Burn-out time data analysis on interaction effects among multiple fires in fire arrays
Burn-out time data analysis on interaction effects among multiple fires in fire arrays
复制标题
DOI：
10.1016/j.proci.2006.08.110
复制
发表时间：
2007
期刊：
影响因子：
--
通讯作者：
Naian Liu;Qiong Liu;Zhihua Deng;Satoh Kohyu;Jiping Zhu
中科院分区：
文献类型：
--
作者：
Naian Liu;Qiong Liu;Zhihua Deng;Satoh Kohyu;Jiping Zhu
本文对由直径 5 厘米、高度 2 厘米的燃料盘引发的 3×3 至 7×7 正庚烷火焰组成的方形火焰阵列的行为进行了实验和方法研究。旨在开发一种燃尽时间（BOT）数据分析方法来分析多起火灾之间的相互作用效应（可能引起火灾合并和火灾漩涡）。在 26 次火灾测试中，每个阵列尺寸的着火点间距 D 在 20 到 50 厘米之间变化，并且在一些情况下从阵列的一侧添加了剪切流。通过考虑火焰高度 L，火合并开始的合理临界条件为 D/L=0.29−0.34，该条件与火阵列尺寸和火点间距无关。通过燃尽时间数据，定义了相互作用指数 I(m) 和相互作用链接指数 A(m,n) 来表征火灾相互作用。详细研究了求解I(m)=ΣnA(n,m)方程组所必需的假设，从而求解了方程组。分析表明，燃尽时间数据分析实现了火灾相互作用效应的定量合理比较，从而表明将燃尽时间作为每个特定着火点平均燃烧速率的度量是合理的。总结了一个表观判据BOT(m)/BOTR=0.5来判断任意火点m是否会完全参与火灾融合（其中BOTR为自由燃烧参考火点的燃尽时间）。这意味着对任何一场火灾的相互作用效应主要归因于其相邻的四场火灾。还讨论了剪切流对火燃烧和火旋流发生的影响。
This paper gives an experimental and methodological investigation on the behaviors of square fire arrays which are composed of 3×3 to 7×7 n-heptane fires initiated from fuel pans of 5cm in diameter and 2cm in height. It is intended to develop a burn-out time (BOT) data analysis method to analyze the interaction effects (which may induce fire merging and fire whirls) among the multiple fires. In 26 fire tests the fire point spacing D varied from 20 to 50cm for each array size and in several cases shear flow was added from one side of the array. By considering the flame height L a reasonable critical condition for initiation of fire merging was implied to be D/L=0.29−0.34, which is independent of the fire array size and fire point spacing. By burn-out time data the Interaction index I(m) and Interaction link index A(m,n) were defined to characterize the fire interactions. The assumptions essential to solve the equation system of I(m)=∑nA(n,m) were examined in detail, whereby the equation system was solved. The analysis showed that the burn-out time data analysis realizes a quantitatively reasonable comparison of the fire interaction effects, thus indicating that it is reasonable to regard the burn-out time as a measure for the average burning rate for each specific fire point. An apparent criterion of BOT(m)/BOTR=0.5 was summarized to identify whether any fire point m will be completely involved in fire merging (where BOTR is the burn-out time of the free burning reference fire point). It was implied that the interaction effect imposed on any fire is mainly ascribed to its adjacent four fires. The effects of shear flow to fire burning and occurrences of fire whirls were also discussed.