Document


Title

A model for fire spread in wildland fuels by radiation
Document Type: Journal
Author(s): F. A. Albini
Publication Year: 1985

Cataloging Information

Keyword(s):
  • fire intensity
  • fire management
  • flame length
  • fuel management
  • fuel moisture
  • fuel types
  • heat
  • heat effects
  • ignition
  • particulates
  • radiation
  • rate of spread
  • temperature
  • wilderness areas
  • wilderness fire management
  • wildfires
  • wildland fuels
  • wind
Record Maintained By:
Record Last Modified: June 1, 2018
FRAMES Record Number: 37265
Tall Timbers Record Number: 11713
TTRS Location Status: In-file
TTRS Call Number: Fire File-DDW
TTRS Abstract Status: Okay, Fair use, Reproduced by permission

This bibliographic record was either created or modified by the Tall Timbers Research Station and Land Conservancy and is provided without charge to promote research and education in Fire Ecology. The E.V. Komarek Fire Ecology Database is the intellectual property of the Tall Timbers Research Station and Land Conservancy.

Description

Fire spread in wildland fuels is modeled as the steady, longitudinal propagation of an isothermal surface at ignition temperature by the process of radiation transport through a uniform layer of randomly-distributed, thermally-thin, radiometrically-black fuel particles. The ignition isotherm is assumed to be a perfect diffuse radiator, as is the idealized planar flame sheet that stands above the fuel bed. An algorithm is described that finds the temperature field everywhere in the fuel bed, the shape of the ignition isotherm, and the fire spread rate. The fire spread rate, multiplied by the heat required to ignite a unit volume of the fuel bed, divided by the hemispherical power flux density from the ignition isotherm, is an eigenvalue of this problem. The approximation of unit emissivity for fuel particles is shown to be robust in the one-dimensional limiting case of an infinitely-deep fuel bed. This limiting case is solved by a different algorithm that takes advantage of the axial symmetry of the radiation intensity field and allows explicit use of the scattering function for randomly-oriented, convex, radiometrically gray, diffuse scattering particles. It is shown that the temperature field is insensitive to particle emissivity for emissivity greater than 0.7 in this limit. ('This manuscript was written and prepared by an employee of the U.S. Government on official time and is therefore in the public domain.')

Citation:
Albini, F. A. 1985. A model for fire spread in wildland fuels by radiation. Combustion Science and Technology, v. 42, no. 5-6, p. 229-258.