Propulsion and steering effects on dynamics of high speed craft

A comprehensive approach to model and simulate high speed craft dynamics during turning circles and zig-zag manoeuvres is presented in this paper. The high performance requirements for propulsion systems and the increasing attention on manoeuvring features suggest the need for a thorough investigation about planing hull dynamics, already in the preliminary stages of the boat design. Dynamic aspects of planing craft during manoeuvres cannot be taken into account by traditional methodologies and purely steady state approaches. For this reason, the boat dynamic behaviour is evaluated by means of a time domain simulator, developed in Matlab-Simulink software environment, able to represent the hull dynamics, including propulsion system and automation behaviour. The considered boat is equipped with two high speed diesel engines that ensure a speed up to 32.5 kn. Manoeuvrability characteristics are simulated on the basis of captive model tests on planing hulls available in open literature. With respect to previous similar studies, in present work a possible strategy is introduced to represent the roll motion due to the propulsion and steering effects. Finally, some preliminary results are discussed to stress the capabilities and shortcomings of the proposed method.