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Author
Ko, G. H. | Hamins, A. | Bundy, M. | Johnsson, E. L. | Kim, S. C. | Lenhert, D. B.
Title
Mixture Fraction Analysis of Combustion Products in the Upper Layer of Reduced-Scale Compartment Fires.
Coporate
National Institute of Standards and Technology, Gaithersburg, MD Kyungil Univ., Kyungsan 712-701, Republic of Korea
Journal
Combustion and Flame, Vol. 156, No. 2, 467-476, February 2009
Sponsor
Korean Research Foundation, Korea
Keywords
compartment fires | mixture fraction | combustion products | ventilation | carbon balance | fuels | experiments | equations | uncertainty | soot | carbon monoxide | heptane | toluene | polystyrene | mass fractions
Identifiers
experimental configuration; average fractional soot, CO and CO/soot ratio at the front and rear compartment measurement locations; average yields of soot, CO, and the ratio at the front and rear compartment measurement locations
Abstract
A mixture fraction analysis is performed to investigate the characteristics of chemical species production in smoky compartment fires burning condensed-phase hydrocarbon fuels. A series of fire experiments were conducted in a 2/5 scale compartment based on the ISO-9705 room. Gas species and soot measurements were made at two locations in the upper layer of the compartment. The fuels considered, heptane, toluene, and polystyrene, generate highly smoky fires over a range of natural ventilation conditions. The mass fractions of measured chemical species, such as unburned hydrocarbons, carbon monoxide, carbon dioxide, oxygen, and soot are presented as a function of mixture fraction and compared with state relationships based on the idealized reactions of a hydrocarbon fuel. The results show that plotting the local composition as a function of the mixture fraction adequately collapses hundreds of species measurements from an assortment of compartment conditions with varying heat release rates and spatial locations into a few coherent lines or bands. It is also shown that about half (or more) of the fuel carbon may exist in the form of carbonaceous soot in the upper layer of smoky compartment fires. Inclusion of soot in the mixture fraction analysis allows identification of fuel-rich or under-ventilated conditions.