FDS SIMULATIONS OF THE TRANSPORT OF COLD FIREBRANDS IN WIND TUNNEL EXPERIMENTS

Abstract

In wildland fires, the transport of firebrands is the main reason causing subsequent spot fires. The embers can travel farther than the fire itself and ignite the houses at the wildland urban interface (WUI). We consider previous experiments performed in a wind tunnel and used to characterize the transport of cold particles in a controlled velocity field that corresponds to a turbulent jet in a cross-flow. We perform numerical simulations of these experiments using the Fire Dynamics Simulator (FDS). The simulated jet and cross-wind velocity field are adjusted and tested to match the flow velocities measured in the experiments. The solid particles are simulated using the FDS Lagrangian model and our study includes comparisons between simulated and measured trajectories. The relationship between the particle flying pattern with the wind velocity field is examined.