Isothermal vs. Adiabatic Mean Value SI Engine Models

Abstract Mean Value Engine Models (MVEMs) are an important paradigm for the study, analysis and control of Spark Ignition (SI) and diesel engines. Such models are simple, physical, compact and contain just enough detail to be statically and dynamically accurate. They are may be analyzed directly using simple techniques. In this paper an analysis is made of a new adiabatic MVEM which more accurately describes the behavior of SI engines with Exhaust Gas Recirculation (EGR) than conventional isothennal MVEM models. This analysis shows that the dynamics of SI engines are dominated by linear and nonlinear elements which may be simply understood.