Title:
MAST FOR SMALL SAILING BOAT
Document Type and Number:
Japanese Patent JPS6456291
Kind Code:
A
Abstract:
PURPOSE:To prevent the separation of air flow by forming a pair of longitudinally continuous projections on an outer surface of a cylindrical mast at symmetrical positions with respect to a center line connecting front and rear ends of the mast, so as to change a boundary layer of the air flow around the mast from a laminar flow to a turbulent flow. CONSTITUTION:A mast 2 for retaining a front end of a sail 1 is formed in a cylindrical shape such that a front portion of the mast 2 is circular in horizontal section and a rear portion is elliptical. The mast 2 is formed on its outer surface with a pair of longitudinally continuous projections 3 and 4 at symmetrical positions with respect to a center line 10 connecting front and rear ends of the mast 2 in such a manner that an angle theta defined between the center line 10 and a tangential line 5 at the projection 3 (4) ranges from 60 to 90 degrees. The formation of the projections 3 and 4 suppresses separation of a boundary layer of air flow around the mast 2 to thereby improve aerodynamic characteristic of the mast 2.
Inventors:
HIGASHIJIMA KAZUYUKI
Application Number:
JP21227387A
Publication Date:
March 03, 1989
Filing Date:
August 25, 1987
Export Citation:
Assignee:
YAMAHA MOTOR CO LTD
International Classes:
B63B15/02; (IPC1-7): B63B15/02
Attorney, Agent or Firm:
Etsushi Kotani