Numerical study of a graphite rod burning under laminar and turbulent flow conditions

This work is devoted to the numerical study of a graphite cylinder reacting under laminar and turbulent hot air flow conditions, as has been studied experimentally by Makino et al. (Combustion & Flame 132, 2003). The geometry and boundary conditions used in this work are taken from the benchmark experiment. The main goal of this work is to study the influence of the flow velocity on the combustion rates. For this, three different flow regimes, steady-state, laminar-unsteady and turbulent, are considered. To solve the Navier-Stokes equations, coupled with the energy and species conservation equations, a finite volume solver was applied. In addition to the solid carbon the model incorporates six gaseous chemical species (O-2, CO, CO2, H-2, H2O and N-2). The reaction mechanism includes the forward and backward water-gas-shift reaction, the reaction of carbon monoxide oxidation and four heterogeneous reactions. The comparison of combustion rates predicted numerically with experimental data showed good agreement for all flow regimes.