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Author
Carrier, G. | Fendell, F. | Fink, S.
Title
Towards Wind-Aided Flame Spread Along A Horizontal Charring Slab: The Steady-Flow Problem. Final Report.
Coporate
TRW Defense and Space Systems Group, Redondo Beach, CA
Journal
Combustion Science and Technology, Vol. 32, 161-209, 1983
Sponsor
National Bureau of Standards, Gaithersburg, MD
Report
NBS GCR 82-377, February 1982, 86 p.
Distribution
Available from National Technical Information Service
Contract
NB80NADA1065
Keywords
ceilings | charring | compartment fires | corridors | flame spread | polymers | room fires | thermal degradation
Abstract
The spread of fire across the ceiling of a large room (or long corridor) in a structure is modeled as wind-aided flame spread along a horizontal char-forming thick slab, in the presence of significant convective, diffusive, and radiative transport. The goal is to predict the rate of streamwise advance of the site on the solid-gas interface at which the pristine solid undergoes endothermic degradation to a combination of (1) a porous carbonaceous heat-retaining matrix, and (2) a mixture of (partially combustible) vapors that move through the matrix to the outer gas. This rate of advance of the thermal-degradation site is sought as a function of normally available data concerning the thermodynamic and physical properties of the solid and the thermodynamic and dynamic state of the hot vitiated bulk gas that flows over the slab. A nonlinear, unsteady, two-spatial-dimension treatment in the Shvab-Zeldovich approximation entails boundary-layer simplification in the manner of Prandtl convective-transport simplification in the manner of Oseen, and thin-flame simplification in the manner of Burke and Schumann. Whereas the formulation given here is general and is to be solved in subsequent work for a partially involved slab, the solution here is limited to the steady-state problem.