This paper presents a mathematical model for agricultural fires based on a multi-phase formulation. The
model includes dehydration and pyrolysis of agricultural fuel and pyrolysis products. The model
considers a homogeneous distribution of the agricultural solid fuel particles, interacting with the gas
flow via source terms. These terms include: drag forces, production of water vapour and pyrolysis
products, radiative and convective heat exchange. A multi-phase radiative transfer equation for
absorbingeemitting medium is considered to account for the radiative heat exchange between the gas
and solid phases of the fire. The main outputs of the present model are most important to study the
influence of agricultural fire occurring beneath high voltage transmission lines. The agricultural fire
causes a flashover due to the ambient temperature rise and soot accumulation on the insulator of these
transmission lines. Numerical results of the present model are obtained for flat grassland fires to study
the effects of wind velocity, solid fuel moisture content and ignition length on some selected fire outputs.
These outputs include the temperature, velocity, soot volume fraction fields of the gas phase, together
with fire propagation rate and flame geometry. The numerical results are compared to the available
experimental work in the literature.