Mathematical models and numerical simulations for the AmericaÕs Cup Nicola Parolini a, * , Alfio Quarteroni a,b a CMCS, Institut d’Analyse et Calcul Scientifique, EPFL, Lausanne, Switzerland b MOX, Dipartimento di Matematica, Politecnico di Milano, Milan, Italy Received 31 July 2003; received in revised form 23 February 2004; accepted 7 June 2004 Abstract This paper presents a review of the mathematical models which can be adopted to describe the different physical phenomena characterizing the flow around a sailing yacht. The complete model accounting for laminar–turbulent tran- sition regime, free-surface dynamics and fluid–sails interaction is introduced as long as some simplified models that have been used to reduce the computational complexity. Drawing on the experience of the Ecole Polytechnique Fe´de´rale de Lausanne (EPFL) as Official Scientific Advisor to the Alinghi Team, winner of the 2003 AmericaÕs Cup, we discuss the role of Computational Fluid Dynamics simulations based on Reynolds Averages Navier–Stokes (RANS) equations and their integration in standard yacht design process. Numerical results in different areas (appendages design, free-surface flows, aerodynamics of sails) are presented and discussed. Ó 2004 Elsevier B.V. All rights reserved. Keywords: Mathematical modeling; Numerical fluid dynamics; Fluid–structure interaction; Free-surface flows; Yacht design; AmericaÕs Cup 1. Introduction The AmericaÕs Cup is a yachting race first run in 1851 and whose prize represents the worldÕs oldest sporting trophy. AmericaÕs Cup yacht races are fiercely competitive. Even after a race of several hours, just seconds can separate two teams at the finish line. Unlike aerospace or automotive applications, for which vast safety margins must be guaranteed, AmericaÕs Cup competition demands the utmost performance. 0045-7825/$ - see front matter Ó 2004 Elsevier B.V. All rights reserved. doi:10.1016/j.cma.2004.06.020 * Corresponding author. Tel.: +41 21 693 2909; fax: +41 21 693 4303. E-mail address: nicola.parolini@epfl.ch (N. Parolini). Comput. Methods Appl. Mech. Engrg. 194 (2005) 1001–1026 www.elsevier.com/locate/cma