Wildland Urban Interface
Firebrands play a vital role in the propagation of fire by starting new fires called spotfires, ahead of the fire front during wildfire progression. Firebrands are a harbinger of damage to infrastructure; their effects particularly pose a threat to people living within the wildland-urban-interface, they can hamper the suppression of wildfire and block evacuation routes for communities and emergency services. Short-range firebrands which travel along with the wind, with little or no lofting, are particularly crucial in increasing fire front propagation and damaging structures situated close to the wildland-urban interface. In the Daylesford fire of 1962 in Australia, massive short-range spotting (the process of spot fire ignition and merging of spots caused by firebrands) occurred in the eucalyptus forest and increased the rate of fire spread by roughly three times more than that computed using an operational fire model. Similarly, long-range firebrands can be transported by the fire plume and ambient wind and can ignite new fire up to 30–40 km from the source of fire as observed in the 2009 Black Saturday fire, Australia.
A large amount of experimental research has been conducted to quantify the effects of firebrands, to develop empirical models and to benchmark results for Computational Fluid Dynamic (CFD) based fire model validations. In recent years, some CFD models have been used mainly for their validations. These studies have been reviewed here. To perform useful parametric studies of firebrand transport using CFD models including further development of CFD models, more targeted studies need to be conducted.