A study of a turbulent jet ignition system fueled with iso-octane: Pressure trace analysis and combustion visualization

Turbulent jet ignition is an advanced pre-chamber ignition enhancement technique for spark ignition engines that uses a discharging jet of hot combusting gases to initiate main chamber combustion. The jet acts as a distributed ignition source, leading to fast burn rates and increased combustion stability. Experiments were performed in an optically accessible rapid compression machine using liquid iso-octane to study the effects of auxiliary fuel injection and ignition distribution due to nozzle geometry. A custom low-flow fuel injector was used to overcome previous limitations of using liquid fuel in the pre-chamber. Jet induced autoignition behavior was also studied in depth by considering high-speed images, pressure traces, and pressure derivative data.