Experimental study of laminar flames obtained by the homogenization of three forest fuels

This work aims to improve the understanding of the parameters involved in the burning of vegetative fuels. As the role of the surface-to-volume ratio is already known, we focused on the influence of other parameters. Three Mediterranean species (Pinus pinaster, Erica arborea and Cistus monspeliensis) were crushed in order to decrease the surface-to-volume ratio effects. The burning of these fuel samples produces unsteady, axisymmetric, non-premixed, laminar flames. The thermal properties and the mass loss of the crushed fuels, the distribution of temperature inside the sample and in the flame, the gases released by the fuels and the flame geometry were investigated. Thanks to these experimental data, the influence of the different fuel properties was underlined. We observed that the mass burning rate of the samples mainly controls the flame dynamics. However, the combustion kinetics in the flame depends on the degradation gases released by the fuels: the reaction zone is shifted and the flame height is changed. It appears that the composition of the degradation gases has to be taken into account to improve forest fire modeling.