Water cannon

Abstract

A water cannon utilizing ultra high pressure to propel a collimated beam of water or other liquid through a nozzle at high speeds at great distances. Ultra high pressure is achieved by multiple serially communicating pumping stations that successively build fluid pressure within respective annular chambers having cross-sectional areas that decrease between the pumping stations as fluid speed increases in the downstream direction. To attain the desired velocity head at the nozzle, a gearbox connected to a prime mover, e.g., a gas turbine engine on-board an ocean vessel, drives multi-stage axial flow pumps at successively increasing speeds commensurate with a volumetric rate of flow. Optionally, the axial flow pumps may include variable stator vanes between rotor blades and/or variable inlet guide vanes at an inlet in order to control flow volume, fluid pressure, engine load, or impact force delivered by the cannon. Further, the collimated beam exiting the cannon may be electrified with a high voltage in order to disable the target's on-board processing or communication equipment. Depending on design criteria, beam size (e.g., three to six inches, more or less), ejection speed, ejection pressure (e.g., 3,000 to 10,000 psi), flow rate (several hundred to several thousand pounds per second), and/or range (e.g., two to five miles) may be adjusted to achieve a desired effect on a target.

1 . A water cannon comprising: 
 an inlet,    a first pumping station having a first multistage axial flow pump,    a second pumping station having a second multistage axial flow pump,    a primary conduit disposed between the first and second pumping stations having a cross-sectional area the converges in a downstream direction,    a third pumping station having a third multistage axial flow pump,    a secondary conduit between the second and third pumping stations having a cross-sectional area the converges in a downstream direction, and    a nozzle that includes a flow straightener that receives water from the third pumping station to produce a coherent beam of fluid.    
   
   
       2 . The water cannon of  claim 1 , comprising independent drive shafts to drive rotor blades in the respective axial flow pumps of the pumping stations and a gearing mechanism coupling an engine to rotate each shaft at a speed commensurate with desired fluid velocity within the respective pumping stations.  
   
   
       3 . The water cannon of  claim 2 , wherein said pumping stations are disposed substantially in physically parallel relation and said primary and secondary conduits are U-shaped.  
   
   
       4 . The water cannon of  claim 2 , wherein said pumping stations are substantially axially aligned with substantially axially disposed primary and secondary conduits between said pumping stations.  
   
   
       5 . The water cannon of  claim 1 , further including a terminal conduit between the third pumping station and the nozzle that converges towards said nozzle whereby to further increase velocity of ejected water.  
   
   
       6 . The water cannon of  claim 5 , further comprising a turret that controls direction of said nozzle about a vertical axis and an azimuth of said nozzle about a horizontal axis.  
   
   
       7 . The water cannon of  claim 1 , wherein said nozzle produces a collimated beam of fluid greater than 100 mm in diameter and said first, second, and third pumping stations include an arrangement of rotors and stators to successively build fluid pressure beyond 3000 psi at said nozzle.  
   
   
       8 . The water cannon of  claim 1 , further including a venturi injector in a flow path of said fluid to add a substance to said fluid prior to ejection from said nozzle.  
   
   
       9 . The water cannon of  claim 1 , wherein said axial flow pumps include variable stator vanes within multistage sections thereof whereby to control loading and fluid flow rate within the axial flow pumps.  
   
   
       10 . The water cannon weapon of  claim 9 , wherein said stator vanes of said axial flow pumps are independently controllable.  
   
   
       11 . The water cannon of  claim 1 , wherein at least said first axial flow pump includes a variable inlet guide vane at an inlet thereof.  
   
   
       12 . A device that generates ultra high fluid pressure, said device comprising: 
 a fluid inlet;    multiple serially communicating pumping stations that each comprise a multistage axial flow pump, each said axial flow pump including multiple rotor sections and stator sections;    a conduit between each pumping station having a decreasing cross-sectional area in a downstream direction, and    a flow straightener to convey a coherent beam of fluid from a final pumping station to an outlet.    
   
   
       13 . The device of  claim 12 , further comprising an independent drive shaft for each pumping station.  
   
   
       14 . The device of  claim 13 , further including an engine having a main shaft and a gearbox coupled to the main shaft of the engine and each said independent shaft in order to rotate each independent shaft at a speed commensurate with a given rate of mass flow of liquid.  
   
   
       15 . A method of ejecting high pressure liquid from a nozzle comprising the steps of: 
 providing at least three serially-communicating multistage axial flow pumps having liquid flow paths therein of decreasing diameters in a downstream direction,    operating said pumps to increase liquid pressure between successive pumps,    conveying said liquid between successive pumps along a path having a decreasing cross-sectional area in the downstream direction whereby to correspondingly increase speed of said liquid along the path, and    ejecting said liquid from a nozzle communicating with a final one of said serially communicating pumps.    
   
   
       16 . The method of  claim 15 , further comprising the step of collimating said liquid prior to said ejecting step in order to reduce dispersion after said ejecting.  
   
   
       17 . The method of  claim 16 , further comprising the step of controlling at least one of a direction and azimuth of ejection of said liquid during said ejecting step.  
   
   
       18 . The method of  claim 17 , further comprising the step of gearing a common shaft to rotate said serially communicating axial flow pumps at different speeds commensurate with a volumetric rate of flow.  
   
   
       19 . The method of  claim 17 , further comprising physically arranging said serially communicating pumps to cancel moments generated by accelerating liquid mass through said pumps.