Interaction between head fire and backfire in grasslands (original) (raw)

This paper deals with 3D numerical simulations of two fires fronts (head and backfire) propagating simultaneously through a grassland fuel. The simulations were carried out using a ''fully'' physical and three-dimensional fire model (namely WFDS). One of the objectives of this work, was to evaluate the potential for fully physical fire model to simulate the interactions between two fire fronts (a head fire and a backfire), in conditions similar to those encountered during suppression fire operations. A set of numerical simulations was first carried out for standalone head fires propagating through grasslands on a flat terrain and for various wind conditions ranging between 1 and 10 m/s. These results were compared with experimental data and numerical results from the literature. The same calculations were then repeated, with a backfire ignited at the downwind side of the plot. The numerical results highlighted that, for these particular conditions, head fire and backfire can interact, mainly, via two mechanisms: