Study of the phase-varying mechanisms of ion current signals for combustion phasing in a gasoline HCCI engine.

Highlights: [•] Free ion formation and recombination mechanism was investigated. [•] A multi-zone ion current predicting model was designed. [•] The predicted phase varying tendency of ion current is same with combustion phase. [•] The phase of ion current signals and heat release curves are not always the same. [•] The ion current phase will be retarded eve later when fuel concentration decreased. [ABSTRACT FROM AUTHOR]