热厚材料表面的近极限火焰传播特性  

Near-Limit Flame Spread over Thick Solid Fuels

作　　者：王双峰[1,2] 朱凤[1,2] 卢占斌[3] Wang Shuangfeng Zhu Feng Lu Zhanbin(Key Laboratory of Microgravity,Institute of Mechanics,Chinese Academy of Sciences,Beijing 100190,China School of Engineering Science,University of Chinese Academy of Sciences,Beijing 100049,China Institute of Applied Mathematics and Mechanics,Shanghai University,Shanghai 200072,China)

机构地区：[1]中国科学院力学研究所中国科学院微重力重点实验室,北京100190 [2]中国科学院大学工程科学学院,北京100049 [3]上海大学应用数学和力学研究所,上海200072

出　　处：《燃烧科学与技术》2016年第5期402-407,共6页Journal of Combustion Science and Technology

基　　金：中国科学院空间科学战略性先导科技专项基金资助项目(XDA04020410)

摘　　要：利用窄通道实验系统对低速气流中聚甲基丙烯酸甲酯(PMMA)平板表面逆风传播火焰的熄灭极限和传播速度进行了研究,主要实验参数为气流速度(≤10,cm/s)和氧气体积分数(≤50%,).实验发现,当气流速度和氧气体积分数接近火焰熄灭边界时,连续火焰分裂成为独立的、可稳定传播的小火焰,该现象的存在使材料的可燃范围扩大到连续火焰边界之外.分析表明,经典的热区火焰传播理论不能很好地预测火焰在低速流动中的传播速度,其偏差随着气流速度和氧气体积分数的减小而增大.Flame spread and extinction phenomena over a thick polymethylmethacrylate（PMMA）sheet in low-speedopposing flows have been experimentally investigated by using a narrow channel apparatus.Two primary variablesconsidered are flow velocity（≤10cm/s）and oxygen concentration（≤50%）.It is found that,when the velocity andoxygen concentration of the gas flow are close to the extinction boundary,the continuous flame breaks into independent,steady-spreading flamelets,which extends material flammability beyond continuous flame boundary.Theclassic spread rate formula,which has been established for the thermal regime of opposed-flow flame spread,isshown to overestimate the spread rate in low-velocity quenching.The difference between model predictions and experimentaldata becomes more significant with the decrease of imposed flow velocity and oxygen concentration.

关 键 词：火焰传播 熄灭极限 热厚材料 低速流动 微重力 

分 类 号：TK16[动力工程及工程热物理—热能工程]