Multiobjective design optimization of a cruise ship

In this paper the multiobjective optimization of a cruise ship is presented. The hull shape is optimized in order to reduce the hydrodynamic resistance and to improve the seakeeping performance. Geometrical and functional constrains are defined to prevent unreliable geometries, and to respect some of the peculiar requirements for this kind of ship, i.e. displacement and comfort. A set of Pareto optimal solutions is presented to design engineers, who can choose the best design among a restrictred number of optimal alternatives. Numerical comparisons of optimized geometries and the original hull shape are shown. The optimization cycle is performed by using efficient multiobjective Global Optimization algorithms. Since each objective function evaluation requires the solution of nonlinear partial differential equations, the calculation is performed on several parallel processors in order to reduce the computational time. Metamodels are also applied to reduce the computational cost.