Effects of Winds From Burning Structures on Ground-Fire Propagation at the Wildland-Urban Interface.
Effects of Winds From Burning Structures on Ground-Fire
Propagation at the Wildland-Urban Interface.
Rehm, R. G.
Combustion Theory and Modelling, Vol. 12, No. 3,
477-496, June 2008.
Sponsor:National Institute of Standards and Technology,
wildland urban interface; wind effects; structures;
combustion; flame propagation; heterogeneous burning;
mathematical models; fire spread; fire models; fire
behavior; heat release rate; plumes; scaling; wildland
fires; equations; computational fluid dynamics;
A simple physics-based mathematical model is developed
for prediction of the propagation of a grass-fire front
driven by an ambient wind and by entrainment winds
generated from one or more burning structures. This
model accounts for the heterogeneous nature of the
burning in a particular wildland-urban-interface (WUI)
setting, where the entrainment from fundamentally
three-dimensional structure-fire plumes can change the
propagation of a two-dimensional ground-fire front. Data
on grass fires and estimates of structure fires are
presented and compared to justify the model. Scaling
effects on the fire-front propagation-speed are given as
a function of the location of the front, of the heat
release rate of a single burning structure, of the total
number of burning structures and of the
burning-structure density. Also, detailed front
propagation changes due to a single and multiple
burning-house scenarios are presented.