JP2018090156A - Floating body structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a wave drift force applied to a floating body structure by using a wave force.SOLUTION: A floating body structure 1 is provided with: a floating body 2 that floats on the water level; and a thrust generating mechanism 3 that is connected to the floating body 2. The floating body 2 is provided with a vibration water pillar 24 and a vibration floating body 25. At the vibration water pillar 24, the water level of an internal vibration water pillar 240 rises/falls depending on an incident wave. The vibration floating body 25 floats on the water level of the vibration water pillar 240. The thrust generating mechanism 3 is mechanically connected to the vibration floating body 25. The thrust generating mechanism 3 is driven by mechanical energy generated by rising/falling of the vibration floating body 25 to generate a thrust toward a wave upper side. Thus, by using a wave force, a wave drift force applied to the floating body structure 1 can be reduced.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a floating structure that floats on a water surface.

  Conventionally, many floating structures floating on the sea surface are moored so as not to flow from a predetermined position due to the influence of waves or the like. Patent Document 1 proposes to provide an annular hydrofoil structure around a floating structure for the purpose of low-cost mooring at a fixed point. The hydrofoil structure is formed of an elastic member. When the hydrofoil structure swings in the vertical direction by the wave force, a propulsive force from the hydrofoil toward the wave is generated. As a result, the wave drift force is reduced by the propulsive force.

  In the floating structure of Patent Document 2, a deck positioned above the water surface is supported from below by two cylindrical floating bodies that extend horizontally in water. The two floats are provided with two fins arranged in the longitudinal direction so that the tip portions thereof face each other. In Patent Document 2, a hydrofoil is constituted by a floating body and a fin, and the fin swings in the vertical direction by the force of the wave, so that a propulsive force is generated from the hydrofoil toward the wave, and the wave acting on the floating structure. Drifting force is reduced.

JP 2005-343337 A JP 2005-125910 A

  By the way, in the floating structure of Patent Document 1 and Patent Document 2, the hydrofoil generates lift when water flows on the upper and lower sides of the hydrofoil, and the horizontal component of the lift acts on the floating structure. It becomes the power of. Therefore, when the water flow with respect to the hydrofoil is an upward flow that goes upward as it goes from upstream to downstream, in order for the hydrofoil to generate a propulsive force toward the wave, the angle of attack of the hydrofoil with respect to the water flow is upward. It is necessary to be an angle that generates the lift force. On the other hand, when the water flow with respect to the hydrofoil is a downward flow that goes downward as it goes from upstream to downstream, the angle of attack of the hydrofoil with respect to the water flow must be It is necessary to be an angle that generates the lift force.

  However, in Patent Document 1 and Patent Document 2, the direction of lift generated by the hydrofoil is determined by the deformation of the hydrofoil by the force of water flowing into the hydrofoil. In other words, the direction of lift generated by the hydrofoil is directly determined by the phase of the waves flowing into the hydrofoil. For this reason, the direction of lift from the hydrofoil is not necessarily an appropriate direction with respect to the inflow angle of water to the hydrofoil. For example, when the hydrofoil is deformed by the upward flow and has a shape that generates downward lift, the horizontal component of the lift is directed downward, so that the wave drift force increases.

  This invention is made | formed in view of the said subject, and it aims at reducing the wave drift force which acts on a floating body structure using the force of a wave.

  The invention according to claim 1 is a floating body structure that floats on a water surface, and includes a floating body body that floats on the water surface and a thrust generation mechanism that is connected to the floating body body. The vibrating water column includes a vibrating water column portion that moves up and down, and a vibrating floating body that floats on the water surface of the vibrating water column. The thrust generation mechanism is mechanically connected to the vibrating floating body and is generated by the lifting and lowering of the vibrating floating body. When driven by mechanical energy, a thrust toward the wave front is generated.

  The invention according to claim 2 is the floating structure according to claim 1, wherein the vibrating water column portion extends in a vertical direction from the water to the water on the wave upper side of the floating body, and the front partition From the partition wall that is disposed on the wave upper side of the partition wall so as to face the front partition wall and extends in the vertical direction from the water to the water, and from the lower end of the partition wall that is located above the lower end of the front partition wall, the wave A partition protrusion extending upward, and the oscillating water column is located in a space between the front partition and the partition wall.

  A third aspect of the present invention is the floating structure according to the second aspect, wherein the oscillating water column portion further includes a transmission wall that extends from the water to the water on the wave upper side than the partition wall.

  The invention according to claim 4 is a floating body structure floating on the water surface, comprising a floating body main body floating on the water surface, and a thrust generation mechanism connected to the floating body main body, the thrust generation mechanism by the incident wave Driven by mechanical energy generated when the floating body moves up and down, it generates thrust toward the wave side.

  Invention of Claim 5 is the floating body structure as described in any one of Claim 1 thru | or 4, Comprising: The said thrust generation mechanism is a hydrofoil arrange | positioned with the front edge facing the wave upper side, A blade angle changing mechanism that is driven by the mechanical energy and changes the blade angle of the hydrofoil, and the horizontal component of the lift of the hydrofoil is the thrust.

  The invention according to claim 6 is the floating structure according to claim 5, wherein the water flowing into the leading edge of the hydrofoil is inclined upward with respect to a horizontal plane. When the wing generates upward lift and the flow of water flowing into the leading edge of the hydrofoil is inclined downward with respect to a horizontal plane, the hydrofoil generates downward lift.

  The invention according to claim 7 is the floating structure according to claim 5 or 6, wherein the blade angle changing mechanism is connected to a rear portion of the hydrofoil and moves up and down the rear portion.

  Invention of Claim 8 is the floating body structure as described in any one of Claim 5 thru | or 7, Comprising: The said hydrofoil is provided in the trailing edge side of the hydrofoil main body and the said hydrofoil main body, A flap capable of changing a relative blade angle with respect to the hydrofoil main body by the blade angle changing mechanism, and changing the blade angle of the hydrofoil by the blade angle changing mechanism is changing the relative blade angle of the flap.

  A ninth aspect of the present invention is the floating structure according to any one of the fifth to eighth aspects, wherein the hydrofoil is disposed on the wave front side of the floating body.

  A tenth aspect of the present invention is the floating structure according to any one of the first to ninth aspects, wherein the thrust generating mechanism determines the period of the mechanical energy as the vibration floating body or the floating body main body. A period changing unit for changing to a period shorter than the ascending / descending period.

  The invention according to an eleventh aspect is the floating structure according to any one of the first to tenth aspects, further comprising a wind turbine for wind power generation disposed on the floating body main body.

  In the present invention, the wave drift force acting on the floating structure can be reduced by utilizing the wave force.

It is a side view of the floating structure according to the first embodiment. It is a top view of a floating structure. It is a front view of a floating structure. It is sectional drawing which shows a part of floating body structure. It is a figure which shows the relationship between the flow of water and the lift of a hydrofoil. It is a figure which shows the relationship between the flow of water and the lift of a hydrofoil. It is a side view which shows a part of other preferable thrust generation mechanism. It is a side view which shows a part of other preferable thrust generation mechanism. It is sectional drawing which shows a part of floating body structure which concerns on 2nd Embodiment. It is sectional drawing which shows a part of floating body structure. It is sectional drawing which shows a part of floating body structure. It is sectional drawing which shows a part of other floating body structure. It is sectional drawing which shows a part of other floating body structure.

