Diffusion combustion of n-decane with unpassivated aluminum nanoparticles additives: Аnalysis of mechanism and numerical simulation

Possible mechanisms of the increase in the flame front temperature, observed in experiments with diffusion combustion of n-decane with the addition of unoxidized aluminum nanoparticles with a diameter of 20 nm, were analyzed numerically. It was shown that at nanoparticle concentrations of 0.5 and 2.5 wt%, which were considered in the experiment, the heat release caused by the oxidation of aluminum can induce only a slight (up to 10 K) increase in the temperature of the front. Numerical modeling of a laminar diffusion flame allowed us to establish that the most probable cause of an increase in the temperature of the flame front is the acceleration of gas-phase reactions of n-decane oxidation. A detailed kinetic mechanism of ignition and oxidation of n-decane in the presence of aluminum vapor was developed to test the previously proposed hypothesis of promoting the n-decane combustion with aluminum vapor. Numerical calculations using the developed kinetic mechanism have shown that gaseous aluminum as a combustion promoter does not allow achieving the same increase in the flame front temperature as in the experiment. It makes the development of alternative mechanisms for promoting the combustion of n-decane by aluminum nanoparticles urgent.