On the surface chemisorption of oxidizing fine iron particles: Insights gained from molecular dynamics simulations

Molecular dynamics (MD) simulations are performed to investigate the thermal and mass accommodation coefficients (TAC MAC, respectively) for combination of iron(-oxide) air. The obtained values TAC MAC then used in a point-particle Knudsen model effect chemisorption transition regime on combustion behavior (fine) iron particles. interactions $\mathrm{Fe}$ with $\mathrm{N_2}$ $\mathrm{Fe_xO_y}$ $\mathrm{O_2}$ is investigated different surface temperatures, while coefficient oxygen initial oxidation stages $Z_\mathrm{O}$, which represents molar ratio $\mathrm{O}/\left(\mathrm{O} + \mathrm{Fe}\right)$, temperatures. decreases fast from unity 0.03 as $Z_\mathrm{O}$ increases 0 0.5 diminishes further 0.57. By incorporating MD-informed into single particle model,a new temperature evolution particles observed compared results previously developed continuum models. Specifically, present show that process continues after reaching peak temperature, previous models predicting maximum was attained when oxidized $Z_\mathrm{O} = 0.5$. Since rate slows down an increasing stage, heat loss exceeds release upon not yet Finally, transition-regime transfer fine discussed.