摘要
分析了均匀水平燃料床从一个点火源的着火过程 ,建立了林火蔓延初期的增长模型 ,采用数值法计算了蔓延初期的加速度与速度的变化趋势。并通过室内模拟实验 ,在燃料床上测取了林火初期蔓延速度。通过对着火后1 0 0 s的实验数据与计算结果的比较 ,说明所使用的初期蔓延过程的增长模型在物理上是合理的。从实验结果分析看出 ,在着火后 2 0 s以内 ,及在着火后 80 s～ 1 0 0 s锥形火焰向环形火焰转化时 ,火蔓延速度与加速度剧烈地波动。由理论模型计算得到 ,森林火灾从一个点火源着火以后 ,大约需要 0 .5h才能达到稳定的蔓延速度 ,由于受实验条件所限 ,在室内模拟这个过程是困难的。
The ignition process of a fire from a point in plain and homogenous fuels bed are analyzed.The growth model of fire spread is studied.The acceleration and rate of fire spread are numerically calculated.The experiment data of the rate of fire spread after ignition were measured in the fuel bed in the laboratory with non-wind.By comparing the calculated result with the experimental data of fire spread rate,we can find that the growth model is reasonable.In 20 s and between 80 s and 100 s after ignition,the rate and acceleration of fire spread violently fluctuate near the average.According to the calculating results,it needed about 32 minutes to approach the steady spread rate after ignition.Because of the limitations of conditions,it is difficult to simulate the whole process in the laboratory.
出处
《燃烧科学与技术》
EI
CAS
CSCD
2000年第3期218-221,共4页
Journal of Combustion Science and Technology
基金
国家科学基金!资助项目 ( 599760 39)
关键词
森林火灾
蔓延速度
室内模拟实验
增加模型
forest fire
growth model
rate of fire spread
acceleration process
