In-Cylinder Combustion in a Spark-Ignited Natural Gas Engine (2nd Report, Effect of Swirl Ratio, Spark Plug Electrode Direction and Spark Plug Position)

摘要

An experimental study was made to investigate the effect of swirl ratio, spark plug electrode direction and spark plug position on in-cylinder combustion in a spark-ignited natural gas engine. Flame propagation in a single-cylinder visualization engine was observed from bottom of the piston by the high speed schlieren method, over the wide range of nominal swirl ratio, spark plug electrode direction and spark plug position. The results showed that larger swirl ratio led to more rapid flame propagation, resulting in larger heat release rate and larger cylinder pressure. Spark plug electrode direction had little effect on flame propagation, resulting in little difference in heat release rate and cylinder pressure. Farther spark plug position to cylinder axis led to more rapid flame propagation, resulting in larger heat release rate and larger cylinder pressure, excluding extremely far spark plug position.