制限換気条件下火源近傍火災プルームの温度・速度場の実験的構造解析

抄録

We experimentally examined large-scale fluid motions generated near a pool of fire plume with ethanol under conditions of limited ventilations. The velocity vectors in a vertical plane of the plume were measured by using a PIV technique. The temporal change in spatial distributions of horizontal and vertical velocities from initial and final stages of limited ventilation conditions showed that the normalized vertical profiles of entrainment rate of ambient air was maintained while the heat release rate monotonically reduces. On the other hand, the vigorous fluid motions, which were estimated by the POD for time-series of instantaneous velocity vectors, revealed the essential change in dynamics of organized motions, i.e., the meandering motions became dominant instead of puffing motions.