On the fluid dynamics of America’s Cup yachts and similarities with other applications

The America’s Cup is the most competitive yacht race in the world. The direct and indirect financial impacts of the America’s Cup on the hosting region are only 20% lower than the impact of the FIFA World Cup. Since the 1990s, the most competitive sailing teams have invested about £20 million each year. The talk will present some of the key features of the design of America’s Cup yachts, including recent advances in sail aerodynamics. In particular, wind tunnel tests, numerical simulations (RANS and DES), and verification and validation for yacht sail aerodynamics will be presented.

It will be shown that sails have unique flow features that allow the generation of very-high lift and lift/drag ratio compared to wings and blades commonly used in other fields such as aeronautics and turbo machinery. Interestingly, sails operate at relatively low Reynolds numbers and unsteady flow conditions, where fluid dynamic efficiency is even harder to be achieved. Therefore, understanding the underlying mechanisms of sails’ flow features can foster cross fertilisation of ideas in research fields (e.g. tidal turbine blades) where the employment of similar features can improve the fluid dynamic efficiency.

Dr Ignazio Maria Viola is Lecturer at the Institute for Energy Systems at the School of Engineering of the University of Edinburgh. His research focus is on viscous fluid flow, including turbulence and boundary layer flow. His current research projects include the generation of lift through vortex flow in turbulent flow conditions, the effect of roughness on the boundary layer at high Reynolds numbers, and tactics under uncertain weather conditions for yacht races. For more on Ignazio Maria see:

www.research.ed.ac.uk/portal/iviola (Research Portal)

www.ignazioviola.com (Personal website)

www.sailingfluids.org (Sailing Fluids project)