A Gas Turbine Modular Model for Ship Propulsion Studies

Abstract: The paper presents an original modular mathematical model, based on physical laws, for the dynamic simulation of open cycle gas turbine (GT) plants, specifically developed for ship propulsion plants studies. Each gas turbine component (i.e. compressor, turbine, combustor) is modelled in a specific module, by means of time dependent momentum, energy and mass equations and non linear algebraic equations. The great application flexibility of the simulator modules gives the possibility of modelling different gas turbine plant configurations. In the paper the General Electric LM 2500 gas turbine is simulated as a significant application example. The simulation results are presented and compared with experimental data provided by the gas turbine manufacturer. As far as the ship propulsion application is concerned, the described gas turbine model may be used and has been already used as part of a more complex, previously developed, propulsion plant simulator. In particular the propulsion system of a fast trimaran ferry, consisting of two steering waterjets driven, through reduction gears, by two gas turbines, has been considered and its dynamic behaviour analysed with reference to deceleration-acceleration manoeuvres, whose results are presented in the paper.