Natural gas fueling: A LES based injection and combustion modeling for partially stratified engines

The Partially Stratified Charge Spark Ignition (PSC-SI) combustion strategy is envisaged as a way of reducing fuel consumption and therefore polluting emissions; the improved fuel economy is mainly due to lean, stratified combustion, and to the reduction of pumping losses at partial load conditions. The aim of this work is to explore the potential capabilities of the PSC-SI combustion strategy over a wide flammability air-to-fuel ratio range with a CFD-based computational approach. A validated LES solver has been used to represent the main occurring phenomena into an experimentally implemented Constant Volume Combustion Chamber (CVCC). For different air fuel ratios, both homogeneous and non-homogeneous combustion processes have been simulated in order to compare and emphasize the benefits of the PSC-SI and the impact of the choice of operating conditions.