Influence of the marine engine load diagram characteristics on the ship propulsion system performance

In this study two four-stroke marine diesel engines, characterized by very similar nominal power and speed, but with very different trend of the power lint curve and specific fuel consumption contours in the engine load diagram, are compared by simulation, using each of them as an alternative to the other engine, for the motorization of a conventional (mechanical) propulsion plant for a small cruise ship. It is thus possible to determine and compare the efficiencies of the two engines and the vessel propulsion system overall performance for different ship speeds. The results of the comparisons are presented and discussed in the paper.