Molecular Dynamics Simulation of n-Heptane Pyrolysis using Adaptive Hyperdynamics Method

Recently, reactive molecular dynamics methods (e.g., ReaxFF) have been developed and have enabled the investigation of complex reactive systems. However, these applications for hydrocarbon pyrolysis and combustion are limited to high-temperature regions (>2000 K) due to time-scale limitations in molecular dynamics methods. Recently, we proposed an “adaptive hyperdynamics (AHD) method” to overcome this issue and simulate reactions at middle to low temperatures. In this study, we apply the AHD method to study n-heptane pyrolysis in a temperature range of 1000-2500 K using ReaxFF. Reasonable agreement is obtained between this method, a detailed chemical kinetic model and experiments for pressure and temperature dependent rate constants and decomposition product distributions. These results indicate that AHD and ReaxFF can be useful tools to assist development of kinetic reaction mechanisms.