Submersible having variable lift depending on the navigation mode

Abstract

An underwater vehicle designed for navigation at the surface or underwater, having a hull, and at least one normal-force generator of force normal to a longitudinal axis of the underwater vehicle, borne by the hull, wherein a forward part of the hull is asymmetric with respect to the longitudinal axis so as to generate lift as the underwater vehicle moves and wherein the lift is in the opposite direction to the resultant of the forces of the normal-force generator or generators is provided.

1 . An underwater vehicle designed for navigation at the surface or underwater, having a hull, at least one propulsion means and at least one normal-force generator of force normal to a longitudinal axis of said underwater vehicle, wherein:
 a forward part of said hull is asymmetric with respect to said longitudinal axis so as to generate lift as said underwater vehicle moves;   said lift is in the opposite direction to the resultant of the normal forces of said normal-force generator or generators;   one said propulsion means is designed to give said vehicle a speed, the speed being designed to govern a pitch angle of said autonomous underwater vehicle that is comprised in a range from to 5° to 20° as said autonomous underwater vehicle moves in said surface navigation.   
     
     
         2 . The underwater vehicle as claimed in  claim 1 , wherein at least one said normal-force generator is arranged in such a way as to be out of the water during surface navigation. 
     
     
         3 . The underwater vehicle as claimed in  claim 1 , comprising at least one motor powered autonomously and designed to actuate at least one said propulsion means. 
     
     
         4 . The underwater vehicle as claimed in  claim 1 , wherein at least one said normal-force generator is borne by said hull and chosen from a fin and a vortex generator. 
     
     
         5 . The underwater vehicle as claimed in  claim 1 , wherein at least one said normal-force generator is chosen from a fin borne by said hull, a vortex generator borne by said hull, and a said propulsion means the thrust of which comprises a component along an axis normal to said longitudinal axis. 
     
     
         6 . The underwater vehicle as claimed in  claim 1 , comprising at least one underwater measurement instrument situated on said forward part of said hull, said part being both submerged during surface navigation and asymmetric with respect to said longitudinal axis. 
     
     
         7 . The underwater vehicle as claimed in  claim 1 , wherein the normal at any point of said forward part of said hull comprises at least one component in the direction of said longitudinal axis and at least one component in the opposite direction to said lift. 
     
     
         8 . The underwater vehicle as claimed in  claim 1 , wherein the nose of said underwater vehicle comprises at least one ballasting system. 
     
     
         9 . The underwater vehicle as claimed in  claim 8  also comprising an air duct connecting an element chosen from at least one combustion engine and at least one fuel cell to at least one said ballast. 
     
     
         10 . The underwater vehicle as claimed in  claim 8 , comprising at least one duct equipped with a submersible air turbine connecting at least one said ballast to the external air. 
     
     
         11 . The underwater vehicle as claimed in  claim 1 , wherein the part that is out of the water in surface navigation contains at least one instrument chosen from at least one aerial measurement instrument and at least one aerial communications instrument. 
     
     
         12 . A method of surface navigation of an underwater vehicle as claimed in  claim 1 , wherein said pitch angle is comprised in a range from 5° to 20°. 
     
     
         13 . A method of surface navigation of an underwater vehicle as claimed in  claim 1 , wherein said pitch angle is sufficient to keep at least one said propulsion means beneath the water surface.