Molecular Dynamics Simulation of Ignition Behavior of Low Palmitic Acid-Coated Nanoaluminum Powder

Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) was used to perform molecular dynamics (MD) simulations of the phase transition and decoating behavior of aluminum nanopowder (ANP)-palmitate composite particles under typical water ram engine conditions. We originally intended to investigate the effect of the degree of coating on the decorrelation behavior of the composite particles but accidentally discovered the premixed ignition behavior of low-coated composite particles. Therefore, we summarized and subdivided the four stages of precombustion adsorption, premixed ignition, melt-off, and full-scale combustion of palmitic acid-coated nanoaluminum powders by combining the simulations and studies of palmitic acid pyrolysis, ANP phase transition, and water molecule adsorption efficiency. We unexpectedly found that among the influencing factors of premixed ignition, the influence of hot and cold mixing degrees was greater than that of the ignition temperature.