Experimental investigations using a transparent single shot compression machine for HCCI - combustion

In this study, experimental results of homogeneous charge compression ignition HCCI of n-butane in a single shot machine are presented. N-butane measurements are compared with a multizone model. Individual zones are calculated using a perfectly stirred reactor and Chemkin chemistry. The influence of temperature before combustion on heat release rate and duration of combustion is shown in a sensitivity analysis. As a perfect homogeneous temperature and fuel distribution are difficult to establish under experimental conditions, deviations from perfect homogeneity are shown. The influence of a hot surface in the cylinder head in terms of heat release rate and ignitability is examined. Further, dual fuel injections of n-butane and diesel are studied to trigger the n-butane ignition with a defined start of combustion.