufficiently high to be covered with bubbles.

  FIG. 11 is a conceptual cross-sectional view showing a bubble holding state during the navigation of a ship having a structure in which the ship bottom 3 has a wing cross-sectional mound in a cross-sectional view according to still another embodiment of the present invention. In the figure, water flows in the direction opposite to the traveling direction of the ship, but bubbles also flow in the direction of the water flow. On the other hand, as the bubbles flow downstream, the bubbles diffuse in water, so that the friction reducing effect by the bubbles is reduced. However, by disposing the wing cross-section mound 102 on the ship bottom 3, it is possible to increase the friction reduction effect by causing bubbles to accompany the ship bottom 3 again. Specifically, the bubbles flow according to the shape of the blade cross-section mound 102. In order for bubbles to flow according to the shape of the blade cross-section mound 102, the surface shape of the blade cross-section mound 102 needs to be a shape having a gentle curve in a cross-sectional view. This is because when the starting end portion of the blade cross-section mound 102 has a non-gradual angle, the surface of the blade cross-section mound 102 becomes a barrier and bubbles may diffuse at the time of collision. In addition, when the terminal portion of the wing cross-section mound 102 has a non-gradual angle, the bubbles suddenly move to the low pressure portion related to the bottom 3 due to the differential pressure generated by the gradient between the end portion and the bottom 3. This is because a portion where no bubbles are attached to the bottom 3 is formed due to the shape. Therefore, by utilizing the differential pressure generated in the blade cross-section mound 102 having such a shape, it is possible to suppress the diffusion of bubbles and achieve the enhancement of the friction reduction effect.

  FIG. 12 is a conceptual cross-sectional view showing a state of holding bubbles during ship navigation, in which the ship bottom 3 is configured to have a gradual step toward the rear in a cross-sectional view, according to another embodiment of the present invention. . In the same figure, as described above, water flows in the direction opposite to the traveling direction of the ship, but bubbles also flow in the direction of the water flow. On the other hand, as the bubbles flow downstream, the bubbles diffuse in water, so that the friction reducing effect by the bubbles is reduced. However, since the ship bottom 3 has a gradual step toward the rear in a cross-sectional view, bubbles can be attached to the ship bottom 3 again to increase the friction reduction effect. Specifically, by the hydrodynamic action due to the shape of the first step and the second step, the bubble diffusion can be suppressed and the friction reducing effect can be maintained. As described above, the end portion of the step needs to have a gently curved shape. If it is not such a shape, the bubble will suddenly move to the low pressure part related to the ship bottom 3 due to the differential pressure generated by the gradient between the terminal end part related to the first step and the start part related to the second step, This is because there is a portion where no bubbles are attached to the bottom 3.

(Second Embodiment)
FIG. 13A is a cross-sectional view for explaining the configuration of the gas-liquid separator 200 in the bubble holding device according to the second embodiment of the present invention. As shown in the figure, the gas-liquid separator 200 includes a main body 201, a bubble separation promoting filter 202, a gas transfer rod 203, a gas release port 204, a liquid transfer unit 205, and valves 206a, 206b and 206c. The The gas-liquid separator 200 applies the principle of the water replacement method. FIGS. 13B and 13C are conceptual diagrams showing a method of using the gas-liquid separator 200 in the bubble holding device according to the second embodiment of the present invention.

  The main body 201 has a moisture inlet B and is always open. In addition, the main body 201 has a function of separating the liquid and the gas through the bubble separation promoting filter 202 therein. The bubble separation promoting filter 202 has a conical shape surrounding a hollow cylinder having a moisture suction port, and the filter is formed in a conical shape. The gas transfer rod 203 has a configuration in which one opening is disposed inside the main body 201 and the other opening is disposed outside the main body 201. The blower 208 has a function of sucking air from the outside opening through the valve 206a. The blower 208 is preferably configured to send air even when water is mixed. A gas release port 204 is provided in the upper part of the main body 201 so that unnecessary gas can be released to the atmosphere via the valve 206b. On the other hand, a liquid transfer unit 205 is provided inside the main body 201 with the bubble separation promotion filter 202 as a boundary, and water can be absorbed by the pump 207 via the valve 206c.

  Next, FIG. 14 is a situation diagram related to the use of the gas-liquid separator 200 in the bubble holding device according to the second embodiment of the present invention. (A) in the figure (hereinafter also referred to as “(a)”) indicates the friction reduction effect when air is fed by the blowers 10, 11, 12, 13, and 14 according to one embodiment of the present invention. FIG. In the figure, the horizontal axis indicates the distance, the vertical axis indicates the friction reduction effect in a numerical value between 0.0 and 1.0, 1.0 is the maximum value of the friction force, and 0.0 is the friction force. The minimum value (no friction) is shown. Further, (b) (hereinafter, also referred to as “(b)”) in the figure is the water in the air after being fed by the blowers 10, 11, 12, 13, 14 according to the embodiment of the present invention. It is a figure which shows a bubble diffusion state. In this figure, the water flow is from left to right in the drawing. Since (a) and (b) are in a correspondence relationship, the following description will be made using both figures and FIG. 13A as needed.

