Diagnostics of stratified charge combustion under the conditions of multiple gasoline direct injection

Spark ignition engines fitted in modern vehicles are not such a uniform group in terms of injection and combustion systems as is in the case of diesel engines. The designs of the combustion systems of spark ignition engines are divided into systems of indirect injection into the intake manifold and direct injection into the cylinder. The paper presents an analysis of the results of investigations into the combustion process of charges of different air excess coefficients during a multiple injection of gasoline. The author presented optical investigations and indicator tests realized on a rapid compression machine. The investigations were carried out using a high-speed camera and an engine indicator system. The author indicated the possibilities of diagnostics of the combustion process using both research methods. The distributions of the flame temperature were determined using dual optics enabling a simultaneous recording of the flame image with optical filters. The flame development was presented, and the differences in its velocity were indicated depending on different direct injection strategies.