Pool Fires in a Corner Ceiling Vented Cabin: Ghosting Flame and Corresponding Fire Parameters

Ghosting flame phenomena and the corresponding fire dynamics in a corner ceiling vented cabin were experimentally studied. Various parameters including fuel mass loss rate (MLR), gas and fuel temperature as well as local oxygen concentration were measured in the experiments. Ghosting flame was observed when the fuel MLR increased to its maximum value and the oxygen concentration dropped to extremely low levels in large ceiling vent tests. A cross flow is expected above the burner. The most striking characteristics of the ghosting flame are its less luminous blue color at the flame base and its location relative to the ceiling vent. Two essential conditions must be satisfied for the occurrence of such flame phenomenon: the flame must blow off from the original location and it must be able to stabilize somewhere else. The transition for ghosting flame behavior is the flame being blown off. Based on the stabilization theory, a flame will destabilize where the local gas flow rate exceeds nearly three times the local premixed flame burning velocity. It is plausible that flame blow-off will occur for these near limit flames. After blow-off, flame moves to a different location where the crossflow velocity is lower and stabilizes in this region.