Defining Flashover for Fire Hazard Calculations. Part 2.
Defining Flashover for Fire Hazard Calculations. Part
Babrauskas, V.; Peacock, R. D.; Reneke, P. A.
Fire Safety Journal, Vol. 38, No. 7, 613-622, November
flashover; fire hazard; computer models; experiments;
fire models; heat flux; temperature correlations;
validation; performance based codes
Comparison of available correlations and predictive
models used to predict the minimum heat release rate
(HRR) necessary to cause flashover show consistent
trends for a range of empirical data. Nonetheless,
available experimental data for HRR at flashover in
compartments of similar geometry and venting show
substantial scatter. Both the experimental data and
theoretical predictions based on computer modeling
indicate that a significant portion of the variability
can be accounted for by the time period involved in the
flashover. Although typically ignored in the available
correlations, qualitatively a clear trend
emerges--shorter exposure times increase the needed
minimum HRR at flashover, due at least in part to the
effects of heat transfer to the compartment surfaces.
Additional measurement needs are suggested to facilitate
better understanding of conditions leading to flashover.