2014 年 56 巻 178 号 p. 298-307
Analysis from both experimental and theoretical viewpoints of the formation of particulate matters (PM) in a gasoline engine is strongly required due to stringent regulations and improvement of atmospheric pollutions. As a gasoline engine usually takes premixed combustion, it was thought that PM would not be a problem. However, as a direct fuel injection system is getting popular, PM formation sometimes becomes a problem during cold start and taking stratified combustion like diesel combustion. In this article, research review in both experimental and theoretical analyses is made. At this moment, unfortunately, we found we do not have enough information on this issue. Further research on this issue is now strongly required to clarify the phenomenon.