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Thermal convective and radiative effects in forest fires simulation. (English) Zbl 0880.76078

(Authors’ summary.) The objective is the presentation of a decision support tool for the real-time modelling of forest fires in Mediterranean ecosystems. Forest fire propagation is affected by the ambient wind field, the terrain topography, the biomass type and distribution. The model presented here is a reliable engineering tool for the real-time modelling of the forest fire spread, taking into account all the above factors. It is a three-dimensional, time-dependent numerical model which uses terrain-fitted coordinates, and the solution is carried out in a transformed space. It is based upon a mass-consistent model for the local wind-field prediction which, combined with the time-dependent momentum equation for the vertical velocity component, takes into consideration the thermal induced buoyancy and complex terrain effects. In addition, the enthalpy and mixture-fraction conservation equations are solved for simulating the temperature distribution and the burning biomass, respectively. Thermal radiation effects are also taken into account through a source term introduced into the enthalpy equation, calculated by the discrete transfer method. As a test case, a forest fire scenario in the complex topography of two idealised Agnesi Witch Hills is simulated. Convective and radiative effects on forest fire propagation are investigated, and their relative importance is assessed for several ambient wind speeds.

MSC:

76R10 Free convection
76M25 Other numerical methods (fluid mechanics) (MSC2010)
86A10 Meteorology and atmospheric physics
80A20 Heat and mass transfer, heat flow (MSC2010)
92D40 Ecology
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