Effects of pre-injection on ignition, combustion and emissions of spray under engine-like conditions

Large-eddy simulation (LES) of multiple-injection spray combustion under engine-like conditions is performed using a coupled model an Eulerian stochastic field transported probability density function (ESF T-PDF) and flamelet generated manifold (FGM). This allows the use T-PDF methods in modeling interaction turbulence chemistry at affordable computational costs for engine applications. Simulation results are compared with available experimental data flames high level exhaust gas recirculation (EGR) relevant to internal engines. It shown that T-PDF/FGM LES capable reproducing not only global characteristics, such as pressure rise ignition delay time but also replicating evolution liftoff length flame structure. The effects pre-injection strategies then investigated, by systematically varying duration dwell between two injections, while keeping total injected fuel mass constant. reveal different mechanisms which can change time, mode emissions flames, depending on injection timing. even extremely short non-igniting substantially characteristics main-injection. single-injection be altered splitting pre- main-injections. current study demonstrates decreasing within range examined here, given pre-injection, will potentially increase soot oxidation rates it does significantly rate formation.