Simultaneously Reduction of NOx and Soot Emissions in a partially premixed gasoline fueled compression ignition

The primary target of emission legislation for CI engines across the world has been the reduction of the emissions of nitric oxides (NOx) and soot. This paper is presented in order to elucidate some numerical investigations related to a partially premixed gasoline fuelled CI engine by means of three dimensional CFD code. Comparing with the diesel fuel, gasoline has lower soot emission because of its higher ignition delay. The application of double injection strategy reduces the maximum heat release rate and leads to the reduction of NOx emission. For validation of the model, the results for the mean in-cylinder pressure, H.R.R., NOx and soot emissions are compared with the corresponding experimental data and show good levels of agreement. The effects of injection characteristics such as, injection duration, spray angle and EGR rate on combustion process and emission formation are investigated yielding the determination of the optimal point thereafter. The results indicated that optimization of injection characteristics leads to simultaneous reduction of NOx and soot emissions with negligible change in IMEP.