Liquid Fuel Spill Fire Dynamics

Despite the fact that liquid fuel spills present a potential fire hazard in numerous industrial and residential settings there has been minimal research conducted to understand the spill and burning dynamics of these types of scenarios (Gottuk et al., NRL/MR/6180-00-8457, 2001; Putorti, NIJ-604-00, 2001; Mealy et al., NIJ-2008-DN-BX-K168, 2010; Ma et al., Fire Technol 40:227–246, 2004). While the findings of these studies were significant in that they demonstrated a substantial decrease in the peak fire size achieved in spill fire scenarios compared to pool fires, the empirical data sets collected were not sufficient to fully understand the phenomena causing this reduction. In general, both studies attributed the decrease to thermal losses to the substrate but indicated that further investigation was required. In order to address this general lack of empirical data, a research program was conducted to characterize fuel spill fire dynamics with respect to the key variables that potentially impact these types of fires. A discussion of the test results is presented in two parts: the first being the development of a liquid spill, specifically spill depths and spill progression, and the second being fuel burning dynamics, specifically the impacts of substrate, ignition delay, and substrate temperature. The development of a spill and the associated liquid depths are described for various fuels and fuel simulants, whose properties provide bounding spill scenarios for most fuels of interest. The burning dynamics of various fuel spill scenarios are evaluated relative to numerous substrates, ignition delay times ranging from 30 s to 300 s, and substrate temperatures ranging from 12°C to 38°C (54°F to 100°F). The impact of these variables was evaluated relative to the heat release and mass burning rates measured during these tests.