Combustion of Turbulent Lean Mixtures by Pulsed Jet Ignition

The performance characteristics of pulsed jet ignition in a turbulent flow with swirl are confirmed by tests carried out in a disk-shaped combustion vessel with lean methane-air mixtures, in comparison to those of plasma jet ignition and standard spark plug ignition. The combustion process was monitored by pressure measurements and high-speed schlieren photography. It was found that the effect of cavity volume on combustion enhancement in a swirl flow was smaller than that in a quiescent mixture, and it can be considered that there was no effect of orifice diameter. The lean flammability limit was most extended by pulsed jet ignition in both quiescent and swirl flow.