Homogeneous charge compression ignition and combustion characteristics of natural gas mixtures: The visualization and analysis of combustion

The purpose of this study is to elucidate autoignition characteristics of HCCI of natural gas mixtures during the compression process in the engine. A rapid compression and expansion machine was used to reproduce and visualize autoiginition combustion. The test results show that initial temperature and density, and hydrocarbon contents other than methane, are important parameters influencing autoignition timing and the successive combustion. A detailed chemical kinetics model combined with a multi-dimensional CFD code supports these autoignition characteristics.