Decreasing the emissions of a partially premixed gasoline fueled compression ignition engine by means of injection characteristics and exhaust gas recirculation

Abstract

This paper is presented in order to elucidate some numerical investigations re-lated to a partially premixed gasoline fuelled engine by means of three dimen-sional computational fluid dynamics code. Comparing with the diesel fuel, gaso-line 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 NO x emission. For validation of the model, the results for the mean in-cylinder pressure, heat release rate, NO x and soot emissions are com-pared with the corresponding experimental data and show good levels of agree-ment. The effects of injection characteristics such as, injection duration, spray angle, nozzle hole diameter, injected fuel temperature and exhaust gas recircula-tion rate on combustion process and emission formation are investigated yielding the determination of the optimal point thereafter. The results indicated that opti-mization of injection characteristics leads to simultaneous reduction of NO x and soot emissions with negligible change in indicated mean effective pressure.