Abstract:
A hull that is part of a system for producing energy through the action of waves. The hull&#39;s shape, dimension and orientation make the system less costly and increase the energy provided by the system.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims the benefit of Provisional Patent Application Ser. No. 61/655,095 filed Jun. 4, 2012, which is incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to a system for producing energy through the action of waves. More particularly, it relates to a ship&#39;s hull that constitutes part of, or contains, a system for producing energy through the action of waves. 
       BACKGROUND OF THE INVENTION 
       [0003]    There are numerous examples in the art of systems and methods for producing energy through the action of waves on ships&#39; hulls and other floating platforms (collectively, herein “hulls”). For example, U.S. Patent Publication No. US-2009-0160191-A1, which is incorporated herein by reference, describes a system for producing electricity through the action of waves on a hull. A second movable mass is carried by and movable relative to the hull, a first movable, the second movable mass creates kinetic energy as a result of varying its position relative to the hull. A mechanism then converts the kinetic energy of the second mass moving relative to the first mass into electricity in a preferred embodiment. In this example, the hull is an integral part of the system for producing energy. 
         [0004]    In other examples of systems for producing energy through the action of waves, hulls merely carry, or contain, the system, Herein, a hull that is an integral part of a system for producing energy through the action of waves, or merely carries or contains such a system, will be referred to as part of the system for producing energy through the action of waves. 
         [0005]    Many parts of these systems for producing energy through the action of waves are described in detail. However, little attention, if any, is paid to hulls that are part of these systems even though the shape, dimension and orientation of the hulls may significantly affect both the costs of producing the systems and the amount of energy provided by the systems. 
         [0006]    It is a goal of the present invention to produce hulls to reduce the costs of producing systems for the production of energy through the action of waves and to increase the energy produced by the systems. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention is hulls that are part of systems for producing energy through the action of waves. The hulls&#39; shapes, dimensions and orientations make the systems less costly and increase the energy produced by the systems. 
         [0008]    These aspects of the invention are not meant to be exclusive and other features, aspects, and advantages of the present invention will be readily apparent to those of ordinary skill in the art when read in conjunction with the following description, appended claims, and accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    These and other features and advantages of the present invention will be better understood by reading the following detailed description of embodiments, taken together with the drawings wherein: 
           [0010]      FIG. 1  is a schematic view of wave periods; 
           [0011]      FIG. 2  is a table showing wave lengths and wave frequencies; 
           [0012]      FIG. 3  is a cross-section of a hull; 
           [0013]      FIG. 3A  is a cross-section of a hull; 
           [0014]      FIG. 4  is a schematic view of a water plane; 
           [0015]      FIG. 5  is a schematic view of tuned elliptical hulls; 
           [0016]      FIG. 5A  is a schematic view of a hull with external ballast retaining means; 
           [0017]      FIG. 6  is a schematic view of the orientation of a single hull; 
           [0018]      FIG. 7  is a schematic view of the orientation of another single hull; 
           [0019]      FIG. 8  is a schematic view of the orientation of multiple hulls connected by trusses; 
           [0020]      FIG. 9  is a schematic view of the orientation of multiple hulls connected to a stationary mooring line and a winch line; 
           [0021]      FIG. 10  is a schematic view of the orientation of multiple hulls connected to a stationary mooring line and multiple winch lines; 
           [0022]      FIG. 11  is a schematic view of a phase array of multiple hulls; 
           [0023]      FIG. 12  is a graph of power produced versus time for a single hull; 
           [0024]      FIG. 13  is a schematic view of a phase array of two hulls; 
           [0025]      FIG. 14  is a graph of power produced versus time for two hulls; 
           [0026]      FIG. 15  is a schematic view of one embodiment of a phase array; 
           [0027]      FIG. 16  is a schematic view of another embodiment of a phase array; 
           [0028]      FIG. 17  is a schematic view of another embodiment of a phase array; 
           [0029]      FIG. 18  is a schematic view of another embodiment of a phase array; 
           [0030]      FIG. 19  is a schematic view of another embodiment of a phase array; 
           [0031]      FIG. 20  is a schematic view of another embodiment of a phase array; 
           [0032]      FIG. 21  is a schematic view of another embodiment of a phase array; and 
           [0033]      FIG. 22  is a schematic view of another embodiment of a phase array. 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0034]    The present invention is a hull constituting part of a system for producing energy through the action of waves. The other parts of the system may be parts of the system described in U.S. Patent Publication US-2009-0160191-A1 or any other system for producing energy through the action of waves. 
         [0035]    A preferred embodiment of the present invention is designed to reduce manufacturing costs. Ocean waves can be divided into two groups based on their frequencies: one group contains waves with frequencies centered around 9 sec. (medium frequency) and one group contains waves with frequencies centered around 12 sec. (long frequency). As shown in  FIG. 1 , a 9 sec. wave has a one-half wavelength, the distance from a peak to an adjacent trough of 207 ft. and a 12 sec. wave has a one-half wavelength of 368 ft. The optimum length of a hull is between one-quarter and three-quarters of a wavelength. Here, as shown in  FIG. 2 , the optimum length of a hull to be used for both 9 sec. and 12 sec. waves would be longer than one-quarter of a wavelength of a 12 sec. or long wave, 184 ft., and shorter than three-quarters of a wavelength of a 9 sec. or medium wave, 311 ft. A preferred embodiment has a hull length of between 200 and 280 feet. 
