On the Interest of Studying Degradation Gases for Forest Fuel Combustion Modeling

The aim of this work is to determine the influence of the degradation gases on the combustion of forest fuels and whether they have to be taken into account in numerical modeling. A laboratory experimental apparatus was designed to generate laminar, axisymmetric, time-varying and non-premixed flames from crushed forest fuels. The experiments highlight that the mass burning rate of the fuel controls the flame dynamics whereas the combustion kinetics depends on the degradation gases. From the analysis of the degradation gases released by one fuel, different combustion mechanisms and gas mixtures were tested numerically. The reaction rates computed with these mechanisms were examined and the temperature distributions were compared with the experimental data. The predictions obtained with the combustion mechanism including both methane and carbon monoxide did agree with the experiments.