A numerical approach to the keel design of a sailing yacht

This paper describes an approach to the keel design of a sailing yacht. The related software, which is fully automatic, leads to the optimal shape by modifying the surface used to define the keel planform. B-spline curves and surfaces have been used due to their ability in following complex shapes. The algorithm integrates ad hoc implemented original software with computational fluid dynamics (CFD) commercial ones. The optimisation procedure uses genetic algorithms (GAs) and a gradient-based optimiser for the refinement of the solution. A careful CAD and CFD modelling leads to a stable and efficient generalised method, which has been applied to the design of the centreboard of the 5o5 international class racing dinghy.