Time-Dependent Model of Forest Fire Spread in Turbulent Gusting Winds

In this paper we describe a model for simulating the spread of large-scale forest fires based on three novel concepts related, respectively to the three main features of the forest-fire problem that make it essentially intractable to simulate from first principles-namely, i) inhomogeneity and irregularity of forest fuel materials, ii) chemistry and radiation, and iii) turbulence. In particular, the complex structural features of the forest are treated as an inhomogeneous, very permeable porous medium; effects of chemistry and radiation are included as a source term in the thermal energy equation, and turbulence is modeled via the standard k-e model. Firebrand trajectories are computed at the end of any given flowfield calculation to estimate maximum spotting distances.