NUMERICAL-SIMULATION OF HEAT AND MASS-TRANSFER OF A SPHERICAL-PARTICLE AND THE FLOW OF A HIGH-TEMPERATURE GAS ABOUT IT

A mathematical model that describes heat and mass transfer of a spheri cal particle in a high-temperature flow is presented. The model takes into account the porosity of the particle acid allows for the penetrat ion of a gas into the particle and the reaction therein. Two possible reaction schemes are treated: the reduction of the particle material b y the gas, and the yield and combustion of volatiles. The product of t he reaction, vaporizing from the particle surface, may react in the ga s region as well. Concentration and temperature fields are obtained, a llowing for certain interpretations to be made about the dynamics of t he chemical reactions.