Prediction of Manoeuvring Characteristics in the Concept Design of a Destroyer

Manoeuvring is one of the fundamental qualities of the ship. It has a direct impact on the operability of the unit and therefore on the shipowner’s perception of quality. Furthermore, the manoeuvrability forecasting models are extremely sensitive to the geometry of the hull and appendages and thus closely related with the type of the unit. In this article, an innovative methodology for predicting the manoeuvring characteristics during the conceptual design phase is presented. It may be applied to all types of vessels, especially those requiring a specific study of manoeuvrability, such as fast hulls. Here, a destroyer has been considered. Starting from 15 hulls geometries, a fleet of 225 ships has been generated, by changing systematically the ratio L/B, B/T and the block coefficient CB. This way a 3-dimensional Central Composite Circumscribed (CCC) has been obtained, that comprehends a total of 15 experimental points for each base hull. Manoeuvring calculations has been performed on each vessel of the fleet and the main manoeuvring dimensionless quantities has been related to some simple variables, known during the conceptual phase. With a greedy approach, the adjusted coefficient of determination R2 has been maximized. This way, from the collected data, the best possible linear models for manoeuvring characteristics are obtained. This is because no statistical significance filtering of the variables is performed, as instead happens in the classic stepwise approach.