Spark assisted compression ignition (SACI) combustion is a potential means of extending the high load limit of homogeneous charge compression ignition (HCCI) while maintaining high thermal efficiency. In these experiments, an HCCI engine equipped with fully-flexible valve actuation was used to...

In this study, an HCCI engine equipped with fully-flexible valve actuation was used to explore the effects of diluent composition on the rates of HCCI and spark assisted compression ignition (SACI) combustion. The diluent composition of the charge was characterized by the molar O2 fraction in...