Hull form optimization of an icebreaker ship considering the performance in ice and open water conditions

This paper describes the hull form optimization method of an icebreaker. In this optimization method, hull forms are generated by the original method we develop. The objective functions to be minimized are ice resistance in level ice and wave making resistance in open water. A multi-objective genetic algorithm is adopted as a numerical optimizer. We optimize a hull form which has the same hull form parameters as the preliminarily designed hull form for an application example. The optimization result provides many hull forms which have different balances of both objective functions as the Pareto solutions. It is found that some hull forms have better performance both in ice and open water conditions than the preliminarily designed hull form. We can develop an icebreaker hull form efficiently using the present optimization method.