Apparatus and method for reducing hydrofoil cavitation

Abstract

A method of reducing underwater hydrofoil cavitation is described; hydrofoil steering vanes trade a small degree of efficiency for significant cavitation reduction, through perforations in the hydrofoil. Some pattern examples are discussed. A method of further cavitation reduction through surface texture variation also reduces underwater hydrofoil drag; some patterns are discussed. Combining the methods provides maximum cavitation reduction.

1 . A method of reducing hydrofoil cavitation on a ship, the method comprising: 
 providing perforations in a hydrofoil, the hydrofoil having a leading edge, a trailing edge, a suction side and a pressure side, the perforations providing a passage for water from the suction side to the pressure side, and    maneuvering the ship through water.    
   
   
       2 . A hydrofoil that reduces cavitation, the hydrofoil comprising: 
 a main body entirely covered by alternating round-hole perforations capable of evenly pressurizing a suction side as well as augmenting surface turbulence and reducing boundary layer drag on a pressure side;    a trailing edge on the main body; and    a surface texturing on the trailing edge.    
   
   
       3 . The hydrofoil of  claim 2  further comprising a leading edge on the main body and surface texturing on the leading edge.  
   
   
       4 . The hydrofoil of  claim 2  wherein the surface texturing comprises dimples.  
   
   
       5 . The hydrofoil of  claim 2  wherein the surface texturing comprises longitudinal grooves.  
   
   
       6 . The hydrofoil of  claim 2  wherein the surface texturing comprises scales.  
   
   
       7 . The hydrofoil of  claim 2  wherein the surface texturing comprises shingles.  
   
   
       8 . A hydrofoil that reduces cavitation, the hydrofoil comprising: 
 a main body having a leading edge, a trailing edge, a suction side and a pressure side; and    perforations in the main body providing a passage for water from the suction side to the pressure side.