Periodic puffing instabilities of buoyant large-scale pool fires in a confined compartment

This article presents an experimental study of the pulsating period of pool fires in a confined and ventilated compartment. Based on large-scale pool fire experiments, two modes of flame pulsation are identified. The first one is the common mode of flame puffing observed in an open atmosphere, and the second one is a perturbed pulsation mode induced by a hot vitiated environment. A description of these modes and their spectral analysis based on image processing are described. The second new mode differs from the common mode by a lower puffing frequency of the reacting gas phase. The effect of the pool diameter is analysed for the two modes.