NIST Time|NIST Home|About NIST|Contact NIST

HomeAll Years:AuthorKeywordTitle2005-2010:AuthorKeywordTitle

Experimental Study of the Effects of Fuel Type, Fuel Distribution and Vent Size on Full-Scale Underventilated Compartment Fires in an ISO 9705 Room.


pdf icon Experimental Study of the Effects of Fuel Type, Fuel Distribution and Vent Size on Full-Scale Underventilated Compartment Fires in an ISO 9705 Room. (9188 K)
Lock, A.; Bundy, M.; Johnsson, E. L.; Hamins, A.; Ko, G. H.; Hwang, C.; Fuss, P.; Harris, R. H., Jr.

NIST Technical Note 1603; NIST TN 1603; 167 p. October 2008.

Keywords:

compartment fires; fuels; room fires; fuel distribution; vents; experiments; ventilation; doorways; burners; heat release rate; gas chromatography; gas samples; storage; soot; thermocouples; heat flux; data processing; uncertainty; temperature; mixture fracture; carbon balance method; hydrocarbon fuels; combustion efficiency; liquid fuels; solid fuels; fire models; field models

Abstract:

This report describes new full-scale compartment fire experiments, which include local measurements of temperature, heat flux and species composition, and global measurements of heat release rate and mass burning rate. The measurements are unique to the compartment fire literature. By design, the experiments provided a comprehensive and quantitative assessment of major and minor carbonaceous gaseous species and soot at two locations in the upper layer of fire in a full scale ISO 9705 room. Fire protection engineers, fire researchers, regulatory authorities, fire service and law enforcement personnel use fire models (such as the NIST Fire Dynamics Simulator, FDS for design and analysis of fire safety features in buildings and for post-fire reconstruction and forensic applications. Fire field models have historically showed limited ability to accurately and reliably predict the thermal conditions and chemical species in underventilated compartment fires. Formal validation efforts have shown that for well ventilated compartment fires, with the exception perhaps of soot, field models do quite well in predicting temperature and species when experimental uncertainty is accounted for. Inaccurate predictions of incomplete burning and soot levels impact calculations of radiative heat transfer, burning rates, and estimates of human tenability. High-quality (relatively low, quantified uncertainty) measurements of fire gas species, temperature and soot from the interior of underventilated compartment fires are needed to guide the development and validation of improved fire field models. The experimental results provided in this report are the continuation of a long-term National Institute of Standards and Technology (NIST) project to generate the data necessary to test our understanding of fire phenomena in enclosures and to guide the development and validation of field models by providing high quality experimental data. The experimental plan was designed in cooperation with developers of the NIST FDS model to assure that the measurements would be of maximum value. Advanced development of FDS and other field models is extremely important, since it will lead to improved accuracy in the prediction of underventilated burning, typical of fire conditions that occur in structures. Improving models for under-ventilated burning will foster improved prediction of important life safety and fire dynamic phenomena, including fire spread, backdraft, flashover, and egress involving the presence of toxic gas and smoke), which are critically important for application of fire models for fire safety.