Research on multi-interval coupling optimization of ship main dimensions for minimum EEDI

Abstract

In order to improve energy-saving effect of the YUKUN ship, minimize the value of the Energy Efficiency Design Index (EEDI), while considering the impact of uncertain factors. In this research, interval analysis method is used in uncertain optimization, and main dimensions of interval optimization research for EEDI are carried out. First, multi-island genetic algorithm (MIGA), particle swarm optimization (PSO) and adaptive simulated annealing algorithm (ASA) optimization methods are used for deterministic optimization, to analyze the influence of different optimization algorithms on the optimization results and to obtain the best deterministic optimization scheme. Second, considering uncertain factors—flow velocity VW, ship's wet surface area S and total resistance coefficient Ct—the interval analysis method is used to determine the main dimensions of the optimization problem and to analyze the influence of single interval and multi-interval coupling on the EEDI. Analysis shows that an increased number of uncertain factors will increase EEDI while decrease the energy saving effect, as will the coupling effect between uncertain factors. Final value of EEDI obtained by multi-interval coupling optimization, however, can be more realistic and guarantees the reliability of the scheme of the ship's main dimensions, and also be feasible as is still below the required baseline.