Multi-objective Optimization of Simultaneous Ship System Design

The optimization of hull-propeller system has always been one of the most important aspects of design to reduce the costs, mechanical losses and increase component life. The proposed design methodology represents a new approach to optimize the propeller-hull system simultaneously. In this paper two objective functions are considered, the first objective function is specific fuel consumption (SFC) and the other one is cost function including trust, torque, open water and skew efficiencies. For a comprehensive optimization the hull form and the propulsion system is considered as an integrated system and the emission profile of the vessel is used to minimize both objective function. The cavitation and propeller stress also is used as problem constraints. The well-known evolutionary algorithm based on NSGA-II is employed to optimize multi-objective function, where the main propeller and hull dimensions are considered as design variables. The results are presented for a series 60 ship driven by the L51/60DF engine and B-series propeller. The results showed the proposed method is an appropriate and effective method for simultaneously propeller-hull system design and is able to minimize both objective functions significantly.