Abstract
In order to understand the combustion phenomenon in a spark ignition engine fueled with the homogeneous mixture of LPG (main component : Propane) and DME (Dimethyl Ether), the authors previously developed a chemical kinetic model (Propane-DME reduced elementary reaction model and turbulent combustion model) for three-dimensional numerical analysis of the combustion process in the engine. The authors' GTT-CHEM code with that chemical kinetic model was able to reproduce an auto-ignition phenomenon at the last period of combustion in the engine. In this study, the authors have investigated the effects of Propane and DME heterogeneous spatial distributions on combustion in the LPG-DME spark ignition engine by three-dimensional numerical analysis using the GTT-CHEM code with the previously developed chemical kinetic model, for better understanding about the contributions of Propane and DME to the auto-ignition phenomenon. The unburned zone DME fraction and its homogeneity were employed to discuss and explain the results. It is found that a well mixed and highly DME contented propane gas locating at end gas region is in the most danger of strong auto-ignition.
