Washington State’s Shilshole Bay was the setting for a new study addressing the dynamics of tacking, a common but challenging sailing maneuver. The research, conducted by mathematicians from New York University and the University of Michigan, provides insights into how sails behave during various tacking motions.
The study offers a detailed analysis of sail behavior across different types and aims to improve sail design. It also seeks to enhance the efficiency and reliability of autonomous sailboats used in oceanographic research when changing direction under unpredictable wind conditions.
Christiana Mavroyiakoumou from NYU’s Courant Institute of Mathematical Sciences, who led the research published in Physical Review Fluids, noted: “Tacking is more than just a turn… By uncovering what determines a successful flip and how long it takes, this research gives sailors and engineers a new resource for mastering the wind.”
University of Michigan Professor Silas Alben highlighted that while much work has focused on optimizing sailboat shapes, understanding fluid-structure interactions during unsteady maneuvers like tacking remains crucial. “The tacking maneuver is one important example where simplified modeling can help us understand the basic physics,” he said.
The researchers used mathematical modeling and simulations to examine sail movement dynamics during tacking. Their findings revealed three critical factors influencing successful flips: sail stiffness, tension before encountering wind, and final angle relative to the wind. A less flexible sail with high tension before meeting the wind and angled at 20 degrees post-tack showed higher success rates. The mass of the sail along with turn speed and acceleration affected flipping speed.
Beyond competitive sailing, this study could aid automated sailing vehicles operating under diverse wind conditions.
This research received support from the National Science Foundation’s Division of Mathematical Sciences (DMS-2204900).
