Physics-Based Modeling of Community Fires.
Physics-Based Modeling of Community Fires.
(1307 K)
Evans, D. D.; Rehm, R. G.; Baker, E. S.; McPherson, E.
G.; Wallace, J. B.
Volume 2;
Interflam 2004. (Interflam '04). International
Interflam Conference, 10th Proceedings. Volume 2. July
5-7, 2004. Organised by Interscience Communications
Ltd. in association with National Institute of Standards
and Technology, Building Research Establishment;
National Fire Protection Association; Society of Fire
Protection Engineers; and Swedish National Testing and
Research Institute, Edinburgh, Scotland, Interscience
Communications Ltd., London, England, 1065-1076 pp,
2004.
Keywords:
fire science; fire safety; wildland/urban interface;
fire hazard; fire models; combustion; experiments; flame
height; heat release rate; weight loss; ignition;
structures; forestry; algorithms
Abstract:
Physics-based modeling of fires in the wildland urban
interface (WUI) is used to develop practical tools for
fire hazard evaluation of landscaped properties. The
approach differs from that used for wildland-fire
operation models in that individual fuel elements, such
as trees, shrubs, and buildings are resolved, and the
ignition and burning characteristics of these fuel
elements are identified separately. The model is an
extension of capabilities of the widely used NIST Fire
Dynamics Simulator (FDS). Burns of single dry
Douglas-fir trees were conducted to measure peak heat
release rates, burn durations and visible flame heights.
The rise and fall in the heat release rate curve for the
Douglas-fir trees is represented well by a simple
triangular shape. Insights from the FDS simulations of
WUI fires are used to construct a user friendly fire
model that can demonstrate major effects of ignition by
radiant flux. This model is being implemented in
EcoSmart, a web-based software tool. It provides a
method to evaluate the vulnerability of structures to
ignition by considering the effects of mitigation
actions, such as relocating landscape plantings, and
removing the lower branches of tall trees.
