Spark Ignition Process in Internal Combustion Engines

Abstract

In recent years, due to the restrictions on exhaust emission and fuel consumption in spark ignition (SI) engines, better ignition systems are needed. In recent fundamental studies of spark ignition, important factors affecting the ignition ability or minimum ignition energy have been investigated [1–5]. These help to obtain optimum conditions in practical ignition systems. However, the mixture conditions in practical SI engines is complicated by high turbulence and variation in fuel concentration [6–9]. Also, flame kernel structure and its formation process have been the subjects of chemical and pysical modeling [10–13]. In practical applications, some new ignition methods have been proposed to assure ignition of mixtures difficult to burn, such as plasma jet ignition, two successive sparks, breakdown spark, laser ignition etc. [14–19]. In the present paper, several topics are discussed, most of them emanating from the authors’ laboratory. The discussions are concerned particularly with very short and rather long duration sparks; the former corresponds to capacitance and the latter inductance components of the composite spark, which is used in most current SI engines.