Dynamic simulation of marine propulsion plants

This paper presents a computer simulation model able to predict the dynamic behaviour of a whole marine propulsion system and to evaluate the influence of its three main elements: ship, propeller and prime mover. The developed procedure, which takes into account the complex interactions between the various plant components, can represent the ship and its propulsion machinery when operating both in the steady-state and in transient conditions (manoeuvring). As a first example, the model is applied to a fishing vessel, whose different load situations and operating conditions could require an optimisation of the propulsion plant design parameters. The presented results, relative to a stern trawler equipped with a supercharged diesel engine, show the flexibility of the model and its ability to compare different design options such as, for instance, the adoption of a fixed pitch versus a controllable pitch propeller, or to evaluate various choices relative to the plant control system.