MODELING OF DIESEL ENGINE TRANSIENT BEHAVIOR IN MARINE PROPULSION ANALYSIS

Abstract

This paper discusses the mathematical modeling of diesel engines for use in computer simulations of marine propulsion transients. The specifics of diesel transient modeling are reviewed in detail; that is, the possible mathematical descriptions of individual components and functions are discussed. The mathematical descriptions are founded on basic thermodynamic and fluid flow principles to the degree thought feasible, but are supported by empirical relationships where necessary. Simulation models based on the modeling specifics are then presented in the form of equations that will provide complete modeling of engine transient behavior within limits imposed by the state of the art, but with good accuracy. Two-stroke and four-stroke models are included, as well as variations on the basic models. Evaluation of engine parameters needed in a simulation model is discussed, with the route to finding values from data likely to be available being pointed out. Comparisons with other published models of marine propulsion engines are offered.