A Two-Zone Diesel Engine model for the Simulation of Marine Propulsion Plant Transients

Abstract: The paper presents a mathematical model for the dynamic analysis of turbocharged diesel engines for use in computer simulations of ship propulsion plants. The engine description is based on a two-zone combustion model which allows a detailed calculation of the thermodynamic processes inside the cylinders and an evaluation of exhaust gas emissions. The thermodynamic study of the in-cylinder phenomena is combined with an analysis of the dynamic behaviour of the turbocharger and of the intake and exhaust systems (intercooler, manifolds, etc.). The procedure has been validated by comparisons with both experimental data obtained by the engine Manufacturer and theoretical results supplied by a phenomenological combustion code. Despite the good accuracy of the results obtained, the computational time is kept reasonably short. This is an important feature, because the engine simulator is part of a broader code, already developed by the authors, simulating the whole propulsion system of a ship.