Abstract:
One embodiment of a fluid mobilizing vessel shown in FIG.  1  comprises a hull ( 14 ) impervious to a surrounding fluid ( 12 ), a solar cell ( 16 ) capable of converting light ( 18 ) into electrical energy, an electromechanical actuator ( 24 ), and a mobile weight ( 28 ) movable with respect to the hull, whereby the electromechanical actuator moves the weight relative to the hull, causing compensatory motion of the hull within the surrounding fluid and thereby motion ( 32 ) of the surrounding fluid.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This applications claims the benefit of provisional patent application Ser. No. 60/971,926, filed 2007 Sep. 13 by the present inventor. 
     
    
     FEDERALLY SPONSORED RESEARCH 
       [0002]    Not Applicable 
       SEQUENCE LISTING OR PROGRAM 
       [0003]    Not Applicable 
       BACKGROUND 
       [0004]    1. Field 
         [0005]    This application relates to devices that create motion in fluids. 
         [0006]    2. Prior Art 
         [0007]    A need exists for the improvement of water bodies in aquaculture systems, reservoirs, fish tanks, artificial ponds and lakes, swimming pools, bays and inlets, and the like, in controlling algae growth, mosquito propagation, ice formation, distributing nutrients, breaking up oil slicks, and other problems generally related to stagnation and/or lack of aeration of the water. Solutions exist that use photovoltaic solar cells as a power source, which are especially useful for remote locations or where it is important to avoid the cost or hazards of electricity from power lines. 
         [0008]    “Solar aeration system,” U.S. Pat. No. 6,676,837, uses an air compressor powered by solar cells and batteries to aerate water. Similarly, solar-powered fountains, such as the “Solar Fountain Pump” produced by Solars-China.com, are commercially available. In some cases, solar powered water pumps powered by the sun are used to re-circulate water to an artificial waterfall in a pond where there is no natural inflow from a stream. However, these solutions suffer from problems with clogging and tangling by algae, seaweed, and other solid matter floating in the water, because their propellers, impellers, or other articulated effectors are in direct contact with the water. 
         [0009]    My fluid mobilizer addresses these problems by creating water motion using a floating vessel inside of which an inertial system causes the entire vessel to move in the water. Such a vessel may remain un-entangled in a pond because of its single, unarticulated exterior surface, especially if the shape of the vessel&#39;s hull is relatively smooth. The overall motion of the vessel may also create a clear space by pushing material floating on the surface away from the vessel. 
       SUMMARY 
       [0010]    In accordance with one embodiment, a fluid mobilizing vessel comprises a hull impervious to a surrounding fluid, a solar cell capable of converting light into electrical energy, an electromechanical actuator, and a mobile weight movable with respect to the hull, whereby the electromechanical actuator moves the weight relative to the hull, causing compensatory motion of the hull within the surrounding fluid and thereby motion of the surrounding fluid. 
     
    
     
       DRAWINGS 
       Figures 
         [0011]      FIG. 1  shows an embodiment based on a motor that moves an eccentric weight in a circular path to generate inertial motion of the vessel. 
           [0012]      FIG. 2  shows an embodiment based on a solenoid that moves a weight periodically in a vertical path to generate inertial motion of the vessel. 
       
    
    
     REFERENCE NUMERALS 
       [0013]      
         [0000]    
       
         
               
               
               
             
           
               
                   
                   
               
             
             
               
                   
                 10 buoyant vessel 
                 12 surrounding water 
               
               
                   
                 14 transparent waterproof hull 
                 16 solar cell 
               
               
                   
                 18 light ray from the sun 
                 20 the Sun 
               
               
                   
                 22 wires 
                 24 electric motor 
               
               
                   
                 26 motor shaft 
                 28 eccentric weight 
               
               
                   
                 30 lever 
                 32 waves generated in water 
               
               
                   
                 34 ring for attaching tether 
                 36 wires 
               
               
                   
                 38 interface 
                 40 wires 
               
               
                   
                 42 solenoid coil 
                 44 solenoid plunger 
               
               
                   
                 46 weight 
                 48 spring 
               
               
                   
