A two-dimensional, unsteady-state, kinetic-diffusion-vaporization-controlled numerical model for aluminum particle combustion is presented. The model solves the conservation equations, while accounting for species generation and destruction with a 15-reaction kinetic mechanism. Two of the major phenomena that differentiate aluminum combustion from hydrocarbon-droplet combustion, namely, condensation of the aluminum-oxide product and subsequent deposition of part of the condensed oxide onto the particle, are accounted for in detail with a submodel for each phenomenon. The effect of the oxide cap in the distortion of the species and temperature profiles around the particle is included into the model. The results obtained from the model, which include two-dimensional species and temperature profiles, are analyzed and compared with experimental data. The combustion process is found to approach a diffusion-controlled process for the oxidizers (O 2 , CO 2 , and H 2 O) and conditions treated. The flame-zone location and thickness are found to vary with the oxidizer. The result shows that the exponent of the particle-diameter dependence of the burning time is not a constant and changes from ≈1.2 for smaller-diameter particles to ≈1.9 for larger-diameter particles. Owing to deposition of the aluminum oxide onto the particle surface, the particle velocity oscillates. The effect of pressure is analyzed for a few oxidizers. Key words: aluminum particle, two-dimensional unsteady-state numerical model, kinetic mechanism, effect of the nature of the gaseous oxidizer, condensed oxide, oxide dissociation, oxide cap, burning time, species and temperature fields INTRODUCTIONAluminum has been added to propellants for many years as an extra energy source for the propellant. Thus, research on the combustion mechanism of burning aluminum has been an ongoing effort. A very significant effort was expended in the 1960s and 1970s shortly after the effects of aluminum were first conceived. In an early study, Glassman [1] and Brzustowski and Glassman [2] recognized that metal combustion would be analogous to hydrocarbon-droplet combustion, that the D 2 law ought to be applied, and that ignition and combustion ought to depend on the melting and boiling points of the metal and the oxide. Glassman speculated that ig-