The Wolfson Unit at the University of Southampton worked with America’s Cup teams for over 30 years, using experimental testing in towing tanks and wind tunnels to define and improve the performance of the racing yachts.
The America’s Cup, the world’s oldest international sporting trophy, was sailed in mono-hulls with traditional soft sails until 2010 but for the 2013 Americas Cup the yachts have been changed to catamarans with solid wing sails. The result is a four-fold increase in speed, and a shift in performance prediction requirements from straight line speed through the water to dynamic manoeuvres and an emphasis on aerodynamic efficiency. In addition, the timescales between events, and restrictions on the number of wing sails that can be made place an emphasis on accurate and detailed modelling of the boat.
With the change to low resistance hull-forms and 40m tall wings, experimental facilities alone are insufficient. Computational fluid dynamics (CFD) allows accurate aerodynamic modelling of the yacht, completing the performance prediction.
During the course of the project, the Wolfson Unit ran aerodynamic CFD simulations of the wing sail for Luna Rossa Challenge (Italy), optimising performance and efficiency, and collaborating with Emirates Team New Zealand on validation, with all simulations run on the Iridis cluster at the University of Southampton. This high performance computational (HPC) facility has allowed the designers to run thousands of simulations, giving quick and accurate results for a complete performance model.
HPC facilities such as Iridis allows the University of Southampton to combine world class experimental and computational resources to produce complete simulations of complex, dynamic environments. This world leading status was recognised in the Queens Anniversary Prize 2011 for our track record in performance sports engineering, combining together our expertise in yacht racing, Formula 1 and most recently the British Olympic team.
This particular project has now closed, but the Wolfson Unit continues to provide professional consultancy primarily for ship model testing, sailing yacht performance and ship design software, but their expertise extends to many other aspects of marine technology and industrial aerodynamics.
Dr Sandy Wright