Multicriterion evolutionary optimization of ship hull forms for propulsion and seakeeping.

Abstract

For a given set of ship design and operational criteria, there exists a trade-off between the ship's calm water powering performance and its seakeeping performance. Ship hulls that are designed for optimal powering performance can have poor sea keeping performance, and vice versa. It is typically not possible to obtain the global optimal objective for both of these objectives due to the competition between the powering and seakeeping performance functions and the design constraints. The set of globally nondominated solutions, or Pareto front, considering these competing criteria is searched for by navigating the multi-modal search space for these criteria using a multicriterion, population-based evolutionary algorithm optimization process. The optimization process uses a nontraditional objective function formulation that eliminates the need to tune the penalty function parameters for each new problem formulation and appears to provide a more thorough representation of the numerically approximated Pareto front. Results show that properly integrating this optimization process with the design criteria yields a set of hydrodynamically superior design solutions. The problem formulation and development is applicable to naval surface vessels and applied to a monohull frigate type example.* *This dissertation is a compound document (contains both a paper copy and a CD as part of the dissertation). The CD requires the following system requirements: Adobe Acrobat.