A Reactive Molecular Dynamics Investigation of Nanoparticle Interactions in Hydrocarbon Combustion

The use of energetic nanoparticles to tailor the properties of a base liquid fuel has attracted attention due to the possibility of decreasing fuel consumption and increasing control over the combustion process. In this study, the role of nanomaterials in the consumption of hydrocarbon fuel vapor is investigated using reactive molecular dynamics. Simulations are performed with aluminum and iron nanoparticles inside an n-heptane and oxygen gas mixture. The role of atomic charges on the dynamics of nanoparticle-hydrocarbon interactions is also investigated using different charge equilibration methods. Results show that both nanomaterials act as catalysts and enhance fuel decomposition. The decomposition of fuel molecules is initiated by dehydrogenation at the particle's surface. This reaction path occurs significantly faster than the oxidation and pyrolysis paths observed for n-heptane in absence of nanoparticles. The oxidation in the presence of aluminum is characterized by more rapid particle heating and fragmentation compared to iron. Metal fragments further enhance the reactivity of the system due to a higher surface area available for reactions. The atomic charge distribution was found to affect the kinetics and reactivity of the system, showing that the non-bonded interactions influence the oxidation process. This study confirms that the use of nanomaterials is beneficial to accelerate the decomposition of fuel and that the combustion behavior of the selected hydrocarbon is strongly dependent on the type of nanomaterial used in combination with the base fuel.