Analysis of the forward speed effects on the radiation forces on a Fast Ferry

The paper presents an analysis of the radiation forces on a ship advancing with forced heave and pitch motions. This analysis is based on experimental data obtained with model tests and on numerical simulations with two codes, one based on 3D time domain Greens function method and the other is a 2D linear strip theory method. The case study consists of a hull shape from a Fast Ferry and several speeds are investigated between 0 and 40 knot. The objective is to quantify the forward speed effects on the radiation forces and to verify the skill of the conventional strip theory and of a time domain panel methods in dealing with large forward speeds. The consequences of applying simplifications on the linear boundary conditions of the common seakeeping codes are investigated. It is concluded that forward speed has a large effect on the radiation forces, especially on the coupling terms, and thus it is important to consider the full linear interactions between the steady and unsteady flows in the numerical calculations as the speed of the ship increases and the time domain panel code is able to represent these effects. (C) 2012 Elsevier Ltd. All rights reserved.