Citation

Corlett RC, Williams FA. Fire Safety J. 1979; 1(6): 323-337.

Copyright

(Copyright © 1979, Elsevier Publishing)

DOI

unavailable

PMID

unavailable

Abstract

A modeling framework for direct suppression of open fires is proposed, with emphasis placed on water application as the primary means of suppression. The modeling capability sought is quantitative determination of the deviation of a fire from its undisturbed history, as a function of the type and extent of suppressive action taken. The approach involves introduction of a length scale of coherent flaming, successful suppression being viewed as reduction of the coherent length below a prespecified value. Mass and energy balances are employed, and a variety of approximations and hypotheses are introduced within the framework of these conservation concepts to obtain simplified suppression criteria. Specific consideration is given to the average flux of energy feedback from the flames to the fuel, its dependence on fuel gasification and on suppressive action, and its potential removal when rates of exothermic reactions in the gas become too low, including possible establishment of transient flaming when diffusional control gives way to a regime of premixed flames. Specific study also is devoted to the gasification rate of the fuel, including its response to energy feedback and to suppressive action, with special attention focused on the time lag of the response and on non-linear phenomena, particularly within the context of charring fuels. Although the analysis is based mainly on results of existing small-scale experiments, the uncertainties emphasize the need for defenitive large-scale testing, if the model is to be corroborated and its critical parameters evaluated.