  FIG. 1 is a side view showing a floating structure 1 according to a first embodiment of the present invention. FIG. 2 is a plan view showing the floating structure 1. FIG. 3 is a front view showing the floating structure 1. The floating structure 1 is a structure that floats on the water surface. In the example shown in FIG. 1 to FIG. 3, the floating structure 1 is a floating structure for wind power generation that is moored on the seabed and performs wind power generation. The floating structure 1 is moored at three points by catenary mooring. The mooring method and the number of mooring points of the floating structure 1 may be variously changed.

  The floating body structure 1 includes a floating body 2, a thrust generation mechanism 3, and a windmill 4. In FIG. 3, only a part of the wind turbine 4 is shown. The floating body 2 is a structure that floats on the water surface. In the example illustrated in FIGS. 1 to 3, the floating body 2 has a substantially rectangular parallelepiped shape. The floating body 2 is substantially rectangular in plan view, for example, is substantially square. A through hole 21 penetrating the floating body 2 in the vertical direction is provided at the center of the floating body 2. The through hole 21 is substantially rectangular in plan view, and is, for example, substantially square. The floating body 2 is made of reinforced concrete, for example. The shape of the floating body 2 in plan view is, for example, a substantially square shape with one side of about 50 m. Moreover, the depth of the floating body 2 is about 10 m, and the draft of the floating body 2 is about 5 m. The shape of the through hole 21 in a plan view is a substantially square with one side of about 25 m.

  The floating body 2 is arranged such that one side surface located on the left side in FIGS. 1 and 2 faces the wave upper side that is the upstream side in the main direction of the wave. In other words, the left side in FIGS. 1 and 2 is the wave upper side, and the right side is the wave lower side. In the following description, the wave front side surface of the floating body 2 is referred to as “front surface 22”, and the wave lower side surface (that is, the right side surface in the drawing) is referred to as “rear surface 23”. 1 and 2 are referred to as “front-rear direction”, and the up-down direction in FIG. 2 and the left-right direction in FIG. 3 are referred to as “width direction”. FIG. 3 is a view of the floating structure 1 as viewed from the front surface 22 side of the floating body 2. In the example shown in FIGS. 1 to 3, mooring lines 91 are connected to the center in the width direction of the front end portion of the floating body 2 and the width direction both ends of the rear end portion of the floating body 2.

  The floating body 2 includes a vibrating water column portion 24 and a vibrating floating body 25. The vibrating water column part 24 and the vibrating floating body 25 are arranged in front of the through hole 21. In the example shown in FIGS. 1 to 3, the oscillating water column portion 24 and the oscillating floating body 25 are provided in the central portion in the width direction at the wave-side end of the floating body 2. FIG. 4 is a cross-sectional view perpendicular to the width direction showing the wave-side portion of the floating structure 1 in an enlarged manner. In FIG. 4, about the structure of a part of floating body structure 1, a side surface is shown.

  As shown in FIGS. 1 to 4, the oscillating water column portion 24 is a recess that is recessed backward from the front surface 22 of the floating body 2 and recessed upward from the bottom surface 26 of the floating body 2. In other words, the oscillating water column portion 24 is a space opened forward and downward at the front end portion and the center portion in the width direction of the floating body 2. The oscillating water column 24 is surrounded by the outer wall of the floating body 2 on the upper side, the rear side (that is, the wave lower side), and both sides in the width direction. The vibrating water column part 24 is a substantially rectangular parallelepiped space that is isolated from the internal space of the floating body 2 by the outer wall, and is open to the water. Therefore, water that is continuous with the water around the floating body 2 exists in the oscillating water column 24.

  The oscillating water column 24 includes a front partition 241, a pair of side partitions 242, a partition wall 243, a partition protrusion 244, a transmission wall 245, and an upper partition 246. The front partition 241 is located at the rear end of the oscillating water column 24. The front partition 241 is a part of the outer wall of the floating body 2, and extends in the vertical direction on the wave side of the center of the floating body 2 in the front-rear direction. The front partition 241 is substantially perpendicular to the front-rear direction. The pair of side partition walls 242 extends forward from both ends of the front partition wall 241 in the width direction. The pair of side partition walls 242 are a part of the outer wall of the floating body 2 and extend in the vertical direction on the wave upper side than the central portion in the front-rear direction of the floating body 2. The pair of side partition walls 242 is substantially perpendicular to the width direction. The front partition 241 and the pair of side partitions 242 extend in the vertical direction from the water (that is, above the water surface) to the water. In other words, the front partition 241 and the pair of side partitions 242 penetrate the water surface.

  The partition wall 243 is a plate-like member that is disposed to face the front partition 241 on the wave front side (that is, the front side) of the front partition 241. The partition wall 243 is a substantially flat plate-like member that is substantially perpendicular to the front-rear direction. In other words, the partition wall 243 is spaced forward from the front partition 241 and the partition wall 243 and the front partition 241 are substantially parallel. The partition wall 243 extends in the up-down direction from the water to the water. That is, the partition wall 243 penetrates the water surface. The lower end of the partition wall 243 is located above the lower end of the front partition 241. Both ends of the partition wall 243 in the width direction are connected to a pair of side partition walls 242.

  The partition protrusion 244 is a plate-like member extending from the lower end of the partition wall 243 toward the wavefront (that is, forward). The partition protrusion 244 is a substantially flat plate member that is substantially perpendicular to the vertical direction. In other words, the partition wall 243 and the partition protrusion 244 are plate-like members having a substantially L-shaped cross section perpendicular to the width direction. The partition protrusion 244 extends in the front-rear direction in water. Both ends of the partition protrusion 244 in the width direction are connected to a pair of side partition walls 242. The front end of the partition protrusion 244 is located at substantially the same position in the front-rear direction as the front ends of the pair of side partition walls 242. The partition wall 243 and the partition protrusion 244 are impermeable members that do not transmit water.

  The upper partition 246 extends forward from the upper end of the partition wall 243. Both ends of the upper partition 246 in the width direction are connected to a pair of side partitions 242. The upper partition wall 246 is substantially perpendicular to the vertical direction and is substantially parallel to the partition protrusion 244. The upper partition wall 246 opposes the partition protrusion 244 in the up-down direction. The upper partition 246 is located below the upper surface 27 of the floating body 2.

  The transmission wall 245 is disposed on the wave upper side than the partition wall 243 and spreads from the water to the water. The transmission wall 245 has a wall-like structure that transmits waves incident from the wave upper side. A space between the transmission wall 245 and the partition wall 243 is a water reserving chamber into which a wave transmitted through the transmission wall 245 flows. The energy of the wave incident on the transmission wall 245 is consumed when passing through the transmission wall 245 and in the water play chamber. For this reason, the force of the wave which acts on the partition wall 243 is reduced. Moreover, the reflected wave from the partition wall 243 is reduced. In other words, the wave force incident on the floating body 2 is reduced by the transmission wall 245 and the water reserving chamber.

  In the example shown in FIGS. 1 to 4, the transmission wall 245 is a vertical slit portion including a plurality of column members 247. The plurality of column members 247 are arranged along the partition wall 243 while being separated from each other. Each of the plurality of column members 247 extends substantially parallel to the vertical direction from the water to the water. In other words, each column member 247 penetrates the water surface. Each column member 247 may be, for example, a prismatic shape or a cylindrical shape. The plurality of column members 247 are arranged at the front end portion of the vibration water column portion 24. The lower end portion of each column member 247 is connected to the front end portion of the partition protrusion 244. Further, the upper end portion of each column member 247 is connected to the front end portion of the upper partition 246. In other words, the partition protrusion 244 is connected to the floating body 2 via the plurality of column members 247.

