PIV Measurement of Plume with a Pool Fire in Ventilation Controlled Compartment

The entrainment process and organized motions near a source of poof fire in a ventilation controlled compartment was experimentally investigated by using a particle image velocimetry technique with spores of lycopodium clavatum, the diameter of which decreases to several um in flame. Special attention was paid to the low ventilation effects: the compartment was poorly ventilated by a mechanical system with a meager negative pressure, and heat release rate of the pool fire and the oxygen concentration in the compartment decreased for the duration of fire, providing the transition to ventilation controlled fire. The transition drastically changed spatial and temporal structures of entrainment of ambient fluid. The fully developed fire generated puffing motions reported also by existing studies. On the other hand, the ventilation-controlled pool fire yielded meandering fluid motions. Such changes in structures activated entrainment of the ambient fluid.