On the Stability of Racing Sailing Boats with Foils
Philippe DESTUYNDER1 Caroline FABRE2
【摘 要】Abstract The development of foils for racing boats has changed the strategy of sailing.Recently,the America’s cup held in San Francisco,has been the theatre of a tragicomic history due to the foils.During the last round,the New-Zealand boat was winning by 8 to 1 against the defender USA.The winner is the first with 9 victories.USA team understood suddenly(may be)how to use the control of the pitching of the main foils by adjusting the rake in order to stabilize the ship.And USA won by 9 victories against 8 to the challenger NZ.The goal in this paper is to point out few aspects which could be taken into account in order to improve this mysterious control law which is known as the key of the victory of the USA team.There are certainly many reasons and in particular the cleverness of the sailors and of all the engineering team behind this project.But it appears interesting to have a mathematical discussion,even if it is a partial one,on the mechanical behaviour of these extraordinary sailing boats.The numerical examples given here are not the true ones.They have just been invented in order to explain the theoretical
developments concerning three points:The possibility of tacking on the foils for sailing upwind,the nature of foiling instabilities,if there are,when the boat is flying and the control laws.
【期刊名称】《数学年刊B辑（英文版）》【年(卷),期】2018(039)003【总页数】24
【关键词】K ey word s Hydrodynamics of foils,Mathematical analysis,Stability
1 Introduction
The control of foiling during the America’s cup appeared to be a determinant point in the success of Oracle Team USA(OTUSA for short).In particular during upwind legs,when the boat had to avoid the waves created by the wake of the preceding boat,the automatic stabilization is a fundamental advantage that OTUSA exploited in a smart way and finally won the competition.Such situations are represented on the Figures 2 taken from TV transmissions during the America’s cup in San Francisco(September 2013).
In this paper,we have tried to give a simple and precise ma the matical model and analysis of such boats.Even if a more industrial 3D analysis would be obviously more realistic,,and
On the Stability of Racing Sailing Boats with Foils
