Aluminum particle combustion model in mixture of oxygen and helium

Abstract

Physical and mathematical models of aluminum particles combustion in oxygen-containing media are developed. In terms of these models substantial regularities of combustion processes and corresponding experimental data are explained. The physical model is based on division of space around particle on preflame region, flame region and region of nonequilibrium processes. In the preflame region a zone of oxygen dissociation is set. In the region of nonequilibrium processes formation of condensed metal oxide does not proceed. In the regions, where equilibrium processes occur, mathematical description of combustion is implemented with taking into account results of thermodynamic calculations. Combustion of particle of initial diameter 200 μm is modeled in medium «79% Не + 21% O2» under pressure 0,1 MPa. Characteristic sizes of regions boundaries, distributions of temperature and oxidative components around particle are determined. Satisfactory agreement of modeling results with experimental data is obtained. Developed calculation methodology can be adapted to analysis of combustion parameters of particles of different sizes in mixtures of oxygen with other gases. Also the methodology may be used in design of technological and energy plants on fuels containing powdery aluminum.