  In the oscillating water column 24, as shown in FIG. 4, the oscillating water column 240 is located in the space between the front partition 241 and the partition wall 243. Specifically, the water in the oscillating water column 24 is surrounded by the front partition 241, the pair of side partitions 242 and the partition wall 243 (that is, the side is surrounded all around). ), A vibrating water column 240 is formed. In the oscillating water column part 24, the water surface of the internal oscillating water column 240 moves up and down by waves incident on the floating body 2 from the wave upper side. The width of the oscillating water column portion 24 (that is, the distance in the width direction between the pair of side partition walls 242) is, for example, 5 m or more and 50 m or less. In the example shown in FIGS. 1 to 4, the width of the oscillating water column 24 is about 12.5 m.

  The vibration floating body 25 is a member that floats on the water surface of the vibration water column 240 of the vibration water column portion 24. The vibration floating body 25 has, for example, a substantially flat plate shape or a substantially rectangular parallelepiped shape. For example, the vibrating floating body 25 floats in the center of the water surface of the vibrating water column 240 and does not come into contact with the surrounding walls of the vibrating water column 240 (that is, the front partition wall 241, the pair of side partition walls 242, and the partition wall 243). It is guided by a guide member (not shown).

  The thrust generating mechanism 3 is a mechanism connected to the floating body 2. Specifically, the thrust generating mechanism 3 is mechanically connected to the vibrating floating body 25 of the floating body 2. The thrust generation mechanism 3 generates a thrust toward the wave upper side by being driven by mechanical energy generated by raising and lowering the vibrating floating body 25.

  The thrust generating mechanism 3 includes a hydrofoil 31 and a blade angle changing mechanism 33. The hydrofoil 31 is a substantially rectangular plate-like member in plan view. As shown in FIG. 4, the hydrofoil 31 is arranged on the wave upper side of the floating body 2 with the front edge 311 facing the wave upper side. The trailing edge 312 of the hydrofoil 31 is disposed on the wave lower side. In the example shown in FIG. 4, the hydrofoil 31 is disposed in front of the front surface 22 of the floating body 2 and above the bottom surface 26 of the floating body 2. More specifically, the hydrofoil 31 is disposed in front of the partition protrusion 244 on the wave upper side of the oscillating water column 24 and faces the transmission wall 245 in the front-rear direction.

  For example, the cross-sectional shape perpendicular to the width direction of the hydrofoil 31 (that is, the airfoil shape) gradually increases in thickness as it goes rearward from the front edge 311 and becomes the maximum thickness on the front side of the center portion in the front-rear direction. After that, the shape gradually decreases toward the trailing edge 312 (so-called blade shape). In the example shown in FIG. 4, the hydrofoil 31 is a symmetric wing (so-called vertical symmetric wing). In other words, the upper surface and the lower surface of the hydrofoil 31 are axisymmetric with respect to a chord line (also referred to as a base line) that is a straight line connecting the leading edge 311 and the trailing edge 312.

  The blade width of the hydrofoil 31 (that is, the distance between the edges in the width direction of the hydrofoil 31) is, for example, 5 m or more and 50 m or less, and is about 10 m in the present embodiment. The chord length of the hydrofoil 31 is preferably equal to or less than the blade width. The chord length of the hydrofoil 31 is, for example, not less than 1 m and not more than 10 m, and is approximately 7.5 m in the present embodiment. The blade thickness ratio of the hydrofoil 31 is, for example, 5% or more and 30% or less, and is approximately 20% in the present embodiment. The hydrofoil 31 is a rigid body that is not deformed by the force of an incident wave (that is, its shape is maintained). The hydrofoil 31 is made of metal such as iron.

  The blade angle changing mechanism 33 is a link mechanism that mechanically connects the hydrofoil 31 and the vibrating floating body 25. 1 to 4 show the structure of the blade angle changing mechanism 33 in a simplified manner. The blade angle changing mechanism 33 is connected to and supported by the floating body 2 by a support structure (not shown) so as to be movable up and down. The structure of the link mechanism used as the blade angle changing mechanism 33 is appropriately selected from, for example, the structures of known link mechanisms.

  As shown in FIG. 4, the wave-side end of the blade angle changing mechanism 33 is connected to the rear part of the hydrofoil 31 (that is, the rear part of the center part in the front-rear direction). The blade angle changing mechanism 33 extends upward from the hydrofoil 31, extends rearward through an opening 221 provided in the front surface 22 of the floating body 2, and further extends downward from a position above the vibrating water column 240. . The wave-side end of the blade angle changing mechanism 33 is connected to the vibrating floating body 25. The vibrating floating body 25 floats on the water surface of the vibrating water column 240 by buoyancy even in a state where it is not connected to the blade angle changing mechanism 33.

  In the floating structure 1, when the water surface of the oscillating water column 240 moves up and down by a wave incident on the floating body 2, the vibrating floating body 25 floating on the water surface moves in the vertical direction. Mechanical energy generated by raising and lowering the vibrating floating body 25 is directly transmitted to the blade angle changing mechanism 33 without being converted into electrical energy or the like. Then, the blade angle changing mechanism 33 is driven by the mechanical energy, and the rear portion of the hydrofoil 31 moves up and down. As a result, the positional relationship in the vertical direction between the leading edge 311 and the trailing edge 312 of the hydrofoil 31 changes, and the blade angle of the hydrofoil 31 with respect to the horizontal plane is changed.

  The blade angle of the hydrofoil 31 with respect to the horizontal plane (hereinafter, also simply referred to as “blade angle”) is an angle formed by a chord line of the hydrofoil 31 in a cross section perpendicular to the width direction and a reference line indicating the horizontal direction. is there. The blade angle when the trailing edge 312 is located below the reference line passing through the leading edge 311 of the hydrofoil 31 is positive, and the blade angle when the trailing edge 312 is located above the reference line is Is negative. The blade angle of the hydrofoil 31 is changed, for example, in the range of −20 ° to 20 °.

  In the floating structure 1, a rotating shaft extending in the width direction may be provided at the front edge portion that is a portion near the front edge 311 of the hydrofoil 31. The hydrofoil 31 may rotate around the rotation axis when the rear part moves up and down as described above. Both ends in the width direction of the rotating shaft are supported by the floating body 2 via a support member extending in the front-rear direction, for example.

  In the floating structure 1, by changing the structure of the blade angle changing mechanism 33, the relationship between the position of the water surface of the vibrating water column 240 (that is, the vertical position of the vibrating floating body 25) and the blade angle of the hydrofoil 31 is obtained. Various changes can be made. For example, the blade angle when the water surface of the oscillating water column 240 is located at the reference position (that is, the position of the still water surface assuming no waves) is 0 °, and the water surface of the oscillating water column 240 is above the reference position and The blade angle when located on the lower side may be negative and positive, respectively. Alternatively, the blade angle when the water surface of the oscillating water column 240 is located above and below the reference position may be positive and negative, respectively.

  FIG. 5 and FIG. 6 are diagrams showing the relationship between the flow of water to the hydrofoil 31 in the waves and the lift of the hydrofoil 31. 5 and 6, the flow of water in the waves flowing into the leading edge 311 of the hydrofoil 31 is indicated by an arrow with a symbol Wf. The water flow Wf in FIG. 5 is an upward flow that is directed upward (that is, inclined upward with respect to the horizontal plane) from upstream to downstream. The water flow Wf in FIG. 6 is a downward flow that is directed downward (that is, inclined downward with respect to the horizontal plane) from upstream to downstream.

