Molecular dynamics simulation of aluminum combustion in an oxygen environment under electric field

Abstract

This study, for the first time, investigates the combustion behavior of aluminum(Al) in an oxygen environment under various electric fields using molecular dynamics simulations. The results indicate that the electric field enhances the mobility of Al atoms and reduces the activation energy, leading to a particle acceleration effect that boosts the burning rate and shortens the reaction time. As the electric field strength increases, the O/Al ratio of the final products approaches the theoretical value of 1.5 for complete combustion, and the number of intermediate species increases, indicating more thorough and intense Al combustion. Specifically, the electric field induces the generation of more free radicals during the reaction and reduces the average distance between Al and O atoms, thereby increasing atomic collision rates and contact frequency, further facilitating Al combustion. Under a strong electric field of 0.01V/Å, the electric field disrupts the original force equilibrium of Al atoms, leading to Al atoms escape and the gradual fragmentation of Al particles. Experimental studies on the electric field regulation of single Al particle combustion reveal that the reaction time is reduced by approximately 40 % under an electric field. Additionally, the combustion flame becomes larger and brighter, verifying that the electric field promotes the combustion of single Al particles. Under a high-voltage electric field of 5 kV, fragmentation of Al is observed during the combustion process. These experimental findings corroborate the molecular dynamics simulations, providing valuable insights for understanding and controlling Al combustion behavior under electric field.