Flow enhancement for underwater turbine generator

Abstract

A flow enhancement improvement for an underwater turbine generator ( 10 ) is disclosed wherein a longitudinal hole ( 240 ) is disposed in the central area ( 26 ), typically a hub ( 20 ) of the generator ( 10 ), and a second, augmentor duct ( 41 ), preferably rigid, is disposed about the outer duct ( 40 ) or housing of the unit to create a slot ( 200 ) area. The slot ( 200 ) and hollow hub ( 20 ) create areas of smooth, laminar fluid flow. The leading edges of the hub ( 20 ) or central ring and the augmentor ( 41 ) and outer ducts ( 40 ) are elliptical to enhance the fluid dynamics of the structure.

1 . A hydro turbine generator apparatus for generating electrical power from water flow, said apparatus comprising at least one rotor disk, and at least one generator, characterized by:
 a) a bi-directional augmentor duct disposed about said at least one rotor disk; and   b) a longitudinal hole through the center of said at least one rotor disk.   
     
     
         2 . The hydro turbine generator apparatus according to  claim 1 , wherein said bi-directional augmentor duct comprises two substantially symmetrical inlets situated at opposing ends of said bi-directional augmentor duct. 
     
     
         3 . The hydro turbine generator apparatus according to  claim 2 , additionally comprising an outer duct disposed about said at least one rotor disk, and situated inside and substantially concentric with said bi-directional augmentor duct. 
     
     
         4 . The hydro turbine generator apparatus according to  claim 2 , wherein said at least one rotor disk comprises an outer rotor rim and one or more blades attached to said outer rotor rim at their tips and extending radially inward from said outer rotor rim. 
     
     
         5 . The hydro turbine generator apparatus according to  claim 4 , wherein each of said one or more blades additionally comprise a root located distally from the outer rotor rim, and wherein said one or more blade roots are attached to an inner rotor rim defining said longitudinal hole through the center of said rotor disk. 
     
     
         6 . The hydro turbine generator apparatus according to  claim 5 , wherein said inner rotor rim defines a hub. 
     
     
         7 . The hydro turbine generator apparatus according to  claim 2 , wherein said generator comprises a flooded generator flooded with ambient water. 
     
     
         8 . The hydro turbine generator apparatus according to  claim 4 , wherein said generator comprises a flooded rim generator flooded with ambient water. 
     
     
         9 . The hydro turbine generator apparatus according to  claim 6 , wherein said generator comprises a flooded hub generator flooded with ambient water. 
     
     
         10 . The hydro turbine generator apparatus according to  claim 4 , wherein said one or more blades are substantially symmetric in cross section. 
     
     
         11 . The hydro turbine generator apparatus according to  claim 2 , wherein said bi-directional augmentor duct is substantially fixed in axial position relative to said at least one rotor disk. 
     
     
         12 . The hydro turbine generator apparatus according to  claim 3 , additionally comprising one or more magnetic bearings situated between said at least one rotor disk and said outer duct. 
     
     
         13 . The hydro turbine generator apparatus according to  claim 6 , additionally comprising one or more magnetic bearings situated between said at least one rotor disk and said hub. 
     
     
         14 . The hydro turbine generator apparatus according to  claim 6 , wherein said hub comprises two ends and an outer surface, said ends having a diameter equal to or lesser than the diameter of said hub at any other point, thereby creating a hydrodynamic shape and improving the efficiency of said hydro turbine generator apparatus. 
     
     
         15 . The hydro turbine generator apparatus according to  claim 6 , additionally comprising a plurality of struts projecting from said hub. 
     
     
         16 . The hydro turbine generator apparatus according to  claim 15 , wherein said plurality of struts project radially from said hub and are operable as guide vanes along a portion of their length situated between said hub and said outer duct. 
     
     
         17 . The hydro turbine generator apparatus according to  claim 16 , wherein said plurality of struts are curved along a portion of their length situated between said hub and said outer duct. 
     
     
         18 . The hydro turbine generator apparatus according to  claim 15 , wherein said plurality of struts are dimensioned for smooth annular flow along a portion of their length situated between said outer duct and said bi-directional augmentor duct. 
     
     
         19 . The hydro turbine generator apparatus according to  claim 2 , wherein said bi-directional augmentor duct comprises an interior wall and wherein said interior wall converges to a central diameter located between said inlets which is smaller than an inlet diameter located proximate to said inlets. 
     
     
         20 . The hydro turbine generator apparatus according to  claim 2 , comprising at least two rotor disks, wherein a first rotor disk rotates in a first direction in response to said water flow and a second rotor disk rotates in a second direction opposite to said first direction.