Ignition and combustion of aluminum and beryllium.

This paper presents a summary of the results of theoretical and experimental studies on metal ignition and combustion conducted at the United Aircraft Corporation Research Laboratories. The burning times of spherical metal particles in rocket motors have been predicted using a computer program based on quasi-steady-state vapor-phase combustion. This program has been applied to the burning of aluminum or beryllium in oxygen, water vapor, or mixtures of one or both of these oxidizers with inert gases. The minimum conditions for ignition and the ignition delay time have also been calculated for metal particles in rocket motors as functions of gas temperature and particle size. Experimental measurements of the ignition temperatures of aluminum and beryllium have been made using electrically heated wires in static oxidizing atmospheres. The results obtained indicate that the ignition temperatures are dependent on the metal species, the pressure, and the oxidizer concentration and species. Of particular importance is the surface treatment or condition of the metal. The ignition temperatures of aluminum and beryllium can be significantly below the melting points of their respective oxides. 2239