Combustion analysis with gas temperature diagrams measured in a prechamber spark ignition engine

Abstract

Up to date, a pressure indicator diagram has been usually used to estimate the heat release rate and mass burned fraction and thereby analyse the combustion process in a spark ignition engine. However, this analysis has only provided unitary information on the combustion process in the engine. Recently, gas temperature diagrams measured by an infrared absorptionemission pyrometer were recognized to give information on the combustion process at various stations in the combustion chamber. The temperature measuring technique and its results are already described in a previous paper. In this paper, to make a more reasonable model of torch combustion in a spark ignition engine with an auxiliary chamber, gas temperature diagrams measured under a wide range of air-fuel ratio and torch nozzle diameter are analysed to determine such combustion characteristics show a reasonable agreement with those estimated from the pressure diagrams. Accordingly, the combustion analysis with gas temperature diagrams are found to provide such a lot of useful local information for combustion modeling as optimum diameter of torch nozzle, two-step combustion and reverse flow through torch nozzle.