Hull Form Multi-Objective Optimization for a Container Ship with Neumann-Michell Theory and Approximation Model

With the continuous development of the shipbuilding industry and shipping business, hydrodynamic optimization of hull forms has drawn the attention of both academia and industry. This paper reports the details of an efficient, numerical, design optimization tool for hull form for container ships. This tool is composed of three functional modules: hull form deformation, hydrodynamic performance prediction, and optimization. The free-form deformation (FFD) and radial basis function (RBF) methods are employed to modify the ship hull globally and locally, respectively. To reduce the cost of the numerical optimization, which is always a challenging problem, a new potential theory, the Neumann-Michell (NM) theory, and the approximation model are adopted. In addition, the analysis of variance (ANOVA) method is used to represent the influence of each design variable on the objective functions. The high efficiency is illustrated by the optimization for a container ship. Wave resistance coefficients at three design speeds are minimized, and a Pareto front of solutions is obtained. The optimal hulls are verified and analyzed by the NM theory and a Reynolds-averaged Navier-Stokes (RANS)-based computational fluid dynamics (CFD) solver. Numerical results confirm the availability and reliability of the optimization tool described.