Experimental study on the spread and burning behaviors of continuously discharge spill fires under different slopes

This paper examines the effects of the slope on the burning and spread process of JP-4 continuous spill fires. Spill fires experiments were conducted on surfaces with different slope angles (0˚~3˚) in a rectangular trench (0.8m×6m). The spread and burning behaviors including the spread process, burning rate and flame height are recorded and analyzed. The results indicate that the whole spread process can be divided, based on the burning area variations with time, into four phases: 1) burning layer spread, 2) shrink process, 3) steady burning, and 4) extinguishment. The results also show that a large slope can increase the spread rate and as a result shorten the duration of the burning layer spread and shrink process phases. In addition, it is found that the slope has a more significant effect on the maximum spread area than the steady burning area. The steady burning rate decreases with increasing slope and the ratio of the steady burning rate of a spill fire and that of the corresponding pool fire is nearly constant. The flame height of continuous spill fires is also well predicted by an empirical model with a dimensionless heat release rate and equivalent pool diameter. The experimental data presented in the work will provide a basis for further studies of liquid fuel spill fire on an inclined surface.