                 50 weight 
                 52 rigid brace 
               
               
                   
                 54 spring 
                 56 permanent magnet 
               
               
                   
                   
               
             
          
         
       
     
       DETAILED DESCRIPTION 
       [0014]    One preferred embodiment of the Solar Powered Inertial Fluid Mobilizer is illustrated in  FIG. 1 . The embodiment comprises a buoyant vessel  10  floating in a body of surrounding water  12 . The buoyant vessel has a spherical hull  14  that is waterproof and transparent. Hull  14  contains solar cell  16  that converts light  18  from the Sun  20  to an electrical current in wires  22  powering electrical motor  24 , which is rigidly attached to hull  14 , to turn shaft  26 , causing eccentric mobile weight  28  attached by lever  30  to rotate around the axis of shaft  26  (movement of the weight is shown with dashed lines). The force employed in moving the weight creates an equal and opposite force that causes hull  14  to move in the water  12  creating waves  32  in the water. A ring  34  is attached to the bottom of hull  14  to provide a means to tether the vessel to prevent it from drifting. The device may be hermetically sealed to extend its functional lifetime. 
         [0015]    The embodiment in  FIG. 1  uses light energy from the sun to move the weight  28  in a circular motion, which causes the vessel to move, creating wave motion  32  in the surrounding fluid  12  without entanglement or clogging of the apparatus, and without requiring connections to an external power-line. The embodiment is therefore inexpensive to operate, safe, and requires little or no maintenance. 
         [0016]    Various other adaptations and implementations of the basic concept are possible. For example, rather than creating rotational motion, it may be advantageous to create vertical periodic motion of the vessel, causing the vessel to bob up and down in the water. The embodiment shown in  FIG. 2  comprises a buoyant vessel  10  floating in a body of surrounding water  12 . The buoyant vessel has a spherical hull  14  that is waterproof and transparent. Hull  14  contains solar cell  16  that converts light  18  from the Sun  20  to an electrical current in wires  36  connected to interface  38  (described in detail below), with interface  38  also connected by wires  40  to electromagnetic solenoid  42  rigidly attached to hull  14 . The plunger  44  of solenoid  42  comprising a ferromagnetic material is attached to a mobile weight  46  suspending on springs  48  such that periodic vertical motion of weight  46  may result when interface  38  generates an appropriate time-varying current in solenoid  42 . Periodic vertical motion (shown with dashed lines) of weight  46  causes vertical motion of hull  14  in water  12  creating waves  32  in without entanglement or clogging of the apparatus. 
         [0017]    Interface  38  may contain a number of components involved in producing a time-varying current in solenoid  42  appropriate for creating periodic vertical motion of weight  46 . 
         [0018]    Interface  38  may preferably contain a control system (which may include analog circuitry, digital circuitry, a computer, or some combination thereof) to control the time-varying current in the solenoid. The direction and magnitude of the time-varying current may be controlled so as to build up harmonic motion of hull  14  and of surrounding fluid  12 . Interface  38  may include inertial sensors to measure the motion of hull  14 , and interface  38  may also include sensors to measure location, motion, or both, of actively moved weight  46  and of passive weight  50  (described below). Interface  38  may employ feedback from these sensors to optimize the time-varying current in the solenoid to maximize the periodic motion of the vessel. 
         [0019]    Interface  38  may include an onboard navigation system to determine the location of the vessel, such as a Global Positioning System (GPS) or other navigation system based on optical tracking, ultrasound, or computer vision. These are well known to those skilled in the art. Interface  38  may include a communications system to provide a means of transferring information to and from a remote system, such as another vessel or a central control station. Such a communications system may use radio, infrared, or other channels well known to those skilled in the art. 
         [0020]    For some applications, such as preventing the buildup of ice on a body of water, interface  38  may contain batteries or other energy storage devices to continue operation during the night, as well as timing and sensing circuitry to conserve battery power by operating intermittently when sunlight is not present. 
         [0021]    Several additional components are shown in the embodiment in  FIG. 2 : 
