Hydro-Fins for Increasing Maneuverability and Speed

Abstract

The fields of application of the present invention is within the industry related to the manufacturing of nautical/marine and sport equipment, and more precisely to the field of fins design for any type of board within a fluid environment. The novelties of the Spinfins, compared to traditional fin designs, are: (i) the curvature in the vertical direction permits the fin to have sufficient surface exposed to the fluid to ensure directional control but its lower height yields to a lower drag in the direction of the motion and consequently is faster than traditional fins; and (ii) the angle of twist in the vertical direction of the fin permits to modify the leading and trailing edges angles relative to the flow resulting in a more uniform pressure on the concave surface of the fin. The more uniform pressure on the concave surface makes the force exerted by the fin more efficient throughout a turn.

1 . The side-Spinfins have a curvature starting from the chord line at the asymmetric base of the fin and extending to the tip of the fin. The side-Spinfins has a continuous convex defbrmation in the vertical direction while the outside surface has a constant concave deformation. 
     
     
         2 . The center-Spinfins is two side-Spinfins put together from their concave outside surface. The two side-fins put together create a symmetric foil at the base and a continuous curvature goes from center line (chord lide) to the point where the two side fins are not connected any longer. From that location to the tip the two extremities keep their unsymmetric foil cross-section. 
     
     
         3 . Spinfins are the only fins that have a twist about the vertical axis. The angle of twist can be counterclockwise or clockwise modifying the angle of attack of the leading edge in the chord wise direction. The angle of twist create a variable angle of attack in the chord wise direction 
     
     
         4 . Spinfins twist angle allows to have a more uniform pressure on the inside of the fin throughout a turn as compared to vertical fins.