Numerical simulation of gasoline-fuelled compression ignition combustion with late direct injection

The auto-ignition characteristics of a charge mixture, which affects significantly the engine-out pollutant emissions, are dependent on fuel kinds as well as thermodynamic conditions and compositions of the charge mixture. In this work, numerical simulations of combustion of direct injection gasoline sprays in a conventional diesel engine using a multi-dimensional CFD code incorporating detailed oxidation chemistry of fuels, are presented and emissions of gasoline-fuelled engine operation are compared with those of diesel fuel. The results show that the combustion behaviour of direct injection (DI) gasoline sprays and their emission characteristics are successfully predicted and are in good agreement with experimental measurements under various operating conditions that have been reported in the literature. It is seen that NOx and particulate emissions in gasoline combustion are significantly reduced compared to the corresponding diesel cases. The results also suggest possible expansion of operating conditions of DI gasoline compression ignition combustion.