Modelling And Simulation Of Spark-Ignition Engines For Control System Design

Abstract

This paper describes modelling techniques and simulation results of spark-ignition (SI) engines operating under steady and transient conditions. A simulation package based on a personal computer for control system design has been developed. This package is capable of predicting the dynamic performance of SI engines, including four-stroke and two-stroke, supercharged or naturally aspirated versions. Engine system design is carried out by matching various engine configurations as well as control strategy investigations. Examples of a multi-valve design, a variable valve timing system, a variable tuning pipe design and a turbocharged version are demonstrated. The governing equations of this package are based on mass continuity and energy conservation of gas flow in each engine compartment. The momentum equation is considered, if the wave action effect is important in that part of the engine component, such as inlet and exhaust pipes. Incorporated with a devised system model, virtually any kind of engine systems can be simulated using this package with good accuracy and acceptable computational time. Effects of new concept designs on engine performance are evaluated from the results of steady-speed simulation at wide-open throttle and the transient response by a sudden throttle depression.