Visualizations of combustion and fuel/air mixture formation processes in a single cylinder engine fueled with DME

This investigation showed that the combustion pressure and heat release rate attained their peak value at the lowest engine speed condition for DME and ULSD fuels. The characteristics of the flame temperature value and distribution due to the differences in engine speed conditions and fuel properties were clearly revealed. When the engine speed increased, an inhomogeneous and low combustion temperature was observed. Furthermore, the nitrogen oxides (NOx) emissions, which are related to the combustion temperature, decreased as the engine speed increased.