Establishment of a design study for comprehensive hydrodynamic optimisation in the preliminary stage of the ship design

Abstract

An automated practical multi-objective optimisation scheme is proposed for ship hull modification. A shift transformation and a self-blending method are sequentially performed based on resistance objectives at multi-design speeds. The Lackenby variation alters hull forms and produces initial designs. Subsequently, self-blending method combines obtained ships to cover design space. All processes are automated by MATLAB coding that connects the ©Maxsurf modeller and ©Maxsurf Resistance in the case of panel method resistance calculation. After whole shape optimisation, the platform defines ship portions in the stern and bow regions. Particularly, an approximation modelling Least-Square approach is investigated to construct a surrogate model. Optimisation results indicate 11.26% cost function reduction contributes to 16.23% resistance reduction at lower speed and 6.12% resistance reduction at higher speed for a passenger catamaran boat. Thus, the developed in-house optimisation code provides an optimal and cost-effective solution for hydrodynamic optimisation in the preliminary stage of ship design.