Cross Wind Effects On Fire Propagation Through Heterogeneous Media

Abstract

A two-phase formulat,ion is used to study the cross wind effects on the propagation of a line fire through a fuel bed. Each phase is described by a set of time-dependent equations and the coupling between them is rendered through exchange terms of mass, momentum, and energy. Turbulence is approached by using a RNG (Renormalization Group) k-E statistical model. The radiative transfer equation in the fuel bed is solved using the discrete ordinates method extended to a two-phase medium. Soot formation is considered. First-order kinetics is incorporated to describe pyrolysis and combustion processes. A finite-volume method including high-order upwind convective scheme and flux limiter strategy along with a projection method for the pressure-velocity coupling is used. The effects of cross wind on the behaviour of a line fire through a bed of pine needles are examined and compared to measurements.