  Further, in FIGS. 5 and 6, the lift generated by the hydrofoil 31 is indicated by an arrow with a symbol L. Further, the vertical component and the horizontal component of the lift L are indicated by broken-line arrows with symbols Lz and Lx. 5 and 6 is an angle formed by the water flow Wf and the chord line 313 of the hydrofoil 31. The angle of attack α when the trailing edge 312 is positioned below the water flow Wf passing through the leading edge 311 of the hydrofoil 31 is positive, and the trailing edge 312 is positioned above the water flow Wf. The angle of attack α is negative.

  As shown in FIGS. 5 and 6, in the thrust generating mechanism 3, the blade angle of the hydrofoil 31 is changed by the blade angle changing mechanism 33 in accordance with the direction of the water flow Wf in the waves. For example, as shown in FIG. 5, when the water flow Wf is an upward flow, the blade angle is changed so that the angle of attack α of the hydrofoil 31 becomes positive. As a result, the hydrofoil 31 generates upward lift L, and the horizontal component Lx of the lift L faces forward (that is, on the wave upper side). In other words, the horizontal component Lx of the lift L of the hydrofoil 31 is a thrust toward the wave side. Thereby, the force which goes to the wave upper side acts on the floating body 2.

  Further, as shown in FIG. 6, when the water flow Wf is a downward flow, the blade angle is changed so that the angle of attack α of the hydrofoil blade 31 is negative. As a result, the hydrofoil 31 generates a downward lift L, and the horizontal component Lx of the lift L is directed forward (that is, on the wave upper side). In other words, the horizontal component Lx of the lift L of the hydrofoil 31 is a thrust toward the wave side. Thereby, the force which goes to the wave upper side acts on the floating body 2.

  In the floating structure 1, the structure of the blade angle changing mechanism 33 is based on the period and wavelength of main waves in the installation sea area of the floating structure 1 and the distance in the front-rear direction between the hydrofoil 31 and the vibrating floating body 25. It is determined. Then, by changing the blade angle of the hydrofoil 31 by the blade angle changing mechanism 33, the angle of attack α of the hydrofoil 31 in the upward flow is positive, and the angle of attack α of the hydrofoil 31 in the downward flow is negative. It is said.

  For example, when the upward flow flows into the hydrofoil 31 due to main waves in the sea area where the floating structure 1 is installed, the water surface of the oscillating water column 240 is positioned below the reference position, and the downward flow flows into the hydrofoil 31. Let us consider a case where the water surface of the oscillating water column 240 is located above the reference position. In this case, the structure of the blade angle changing mechanism 33 is such that the blade angle of the hydrofoil 31 is negative when the water surface of the vibrating water column 240 is above the reference position, and the water surface of the vibrating water column 240 is below the reference position. The blade angle of the hydrofoil 31 is determined to be positive. In addition, it is preferable that the maximum value and the minimum value of the blade angle of the hydrofoil 31 changed by the blade angle changing mechanism 33 are determined so that the angle of attack α of the hydrofoil 31 is smaller than the stall angle.

  As shown in FIGS. 1 to 3, the windmill 4 is a structure for wind power generation arranged on the floating body 2. The windmill 4 includes a plurality of blades 41, a nacelle 42, and a support 43. A plurality of (for example, three) blades 41 are rotatably attached to the nacelle 42 about a substantially horizontal rotation axis. The plurality of blades 41 and the nacelle 42 are supported above the upper surface 27 of the floating body 2 by support columns 43 extending substantially in the vertical direction. In the windmill 4, the plurality of blades 41 are rotated by receiving wind, whereby power is generated by a generator (not shown) connected to the rotation shafts of the plurality of blades 41. For example, the rotor diameter of the windmill 4 is about 100 m, and the height of the column 43 is about 70 m to 80 m. The rated output of the windmill 4 is 5 MW (megawatts), for example.

  On the wave lower side of the floating body 2, a weight 29 is provided that balances the buoyancy of the floating body 2 by the vibrating water column portion 24 and the weight of the thrust generating mechanism 3. In other words, the moment generated by the oscillating water column 24 and the thrust generating mechanism 3 (that is, the moment about the rotation axis facing the width direction of the floating structure 1) is canceled by the moment generated by the weight 29. The weight 29 is disposed, for example, inside the floating body 2. Alternatively, the weight 29 is connected to the bottom surface 26 of the floating body 2 from below. When the floating body 2 is in a stationary state, the upper surface 27 and the bottom surface 26 of the floating body 2 are substantially horizontal. In other words, in a state in which the floating body 2 floats on the still water surface, the upper surface 27 and the bottom surface 26 of the floating body 2 are substantially perpendicular to the vertical direction (that is, the direction of gravity). In the floating structure 1, instead of providing the weight 29, for example, when the shape of the floating body 2 is changed on the wave upper side or wave lower side, the moment generated by the vibrating water column portion 24 and the thrust generating mechanism 3 is increased. It may be offset.

  As described above, the floating body structure 1 includes the floating body 2 that floats on the water surface and the thrust generation mechanism 3 that is connected to the floating body 2. The floating body 2 includes a vibrating water column portion 24 and a vibrating floating body 25. In the oscillating water column 24, the water surface of the internal oscillating water column 240 is raised and lowered by the incident wave. The vibrating floating body 25 floats on the water surface of the vibrating water column 240. The thrust generating mechanism 3 is mechanically connected to the vibration floating body 25. The thrust generation mechanism 3 generates a thrust toward the wave upper side by being driven by mechanical energy generated by raising and lowering the vibrating floating body 25. Thereby, the wave drift force which acts on the floating structure 1 can be reduced using wave force.

  Further, as described above, the thrust generating mechanism 3 is not driven by the wave force directly incident on the thrust generating mechanism 3 (that is, the wave force flowing into the hydrofoil 31), and the vibration floating body 25 is moved up and down. Driven by mechanical energy generated by For this reason, the structure and installation position of the thrust generating mechanism 3 (that is, the distance in the front-rear direction from the vibrating floating body 25) should be appropriately designed based on the period and wavelength of main waves in the installation sea area of the floating structure 1. Thus, the thrust generating mechanism 3 can be appropriately driven in accordance with the direction of the water flow Wf incident on the thrust generating mechanism 3. As a result, the wave drift force acting on the floating structure 1 can be efficiently reduced by utilizing the wave force.

  As described above, the floating structure 1 further includes the wind turbine 4 for wind power generation disposed on the floating body 2. For this reason, the wave drift force of the floating structure 1 may increase due to the wind pressure applied to the windmill 4. In addition, the center of gravity of the floating structure 1 is increased, and pitching and the like are relatively large, which may increase the wave drifting force. Therefore, the structure of the floating structure 1 described above that can reduce the wave drift force acting on the floating structure 1 is particularly suitable for a floating structure including a wind turbine for wind power generation.

  In the floating structure 1, the oscillating water column portion 24 includes a front partition 241, a partition wall 243, and a partition protrusion 244. The front partition 241 extends in the vertical direction from the surface of the water to the water on the wave side of the floating body 2. The partition wall 243 is disposed opposite to the front partition 241 on the wave front side of the front partition 241 and extends in the vertical direction from the water to the water. The lower end of the partition wall 243 is located above the lower end of the front partition 241. The partition protrusion 244 extends from the lower end of the partition wall 243 to the wave side. An oscillating water column 240 is located in the space between the front partition 241 and the partition wall 243. Thereby, the structure of the vibration water column part 24 can be simplified and the vibration water column part 24 can be easily provided in the floating structure 1.

