Abstract
We have experimentally investigated a ventilation-controlled and medium-size pool fire (fuel: ethanol). Special attention was paid to meandering processes with the low frequency velocity fluctuations in the vicinity of a pool, which were revealed by our previous study. The velocity vectors were measured by using a PIV technique with spores of lycopodium clavatum as tracer particles (the diameter becomes several μm in flame). The dominant flow structures, which were obtained by the proper orthogonal decomposition with measured velocity vectors, clearly show the impacts of under ventilation conditions: the deficient O2 supply yields suppression of puffing motions and activation of leisured fluid motions in horizontal direction.
