FIRE SPREAD MODEL FOR A LINEAR FRONT IN A HORIZONTAL SOLID POROUS FUEL BED IN STILL AIR

Abstract

A semi-empirical model for a steady linear fire front propagating through a statistically homogeneous porous bed, for the basic case of no wind, no slope, and fine fuel particles, is presented. The model structure is modular, based on an open library of submodels for the relevant phenomena. The submodeling of moisture heat absorption and radiation is addressed in detail. Presently, the model is not closed; it requires two properties of the fire front as inputs. Various sensitivity analyses and parametrical studies are performed. A laboratory test in a bed of pine needles showed that the model predictions are very sensitive to the flame height estimation and that the empirical submodels available in the literature are not adequate. However, if the flame height is considered an input, the rate of spread and the profile of the leading edge of the front in the fuel bed are predicted within the experimental errors.

Keywords:

• fire line spread
• porous bed
• modeling
• experiment
• forest fires

Acknowledgments

The authors are indebted to the European Union for financing through the Program PRODEP of the European Social Fund (first author) and the research projects INFLAME and SPREAD of (Program Climate and Environment of DG XII).

Notes

¹The mean and, when available, the standard deviation and the dimension of the sample are given.

²Restricted input variable with imposed value.

¹Inputs in Table 1.

²The mean and, when available, the standard deviation and the dimension of the sample are given.

³Withdrawing box III-A from the model network and taking the measured value as input for H _F.