  In the above-described example, the partition wall 243 is a flat plate-like member that is substantially perpendicular to the front-rear direction, and the partition protrusion 244 is a flat-plate member that is substantially perpendicular to the vertical direction. In other words, the partition wall 243 and the partition protrusion 244 are plate-like members having a substantially L-shaped cross section perpendicular to the width direction. Thereby, the manufacturing cost of the vibration water column part 24 can be reduced.

  In the floating structure 1, the shapes of the partition wall 243 and the partition protrusion 244 may be changed as appropriate. For example, even if the lower end of the partition wall 243 extending in the vertical direction is curved toward the wave upper side, and the partition protrusion 244 extends to the wave upper side from the tip of the curved portion (that is, the lower end of the partition wall 243). Good. Thus, the amplitude of the oscillating water column 240 in the oscillating water column portion 24 can be increased by making the connecting portion between the partition wall 243 and the partition projecting portion 244 a curved surface. Thereby, the mechanical energy produced by the raising / lowering of the vibration floating body 25 can be increased. As a result, supply of mechanical energy required for driving the thrust generating mechanism 3 can be easily realized.

  As described above, the oscillating water column portion 24 further includes the transmission wall 245 that extends from the water to the water on the wave upper side than the partition wall 243. Thereby, the force of the wave incident on the partition wall 243 can be reduced, and as a result, the wave drift force acting on the floating structure 1 can be further reduced.

  The transmission wall 245 is a vertical slit portion including a plurality of column members 247 extending in the vertical direction from the water to the water. The plurality of column members 247 are arranged along the partition wall 243 while being separated from each other. Thereby, the structure of the permeable wall 245 can be simplified and the manufacturing cost of the floating structure 1 can be reduced.

  The structure of the transmission wall 245 may be changed as appropriate. For example, the transmission wall 245 may be a horizontal slit portion in which a plurality of column members extending substantially horizontally are arranged in the vertical direction. Alternatively, the transmission wall 245 may have a structure in which a plurality of through-holes penetrating in the front-rear direction are provided substantially uniformly in a flat wall member. In any case, the wave drift force acting on the floating structure 1 can be further reduced as described above.

  In the floating structure 1, the thrust generating mechanism 3 includes a hydrofoil 31 and a blade angle changing mechanism 33. The hydrofoil 31 is disposed with the leading edge 311 facing the wave upper side. The blade angle changing mechanism 33 is driven by mechanical energy generated by raising and lowering the vibrating floating body 25 and changes the blade angle of the hydrofoil 31. The thrust toward the wave side generated by the thrust generating mechanism 3 is a horizontal component of the lift force of the hydrofoil 31. Thus, in the floating structure 1, by using the lift of the hydrofoil 31, a relatively large thrust can be obtained while the movement of the movable part in the thrust generating mechanism 3 is relatively small. As a result, the wave drift force acting on the floating structure 1 can be further reduced.

  In the floating structure 1, by providing the hydrofoil 31 outside the floating body 2, it is possible to increase the moment of inertia around the rotation axis that faces the width direction of the floating structure 1. Thereby, pitching of the floating structure 1 can be suppressed. As a result, the wave drift force acting on the floating structure 1 can be further reduced.

  In the floating structure 1, the moment of inertia can be further increased by providing the hydrofoil 31 on the wave upper side than the floating body 2. As a result, the wave drift force acting on the floating structure 1 can be further reduced. Further, the maintenance of the hydrofoil 31 and the blade angle changing mechanism 33 can be facilitated as compared with the case where the hydrofoil 31 is disposed vertically below the floating body 2. In the floating structure 1, since the hydrofoil 31 is a rigid body, the hydrofoil 31 can be prevented from being damaged or deteriorated due to a collision with an underwater float or the like.

  As described above, the hydrofoil 31 faces the transmission wall 245 in the front-rear direction on the wave upper side of the vibrating water column part 24. In the floating structure 1, since the reflected wave of the wave incident on the floating body 2 can be reduced by the transmission wall 245, it is possible to suppress the performance degradation of the hydrofoil 31 due to the reflected wave. As a result, the wave drift force acting on the floating structure 1 can be suitably reduced.

  In the thrust generation mechanism 3, when the water flow Wf flowing into the leading edge 311 of the hydrofoil 31 is inclined upward with respect to the horizontal plane, the hydrofoil 31 generates upward lift. Further, when the water flow Wf flowing into the leading edge 311 of the hydrofoil 31 is inclined downward with respect to the horizontal plane, the hydrofoil 31 generates a downward lift. Thereby, even if the flow Wf of the water with respect to the hydrofoil 31 is an upward flow or a downward flow, the hydrofoil 31 can generate a thrust toward the wave side. As a result, the wave drift force acting on the floating structure 1 can be efficiently reduced.

  In the thrust generating mechanism 3, it is not always necessary for the hydrofoil 31 to generate thrust toward the wave upper side in both cases where the water flow Wf with respect to the hydrofoil 31 is an upward flow and a downward flow. In other words, when the water flow Wf with respect to the hydrofoil 31 is an upward flow or a downward flow, the hydrofoil 31 only needs to generate a thrust toward the wave upper side. For example, the blade angle changing mechanism 33 causes the blade angle of the hydrofoil 31 so that the lift of the hydrofoil 31 is upward and generates thrust toward the wave-side only when the water flow Wf with respect to the hydrofoil 31 is an upward flow. May be changed. In this case, in a state where the water flow Wf with respect to the hydrofoil 31 is a downward flow, for example, the blade angle of the hydrofoil 31 is changed so that the lift of the hydrofoil 31 becomes substantially zero.

  As described above, the blade angle changing mechanism 33 is connected to the rear part of the hydrofoil 31 and moves up and down the rear part of the hydrofoil 31. Thereby, the blade angle of the hydrofoil 31 can be changed easily. Further, as compared with the case where the blade angle changing mechanism 33 is connected to the front portion of the hydrofoil 31, it is possible to suppress the water flow around the hydrofoil 31 from being disturbed by the influence of the blade angle changing mechanism 33. . For this reason, the hydrofoil 31 can generate | occur | produce the thrust which goes to a wave side efficiently.

  When a desired thrust toward the wave side can be obtained from the hydrofoil 31, the blade angle changing mechanism 33 may be connected to the front part of the hydrofoil 31, for example. Further, the structure of the hydrofoil 31 may be variously changed.

  FIG. 7 is a side view showing another preferable thrust generating mechanism 3a. In the thrust generating mechanism 3a, a hydrofoil 31a having a structure different from that of the hydrofoil 31 shown in FIGS. 1 to 4 is provided in place of the hydrofoil 31. In FIG. 7, only a part of the blade angle changing mechanism 33 is shown.

  As shown in FIG. 7, the hydrofoil 31 a includes a hydrofoil main body 315 and a flap 316. The flap 316 is provided on the rear edge side of the hydrofoil main body 315. The combined shape of the hydrofoil main body 315 and the flap 316 is substantially the same as the hydrofoil 31 shown in FIG. In other words, the rear edge portion that is a portion near the trailing edge 312 of the hydrofoil 31 shown in FIG. 4 corresponds to the flap 316, and the portion other than the rear edge portion of the hydrofoil 31 corresponds to the hydrofoil main body 315.