         [0036]    As shown in  FIG. 3 , a cross-section  345  of a hull in another preferred embodiment is an ellipse having a cross-section with a long axis that is vertical  346  of 75 ft. and a short axis that is horizontal  349  of 53 ft. The curved walls of the ellipse cause it to have greater strength than structures with straight sections of wall. This, in turn, allows the use of thinner, less expensive walls. 
         [0037]    In addition, this elliptical shape is optimized for displacement and water plane to be self-tuning to multiple wave frequencies ranging from 7 sec. to 15 sec. Other cross-section geometries, such as a diamond shape, as shown in  FIG. 3A , that are similar to an ellipse in increasing or decreasing waterplane as the hull pitches or heaves can also be used. The elliptical geometry of the hull is used to tune the phase of the hull to wave lengths via changes to the waterplane, which is the plane formed by the intersection of the hull and the waterline, as shown in  FIG. 4 . As shown in  FIG. 5 , as the waterplane of the ellipse increases or decreases for a given moment of inertia, the hull becomes stiffer or softer, tuning it to higher or lower frequency waves. As the waterplane increases and the hull becomes stiffer  571 , it is tuned to higher frequency waves, and as the waterplane decreases and the hull becomes softer  572 , it is tuned to lower frequency waves as it pitches and heaves. 
         [0038]    The draft of the ellipse determines the static waterplane of the hull. As the draft increases, the waterline rides higher on the ellipse  572 , which then has a smaller waterplane, which softens the hull. As the draft decreases and the waterline rides closer to the geometric horizontal centerline of the ellipse  571 , the waterplane of the hull increases, which stiffens the hull. 
         [0039]    In addition, as the moment of inertia of a hull increases, the hull can be tuned to longer and longer wave frequencies. By adding mass externally at the bow or stern of the hull, the moment of inertia of the hull increases without adding additional volume to the hull. The relocation of the additional mass is much less expensive than adding volume to the hull to accommodate more mass needed to create a similar moment of inertia if the mass were added within the hull. 
         [0040]    The addition or subtraction of additional mass, located externally at the bow and stern of the hull, also increases or decreases the displacement of the hull, which, in turn, increases or decreases the moment of inertia of the hull, without adding volume to the hull, which, in turn, tunes the phase of the hull to longer or shorter wave periods, respectively. 
         [0041]    In another preferred embodiment, as shown in  FIG. 5A , a hull  501  has an external ballast retaining means  502  at its bow  503 , which can also be at its stern (not shown). The ballast retaining means can consist of a hook  502  for hanging modular ballast  504  such as blocks of concrete or sheets of metal or cages into which such ballast can be placed, or other retaining means known to those skilled in the art. The modular ballast is added to, or subtracted from, the ballast retaining means. The addition or subtraction of such ballast increases or decreases hull length, displacement and moment of inertia, respectively, to tune the phase of the hull to operate in phase with higher frequency or lower frequency waves and increase power generation. 
         [0042]    A typical hull  210 , as shown in  FIG. 6 , has a greater moment of inertia along the line  211  from bow  212  to stern  213  than the moment of inertia along the line  214  from port  215  to starboard  216 . This will result in the hull turning so that the line  211  from bow  212  to stern  213  is perpendicular to the direction  217  of the waves  218 , causing the hull to roll from port to starboard. It should be noted that, as used herein, the direction of the wind is parallel to the direction of the waves and perpendicular to the wavefront. 
         [0043]    In order to build a hull that will orient itself so that the line from bow to stern is parallel to the direction of the waves, the moment of inertia along the line from port to starboard must be increased so that it is greater than the moment of inertia along the line from bow to stern. This has been done in the prior art by increasing the dimension of the hull along the line  220  from port  221  to starboard  222 , as shown in  FIG. 7 . However, the cost of materials for such a hull and the cost of manufacturing and transporting it are significant. 
         [0044]    In a preferred embodiment, as shown in  FIG. 8 , multiple hulls (here two but more than two can be used)  303 ,  304  are held in position parallel to each other by simple trusses  305 . The trusses hold the hulls apart such that the first hull is closest to the second hull between the starboard side of the first hull and the port side of the second hull. The distance between the hulls  306  is chosen, in part, so that the moment of inertia along the line  307  from the port side of the left-most hull to the starboard side of the right-most hull exceeds the moment of inertia along the line  308  from the bow to the stern of a hull. This will result in the multiple hulls structure orienting itself so the line  308  from bow to stern is parallel to the direction  310  of the waves  311 . 
