A Diagnostic Two-Zone Combustion Model for Spark-Ignition Engines Based on Pressure-Time Data

A simple diagnostic combustion model for spark-Ignition engines, based on pressure-time data, is described. It considers the charge to be made up of two zones, burnt products and unburnt reactants, each of which is undergoing a series of continuously varying yet distinctly different polytropic processes. The two zones exchange mass across the flame front, due to combustion. This simple approach which utilizes essentially no correlations or empirical formulae produces results such as the rate of burning of the reactants, the rate of change of volume of each of the two zones, as well as the mean temperature hirstories of each of the two zones throughout the combustion period.