In-Cylinder Temperature Distribution Measurement and Its Application to HCCI Combustion

This paper presents a measurement technique to visualize the distribution of the in-cylinder mixture temperature and an experimental approach for analyzing the effect of the temperature distribution prior to ignition on homogeneous charge compression ignition (HCCI) combustion. First, a visualization technique for mixture temperature distribution based on the temperature dependence of laser induced fluorescence (LIF) was developed. As the next step, measurement of the temperature distribution was applied to an analysis of HCCI combustion. Controlled non-uniform temperature distributions in the mixture prior to ignition were generated by a special intake system with a completely divided intake port having separate electrical heaters. The correlation between the temperature distribution prior to ignition and ignition timing of HCCI combustion was shown experimentally by means of a comparison between the quantitative temperature distribution in the combustion chamber measured by LIF and combustion flame imaging.