Study of Rigid Sail Aerodynamics

Abstract

Most sailboats use flexible sails to generate the aerodynamic propulsive force. However, for the 2013 America's Cup sailboat competition, rigid sails were specified. These sails resemble an airplane's wing and traditional wing-design tools (computational and experimental) were used to study the performance of the multi-element sail system. The shape of the proposed sail is based on two, tandem, symmetric airfoils, resulting in a geometry, unlike any traditional two-element airfoil. Because racing regulations limit the sail shape, only the two-dimensional airfoil geometry was open for a redesign. Therefore, the first objective of this study was to identify the possible variables affecting the aerodynamic performance of such sails (within the framework of racing regulations). At the same time, a secondary objective was to evaluate the effectiveness of simple computational and experimental tools for such a design exercise.