2001 年 67 巻 662 号 p. 2596-2603
Quantitative investigation of the gravity effect was performed for acetone and kerosene pool fires. A centrifuge was used to examine the gravity effect. Small-scale pool fires were observed under various high gravity fields. Regions of stable flame, puffing flame and irregular oscillatory flame were mapped with the gravity level and pool diameter. Flame height decreased and oscillatory frequency increased with an increase in the gravity level. Behavior of the flame height was agreed quantitatively with the scaling prediction presented by Orloff and Heskestad. Puffing phenomena observed under various gravity fields were summarized with the Strouhal number and Froude number. As the result, we could obtain an empirical equation of St=0.517Fr-0.502. From this equation, puffing frequency could be estimated for a flame of various pool diameter varying from 0.01 to 50 meters.