         [0022]    Energy may not be stored in the periodic vertical motion of weight  46 , in  FIG. 2 , as efficiently as in the circular motion of eccentric weight  28 , in  FIG. 1 . To remedy this, the embodiment in  FIG. 2  includes an additional passive weight  50  suspended by springs  54  from rigid brace  52  attached to hull  14 . Vertical periodic motion (shown with dashed lines) induced in weight  50  by motion of hull  14  may increase the ability of vessel  10  to store mechanical energy, and thereby increase the magnitude of the resulting periodic motion of hull  14  and of waves  32  produced in the surrounding water  12 . Additional energy may be stored in the waves  32  themselves. Interface  38  may use measurements of the vessel motion from its motion sensors in determining the time-varying current in solenoid  42 . Use of such regenerative feedback to create of harmonic motion is well known to those skilled in the art. 
         [0023]    Finally, the embodiment in  FIG. 2  includes a permanent magnet  56  with its north “N” and south “S” poles oriented so as to cause the vessel to turn in the Earth&#39;s magnetic field to a preferred orientation, much as a compass needle turns to a preferred orientation in a magnetic compass. The purpose of this may be to maximize exposure of the solar cell  16  to sunlight at latitudes away from the equator, or to optimize the response of a radio antenna in a communications system included in interface  38 . 
         [0024]    Other embodiments are possible. The shape of the fluid-mobilizing vessel may be designed so as to facilitate the vessel&#39;s periodic motion in the water by minimizing drag. Alternatively, the vessel may be shaped in such a way as to produce a net non-periodic motion across the water surface, along a straight or a curved path, by employing asymmetry in the vessel&#39;s shape. This may permit the vessel to bring its beneficial effect to a larger area of the water surface over time. Various curved or flat regions in the vessel&#39;s exterior at specific heights relative to its resting position in the water may yield impact with the water to facilitate aeration. For example, a horizontal plane in the external surface of the hull may be made to repeatedly “slap” against the surface of the water by periodic vertical motion of the hull, thereby facilitating aeration of the water. The vessel&#39;s exterior surface shape may also be designed to maximize clearance of the surface algae by generating a net flow of surface water towards or away from the vessel. 
       CONCLUSION, RAMIFICATION, AND SCOPE 
       [0025]    Accordingly, the reader will see that the Solar Powered Inertial Fluid Mobilizer operates without tending to tangle or clog, because using a movable weight to create inertial motion of the hull prevents articulated moving parts from touching the surrounding fluid. The solar cell provides a safe, independent, and non-diminishing source of energy. 
         [0026]    Although the description above contains many specificities, these should not be construed as limiting the scope of the embodiments but as merely providing illustrations of some of the presently preferred embodiments. For example, in  FIG. 1 , motor  24 , shaft  26 , lever  30 , and mobile weight  28  may all be represented by a miniature cell phone vibrator; plunger  44  in solenoid  42  in  FIG. 2  may be a permanent magnet rather than simply a ferromagnetic material, permitting electromechanical forces to be created between solenoid  42  and weight  46  in both upward and downward directions, depending on the direction of the current in the solenoid; an electromechanical actuator other than a motor or a solenoid may be employed, based, for example, on other configurations of permanent magnets, electromagnets, electrostatic drivers, electrochemical actuators, or other means of converting electrical energy into mechanical energy. 
         [0027]    Although the surrounding fluid in embodiments thus far described has been water, nothing in the description should be construed to limit the mobilized fluid to water. The mobilizer may be used for other purposes, such as circulating warm pools of oil to cool them, or preventing the formation of a “skin” on the surface of a vat of liquid sewage. 
         [0028]    Nothing in the description of the particular uses should limit the fluid mobilizer to those uses. For example, in growing algae for food or fuel, maximal rather than minimal algae growth may be the goal. Algae grown in large vats may benefit from fluid motion to circulate nutrients. Alternatively, colored water and oil may be stirred in a decorative jar by a miniature solar powered mobilizer, when placed in a sunlit window, strictly for aesthetic purposes. 
         [0029]    Thus the scope of the embodiments should be determined by the appended claims and their legal equivalents, rather than by the examples given.