Abstract
Keywords :
Controlled Auto-ignition™, CFD, Auto-ignition modelling
Abstract
Focusing on engine efficiency and the reduction of harmful pollutant emissions, engineers are looking for complementary solutions to the continuously evolving conventional gasoline spark ignition combustion. Among the existing concepts, Controlled Auto-Ignition™ (CAI™), founded on the auto-ignition of a highly diluted gasoline-based mixture, is an efficient way to improve both fuel consumption and pollutant emissions at part load without a major modification of the engine design. As CAI™ is a compression ignition combustion mode using gasoline as fuel, its modelling requires to account for the chemical characteristics of the fuel in low temperature, low equivalence ratio operating conditions. Therefore, a dedicated auto-ignition model derived from detailed chemical kinetics calculations for a wide range of burnt gas dilution ratios and octane numbers has been implemented and tested on a reference operating point using an optical engine.