  The hydrofoil main body 315 is fixed to the floating body 2 by, for example, support members (not shown) connected to both sides in the width direction. The flap 316 is connected to the hydrofoil main body 315 via a rotation shaft 317 extending in the width direction. The flap 316 is rotatable about the rotation shaft 317. At both ends in the width direction of the rotation shaft 317, for example, protrusions 318 that protrude to the wave lower side are provided. The protrusion 318 is mechanically connected to a blade angle changing mechanism 33 having a structure substantially similar to that shown in FIGS.

  In the thrust generating mechanism 3a, the mechanical energy generated by raising and lowering the vibrating floating body 25 (see FIG. 4) is directly transmitted to the blade angle changing mechanism 33 without being converted into electrical energy or the like. Then, the blade angle changing mechanism 33 is driven by the mechanical energy, whereby the projecting portion 318 of the hydrofoil 31a is pushed down or lifted upward. As a result, the flap angle β, which is the relative blade angle of the flap 316 with respect to the hydrofoil main body 315, is changed as indicated by a two-dot chain line in FIG. The flap angle β is an angle formed by the chord line 313 of the hydrofoil 31a and the chord line 319 of the flap 316. The flap angle β is positive when the trailing edge 312 of the flap 316 (ie, the trailing edge 312 of the hydrofoil 31a) is located below the chord line 313 of the hydrofoil 31a, and the chord line of the hydrofoil 31a is positive. The flap angle β is negative when the trailing edge 312 of the flap 316 is positioned on the upper side than the reference numeral 313.

  In the hydrofoil 31a, by making the flap angle β positive by the blade angle changing mechanism 33, the blade angle of the hydrofoil 31a becomes substantially positive, and by making the flap angle β negative, the blade angle of the hydrofoil 31a. Is substantially negative. In other words, the blade angle of the hydrofoil 31a is substantially changed by changing the relative blade angle (that is, the flap angle β) of the flap 316 with respect to the hydrofoil main body 315 by the blade angle changing mechanism 33.

  Also in the floating structure 1 provided with the thrust generation mechanism 3a, the hydrofoil 31a moves toward the wave-side as the thrust generation mechanism 3a is driven by the mechanical energy generated by the lifting and lowering of the vibration floating body 25, as described above. Generates thrust. Thereby, the wave drift force which acts on the floating structure 1 can be reduced using wave force.

  Further, in the thrust generating mechanism 3a, not the entire hydrofoil 31a but only the flap 316 is driven by the blade angle changing mechanism 33 to change the angle. In other words, changing the blade angle of the hydrofoil 31 a by the blade angle changing mechanism 33 is changing the flap angle β of the flap 316. Thereby, the blade angle of the hydrofoil 31a can be substantially changed with relatively small mechanical energy. As a result, the structure of the thrust generating mechanism 3a can be reduced in size or simplified. Note that the change of the flap angle β by the blade angle changing mechanism 33 may be performed by various structures different from the above-described example.

  FIG. 8 is a side view showing a part of another preferable thrust generating mechanism 3b. In FIG. 8, about the structure of a part of floating body structure 1, a cross section is shown. The thrust generating mechanism 3b further includes a cycle changing unit 34 in addition to the hydrofoil 31 and the blade angle changing mechanism 33 similar to those in FIGS. For example, when a wave having a large wave height is incident on the oscillating water column 24 of the floating structure 1 due to the influence of a typhoon, the cycle changing unit 34 sets the cycle of the mechanical energy that drives the thrust generating mechanism 3b to Change to a cycle shorter than the lifting cycle.

  In the example shown in FIG. 8, the period changing unit 34 is provided between the end of the blade angle changing mechanism 33 opposite to the hydrofoil 31 (see FIG. 4) and the vibrating floating body 25. The period changing unit 34 mechanically connects the blade angle changing mechanism 33 and the vibrating floating body 25.

  The period changing unit 34 includes a pinion 341, a rack 342, a ball screw 343, and a cam 344. The pinion 341 is connected to the vibration floating body 25 and extends upward from the vibration floating body 25. The pinion 341 moves up and down as the vibrating floating body 25 moves up and down. The rack 342 engages with the pinion 341 and converts the raising and lowering of the pinion 341 into a rotational motion. A screw shaft 345 facing the front-rear direction of the ball screw 343 is fixed to the rack 342, and the screw shaft 345 rotates with the rotation of the rack 342. Accordingly, the cam 344 connected to the nut 346 (that is, the slider) of the ball screw 343 moves in the front-rear direction. The upper end of the cam 344 has substantially sinusoidal irregularities. In the example illustrated in FIG. 8, the cam 344 includes three convex portions and three concave portions that are alternately arranged in the front-rear direction. A roller-like contact 331 provided at the tip of the blade angle changing mechanism 33 contacts the upper end of the cam 344.

  In the thrust generating mechanism 3 b, the right slope of the central convex portion of the cam 344 comes into contact with the contact 331 of the blade angle changing mechanism 33 when a normal wave height is incident. In other words, the contact 331 of the blade angle changing mechanism 33 reciprocates between the central convex portion and the central concave portion of the cam 344. For example, when the vibration floating body 25 is positioned at the rising apex, the contact 331 is positioned at the apex of the central convex portion of the cam 344, and when the vibration floating body 25 is positioned at the descending apex, the contact 331 is Located at the bottom of the central recess.

  On the other hand, when a wave having a higher wave height than normal is incident on the vibrating water column 24 of the floating structure 1 due to the influence of a typhoon or the like, the vertical amplitude of the vibrating floating body 25 is increased, and the moving distance of the cam 344 in the front-rear direction is also increased. growing. In other words, the moving distance of the contact 331 of the blade angle changing mechanism 33 on the cam 344 increases. For example, when the amplitude of the vibrating floating body 25 is three times that of the normal time, the contact 331 of the blade angle changing mechanism 33 reciprocates between the concave portion on the uppermost wave side and the convex portion on the lowermost wave side of the cam 344. To do.

  Thereby, the vertical reciprocation of the blade angle changing mechanism 33 is performed three times during one vertical reciprocation of the vibration floating body 25. In other words, the period of mechanical energy provided for changing the blade angle of the hydrofoil 31 via the blade angle changing mechanism 33 is about 1/3 of the raising / lowering cycle of the vibrating floating body 25. In addition, since the vertical movement distance (that is, amplitude) of the blade angle changing mechanism 33 is the same as that when a normal wave is incident, the fluctuation range of the blade angle of the hydrofoil 31 is also incident with the normal wave. Same as the case.

  As described above, the cycle changing unit 34 changes the cycle of the mechanical energy for driving the thrust generating mechanism 3 b to a cycle shorter than the lifting / lowering cycle of the vibrating floating body 25. Thereby, even when a wave with a large wave height due to the influence of a typhoon or the like is incident on the floating structure 1, the moving range of the movable portion (for example, the hydrofoil 31) of the thrust generating mechanism 3 b becomes excessively large. Can be suppressed. Thereby, damage to the thrust generation mechanism 3b can be prevented or suppressed. Further, when a long wavelength wave due to the influence of a typhoon or the like enters the floating structure 1, the hydrofoil 31 can be swung up and down relatively frequently with a period shorter than the wave period. And the wave drift force which acts on the floating structure 1 can further be reduced by generating the thrust which goes to the wave upper side also by the said rocking | fluctuation. Note that the structure of the period changing unit 34 (for example, the shape of the cam 344) may be changed as appropriate.

