Buoyancy system for an underwater device and associated methods for operating the same

Abstract

A buoyancy system includes a chamber having a volume associated therewith, and bladders within the volume of the chamber. Each bladder contains a clathrate mixture in a liquid state. The chamber includes an opening to allow surrounding water to circulate within the volume and contact the bladders. As the chamber is submerged in the surrounding water, the bladders expand based on the clathrate mixture changing from the liquid state to a solid state. This changes buoyancy by allowing less water to circulate within the volume of the chamber.

1 . A buoyancy system comprising:
 a chamber having a volume associated therewith; and   a plurality of bladders within the volume of said chamber, each bladder containing a clathrate mixture in a liquid state;   said chamber including at least one opening to allow surrounding water to circulate within the volume and contact said plurality of bladders, and as said chamber is submerged in the surrounding water said plurality of bladders expand based on the clathrate mixture changing from the liquid state to a solid state, thereby changing buoyancy by allowing less water to circulate within the volume of said chamber.   
     
     
         2 . The buoyancy system according to  claim 1 , wherein the clathrate mixture comprises water and a clathrating agent; and wherein the clathrating agent comprises at least one of methane, floro-methane, propane, floro-propane and hydrogen. 
     
     
         3 . The buoyancy system according to  claim 1 , wherein each bladder comprises a water-tight enclosure so that the clathrate mixture therein does not directly contact the water. 
     
     
         4 . The buoyancy system according to  claim 1 , wherein each bladder comprises an elastic enclosure that expands as the clathrate mixture changes to the solid state. 
     
     
         5 . The buoyancy system according to  claim 4 , wherein the elastic enclosure comprises a thermally conductive material. 
     
     
         6 . The buoyancy system according to  claim 1 , wherein the clathrate mixture comprises water and a clathrating agent, and each bladder maintains a predetermined pressure on the clathrate mixture so that the clathrating agent does not vaporize when the clathrate mixture is in the liquid state. 
     
     
         7 . The buoyancy system according to  claim 1 , further comprising a water permeable enclosure surrounding said plurality of bladders within the volume of said chamber. 
     
     
         8 . The buoyancy system according to  claim 1 , wherein each bladder is spherically shaped. 
     
     
         9 . The buoyancy system according to  claim 1 , further comprising a respective spacer coupled between adjacent bladders so that said bladders are spaced apart from one another within the volume of said chamber. 
     
     
         10 . The buoyancy system according to  claim 1 , wherein said plurality of bladders form a three-dimensional array of bladders. 
     
     
         11 . An underwater device comprising:
 a housing; and   a buoyancy system carried by said housing, and comprising
 a chamber having a volume associated therewith, and 
 a plurality of bladders within the volume of said chamber, each bladder containing a clathrate mixture in a liquid state, 
 said chamber including at least one opening to allow surrounding water to circulate within the volume and contact said plurality of bladders, and as said chamber is submerged in the surrounding water said plurality of bladders expand based on the clathrate mixture changing from the liquid state to a solid state, thereby changing buoyancy of the underwater device by allowing less water to circulate within the volume of said chamber. 
   
     
     
         12 . The underwater device according to  claim 11 , wherein the clathrate mixture comprises water and a clathrating agent; and wherein the clathrating agent comprises at least one of methane, floro-methane, propane, floro-propane and hydrogen. 
     
     
         13 . The underwater device according to  claim 11 , wherein each bladder comprises a water-tight enclosure so that the clathrate mixture therein does not directly contact the water. 
     
     
         14 . The underwater device according to  claim 11 , wherein each bladder comprises an elastic enclosure that expands as the clathrate mixture changes to the solid state. 
     
     
         15 . The underwater device according to  claim 14 , wherein the elastic enclosure comprises a thermally conductive material. 
     
     
         16 . The underwater device according to  claim 11 , wherein the clathrate mixture comprises water and a clathrating agent, and each bladder maintains a predetermined pressure on the clathrate mixture so that the clathrating agent does not vaporize when the clathrate mixture is in the liquid state. 
     
     
         17 . The underwater device according to  claim 11 , further comprising a water permeable enclosure surrounding said plurality of bladders within the volume of said chamber. 
     
     
         18 . The underwater device according to  claim 11 , wherein each bladder is spherically shaped. 
     
     
         19 . The underwater device according to  claim 11 , further comprising a respective spacer coupled between adjacent bladders so that said bladders are spaced apart from one another within the volume of said chamber. 
     
     
         20 . The underwater device according to  claim 11 , wherein said housing and said buoyancy system are configured so that the underwater device is an underwater glider. 
     
     
         21 . The underwater device according to  claim 11 , wherein said housing and said buoyancy system are configured so that the underwater device is a sonar buoy. 
     
     
         22 . A method for changing buoyancy of an underwater device comprising a buoyancy system, the buoyancy system comprising a chamber having a volume associated therewith, and includes at least one opening to allow water to circulate within the volume, and a plurality of bladders within the volume of the chamber, with each bladder containing a clathrate mixture in a liquid state, the method comprising:
 placing the underwater device in the water;   submerging the underwater device based on the surrounding water entering the at least one opening within the chamber and contacting the plurality of bladders; and   expanding the plurality of bladders based on the clathrate mixture changing from the liquid state to a solid state so that less water is circulated within the volume of the chamber, thereby changing the buoyancy of the underwater device.   
     
     
         23 . The method according to  claim 22 , further comprising contracting the plurality of bladders after having been expanded, the contracting based on the clathrate mixture changing from the solid state back to the liquid state so that more water is circulated within the volume of the chamber, thereby changing the buoyancy of the underwater device. 
     
     
         24 . The method according to  claim 22 , wherein the clathrate mixture comprises water and a clathrating agent; and wherein the clathrating agent comprises at least one of methane, floro-methane, propane, floro-propane, and hydrogen. 
     
     
         25 . The method according to  claim 22 , wherein each bladder comprises a water-tight enclosure so that the clathrate mixture therein does not directly contact the water. 
     
     
         26 . The method according to  claim 22 , wherein each bladder comprises an elastic enclosure that expands as the clathrate changes to the solid state. 
     
     
         27 . The method according to  claim 26 , wherein the elastic enclosure comprises a thermally conductive material. 
     
     
         28 . The method according to  claim 22 , wherein each bladder maintains the clathrate mixture pressure above the vaporization pressure of the clathrating agent. 
     
     
         29 . The method according to  claim 22 , wherein the buoyancy system further comprises a water permeable enclosure surrounding the plurality of bladders within the volume of the chamber. 
     
     
         30 . The method according to  claim 22 , wherein each bladder is spherically shaped. 
     
     
         31 . The method according to  claim 22 , wherein the buoyancy system further comprises a respective spacer coupled between adjacent bladders so that the bladders are spaced apart from one another within the volume of the chamber. 
     
     
         32 . The method according to  claim 22 , wherein the housing and the buoyancy system are configured so that the underwater device is at least one of an underwater glider and a sonar buoy.