An Automatic Hull Form Generation and Multi-Objective Approach for Optimization of Ship Hull Forms

Abstract

Optimization is finding the solution with the most cost effective or highest achievable performance under the given constraints, by maximizing desired factors and minimizing undesired ones. Hull form optimization from a hydrodynamic performance point of view in calm water is important in preliminary ship design. The challenge of this work is getting a ship with lowest energy consumption in calm water by various optimization approaches to minimize the ship resistance at its given displacement and its service speeds. Different speeds were taken into account for the analysis of resistance performance of a vessel. An academic container vessel (Duisburg Test Case developed and tested by the University of Duisburg-Essen) was taken for the study case. The parametric model of the vessel was developed by modifying the initial geometry with the use of CAESES 4.1.2. After getting a parametric model, it was simulated by OpenFOAM, the open Source code developed to validate with experimental results. After coupling OpenFOAM solver with CAESES, different optimization approaches were done by using CAESES/Dakota interface. The optimization was focused on the changes of the forward part of the vessel (bulbous bow) and stern (underwater part).The optimal hull form was obtained in calm water condition by different optimization algorithms and was checked in different operation profiles. Finally, the results of the optimal hull form were compared with original design.