  FIG. 9 is a cross-sectional view showing a part of a floating structure 1a according to the second embodiment of the present invention. In FIG. 9, the wave-side part of the floating structure 1a is shown. Moreover, in FIG. 9, a side surface is shown about a part of structure of the floating structure 1a. In the floating structure 1a, a movable body 25a is provided in the floating body 2 in place of the vibrating water column portion 24 and the vibrating floating body 25 shown in FIGS. In the floating structure 1a, a thrust generating mechanism 3c including a blade angle changing mechanism 33a having a structure different from that of the blade angle changing mechanism 33 is provided instead of the thrust generating mechanism 3 shown in FIGS. Other structures of the floating structure 1a are substantially the same as those of the floating structure 1 shown in FIGS. In the following description, the same reference numerals are given to the configurations of the floating structure 1 a corresponding to the configurations of the floating structure 1.

  As shown in FIG. 9, the floating body 2 includes a mover 25 a and a guide member 251. The mover 25a can move smoothly in the vertical direction along the guide member 251 fixed to the floating body 2. The mover 25a is, for example, a weight having a relatively large mass.

  A rotating shaft 314 extending in the width direction is provided at the front edge portion, which is the vicinity of the front edge 311 of the hydrofoil 31. The hydrofoil 31 can rotate around the rotation shaft 314. Both ends of the rotation shaft 314 in the width direction are supported by the floating body 2 via support members (not shown).

  The blade angle changing mechanism 33 a includes an upper connection line 332, two upper pulleys 333, a lower connection line 334, and two lower pulleys 335. The two upper pulleys 333 are respectively disposed above the hydrofoil 31 and above the mover 25a. The upper connection line 332 connects the moving element 25 a and the rear edge of the hydrofoil 31 via the two upper pulleys 333. An elastic member 332 a is provided in a portion between the upper pulley 333 and the hydrofoil 31 above the hydrofoil 31 in the upper connection line 332. The two lower pulleys 335 are respectively disposed below the hydrofoil 31 and below the mover 25a. The lower connection line 334 connects the moving element 25 a and the rear edge of the hydrofoil 31 via two lower pulleys 335. An elastic member 334 a is provided in a portion of the lower connection line 334 between the lower pulley 335 below the hydrofoil 31 and the hydrofoil 31. The upper connection line 332 and the lower connection line 334 are, for example, metal wires. The elastic member 332a and the elastic member 334a are, for example, coil springs.

  As shown in FIG. 9, when the blade angle of the hydrofoil 31 is 0 °, the elastic member 332a and the elastic member 334a are in the extended state, and the moving element 25a is located at the center in the vertical direction of the guide member 251. . The mover 25a is supported by the restoring force of the elastic members 332a and 334a. When upward acceleration is applied to the floating body 2, the mover 25 a moves downward by inertial force, as shown in FIG. 10. As a result, the trailing edge of the hydrofoil 31 is pulled upward, and the blade angle of the hydrofoil 31 is changed to negative. On the other hand, when downward acceleration is applied to the floating body 2, the mover 25 a moves upward by inertial force as shown in FIG. 11. As a result, the trailing edge of the hydrofoil 31 is pulled downward, and the blade angle of the hydrofoil 31 is changed to positive.

  In other words, in the floating structure 1a, when the floating body 2 is moved up and down by a wave incident on the floating body 2, the mover 25a is moved in the vertical direction by inertial force. The mechanical energy generated by the movement of the moving element 25a is directly transmitted to the blade angle changing mechanism 33a without being converted into electrical energy or the like. Then, the blade angle changing mechanism 33a is driven by the mechanical energy, and the trailing edge of the hydrofoil 31 moves up and down to change the blade angle of the hydrofoil 31.

  In the floating structure 1a, the hydrofoil 31 is based on the period and wavelength of the main wave in the sea area where the floating structure 1a is installed, and the swing (particularly pitching and heaving) of the floating structure 1a caused by the main wave. And the distance in the front-rear direction between the body 2 and the floating body 2 is determined. Then, by changing the blade angle of the hydrofoil 31 by the blade angle changing mechanism 33a, the angle of attack α of the hydrofoil 31 in the upward flow is made positive, and the angle of attack α of the hydrofoil 31 in the downward flow is negative. It is said.

  Specifically, when an upward acceleration acts on the floating structure 1a due to main waves in the installation sea area of the floating structure 1a and the blade angle of the hydrofoil 31 becomes negative, as shown in FIG. The hydrofoil 31 is disposed at a position in the front-rear direction where the water flow Wf flowing into the hydrofoil 31 becomes a downward flow. The position of the hydrofoil 31 in the front-rear direction also flows into the hydrofoil 31 as shown in FIG. 5 when downward acceleration acts on the floating structure 1a and the blade angle of the hydrofoil 31 becomes positive. It is also a position where the water flow Wf becomes an upward flow. In addition, it is preferable that the maximum value and the minimum value of the blade angle of the hydrofoil 31 changed by the blade angle changing mechanism 33a are determined so that the angle of attack α of the hydrofoil 31 is smaller than the stall angle.

  As described above, the floating structure 1 a includes the floating body 2 that floats on the water surface and the thrust generation mechanism 3 c that is connected to the floating body 2. The thrust generating mechanism 3c is driven by mechanical energy generated when the floating body 2 moves up and down by an incident wave, and generates a thrust toward the wave upper side. Thereby, the wave drift force which acts on the floating structure 1a can be reduced using the force of a wave.

  Further, as described above, the thrust generating mechanism 3c is not driven by the wave force directly incident on the thrust generating mechanism 3c (that is, the wave force flowing into the hydrofoil 31), and the floating body 2 is moved up and down. Driven by mechanical energy generated by For this reason, based on the period and wavelength of the main wave in the installation sea area of the floating structure 1a, the structure and installation position of the thrust generating mechanism 3c (that is, the distance in the front-rear direction from the mover 25a) are appropriately designed. Thus, the thrust generating mechanism 3c can be appropriately driven in accordance with the direction of the water flow Wf incident on the thrust generating mechanism 3c. As a result, the wave drift force acting on the floating structure 1a can be efficiently reduced using the wave force.

  In the floating structure 1a, the structure for driving the blade angle changing mechanism 33a by mechanical energy generated when the floating body 2 moves up and down is not limited to the above-described moving element 25a, and may be changed as appropriate. The structure for changing the blade angle of the hydrofoil 31 is not limited to the blade angle changing mechanism 33a described above, and may be changed as appropriate. Further, in the floating structure 1a, the hydrofoil 31a shown in FIG. 7 is provided instead of the hydrofoil 31, and the blade angle of the hydrofoil 31a is substantially changed by changing the flap angle β. Good.

  Various modifications can be made in the above-described floating structures 1 and 1a.

  For example, in the floating structure 1 shown in FIG. 1, the hydrofoil 31 does not necessarily have to be disposed in front of the front surface 22 of the floating body 2 and does not have to be disposed above the bottom surface 26. For example, the hydrofoil 31 may be disposed vertically below the front surface 22 below the bottom surface 26 of the floating body 2.

  In the floating structure 1 shown in FIG. 1, the structure of the oscillating water column portion 24 is not limited to the above-described structure, and may be changed as appropriate. For example, the transmission wall 245 may be omitted from the vibrating water column part 24. Moreover, the vibration water column part 24 may be provided, for example, on the wave lower side of the floating body 2 (that is, near the rear surface 23).

