Ship optimization using viscous flow computations in combination with generic shape variations and Design of Experiments

Today, optimization procedures based on CFD-computations are used more and more in practical ship design projects. Potential-flow solvers are used routine-ly nowadays to optimize the front part of ships, for example, in order to minimize wave resistance. For the aft part of ships, however, where the flow is often dom-inated by viscous effects, viscous flow solvers have to be used. Until now it is not unusual in ship design to analyze the results of a limited number of computations, and derive recommendations on hull form changes from that; based on an understanding of the flow physics and its relation with the hull form. Better quantified im-provements can be obtained by automatic optimization procedures based on a series of CFD computations (Van der Ploeg and Raven, 2010 and Van de Ploeg, Starke and Veldhuis, 2013). These studies focused on system-atic hull-form variations based on specifically designed basis hull forms. The calculations accounted for the influence of ship's generated waves, viscous effects on these waves and the influence of dynamic trim and sinkage on the computed trends, all at full-scale.