  First, as shown in (b), the air ejected through the air ejection port 20 drifts in the vicinity of the ship bottom 3. Therefore, in (a), it can be confirmed that there is almost no friction due to the friction reducing effect. However, in (b), once the bubbles are ejected, they move along the water flow, so that the bubbles diffuse in the water and leave the vicinity of the ship bottom 3. Therefore, in (a), the friction reduction effect decreases rapidly (the friction force increases rapidly), and then the friction force increases at a constant rate (a state in which the numerical value approaches 0.0 to 1.0). This is also considered to be a phenomenon that occurs because moisture enters between the bubbles and the ship bottom 3. Therefore, in (b), before the bubbles are diffused to the ship bottom 3 in the stern direction (downstream direction of the water flow) with respect to the air outlet 20 (when the bubbles are separated from the ship bottom 3 by about 5 to 7 mm), A moisture suction port B that sucks intruded moisture is provided, and a little moisture is sucked through the moisture suction port B by the gas-liquid separator 200 shown in FIG. As a result, the air bubbles are attracted again to the vicinity of the ship bottom 3, and in (a), the frictional force is rapidly reduced immediately after moisture suction, and the friction reduction effect is restored. After the suction, the bubbles again diffuse in the water, so that the frictional force gradually increases.

  Hereinafter, the operation and usage of the gas-liquid separator 200 according to the bubble holding device according to the embodiment of the present invention will be described with reference to FIGS. 13A, 13B, and 13C. Note that the gas-liquid separator 200 according to FIG. 13A is a cross-sectional view of the gas-liquid separator according to FIGS. 13B and 13C as viewed from the back side. Therefore, the left and right are reversed in FIGS. 13B and 13C and FIG. 13A.

  As shown in FIG. 13A, the moisture inlet B is always open. Therefore, the moisture is immersed in the main body 201 of the gas-liquid separator 200 through the moisture inlet B. At this time, the water in the main body 201 can be recovered by the water absorption of the pump 207. When collecting, the bubble separation promoting filter 202 separates the gas and the liquid contained in the water, so that only the liquid can be collected via the liquid transfer unit 205. The recovered water can be used as cooling water for the ship engine. In addition, the presence or absence of water absorption can also be operated by opening and closing the valve 206c, and the pump 207 may be always driven. On the other hand, the gas separated by the bubble separation promoting filter 202 can be recovered by the intake air of the blower 208 via the gas transfer rod 203. Note that the presence or absence of intake air can be controlled by opening and closing the valve 206a, and the blower 208 may be constantly driven.

  Therefore, as shown in FIG. 13B, the gas-liquid separator 200 releases the gas to the bottom of the ship by opening the gas sucked by the blower 208 to the atmosphere and opening the gas in the main body 201 to the atmosphere via the valve 206b. 3 can be attracted again. Further, as shown in FIG. 13C, the gas sucked by the blower 208 is re-injected through the recovery air outlet C, whereby the friction reduction effect can be amplified.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

  Further, the above-described examples are merely examples of embodiments for embodying the technical idea according to the present invention, and the technical ideas according to the present invention can be applied to other embodiments. Is possible.

  The ship frictional resistance reducing device according to the present invention is not limited to use in the ocean, but can be used in ships used in all water systems such as rivers and lakes.

  In addition, it can be widely applied to navigating bodies and floating bodies in water systems that do not take the shape of a ship, and contributes to energy saving effects by reducing frictional resistance, and is also widely used in general society and various industries in terms of convenience such as use of recovered water It brings great benefits to the whole.

DESCRIPTION OF SYMBOLS 1 ... Ship, 3 ... Ship bottom 10, 11, 12, 13, 14 ... Blower (air supply means), 21, 22, 23, 24, 25 ... Air outlet, 60 ... Electric motor (drive device), 200, 201 DESCRIPTION OF SYMBOLS ... Gas-liquid separator, 202 ... Bubble separation promotion filter, 203 ... Gas transfer tank, 204 ... Gas release port, 205 ... Liquid transfer part, 206 ... Valve (gas control means), B ... Moisture intake port, C ... Collected air Spout

Claims (5)

A gas outlet for ejecting bubbles along the bottom of the ship provided at the bottom of the ship; an air supply means for supplying gas to the gas outlet; a drive device for driving the air supply means; and at least one of the ship bottoms A bubble holding device for a ship, comprising bubble suction means for sucking the bubbles ejected to the rear of the gas ejection port together with water. 2. The air bubble holding device for a ship according to claim 1, wherein the air bubble sucking means sucks the air bubbles before they diffuse to the ship bottom. The ship bubble holding device according to claim 2, wherein the bubble sucking means sucks the bubble in a range not exceeding 7 mm as a distance from the ship bottom.   4. The ship bubble holding device according to claim 1, wherein the bubble sucked by the bubble sucking unit is again ejected from the ship bottom. 5. 5. The ship bubble holding device according to claim 1, further comprising a gas-liquid separator that separates the water sucked by the bubble sucking means and the bubbles. 6.

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