  In the floating structure 1a shown in FIG. 9, the mover 25a may be connected to the vibrating floating body 25 floating on the water surface of the vibrating water column portion 24 shown in FIG. 4 via a roller cam or the like. In this case, the mover 25a is moved in the vertical direction by raising and lowering the vibrating floating body 25.

  In the floating structure 1, 1a, various configurations that generate thrust toward the wave upper side may be used instead of the hydrofoil 31, 31a. For example, the thrust generating mechanism 3 d shown in FIG. 12 includes a propeller 35 in addition to the above-described vibrating water column portion 24 and the vibrating floating body 25. The propeller 35 rotates about a rotation shaft 351 that faces in the front-rear direction. The propeller 35 is driven by a drive mechanism such as a pinion 352, a rack 353, bevel gears 354 and 355, a one-way clutch 356, etc. connected to the vibration floating body 25, for example. The drive mechanism converts the lifting and lowering of the vibrating floating body 25 into the rotation of the rotating shaft 351 of the propeller 35. In the thrust generating mechanism 3d, the propeller 35 is rotated in one direction by mechanical energy generated by the raising and lowering of the vibrating floating body 25, thereby generating a thrust toward the wave upper side.

  A thrust generating mechanism 3e shown in FIG. 13 includes fins 36 in addition to the vibrating water column 24 and the vibrating floating body 25 described above. The fins 36 are substantially flat members that are substantially perpendicular to the width direction. The fin 36 is a rigid body that is not deformed by the force of an incident wave (that is, its shape is maintained). The wave-side end of the fin 36 is fixed to a rotary shaft 361 that faces in the vertical direction. The fin 36 rotates (i.e., swings in the width direction) about the rotation shaft 361 as the rotation shaft 361 rotates. The fin 36 is driven by a driving mechanism such as a pinion 362, a rack 363, and a bevel gear 364 connected to the vibration floating body 25, for example. The drive mechanism converts the lifting and lowering of the vibration floating body 25 into the rotation of the rotation shaft 361 of the fin 36. In the thrust generation mechanism 3e, the fin 36 is swung in the width direction by the mechanical energy generated by the raising and lowering of the vibration floating body 25, and thus a thrust toward the wave side is generated. Note that the fin 36 may be formed of an elastic body.

  In the example shown in FIGS. 12 and 13, the propeller 35 and the fin 36 are disposed below the wave-side portion of the floating body 2, but the positions of the propeller 35 and the fin 36 may be variously changed. Further, the mechanical energy for driving the propeller 35 and the fins 36 is not limited to that generated by raising and lowering of the vibrating floating body 25. For example, even if it is generated by raising and lowering of the floating body 2 as shown in FIG. Good.

  In the floating structure 1, 1a, the size and shape of the floating body 2, the thrust generating mechanisms 3, 3a to 3e, and the windmill 4 may be variously changed. For example, the shape of the floating body 2 in plan view may be a substantially hexagonal shape or a substantially octagonal shape. Thereby, the drag coefficient of the floating body 2 is reduced, and the wave drift force generated in the floating body 2 is reduced. Moreover, the draft etc. of the floating body 2 may be changed as appropriate. In the windmill 4, the number of blades 41 may be one, two, or four or more. Moreover, the windmill 4 is not limited to the horizontal axis type windmill (that is, the horizontal axis windmill) as described above, and may be a vertical axis type windmill such as a Darrieus type windmill (that is, the vertical axis windmill).

  The floating structures 1 and 1a are not necessarily moored, and the positions of the floating structures 1 and 1a may be held by DPS (Dynamic Positioning System).

  The floating structures 1 and 1a are not necessarily provided with the wind turbine 4 for wind power generation. The floating structure 1, 1a may be used for various purposes other than wind power generation.

  The configurations in the above-described embodiments and modifications may be combined as appropriate as long as they do not contradict each other.

DESCRIPTION OF SYMBOLS 1,1a Floating structure 2 Floating body main body 3,3a-3e Thrust generating mechanism 4 Windmill 24 Oscillating water column part 25 Oscillating floating body 31,31a Hydrofoil 33,33a Blade angle changing mechanism 34 Period changing part 240 Oscillating water column 241 Front partition 243 Partition wall 244 Partition protrusion 245 Permeation wall 315 Hydrofoil main body 316 Flap

Claims (11)

A floating structure floating on the surface of the water,
A floating body that floats on the water surface;
A thrust generating mechanism connected to the floating body;
With
The floating body is
An oscillating water column that raises and lowers the water surface of the internal oscillating water column by the incident wave
A vibrating floating body floating on the water surface of the vibrating water column;
With
A floating structure according to claim 1, wherein the thrust generating mechanism is mechanically connected to the vibrating floating body and is driven by mechanical energy generated by raising and lowering of the vibrating floating body, thereby generating a thrust toward the wave upper side. The floating structure according to claim 1,
The vibrating water column is
A front partition wall extending vertically from the water to the water on the wave side of the floating body; and
A partition wall disposed on the wave front side of the front partition wall so as to face the front partition wall and extending in a vertical direction from above water to underwater;
From the lower end of the partition wall located above the lower end of the front partition, the partition protrusion extending to the wave side,
With
The floating structure is characterized in that the oscillating water column is located in a space between the front partition and the partition wall. The floating structure according to claim 2,
The floating structure according to claim 1, wherein the oscillating water column portion further includes a transmission wall that extends from the water to the water on the wave upper side than the partition wall. A floating structure floating on the surface of the water,
A floating body that floats on the water surface;
A thrust generating mechanism connected to the floating body;
With
The floating structure, wherein the thrust generation mechanism is driven by mechanical energy generated when the floating body is moved up and down by an incident wave, and generates a thrust toward the wave upper side. A floating structure according to any one of claims 1 to 4,
The thrust generation mechanism is
A hydrofoil arranged with the leading edge facing the wave upper side,
A blade angle changing mechanism that is driven by the mechanical energy and changes the blade angle of the hydrofoil;
With
A floating structure having a horizontal component of lift of the hydrofoil as the thrust. The floating structure according to claim 5,
When the flow of water flowing into the leading edge of the hydrofoil is inclined upward with respect to a horizontal plane, the hydrofoil generates upward lift,
The floating structure according to claim 1, wherein when the flow of water flowing into the leading edge of the hydrofoil is inclined downward with respect to a horizontal plane, the hydrofoil generates a downward lift. The floating structure according to claim 5 or 6,
The floating structure, wherein the blade angle changing mechanism is connected to a rear portion of the hydrofoil and moves up and down the rear portion. A floating structure according to any one of claims 5 to 7,
The hydrofoil is
The hydrofoil body,
A flap that is provided on a rear edge side of the hydrofoil main body and that can change a relative blade angle with respect to the hydrofoil main body by the blade angle change mechanism;
With
Changing the blade angle of the hydrofoil by the blade angle changing mechanism is changing the relative blade angle of the flap. A floating structure according to any one of claims 5 to 8,
The floating structure according to claim 1, wherein the hydrofoil is disposed on the wave side of the floating body. A floating structure according to any one of claims 1 to 9,
The floating structure according to claim 1, wherein the thrust generation mechanism includes a cycle changing unit that changes the cycle of the mechanical energy to a cycle shorter than a lifting / lowering cycle of the vibrating floating body or the floating body main body. A floating structure according to any one of claims 1 to 10,
A floating structure, further comprising a wind turbine for wind power generation disposed on the floating body.

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