ReaxFF simulations on the combustion of Al and n-butanol nanofluid

The renewable biofuel n-butanol is an alternative to gasoline and diesel in internal combustion engines. The addition of aluminum nanoparticles (ANPs) would improve the performance of these nanofluid fuels. The reactive dynamics simulation of the ignition and combustion process of ANP/n-butanol nanofluid fuel was carried out. The combustion mechanisms of n-butanol fuel with and without ANPs, as well as the aggregation of nanodroplets and the sintering degree of nanoparticles were explored. Simulation results show that the combustion of aluminum-based n-butanol fluid fuel undergoes a three-stage: chain expansion, micro-explosion, and steady reaction. In general, the addition of ANPs improves combustion completeness and reduces the ignition delay of n-butanol. The kinetic calculations show that the activation energy of n-butanol combustion is reduced by 39.9%. A new reaction mechanism was proposed from the results: n-butanol reacts with oxygen free radicals generated by Al rather than O. On the other hand, n-butanol prevents the aggregation and sintering of aluminum nanoparticles. Therefore, the ANP additives and n-butanol nanofluid promote mutually in the combustion. This work is expected to guide the practical application of aluminum-based alcohol fuels.