Search Results

This paper describes theoretical analysis and experimental observations of very early stages of the flame development in a spark-ignition engine. The experimental work applies a high-speed imaging and image analysis techniques to the onset of spark and immediate post-spark stages of ignition, for steady state operation under a wide range of engine speeds, engine loads, equivalence ratios, spark advance and fuel injection timing. The results of the experimental studies are compared with a theoretical thermodynamic model of the flame kernel development. The theoretical analysis describes the situation from the onset of the spark discharge and includes input of electrical energy, combustion energy release and heat loss to the spark plug. In addition an approach is discussed which should prove of value in determining the combustion temperature during the very early stages after ignition.