Flame structure and dynamics in pool fires of different geometries: Experimental and numerical investigation

Abstract

Fire accidents might be caused by liquid fuel leakage, which can accumulate in a prescribed area under the action of physical barriers. Therefore, pool fires could be of an arbitrary geometry in less ideal configurations. The current objective is to uncover the underlying physics of flame structure and dynamics in pool fires of different geometries. In this work, pool fires with seven different geometries were examined. Flame base structure and instantaneous flame height in pool fires of different geometries were recorded. Temperature, velocity/vorticity fields and coherent vortical structures were further presented by Large Eddy Simulation (LES). Results show that mean flame height of circular pool fire is the highest, while that of right triangle fires is the lowest. Mean flame height of the other noncircular geometries lies in these two extremes. The presence of vertices and hypotenuses has a dramatic influence on the formation and development of vortical structures. Triangular pool fires have the highest oscillation frequency, followed by quadrangular and circular geometries. To account for the physics of air entrainment and vortex dynamics due to pool fire geometry, pool perimeter is used as a characteristic length scale to propose new scaling relations for describing flame height and oscillation frequency.