A numerical study of reverse smoldering

In this paper, we present the results from a one-dimensional transient model of reverse smoldering. Two step chemistry which includes oxidative and pyrolytic steps is used. In contrast to many earlier models, local thermal nonequilibrium between the solid and gas phase was allowed. Radiative transfer was included using the diffusion approximation. The solid energy, solid species, gas energy, oxygen species, and overall mass conservation equations were discretized in space using finite difference techniques and were solved using VODE tan ordinary differential equation integrator designed for stiff equations). The effects of inlet gas velocity, oxygen concentration, mass diffusion of oxygen, radiation, gas phase conduction, and volumetric heat transfer coefficient were studied using this model. Of particular interest were processes which led to extinction of the smolder wave. One example is the observation that the strong coupling between the volumetric heat transfer coefficient and inlet gas velocity modifies the smolder velocity and quenching dynamics of the wave.