Simulation of a two-stroke diesel engine for propulsion in waves

Abstract

Propulsion in waves is a complex physical process that involves interactions between a hull, a propeller, a shaft and a prime mover which is often a diesel engine. Among the relevant components, the diesel engine plays an important role in the overall system dynamics. Therefore, using a proper model for the diesel engine is essential to achieve the reasonable accuracy of the transient simulation of the entire system. In this paper, a simulation model of a propulsion system in waves is presented with emphasis on modeling a two-stroke marine diesel engine: the framework for building such a model and its mathematical descriptions. The models are validated against available measurement data, and a sensitivity analysis for the transient performance of the diesel engine is carried out. Finally, the results of the system simulations under various wave conditions are analyzed to understand the physical processes and compare the efficiency for different cases.