Rans-based optimization of the aft part of ships including free surface effects

Abstract

A procedure for optimizing the aft body of a ship for minimal power and best wake field quality is described, based on full-scale RANS computations possibly including free- surface effects. A flexible and effective definition of parametric hull form variations is used, based on interpolation between a limited number of basis hull forms. This keeps the dimension of the search space low, which enables to do systematic variations. For a test case in which the ship’s wave making can be neglected it is shown that the grid dependence in the computed trends is low, and for a test case including free-surface effects it is demonstrated how the search space can be set up in such a way that a considerable decrease in required power can be obtained without spoiling the wake quality.