         [0045]    In another preferred embodiment, as shown in  FIG. 9 , multiple hulls  320 - 329  are attached to a stationary mooring, which can be either a mooring line  330  with ends attached to buoys  331  and  332  or individual stationary moorings for each hull (not shown). The multiple hulls  320 - 329  are also attached to a winch line  333  with ends attached to winches  334  and  335  in buoys  331 ,  332 . As waves change direction, the winches  334  and  335 , by moving the winch line from one winch to the other, actively orient the hulls to the wave direction so that the line  336  from the stern  338  to the bow  337  of a hull, or the direction in which the hull is headed, is parallel to the direction  339  of a wave  340 . A string mooring, excluding the active winch line, can also be used to moor hulls with trusses, as described above, that are self-orienting. In another embodiment, as shown in  FIG. 10 , multiple hulls  520 - 529  are attached to a stationary mooring, which can be either a mooring line  530  with ends attached to buoys  531 - 532  or an individual stationary mooring for each hull (not shown). A winch  540 - 549  can be attached to each individual  520 - 529  hull with winch lines  560  having one end attached to the winch and one end attached to the stationary mooring. Each hull winch  540 - 549 , by moving an individual winch line  550 - 568 , can actively orient each individual hull  520 - 529  so that the line from the stern to the bow of the hull, or the direction in which the hull is headed, is parallel to the direction of a wave. 
         [0046]    In another preferred embodiment, multiple hulls that are part of a system to produce electricity through the action of waves are arranged in a phase array as shown in  FIG. 11 . The purpose of the phase array is to address the problem of the intermittent nature or granularity, as described below, of the electricity produced by one or more independent hulls. 
         [0047]    With one hull, electricity is produced while a wave is acting on the hull. However, no electricity is produced during the period from one wave ceasing to act on the hull to the next wave beginning to act on the hull. The electricity produced is granular, as shown in  FIG. 12 , for waves with peaks 10 secs. apart. Such granular electricity cannot be transmitted directly to commercial electric grids but must be stored in batteries or other costly storage devices, adding to the expense of producing the electricity. 
         [0048]    The solution is to orient multiple hulls so that the peak of a first wave in a series of waves is acting on a second when the peak of a second wave is not acting on the first hull. For example, if two hulls  401 ,  402  are moored by mooring lines  403 ,  404  in a phase array  400 , as shown in  FIG. 13 , the peak of a wave in a series of waves traveling in direction  405  with peaks 10 secs. apart acts on hull  401  first and 5 seconds later on hull  402 . In this phase array, as shown in  FIG. 14 , the granularity of electricity  406  produced, which is a combination of the electricity produced by hulls  401  and the electricity produced by hull  402 , begins to be smoothed out. With a larger number of hulls arrayed appropriately the aggregate total of the electricity produced by all the hulls loses its graininess and the need for costly storage devices goes away. 
         [0049]    In another preferred embodiment, shown in  FIG. 11 , multiple hulls  410 - 419  are attached to mooring lines  420 ,  421 , the ends of which form a right array angle  422  to form phase array  424 . The phase array allows the hulls  410 - 419  to be moved so that waves of different frequencies or waves coming from different directions, in this embodiment +/−20°, will still produce electricity from hulls  410 - 419  that is not granular. For example, if the time between wave peaks increases, the distance  423  from the bow of one hull  411  to the bow of another hull  412  can be increased by moving the hulls apart on mooring line  420 . Also, the array angle  402  can be decreased, in effect increasing the distance from the bow of one hull to the bow of another hull. 
         [0050]    Other mooring line configurations in other phase arrays are shown in  FIGS. 15-22  as examples. In  FIG. 15  the ends of the mooring lines  601 ,  602  form a 90° angle, which can be increased or decreased to change the distance between the bow of one hull on one of the mooring lines to the bow of another such hull. In  FIG. 16 , the mooring lines  601 ,  602  do not intersect so they can be moved perpendicular to the direction of the wind to take into account changes in wind direction. In  FIG. 17 , the mooring lines  601 ,  602  do not intersect so that one or both can be moved parallel to the general direction of the wind. 
         [0051]    In  FIG. 18  the mooring lines  601 ,  602  each form a different angle with a line parallel to the general direction of the wind. Each of those angles can be increased or decreased. In  FIG. 19  the mooring lines  601 ,  602  are of different lengths. The lengths of each of the mooring lines can be increased or decreased. In.  FIG. 20 , the hulls along one mooring line  601  can be spaced apart or the entire mooring line can be moved. 
         [0052]    In  FIG. 21  there are multiple phase arrays. Each one consists of two mooring lines  601 ,  602  with ends meeting at a 90° angle. The phase arrays can be moved closer together or further apart in the direction perpendicular to the general direction of the wind. In  FIG. 22 , there are multiple phase arrays. Again, each one consists of two mooring lines  601 ,  602  with ends meeting at a 90° angle. The phase arrays can be moved closer together or further apart in the direction parallel to the general direction of the wind. 
         [0053]    While the principles of the invention have been described herein, it is to be understood by those skilled in the art that this description is made only by way of example and not as a limitation as to the scope of the invention. Other embodiments are contemplated within the scope of the present invention in addition to the exemplary embodiments shown and described herein. Modifications and substitutions by one of ordinary skill in the art are considered to be within the scope of the present invention.