Numerical Investigation of the Diesel Combustion Characteristics with Different Ambient Conditions and Nitrogen Substituted by Carbon Dioxide

The idea of N2 substitution in ambient air for combustion has drawn attention for applications where there is no access to atmospheric air simply or to exclude nitrogen oxides formation entirely. In this paper, the combustion characteristics of diesel with the ambient air containing carbon dioxide instead of nitrogen that provides a synthetic air consisting of the same 21% oxygen content is investigated numerically. N-dodecane is considered as the fuel with characteristics close to diesel. Combustion takes place in a thermally isolated constant volume combustion chamber and the effects of the ambient condition variation including initial temperature, pressure, oxygen concentration, and air to fuel equivalence ratio on the ignition delay time and maximum temperature are studied. According to the results, carbon dioxide addition can increase the ignition delay time and reduce the peak temperature.