Spark Distribution to Improve Diluted Gasoline Combustion

Abstract

In this work, a spatially distributed spark ignition strategy is employed to improve the combustion of diluted gasoline engine under homogenous mixture mode. The ignition energy is delivered via a three-pole ignitor which generates three sparking sites in the perimeter of the ignitor. The experimental results on a single-cylinder engine show that on the basis of similar total spark energy levels, the three-pole distributed spark ignition can significantly shorten the ignition delay and reduce the cyclic variation of the combustion phasing for lean and exhaust gas recirculation (EGR) diluted combustion. The operable limits for lean burn and EGR dilution are extended substantially compared to the conventional single-pole spark ignition, which leads to improvement of fuel efficiency and reduction in engine-out NOx emissions.