Limiting lip-height of pool fires

The lip height at which an unsteady pool fire self-extinguishes, called the limiting lip-height is investigated. Experiments have been conducted in 14 cylindrical containers with inner diameters from $2.5\mathrm{mm}$ to $400\mathrm{mm}$ and heptane as fuel. The dimensionless limiting lip-height (limiting lip-height divided by the container diameter) in unsteady pool fires increases from 2 for the smallest containers to almost 5 for the largest container. The values are higher than for corresponding experiments with steady pool fires (cold containers). The flame position and motion, laterally and vertically, are described. The fuel surface temperature increases weakly with container diameter.

Pool fires during industrial accidents and laboratory experiments will, in most cases, evolve according to an unsteady pool fire scheme with increasing lip height. For these situations, it is crucial to understand how various factors influence the evolution of the pool fire. Consequently, results are reported here for a wide range in container size.