An n-Heptane Oxidation Mechanism Suitable for Low- to High-Temperature Combustion

The detailed n-heptane mechanism, which is widely used today, is suitable for a wide range of operating conditions. However, due to the large model involved, it is difficult to use this mechanism for computational fluid dynamics (CFD) simulation. In addition, the prediction accuracy of the existing simplified mechanism cannot meet simulation requirements with respect to low-temperature combustion and the negative temperature coefficient region. In this study, we sought to solve these problems by constructing a new simplified mechanism (NC2024) of the n-heptane chemical reaction based on the mechanism of Kuiwen Zhang using path analysis and sensitivity analysis. The mechanism involves 72 substances and 126 reactions. A comparison with the commonly used mechanism and an analysis of experimental data revealed that the NC2024 mechanism delivers high accuracy in predicting the ignition delay period under the low- to high-temperature conditions of 600–1100 K and a large pressure range of 13.5–42 bar and thus meets the accuracy requirements for CFD simulation of diesel low-temperature combustion.